Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Utilization of carbon dioxide in polyurethane
LI Xiao-yun, LI Qi-feng, ZHAO Yu-hua, KANG Mao-qing, WANG Jun-wei
 doi: 10.1016/S1872-5813(21)60145-7
Abstract(48) HTML(24) PDF 1413KB(5)
With the rapid development of modern society, the demand for energy is increasing with time. Currently, fossil fuel is still the dominant source of energy in developing countries. The greenhouse effect and environmental problems lead by excessive emission of carbon dioxide causing by the combustion of fossil resources has arouse worldwide concern. Therefore, to achieve carbon emission reduction and carbon neutralization through the capture, storage, conversion and utilization process of carbon dioxide has become the focus of research. Among the utilization of carbon dioxide, the preparation of polymer with carbon dioxide could not only realize the resource utilization of carbon dioxide, but also provide a new approach for the green production of polymer. This paper summarizes the current resource utilization of carbon dioxide in polyurethane, mainly focusing on its physical and chemical applications in materials and introducing its preparation technologies in the process of utilization in detail.
Research progress on mordenite catalyzed carbonylation of dimethyl ether
ZHAO Sheng-ying, GENG Hai-lun, XU Bing, WU Xue-mei, TAN Ming-hui, YANG Guo-hui, TAN Yi-sheng
 doi: 10.19906/j.cnki.JFCT.2021083
Abstract(47) HTML(11) PDF 1383KB(9)
The carbonylation reaction of dimethyl ether is an important carbon addition reaction with directed insertion of carbon monoxide into dimethyl ether molecule, which is of great significance in industrial production. In recent years, it has been found that inexpensive mordenite has higher activity and very excellent carbonylation product selectivity for catalyzing the carbonylation reaction of dimethyl ether, hence widely studied. This review has surveyed researches on mordenite catalyzed carbonylation of dimethyl ether, which introduces the mechanism of carbonylation reaction, and summarizes the various methods of controlling the acidic sites inside mordenite and their effects on the carbonylation reaction.
In-situ catalytic upgrading of tar from integrated process of coal pyrolysis with steam reforming of methane over carbon based Ni catalyst
WANG Zheng-wei, WEI Bao-yong, LV Jian-nan, WANG Yi-ming, WU Yun-fei, YANG He, HU Hao-quan
 doi: 10.1016/S1872-5813(21)60169-X
Abstract(20) HTML(6) PDF 2159KB(4)
In our previous work, high tar yield was achieved by coal pyrolysis coupled with steam reforming of methane (CP-SRM), but the tar has high content of heavy fractions. In order to improve the tar quality by decreasing the heavy tar content and ensuring high tar yield, in-situ catalytic upgrading of tar from the integrated process of coal pyrolysis coupled with steam reforming of methane was conducted over carbon (KD-9) based Ni catalyst. The results showed that at 650 oC, the tar yield of CP-SRM over 5Ni/KD-9 is 24.4%, which is a little lower than that of without catalyst, while the light tar yield (i.e.,18.9%) is 1.4 times higher than that of without catalyst, and the content of C2, C3 and C4 alkyl used as a substitute for benzene significantly increases tar yields by 0.5, 0.6 and 4.0 times, respectively. The content of phenols and naphthalenes in tar also increased dramatically after upgrading. Isotope tracer approach combined with the mass spectra of typical components was employed in exploring the mechanism of the upgrading process. The results showed that 5Ni/KD-9 catalyzes coal tar cracking and SRM at the same time. Small free radicals such as ·CHx, ·H and ·OH generated by SRM can combine with free radicals from tar cracking, thus avoiding excessive cracking of tar.
The structure and hydrogenation performance for methyl benzoate of MnOx/ZrO2-Cr2O3 catalyst
ZHAO Yu, WANG Qi-feng, SONG Bing-jie, SUN Pei-yong, ZHANG Sheng-hong, YAO Zhi-long
 doi: 10.1016/S1872-5813(21)60104-4
Abstract(57) HTML(23) PDF 1424KB(2)
MnOx/ZrO2-Cr2O3 catalysts were prepared by cocurrent coprecipitation and impregnation. The structure and surface properties of the catalyst were characterized by X-ray diffraction (XRD), N2 physical adsorption (BET), hydrogen temperature programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS). These results showed that the addition of Cr led to the transformation of ZrO2 crystal form from m-ZrO2 to t-ZrO2. With the increase of Cr content, the BET of the composite oxide ZrO2-Cr2O3 increased gradually, the average pore size decreased and the pore structure also changed. The impregnation of Mn caused the migration of Cr in the ZrO2-Cr2O3 composite oxide, and promoted the transformation of the ZrO2 crystal form from m-ZrO2 to t-ZrO2, the BET and pore structure of the catalyst changed also. The conversion and selectivity of MnOx/ZrO2-Cr2O3 catalysts containing 4% Mn and 2.5% Cr for methyl benzoate hydrogenation were 93.86% and 86.05%, respectively.
Research progresses in the hydrogenation of carbon dioxide to certain hydrocarbon products
WANG Han, FAN Sheng, WANG Sen, DONG Mei, QIN Zhang-feng, FAN Wei-bin, WANG Jian-guo
 doi: 10.1016/S1872-5813(21)60122-6
Abstract(115) HTML(22) PDF 905KB(33)
Accompanying with the rapid consumption of fossil fuel resources, a huge amount of CO2 has being released into the atmosphere, which brings serious environmental concerns. However, CO2 can also be considered as a clean and non-toxic carbon resource; the utilization of CO2 by converting it into various hydrocarbons can not only alleviate the greenhouse effect, but also provide a new sustainable route to produce clean fuel and chemical products. In this paper, we attempt to make a review on the recent research progresses in the hydrogenation of CO2 to certain hydrocarbons (including methane, olefins and aromatics) in recent years; in particular, the advance in the development of efficient catalysts for the hydrogenation of CO2 to methane, light olefins and aromatics as well as in the exploration of catalytic reaction mechanisms were retrospectively summarized. Lastly, we would like to have an outlook on the possible trends in the utilization of CO2 as a carbon resource through hydrogenation.
Effects of incineration conditions on dioxins from simulated municipal solid waste incineration
ZHANG Kai-wen, LIU Xu, ZHANG Hai-jun, GAO Xiao-han, LÜ Xue-chuan, ZHANG Lei, WANG Sheng
 doi: 10.19906/j.cnki.JFCT.2021071
Abstract(53) HTML(32) PDF 1127KB(2)
By changing the simulation conditions of municipal solid waste incineration experiment (nickel catalyst, water), analysing the reaction temperature, incineration exhaust gas flow, concentration of exhaust gas composition, the dioxin concentrations, the toxicity of dioxin equivalent of absorbing liquid, and the change of the absorption liquid organic matter concentration, the effect of different combustion conditions on dioxins from simulated municipal solid waste incineration was explored. The results showed that the addition of nickel catalyst and water could promote the conversion of macromolecule organic matter to small molecule organic matter during the incineration process, and effectively inhibited the precursor synthesis of dioxins, while the suppression ratio of dioxins were 80.7% and the total equivalent toxicity of dioxins were decreased by 98%.
The effects of coal ash on sulfur transformation during secondary reactions of coal pyrolysis
JIA Xin, WANG Qin-hui, ZHANG Yu-hui, HAN Zhen-nan, SONG Xing-fei, WANG Chao, FU Liang-liang, XU Guang-wen
 doi: 10.19906/j.cnki.JFCT.2021081
Abstract(27) HTML(12) PDF 1168KB(5)
During the coal pyrolysis with the coal ash as heat carrier, the interactions of coal ash and volatile matters could occur in the secondary reactions, which would affect the final sulfur-containing product yields of volatile matter. The objective of this paper was to reveal the effects of coal ash on the sulfur transformation during the secondary reactions. The results showed that the presence of XLT ash during secondary reactions inhibited H2S and COS release at low temperatures due to the sulfur fixation of Fe2O3 existed in the ash. However, it enhanced H2S and COS release at high temperatures, which was mainly caused by the formation of sulfur-containing gases through the reactions between CaSO4 and reducing gas (i.e. H2, CO, and CH4). The influences of Fe2O3 and CaSO4 were also investigated to reveal the mechanism of the influence of coal ash, and it was found that H2S and COS yields were reduced with the addition of Fe2O3, but those two gases were slightly increased by the presence of CaSO4 at 800 ℃, indicating that Fe2O3 and CaSO4 played important roles in the interactions between the coal ash and sulfur-containing gases.
Influence of vacuum degrees in rectification system on distillation characteristics of bio-oil model compounds
MA Ya-kai, YUAN Xin-hua, LUO Ze-jun, ZHU Xi-feng
 doi: 10.1016/S1872-5813(21)60140-8
Abstract(34) HTML(10) PDF 918KB(2)
The batch distillation experiments of bio-oil model compounds were carried out in a pilot rectification column. The distilled fractions of bio-oil model compounds at atmospheric pressure and vacuum distillation were compared by changing the vacuum degree in the system, and the variations of each component in the fractions were analyzed and summarized. The results showed that the total distillate rate of bio-oil model compounds increased and the coking rate decreased, the water was more likely to be evaporated, the initial distillation temperature of organics in the fraction decreased and the distillation rate increased with the decrease of vacuum degree in the system. Therefore, increasing the vacuum degrees can effectively separate the components of the bio-oil model compounds and reduce the energy loss. When the vacuum degree is −0.08 MPa, the distillation effect of the bio-oil model compounds are optimum. The distillation rates of acetic acid and furfural can reach 99.50% and 65.88%, and the distillation rates of phenol and guaiacol both exceed 25%.
Study on the oxy-fuel co-combustion and pollutants emission characteristics of coal gangue and semicoke
DAI Ruo-wei, ZHAO Rui-dong, WANG Zhi-qi, QIN Jian-guang, CHEN Tian-ju, WU Jin-hu
 doi: 10.1016/S1872-5813(21)60132-9
Abstract(22) HTML(3) PDF 1054KB(2)
The oxy-fuel co-combustion and pollutants emission characteristics of coal gangue and semicoke were studied by thermogravimetric analyzer and tube furnace experiments. The effects of semicoke blending ratios, O2 concentration and temperature were investigated. The results show that the combustion performance of blended fuel can be improved with the addition of semicoke and the increases of O2 concentration. The maximum ignition and burnout index are obtained when semicoke blending ratio is 75 %. The CO and SO2 conversion gradually decreases with the increase of semicoke blending ratios. As the increase of temperature, the CO conversion decreases, SO2 conversion increases while NO conversion firstly increases then decreases or slowly grows. The NO emission can be reduced with the addition of semicoke when the temperature is 900°C. However, it will aggravate NO emission at other temperatures. With the increase of O2 concentration, the CO conversion decreases, NO conversion increases while SO2 conversion firstly decreases and then increases. The minimum SO2 conversion is obtained when O2 concentration is 20 %.
Preparation of activated carbon from unburned carbon in biomass fly ash and its supercapacitor performance
SONG Chuan-lin, REN Ke, TENG Zhao-cai, WANG Mei-mei, ZHANG Ji-gang, HAN Kui-hua, LONG Shen-wei, ZHU Ying-quan
 doi: 10.1016/S1872-5813(21)60129-9
Abstract(66) HTML(19) PDF 1037KB(11)
After the fuel undergoes pyrolysis and combustion in a biomass boiler, the fly ash contains some unburned carbon with abundant pores. However, their low porosities and specific surface areas cannot meet the requirements of the activated carbon for commercial supercapacitors, and the activation method to improve their pore structures is the key to enhance their applicability. After the one-step KOH activation treatment of the unburned carbon with the particle sizes > 0.2 mm, the results showed that the activated carbon has the largest specific area (1982 m2 g−1) at an impregnation ratio of 3.5:1, and the specific capacitance reached 207 F g−1 at the current density of 1 A g−1. The above results indicate that unburned carbon-based activated carbon has a good double layer capacitance performance, providing a reference for the high value-added utilization of biomass fly ash.
Synergistic hydrogenolysis of biomass furfuryl alcohol over Ru/solid base catalysts in hydrothermal reaction environment
WENG Yu-jing, MENG Shi-hang, ZHU Wan-sheng, ZHANG Ming-wei, SUN Qi, ZHANG Yu-long
 doi: 10.1016/S1872-5813(21)60111-1
Abstract(64) HTML(57) PDF 2197KB(12)
Furfuryl alcohol is a kind of biomass furan platform compound that cannot be obtained from fossil resources, through which many fine chemicals and fuel additives can be developed. Among them, tetrahydrofurfuryl alcohol (THFA) is a common solvent and an important raw material, and 1,2-pentanediol (1,2-PeD) is an important intermediate for the synthesis of the fungicide propiconazole. In this paper, Ru/solid base catalysts were employed to realize the direct hydrogenolysis of furfuryl alcohol into tetrahydrofurfuryl alcohol and 1,2-pentanediol. Moreover, the catalyst preparation, activation and reaction conditions were screened. It was found that the yield and selectivity of 1, 2-pentanediol were improved by the preparation of Ru based catalyst with basic metal oxides as support. The total yield of tetrahydrofurfuryl alcohol (53%) and 1, 2-pentanediol (32%) was 85% under the optimal reaction conditions over Ru/MnO2. Subsequently, N2 adsorption-desorption, XRD and XPS were employed to reveal the catalytic mechanism which suggested that the synergistic between the surface basic groups and active metals might account for the better catalytic performance.
Reaction characteristics and mechanisms of sorbitol fast pyrolysis
HU Bin, GUO Xue-wen, LI Yang, CHENG An-shuai, LIU Ji, LU Qiang
 doi: 10.1016/S1872-5813(21)60150-0
Abstract(47) HTML(12) PDF 7103KB(3)
Sorbitol is an important biomass resource, but its fast pyrolysis characteristics and reaction mechanism are not well-studied. In the present study, the fast pyrolysis characteristics of sorbitol were deeply explored and the formation mechanism of the main products was revealed using fast pyrolysis experiments and density functional theory (DFT) calculations. The results show that the fast pyrolysis of sorbitol mainly produces low molecular weight products such as hydroxyacetaldehyde (HAA) and hydroxyacetone (HA), furan-based products such as furfural (FF) and 1-(2-furanyl)-ethanone (2-FE), and anhydrosugar product (isosorbitol (IS)). The yield of HA and HAA products is the highest, due to their lower overall energy barriers. Notably, the generation of HA and HAA are simultaneous. The formation of furan-based products 2-FE and FF needs to overcome relatively higher overall energy barriers, despite that some intermediates also appear in the formation of HA and HAA. Hence, the yields of furan-based products are lower than those of low molecular weight products. The reaction intermediates for formation of anhydrosugar IS are different from those of HA/HAA and 2-FE/FF. The overall energy barrier is high that leads to a very low yield of IS. This study provides a theoretical insight into the mechanism research and technique development for selective pyrolysis of sorbitol.
Selective depolymerization β−O−4 linkage of lignin over Pd/C and NaOH
WANG Wen-jin, XU Ying, ZHU Yu-ting, MA Long-long
 doi: 10.19906/j.cnki.JFCT.2021056
Abstract(26) HTML(16) PDF 691KB(3)
β–O–4 is the most abundant linkage in the lignin structure. It is of great significance to convert lignin into monophenols by breaking the β−O−4 linkage. Therefore, β−O−4 dimer model compound is used as raw materials in this paper. The effects of metal catalysts, temperature, time and hydrogen pressure on the conversion of dimer and yield of monophenols were investigated, analyzing by GC-MS, GC-FID, HSQC NMR characterization. The results show that: NaOH and carbon-supported metal catalysts have a synergistic effect, which can enhance the breakage of β−O−4 linkage. The best promotion effect was obtained over Pd/C and NaOH, monomer yield increased from 44.1% to 83.4%. Studies have shown that: NaOH and Pd/C can inhibit the removal of Cα−OH of the dimer and enhance the breakage of β−O−4 linkage effectively, leading to the increment in monomers. And the catalytic system of NaOH and Pd/C have showed excellent performance during the breakage of α−O−4. To the best, alkali lignin was converted into monophenols over NaOH and Pd/C with the yield of 37.5%. The selectivity of benzyl alcohol is as high as 48%.
Characteristics of cyanobacteria pyrolysis and gasification during chemical looping process with red mud oxygen carrier
ZHANG Hai-feng, CHEN Lu, LIU Xian-yu, GE Hui-jun, SONG Tao, SHEN Lai-hong
 doi: 10.1016/S1872-5813(21)60087-7
Abstract(67) HTML(20) PDF 1285KB(12)
The pyrolysis and gasification characteristics of pelletized cyanobacteria during chemical looping process with red mud oxygen carrier were investigated. The objective is to evaluate influence of red mud oxygen carrier on the pyrolysis and gasification behavior. In a fluidized bed reactor effects of reaction temperature (750−900 ℃) and oxygen carrier to fuel ratio (0.1−0.7) on syngas distribution, carbon conversion and its conversion rate, syngas content and ratio of H2/CO in syngas were investigated. The results indicate that the presence of oxygen carrier has remarkably positive effect on the pyrolysis and gasification processes. It improves pressure gradient caused by devolatilization of the sample. Consequently, the volatiles could be released gradually through the relatively developed channels. During chemical looping gasification H2 content in the syngas has the highest concentration of higher than 45%, followed by CO2, CH4 and CO. The increase of reaction temperature or oxygen carrier to fuel ratio leads to increase in carbon conversion. When reaction temperature increases from 750 to 950 ℃, ratio of H2/CO in the syngas decreases from 7.26 to 4.83. Meanwhile, with increasing oxygen carrier to fuel ratio, ratio of H2/CO first increases and then decreases, and the peak is 5.6 as oxygen carrier to fuel ratio is 0.5.
Low temperature pretreatment of poplar using deep eutectic solvent and the structural evolution of three components of poplar
PI Qi-feng, ZHU Yu-ting, LÜ Wei, LIAO Yu-he, WANG Chen-guang, MA Long-long
 doi: 10.1016/S1872-5813(21)60086-5
Abstract(59) HTML(12) PDF 2184KB(8)
In this work, the impacts of ChCl/carboxylic acids, molar ratios of hydrogen bond acceptors to donors, pretreatment temperature and time on the delignification of poplar were investigated. Characteristic methods including XRD, FT-IR, GPC, and HSQC were used to analyze the solid residue and extracted lignin for the study of the structural evolution of the three components. The results showed that under low temperature of 90 ºC, the delignification of poplar wood was 91% with ChCl/FA pretreatment. About 63% of lignin was collected and the purity of lignin was 90%. Over 98% cellulose remained intact with Iβ type crystal form, and the crystallinity was 70%. The β−O−4 bond content of extracted lignin was 84.8% (71% of the original β−O−4 bond), and M n of the lignin was 1400 g/mol, suggesting the extracted lignin to be an ideal raw material for monophenlics production.
Advances on the catalytic hydrogenation of biomass-derived furfural and 5-hydroxymethylfurfural
ZHANG Jun, LI Dan-ni, YUAN Hao-ran, WANG Shu-rong, CHEN Yong
 doi: 10.1016/S1872-5813(21)60135-4
Abstract(108) HTML(80) PDF 1220KB(23)
In recent years, the conversion of biomass-derived platform compounds into a variety of high value fuel and chemical products has attracted increasing attention from researchers. 5-Hydroxymethylfurfural (HMF) and furfural (FFR) belong to a class of important biomass-derived platform chemicals. The molecular structure of HMF and FFR is consisted of aldehyde group, furan ring and other functional groups, which endow them with unique chemical properties. In this paper, the research advances on the catalytic hydrogenation of HMF and FFR in various hydrogen sources, such as hydrogen, alcohol, silanes and formic acid, have been reviewed in detail. In addition, the main influencing factors like catalyst type and reaction conditions on the hydrogenation process as well as the reaction mechanism are discussed in depth. Meanwhile, research foreground in the catalytic hydrogenation of HMF/FFR has been prospected.
Advance on the pyrolytic transformation of cellulose
LI Cheng-yu, ZHANG Jun, YUAN Hao-ran, WANG Shu-rong, CHEN Yong
 doi: 10.1016/S1872-5813(21)60134-2
Abstract(125) HTML(16) PDF 1108KB(20)
Pyrolysis technology has a great application prospect in the future. The essential properties of cellulose, pyrolysis mechanism, research tools, catalyst type and other important factors affecting the products distribution are discussed in detail. Particularly, the addition of a variety of catalysts and the optimum design of reaction device can significantly accelerate the cellulose pyrolysis, improve the product distribution and increase the selectivity of some high-value chemicals, thus effectively enhancing the resource and energy utilization value of pyrolysis products. Last but not the least, the future research orientation of cellulose pyrolysis technology is put forward based on some key questions to be solved.
Effect of support factors on the selective catalytic oxidation of benzyl alcohol over Au/BN catalyst
CHANG Tong, MA Rui-jing, SONG Chang
 doi: 10.19906/j.cnki.JFCT.2021060
Abstract(36) HTML(21) PDF 8528KB(7)
The selective oxidation of primary alcohols represents a premier route for the synthesis of aldehydes as intermediates of multiple commercial fine chemicals such as drugs and perfumes. In particular, catalytically selective oxidation of primary alcohol in use of oxygen is of great interest, owning to its high efficiency, solvent-free, and easy separation. As such, choosing this route to pursue desired atomic economy has been an essential topic of common concern in both academic and industrial circles in recent years. Boron nitride with graphite like structure is a new catalyst developed in recent years, which has the characteristics of stability and good thermal conductivity. In this contribution, three kinds of boron nitride (BN) with different structural characteristics were used as carriers to support Au nano metal for selective oxidation of benzyl alcohol. It was found that the crystallinity and specific surface area of the carriers had a great influence on the size of active phase Au. The specific surface area of ​​Au/BN500 is four times higher than that of the Au/BN600 and Au/BN700. Compared with Au/BN700, Au/BN500 catalyst has better dispersion and smaller particle size (13 vs. 3.2 nm). And the catalytic activity of Au/BN500 is about as twice much as that of the other two, except the activity loss by ca. 30% within 5 hours. The results in this paper provide enriched experimental and theoretical references for rational design and development of novel high-performance boron nitride-based oxidative dehydrogenation catalysts.
Selective xylose hydrogenolysis to 1,2 – diols using Co@NC catalysts
LIANG Yuan, LI Zhi-jian, LIU Qi-ying, MA Long-long
 doi: 10.1016/S1872-5813(21)60125-1
Abstract(61) HTML(14) PDF 1854KB(3)
Xylose is the predominant component of hemicellulose, and converting xylose to valuable compounds is essential to achieve biomass utilization. Herein, N-doped carbon nanotubes encapsulated metal catalysts (Co@NC) with hydrogenation and isomerization capacities were synthesized via bottom-up method for catalyzing xylose hydrogenolysis into 1,2-diols. The physicochemical properties of Co@NC prepared with different calcination temperature were determined by XRD, TEM, XPS and so on. The Co@NC prepared at 600 oC exhibited the optimal catalytic activity, and the yield of diols reached 70.1% with ethylene glycol, 1,2-propylene glycol and 1,2-pentanediol being 17.6%, 25.1% and 27.4%, respectively. The doping N species served as the basic sites which benefited the isomerization of xylose to xylulose. Xylulose was subsequently converted to glycolaldehyde and acetol through Retro-aldol reaction, followed by hydrogenation to produce ethylene glycol and 1,2-propylene glycol. 1,2-Pentanediol derived from the selective hydrodeoxygenation of xylose, the yield of which surpassed the results that had been reported. The Co@NC catalysts with high robustness under harsh hydrothermal conditions provided new insights into the effective conversion of lignocellulosic biomass to 1,2-diols.
Microalgae co-pyrolysis with waste plastics to prepare low-O/N and hydrocarbon-rich liquid oil
TANG Zi-yue, CHEN Wei, HU Jun-hao, YANG Hai-ping, CHEN Ying-quan, CHEN Han-ping
 doi: 10.19906/j.cnki.JFCT.2021070
Abstract(67) HTML(24) PDF 1202KB(13)
In order to reduce N-/O-compounds content and improve the quality of microalgae bio-oil, the co-pyrolysis /catalytic of Nannochloropsis sp. (NS) and polyethylene (LDPE) were studied in a fixed bed, and discussed the distribution of N and O, as well as the interaction between microalgae and LDPE and the influence of the addition of catalyst. It is found that co-pyrolysis could effectively inhibit the transformation of O and N to oil, promote O releasing as H2O and N conversion to gas products. In addition, plastic adding significantly reduced the content of O-/N-compounds in oil, such as carboxylic acid, amide and N-heterocyclic, and increased the aliphatics content. Besides, it effectively promoted the formation of hydrocarbon gas, and showed a certain synergistic effect on CO and H2, and the interaction reached the maximum at 25%LDPE. Furthermore, ZSM-5 could promote the formation of hydrocarbon gas, increase the LHV of gas products (35.6 MJ/Nm3), and further reduce the nitrogen compounds in the oil, while the N in microalgae transferred to gas, and O converted to gas and H2O, which resulted in the further reduction of the O and N contents in the oil. Moreover, catalytic co–pyrolysis could inhibit the formation of aromatic hydrocarbons to a certain extent and improve the selectivity of aliphatic hydrocarbons.
Production of renewable aromatics and olefins by catalytic co-cracking of fatty acid methyl esters and methanol
LIU Sen, GUO Yu-qian, SUN Pei-yong, ZHANG Sheng-hong, YAO Zhi-long
 doi: 10.1016/S1872-5813(21)60146-9
Abstract(39) HTML(7) PDF 1621KB(11)
Catalytic cracking of triglycerides and their derivatives (e.g., fatty acid methyl esters, FAMEs) by HZSM-5 zeolite offers a promising route to produce renewable aromatics and olefins, but it is primarily hindered by the rapid catalyst deactivation caused by coke. In this work, the co-cracking of FAMEs and methanol over HZSM-5/Al2O3 composites was developed to regulate the product distribution and slower the catalyst deactivation. Co-feeding methanol with FAMEs enhanced the olefin selectivity at the expense of aromatics, and the total selectivities of aromatics and olefins added up to 70.9% with an optimized methanol content of 60%. The co-feeding of methanol not only promoted the olefin yield but also retarded the consecutive H-elimination of aromatics to polycyclic aromatics, thus reducing the coke formation and prolonging the catalyst lifespan. Under the conditions of 450 °C, 0.16 MPa and a space velocity of FAMEs at 4 h−1, increasing the methanol blending ratio in FAMEs from zero to 50% reduced coke from 17.8% to 10.1% after reaction for 12 h. Besides, the spent catalyst for the co-cracking reaction could be easily regenerated by coke combustion, yielding similar structure, acidity and activity to those of the fresh one.
Catalytic depolymerization of Kraft lignin for liquid fuels and phenolic monomers over molybdenum-based catalysts: The effect of supports
WANG Yi-shuang, CHEN Ming-qiang, SHI Jing-jing, ZHANG Jin-hui, LI Chang, WANG Jun
 doi: 10.1016/S1872-5813(21)60167-6
Abstract(18) HTML(5) PDF 1197KB(2)
Catalytic lignin depolymerization (CCLD) for liquid fuels and phenolic monomers was investigated over various supports including clays (e.g., sepiolite (SEP), attapulgite (ATP), and montmorillonite (MTM)), and oxides (e.g., Al2O3 and SiO2) as well as their supported Mo-based catalysts under supercritical ethanol. The characterization results demonstrated that different supports with diverse structural properties could affect the textural structures, surface Mo5+ content, and acid sites distribution. Clay-based supports had more strong acid sites as compared with Al2O3 and SiO2, which went against the production of lignin oil (LO) and led to form more solid products during CLD experiments. Meanwhile, the obtained petroleum ether-soluble product (PEsp) in LO catalyzed by sole supports was mainly alkyl/alkoxy substituted phenols. Additionally, Mo species (especially Mo5+) significantly increased the yields of LO and PEsp. Mo/SiO2 had the highest surface Mo5+ species, showing the highest LO yield of 85.2%, in which the produced alkyl/alkoxy substituted phenols reached 450.3 mg/glignin. Among the clay-supported Mo catalysts, Mo/SEP presented superior LO (82.3%) and PEsp (70.8%) yields and the generated substituted phenols reached 398.8 mg/glignin. This paper systematically reported the application of green and environmentally friendly clay-based materials in lignin conversion, which provides some key information for the development of clay catalysts for biomass conversion.
Progress on using biomass derivatives to replace petroleum for synthesis of high-density fuels
LIU Ning, SHI Cheng-xiang, PAN Lun, ZHANG Xiang-wen, ZOU Ji-jun
 doi: 10.19906/j.cnki.JFCT.2021076
Abstract(158) HTML(26) PDF 1104KB(51)
The goal of “carbon peak and carbon neutrality” provides a powerful engine for the transformation of energy structure in China. As response to the sustainable development and energy structure transformation, the development of biomass high-density fuels is necessary, which can provide renewable alternatives for traditional petroleum-based high-density fuels. Herein, the properties and applications of typical petroleum-based high-density fuels including RJ-4 and JP-10 are reviewed. We also introduce the routes for synthesizing RJ-4, JP-10 and other polycyclic fuels from terpenoids and lignocellulose platform compounds, showing the feasibility of converting biomass to high-density fuels. Finally, we emphasize the current bottlenecks and development trends in the synthesis and application of biomass high-density fuels.
Preparation of platform compounds by hydrothermal conversion of lemon peel under the catalysis of sulfuric acid
XIONG Shan-shan, LING Yi-lu, TAN Jun-yao, HAN Yi-fan, LUO Chao, ZHU Ling-jun, WANG Shu-rong
 doi: 10.1016/S1872-5813(21)60142-1
Abstract(31) HTML(12) PDF 869KB(2)
Lemon peel, as a typical carbon solid waste in fruit processing industry, of which efficient recycling and resource utilization contribute to the development of renewable liquid fuel and economic benefits. Citric acid contained in lemon peel has been proved to be a weak acid that can effectively promote the hydrothermal conversion of biomass and its derivatives to produce high value-added furan products. Therefore, sulfuric acid is used to catalyze the hydrolysis of lemon peel to produce precursor of important liquid fuel, such as levulinic acid (LA) and furfural (FF). The promotion effect of common metal salt on catalysis of sulfuric acid to the hydrolysis process of lemon peel is explored. The citric acid contained in lemon peel promotes the hydrolysis process. Combined with catalysis of sulfuric acid, the LA yield as 22.6% can be obtained under the mild hydrolysis conditions of 170 ℃ and 90 min, and the addition of the KCl can effectively inhibit the secondary reaction of the hydrolysis process of the lemon peel and enhance the interaction of the sulfuric acid and the lemon peel. Compared with AlCl3 and FeCl3, the LA yield is increased to 27.9% by the addition of KCl. Preparing conditions of glucose and FF are milder than that of LA. Enhancement of temperature and acidic concentration, and prolonging reaction time all lead to significant decrease in glucose and FF yield.
Study on durability of online catalytic upgrading of bio-oil based on Ru/HZSM-5
XIONG Yong-lian, LU Dong-sheng, FAN Yong-sheng, HOU Guang-xi, CHEN Yu-wei
 doi: 10.1016/S1872-5813(21)60114-7
Abstract(55) HTML(18) PDF 2059KB(10)
Ru/HZSM-5 was prepared and used to upgrade bio-oil online and the changes of bio-oil yield and physicochemical properties were analyzed through the total quality index ( TQI ). The changes of the chemical compositions of the bio-oils were compared; simultaneously, the coking situation of the catalyst was characterized. The results showed that the yield and physicochemical properties of bio-oil obtained by using fresh catalyst were high, and the TQI increased from 0.15 to 6.45; with the increase of using times, the TQI first increased slightly to 6.68, then decreased rapidly to 1.25, and reduced to only 0.27 after the fourth usage. In the initial stage, a small amount of coking reactions made the strong acid sites partially passivated, which improved the aromatization performance. When the catalyst was used twice, the relative content of hydrocarbons in the bio-oil reached 53.79%, of which the relative content of light aliphatic hydrocarbons was 16.87%, and the relative content of monocyclic aromatic hydrocarbons was 32.65%. After the fourth usage, the relative content of hydrocarbons in the bio-oil was only 9.32%, and the catalyst layer basically lost the upgrading effect, and had adverse effects on pyrolysis vapors such as secondary cracking or polymerization. Before the third usage, the low-temperature pyrolytic coke attached to the catalyst surface was dominant. After the third usage, the low-temperature pyrolytic coke and high-temperature catalytic coke increased significantly, and the catalyst activity decreased sharply. Continuous usage of catalyst slightly increased coke, of which the pyrolytic coke increased mainly.
Preparation of modified β zeolite with phosphorus for catalytic alkylation of C9 aromatics with propylene
CHEN Qiang-qiang, GUO Yu, WU Hong-mei
 doi: 10.19906/j.cnki.JFCT.2021074
Abstract(27) HTML(16) PDF 1691KB(1)
To investigate the catalytic properties of β zeolite for catalytic alkylation of C9 aromatics with propylene, β zeolites modified with phosphorus were prepared by using impregnation method. The modified β catalysts with different loading amount of phosphorus were characterized by XRD, SEM, EDX, MAS NMR, Py-IR, N2 adsorption-desorption, and NH3-TPD. The results showed that the morphology and crystal structure of the β zeolite catalysts did not change obviously after modification with phosphorus. However, the specific surface area and the surface Si/Al mass ratio of the β zeolite decreased with the increase of amount of phosphorus. It was proved that the interaction between the phosphorus and β zeolite would affect the acid strength distribution of β zeolite and the catalytic performance of alkylation of C9 aromatics. In comparison with β zeolite, the β zeolite modified with 0.5 wt.% phosphorus (β-0.5P) has good catalytic performance in alkylation reaction of C9 aromatics. The ratio of ${\rm{C}}_{12}^+ $ aromatics in the alkylation products was up to 17%, and the value of m1,3,5-TMB/mC9 was increased by 5.3%. The β-0.5P catalytic activity showed stable after reaction for 10 h. However, when the loading amount of phosphorus on β zeolite was too high, the alkylation activity of the catalyst decreased and the isomerization and disproportionation performance of the catalyst increased.
Low-cost preparation of Ni/C/CG composites for microwave absorption by recycling coal gangue
LIANG Li-ping, GAO Fei, WANG Ya-ke, ZHU Bao-shun, LI Guo-min
 doi: 10.19906/j.cnki.JFCT.2021066
Abstract(42) HTML(21) PDF 1529KB(5)
With coal gangue (CG) as the carbon-containing carrier, starch as supplementary C source and nickel nitrate as Ni source, Ni/C/CG composite microwave absorbing materials were prepared by a solution impregnation and then a carbothermal reduction process. The influence of the carbothermal reduction temperature on the composition, microstructure and performance of materials was carefully studied. It was found that, the carbothermal reduction temperature had a great effect on the crystalline state of carbon and Ni, as well as the size of Ni particles, further greatly affected the electromagnetic properties, especially the dielectric properties of the materials. Due to the combination of good impedance match and strong microwave attenuation ability, the Ni/C/CG composites prepared under a wide temperature range of 600−800 ℃ all displayed excellent microwave absorption performance. For the sample heat-treated at 800 ℃, the minimum reflection loss could reach −20.9 dB at 12.9 GHz and the corresponding effective absorption band was 3.7 GHz with a coating thickness of only 2 mm. In addition, the dielectric loss was the dominant microwave absorption mechanism, which mainly originated from the conductive loss caused by the graphite carbon and Ni particles, and the interfacial polarization loss due to the existence of interface between Ni, C and CG.
Study on the mechanism of oxidation of nitrogen–containing char by CO2 based on density functional theory
ZHOU Sai, LIU Hu, YU Peng-fei, YUAN Mao-bo, XUE Jing-wen, CHE De-fu
 doi: 10.19906/j.cnki.JFCT.2021061
Abstract(60) HTML(25) PDF 2569KB(3)
In order to obtain the NO formation mechanism during the coal combustion, the heterogeneous oxidation of nitrogen-containing char by CO2 were investigated based on density functional theory. Simplified char models containing pyrrole nitrogen or pyridine nitrogen were selected as the carbonaceous surfaces. Geometric optimizations were carried out at the B3LYP–D3/6–31G(d) level. Energies of optimized geometries were calculated at the B3LYP–D3/def2–TZVP level. The results show that CO2 oxidation of nitrogen-containing char is composed of three stages: namely CO2 adsorption, CO desorption and NO desorption. In the reaction of CO2 heterogeneous oxidation of pyrrole nitrogen-containing char, CO2 molecules tend to absorb in the C−O−down mode (C−C bonding, N−O bonding) to form a five-membered heterocyclic structure containing nitrogen and oxygen atoms. Then, the surface carbonyl groups and N(O) could form when the C−O bonds of the original CO2 molecules in the five-membered ring broken, and the CO and NO are desorbed, respectively. The reaction is 401.2 kJ/mol endothermic, and the highest energy barrier is 197.6 kJ/mol. In the reaction of CO2 heterogeneous oxidation of pyridine nitrogen-containing char, CO2 molecules tend to form six-membered heterocyclic ring containing nitrogen and oxygen atoms after adsorption in the C−O−down and C−C bonding and C−O bonding mode. And then CO and NO molecules are desorbed. The reaction is 598.6 kJ/mol endothermic, and the energy barrier of rate–determining step is 292.0 kJ/mol.
The effect of NaF amount on solid base catalysts derived from F-Ca-Mg-Al layered double hydroxides and dimethyl carbonate synthesis
LI Feng, LIAO Yun-hui, ZHAO Ning, XIAO Fu-kui
 doi: 10.1016/S1872-5813(21)60165-2
Abstract(18) HTML(8) PDF 1460KB(2)
Versatile and environmentally benign dimethyl carbonate (DMC) synthesized by propylene carbonate (PC) and methanol via transesterification is green and energy efficient. A series of solid base catalysts derived from F-Ca-Mg-Al layered double hydroxides (LDHs) with different NaF amount were prepared, characterized and tested for the transesterification reaction. The properties of the catalysts modified by fluorine have improved obviously. The catalytic activity increases in the order of: FCMA-0.8 > FCMA-0.4 > FCMA-1.2 > FCMA-1.6 > FCMA-0, which is consistent with the total basic sites amount and the strong basic sites amount. FCMA-0.8 has the best catalytic activity as pure CaO catalyst, and the PC conversion, DMC selectivity and DMC yield are 66.8%, 97.4% and 65.1%, respectively. Furthermore, the DMC yield for FCMA-0.8 just decreased 3.9% (33.2% for CaO catalyst) after 10 recycles. FCMA-0.8 has good prospects in the transesterification of PC with methanol to DMC for industrial application.
Extraction of phenols from bio-oil aqueous fraction by hydrophobic ionic liquids
DENG Jing-jing, LUO Ze-jun, WANG Chu, ZHU Xi-feng
 doi: 10.1016/S1872-5813(21)60108-1
Abstract(92) HTML(26) PDF 1053KB(5)
Acetic acid, phenol, guaiacol and 4-methylguaiacol in bio-oil aqueous fraction were extracted and separated experimentally with the choice of hydrophobic ionic liquid [Bmim][NTf2] as extractant. The effects of extraction time and extractant dosage on the extraction efficiency were explored. With the help of density functional theory (DFT) calculations, the interaction mechanism between [Bmim][NTf2] and phenol was also clarified. The results showed that under the optimal extraction condition (mIL/mW = 0.4, extraction time = 5 min), the extraction efficiencies of acetic acid, phenol, guaiacol and 4-methylguaiacol in the aqueous fraction were 2.71%, 95.41%, 92.04%, and 97.98%, respectively. It was indicated that [Bmim][NTf2] had better selectivity and superior extraction efficiency for phenols in bio-oil aqueous fraction. The results of DFT calculation demonstrated that the strong hydrogen bonding interaction as well as weak vdW interaction between [Bmim][NTf2] and phenols played an important role in extraction and dephenolization of bio-oil aqueous fraction. The phenols in [Bmim][NTf2] can be effectively removed by alkali washing treatment to achieve recovery of [Bmim][NTf2] and next high efficiency extraction.
Influence of water leaching on alkali-induced slagging properties of biomass straw
LIU Yan-jing, YAN Ting-gui, AN Yan, ZHANG Wei, DONG Yang
 doi: 10.1016/S1872-5813(21)60147-0
Abstract(77) HTML(8) PDF 1042KB(18)
Deposition or slagging problem caused by the alkali metal species is one of the major obstacles to utilize biomass fuel in combustion and gasification plant. The paper mainly studies the effect of water leaching on alkali-induced slagging properties of corn straw and rice straw. The original mineral form of alkali elements in biomass straw was studied with comparison of low temperature ash of biomass before and after water leaching. The release and transformation of alkali compounds in biomass straw at different temperatures during heating were analyzed with combination of the XRD result of the heated biomass and the chemical composition of the digested samples. The result shows that the potassium in corn and rice straw mainly exists in the form of KNO3, KClO4, K2SO4 and KAlSi3O8, in which KNO3, K2SO4 and KClO4 is mostly removed in water leaching. The fusion temperatures increased after water leaching, especially for rice straw ash, which is a typical sample that the basic compounds are mainly potassium-containing compounds. The decrease of potassium content with temperature in the original corn and rice was because the potassium-containing minerals decomposed and escaped at 25−1000 °C. The release of potassium in the range of 400−800 °C significantly reduced for corn and rice straw after water leaching, but the potassium content will still decrease above 800 °C. The decrease of magnesium content in corn with increasing temperature may be due to the volatilization of magnesium oxide under the action of carbon reduction. For fuels with high alkali metal content after water leaching, the residual alkali metal will still escape and cause deposition or slagging in the furnace, especially in the temperature range above 800 °C.
Effect of oxidative torrefaction upgrade on physicochemical properties of rice straw
KAI Xing-ping, YU Yi-teng, YANG Tian-hua, ZHU Jing-bo
 doi: 10.19906/j.cnki.JFCT.2021064
Abstract(39) HTML(30) PDF 1830KB(5)
Torrefaction atmosphere is one of the key problems in industrial application of torrefaction technology. In this paper, the effects of oxygen concentration and torrefaction temperature on the physicochemical properties of rice straw during oxidative torrefaction were investigated by simulating the atmosphere of oxy-fuel combustion flue gas. The results show that the effect of temperature on oxidative torrefaction is more significant compared with oxygen concentration. At low temperature (< 250 ℃), oxygen concentration has little effect on the mass and energy yield of torrefied rice straw, but it has obvious effect at high temperature (> 250 ℃). With an increase of temperature (> 250 ℃), the mass and energy yield of torrefied rice straw decreased significantly. When the temperature and oxygen concentration are 250 ℃ and 6%, respectively, it is a suitable oxidative torrefaction condition. Under this condition, the mass and energy yield of torrefied rice straw can be maintained above 70% and 80%, respectively. Increasing the temperature mainly enhances the torrefaction reaction, and the oxidation reaction has an obvious effect when the oxygen concentration exceeds 6%. The retention ratio of chlorine and potassium showed an downward trend with the increase of temperature and oxygen concentration, but the effect of increasing temperature was more significant.
Research progress of catalysts and reaction mechanism in glycerol condensation to acetone glycidol
ZENG Xiang-ke, WANG Wei-lu, LI Liang-ju, OU-YANG Ping, ZHANG Xian-ming
 doi: 10.19906/j.cnki.JFCT.2021063
Abstract(115) HTML(35) PDF 820KB(7)
With the booming of biodiesel industry, it is urgent to high-valued to recycle glycerol as the main by-product. The condensation of glycerol (GLY) with acetone to produce acetone glycidol (2, 2-dimethyl-1, 3-dioxolane-4-methanol, Solketal) is promising direction for GLY utilization, because Solketal can function as fuel additive to modify the fuel viscosity and low-temperature performance of oil significantly, due to the function of Solketal as fuel additive to modify the fuel viscosity and low-temperature performance of oil significantly, and reducing the emission of carbon monoxide, small solid particles and other environmentally unfriendly substances further. However, the reaction needs to be accelerated by the catalyst with acid nature, thus the design and modification over the structure and acid properties of catalysts are dominating the process of glycerol ketonization reaction. So, this paper systematically reviews the progress of homogeneous and heterogeneous acid catalysts in this reaction and the reaction mechanism, taking into account the relevant literature in recent years. It is first classified based on the perspective of structural properties, followed by representations in advantages and characteristics of different catalysts, and highlighted in terms of the influence of their structural properties on catalytic activity. Finally, some future directions for this research field are pointed out.
Study on Preparation of Methyl Levulinate by Directional Alcoholysis of Bamboo Biomass
XU Yang-yang, ZHU Hui-min, LI Chen, PAN Hui, FENG Jun-feng
 doi: 10.19906/j.cnki.JFCT.2021069
Abstract(50) HTML(20) PDF 764KB(6)
The process of directional alcoholysis of cellulose and hemicellulose in bamboo was investigated using solid acid as catalyst and dialkoxymethane/lower alcohol as co-solvent. By adjusting the reaction conditions (composition and ratio of the co-solvent, the type and amount of solid acid catalyst, reaction temperature and time), the optimal reaction conditions are obtained (dimethoxymethane/methanol with a mass ratio of 5 g/15 g, the solid acid catalyst silicotungstic acid 0.002 mol, reaction time 120 min, and reaction temperature 200 ℃), the conversion of bamboo was 81.53 wt%, and the yield of methyl levulinate was 28.39 wt%. At the same time, the conversion process of a variety of biomass model compounds (xylose, glucose, furfural, 5-hydroxymethyl furfural, pentosan and microcrystalline cellulose) was studied in detail, then the fundamental mechanism of directional alcoholysis conversion of cellulose and hemicellulose to produce methyl levulinate was put forward according to the detection results of intermediate products in the reaction process.
Research progress in the direct, nonoxidative conversion of methane to olefins/aromatics (II)
HUANG Xin, JIAO Xi, WANG Xiao-bo, ZHAO Ning
 doi: 10.19906/j.cnki.JFCT.2021073
Abstract(79) HTML(30) PDF 628KB(15)
Direct, nonoxidative conversion of methane towards olefins/aromatics is a hot topic in the background of “carbon peak, carbon neutrality”, owing to zero CO2 emissions, high carbon atom utilization efficiency and hydrogen production. In the present paper, the advances of methane dehydroaromatization (MDA) and direct nonoxidative conversion of methane to olefins, aromatics, and hydrogen (MTOAH) are reviewed, based on our research works and the publications from 2018 to 2021. The determination of active sites, reaction intermediates, reaction mechanism, catalyst modification and improvement were considered. Finally, the future prospect was given for the direct nonoxidative conversion of methane to olefins/aromatics.
Effect of Temperature on the Oxygen Reduction Reaction of Pt3Co Binary Metal Nanoparticles and its Corresponding DFT Calculation Investigation
MAI Yi-lang, XIE Xiang-sheng, WANG Zhi-da, YAN Chang-feng, LIU Guang-hua
 doi: 10.1016/S1872-5813(21)60099-3
Abstract(46) HTML(11) PDF 977KB(8)
Synthesis of low-cost, high-activity and high-stability Pt-based catalysts is of great importance to the large commercialization of proton exchange membrane fuel cell (PEMFC). Doping non-precious metals such as cobalt (Co) with Pt is attractive due to the reduced depletion of Pt and, more importantly, the enhanced activity on the oxygen reduction reaction (ORR) compared with pure Pt. In this work, carbon-supported platinum-cobalt nanoparticles(NPs) were prepared by the impregnation reduction method for the ORR catalyst. By changing the heat treatment temperature, the structure, the crystal phase and the size of the Pt3Co nanoparticles could be controlled. TEM and XRD characterizations show that larger size NPs with higher alloying degree are obtained at higher temperature. The electrochemical results demonstrate that the Pt3Co NPs at 800 ℃ have the highest mass activity (0.41 A/mgPt) and the best stability among all the samples due to their lower particle size and higher alloying degree. Further Density functional theory(DFT) calculation shows that the surface of the Pt3Co structure with high alloying degree can reduce the rate-determining step barrier and improve the ORR activity.
Effect of sulfidation temperature on component transformation and catalytic performance of direct coal liquefaction catalyst
CHEN Chen, LI Hai-jie, BAI Yang, FENG Fu-xiang, TIAN Lei, YANG Yong, LIU Yuan, GUO Qiang
 doi: 10.1016/S1872-5813(21)60118-4
Abstract(44) HTML(14) PDF 1245KB(6)
A series of iron sulfide catalysts were prepared in 5% H2S/H2 atmosphere at different pre-sulfidation temperature, and their catalytic activity for naphthalene hydrogenation was studied at 360°C in 1% H2S/H2 atmosphere of 5MPa. Assisted with MES, XRD and XPS, the component transformation of the catalyst under varied pre-sulfidation temperature and reaction conditions was researched. Data showed that the sulfidation process was of sulfurizing from surface to interior in the order of FeS2→FeS、Fe1–xS→Fe3S4→Fe2O3, during which the rise of temperature benefited sulfur transferring to the body phase; after contacting 1% H2S/H2 gas, particles rapidly transformed to Fe1–xS from outside to inside. By adjusting sulfidation conditions, the content of Fe1–xS was high while the particle size was small, making it possible to obtain the highest activity of the catalyst.
Oxidation characteristics of soot in different entrained flow gasification processes
GAO Ming, TAO Xun, DING Lu, CHEN Zhe-kun, DAI Zheng-hua, YU Guang-suo, WANG Fu-chen
 doi: 10.1016/S1872-5813(21)60116-0
Abstract(46) HTML(35) PDF 5219KB(2)
The morphological structure of six samples including the rapid pyrolysis soot of solid fuels (coal, biomass), the soot from non-catalytic partial oxidation(NC-POX) of natural gas in a laboratory pilot plant and an industrial plant, the commercial carbon black in natural gas furnace /coal tar furnace, were characterized by using a high-resolution transmission electron microscope. Based on atmospheric thermogravimetric analyzer, the non-isothermal method (50 °C−800 °C) was adopted to study the ignition point and the oxidation reaction rate of soot, and the oxidation reaction kinetic parameters of soot was obtained. Studies showed that the physical and chemical properties of varied soot were quite different. The soot from the rapid pyrolysis of coal and biomass presented a higher sphericity and a larger particle size. The soot from NC-POX of natural gas in a laboratory pilot plant was formed at a lower temperature which caused the particle being wrapped by a carbon capsule. The soot from NC-POX of natural gas in an industrial plant had a hollow structure and a small particle size. The reactivity of the soot from NC-POX of natural gas in a laboratory pilot plant is close to that of the industrial plant, which is 3.1 times that of the commercial natural gas furnace carbon black and 3.2 times that of the commercial coal tar furnace carbon black; the reactivity of NC-POX soot is 9.0 times of the rapid pyrolysis soot of coal, and 26.6 times of the rapid pyrolysis soot of biomass. The activation energy of 2 kinds of NC-POX soot and 2 kinds of commercial carbon blacks present staged forms with increasing temperature. The activation energy of the 2 rapid pyrolysis soot was basically unchanged with increasing the temperature.
Release characteristics of arsenic, selenium, lead and transformation of minerals during ashing process of coal
LI Yang, LU Zi-long, YANG He, JIN Li-jun, HU Hao-quan
 doi: 10.1016/S1872-5813(21)60115-9
Abstract(50) HTML(19) PDF 1312KB(9)
In this paper, two kinds of coal (Baiyinhua lignite and coal from Ezhou Power Plant) were selected to study the occurrence of heavy metal arsenic, selenium, and lead in coal and their release during the ashing process; combined with the changes of minerals in coal, the influence of ashing conditions on mineral conversion were also studied. The burn-out temperature of the coal was determined from the thermal weight loss curve by extrapolation method, and then the coal sample was ashed separately in combination with the national standard method. The obtained ash samples were characterized by XRD, XRF, and TG-DTG to analyze the change characteristics of coal minerals at different ashing temperatures. The content and occurrence of arsenic, selenium, and lead in coal samples were extracted by sequential chemical extraction method. The heavy metals in the ash sample were extracted by HNO3 + HF, and the heavy metal content in the extract was detected by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results show that the heavy metals in BYH coal are mainly As in the form of sulfide bound state, making the volatility of arsenic increase with temperature easily; the heavy metals in EZ are mainly sulfide-bound Pb, which is also easy to varies with temperature; selenium in coal mainly exists in the form of organic binding state and sulfide binding state. The main mineral changes occuring during coal ashing are that kaolin is gradually dehydroxylated into metakaolin and finally converted into mullite; pyrite is oxidized to form hematite; gypsum is dehydrated to form anhydrite. The release rate of heavy metals during coal ashing is affected by the content and occurrence of heavy metals in coal and the temperature. The release rate of each heavy metal is greatly affected by the combustion temperature in the ashing process. The higher the content of the sulfide bound state, the larger the release rate increases with the temperature.
Effect of thermal treatment temperature on catalytic performance of Pt/TiO2 nanobelt composite for HCHO oxidation
CUI Wei-yi, WANG Xi-yue, TAN Nai-di
 doi: 10.1016/S1872-5813(21)60113-5
Abstract(47) HTML(8) PDF 1101KB(2)
TiO2 nanobelts were prepared by hydrothermal synthesis and acid treatment, then calcination at different temperatures. And subsequently Pt nanoparticles were deposited on the TiO2 nanobelts. Pt/TiO2 catalytic properties were investigated in the oxidation of formaldehyde. These catalysts were characterized by various techniques and the characterization results showed that the applied thermal treatment temperature greatly influenced the phase composition and surface structure of TiO2 nanobelts, as well as the number of oxygen vacancies and hydroxyl groups on the surface. The Pt/TiO2 nanobelts thermally treated at 600 °C had more oxygen vacancies, which were conducive to the activation of adsorbed oxygen, formed more Ti-(OH)x-Pt species, and showed higher catalytic activity. At 25 °C and relative humidity of 55%, the conversion of formaldehyde reach 91.6%.
The distribution and variation of aromatic nuclei in the pyrolysis products of Naomaohu coal
YANG He, XIE Zhou-wei, SHANG Yan, XIONG Yan-kun, JIN Li-jun, LI Yang, HU Hao-quan
 doi: 10.19906/j.cnki.JFCT.2021062
Abstract(101) HTML(21) PDF 1675KB(13)
The size distribution of aromatic nuclei in coal influences the composition of tar and char during pyrolysis. Pyrolytic experiments of Naomaohu (NMH) coal from Xinjiang in China were carried out in a fixed-bed reactor at different temperatures to study the size distribution of aromatic nuclei during coal pyrolysis. With the increase of pyrolysis temperature, the aromaticity of char, the graphitization degree, and the order degree of aromatic layers increase. The tar is mainly composed of aromatic clusters with 1−2 rings and contains a small amount of aromatic clusters with 3 or more rings. The tar yield increases first and then decreases with increasing temperature (maximum at 550 ℃). However, the changes in the Synchronous fluorescence spectra of the tars with increasing temperature are not significant, indicating that the size distribution of aromatic nuclei in tar changes little with no significant condensation polymerization, and also indicating that the number of bridged bonds and the cracking activity distribution of these bridge chains in different size aromatic rings are relatively uniform. With the increase of pyrolysis temperature, the content of 1 × 1 aromatic layers in the pyrolysis products (char and tar) decreases gradually. When the pyrolysis temperature is at between 500 and 600 ℃, the 1 × 1 aromatic layers are mainly transformed into 2 × 2 and 3 × 3 aromatic layers. When the temperature is higher than 650 ℃, the formation of aromatic layers with the size of 4 × 4 and above takes the main part of condensation polymerization.
One-pass conversion of benzene and syngas to alkylbenzenes by ZnAlOx/ZSM-5 composite catalyst
HAN Teng-fei, LIU Jian-chao, DU Ming-xian, XU Hong, DONG Jin-xiang, LI Xue-kuan, GE Hui
 doi: 10.1016/S1872-5813(21)60123-8
Abstract(73) HTML(24) PDF 3318KB(11)
Alkylbenzenes are important bulky chemicals. The production of alkylbenzenes through benzene and syngas alkylation technology of coal chemical industry can reduce the domestic dependence on petroleum. In this study, mechanical mixture of ZnAlOx and ZSM-5 were used to catalyze the alkylation reaction of benzene and syngas. The results showed that the best performance catalyst was obtained with the 1∶1 mass ratio of the two components and the 2∶1 molar ratio of zinc to aluminum. It was suggested that the main reaction intermediates of methanol and dimethyl are produced on the O vacancy of ZnO and L acidic center of Al2O3 in ZnAlOx. And the alkylated benzenes are formed by the reaction of benzene with the intermediates over ZSM-5. Due to the high temperature property of ZnAlOx for methanol synthesis which can accommodate to the reaction of ZSM-5 for benzene alkylation, the high catalytic activity and selectivity was obtained.
Preparation of TS-1 by dynamic method and study on the performance of thiophene sulfur removal
TANG Ming-yu, WANG Hai-yan, REN Tie-qiang, WEI Min, SUN Na, XIAN Hong-fei
 doi: 10.19906/j.cnki.JFCT.2021054
Abstract(57) HTML(22) PDF 1161KB(9)
Using TPAOH as the template, TEOS as the silicon source and TBOT as the titanium source, the as-prepared samples utilizing a dynamic crystallizating kettle have possessed regular morphology and the average particle size of 600 nm. By modulating the dosage of TBOT, and then changing the molar ratio of titanium to silicon in the initial synthesis solution, the effect of silicon to titanium ratio on TS-1 molecular sieve has been investigated. TS-1 zeolite properties were characterized by means of SEM, TEM, XRD, FT-IR, UV-vis, XPS, N2 adsorption and desorption technology. Finally, using a simulated system of thiophene n-octane dissolved in octane, the catalytic oxidative desulfurization performance of TS-1 zeolite has been investigated.
Effect of preparation method on the performance of Fe-Ag/Al2O3 catalyst in the selective catalytic reduction of NO with propene
TIAN Feng-guo, YANG Xi, WEN Ni-ni, SU Ya-xin
 doi: 10.1016/S1872-5813(21)60121-4
Abstract(70) HTML(19) PDF 1383KB(11)
Previous works demonstrated that the Fe-Ag/Al2O3 catalyst could efficiently reduce NO into N2 by propene with a good resistance towards H2O and SO2. In this work, the effect of preparation method on the performance of Fe-Ag/Al2O3 catalyst in the selective catalytic reduction (SCR) of NO with propene was investigated. Three typical methods, viz., physical grinding (PG), direct impregnation (DI) and sol-gel-impregnation (SGI), were comparatively used to load the active components on the supports. The results indicate that all the catalysts prepared by these three methods display good tolerance towards water vapor and SO2. However, they are rather different in the denitration efficiency; the maximum NO removal efficiency of the catalysts prepared by three methods follows the order of SGI (100%) > PG (62%) > DI (58%). Various characterization results reveal that the catalytic performance of Fe-Ag/Al2O3/CM was mainly related to the porous surface and Fe–Ag interaction. By using the SGI approach, the primary support of cordierite and the secondary support of Al2O3 work together to achieve a large surface area and an intense interaction between Fe and Ag on the resultant DP-Fe/Ag/Al2O3/CM catalyst, forming the bimetal AgFeO2 oxide and displaying the best reducibility. In terms of the PG method, the prepared GR-Fe/Ag/Al2O3 catalyst is powdery and shows the largest surface area; however, without cordierite serving as the monolithic support, Ag2O and Fe3O4 exist as separate oxides together with a hint of elemental Ag. As a result, the GR-Fe/Ag/Al2O3 catalyst shows poor reducibility due to the lack of porous surface to facilitate the Fe–Ag interaction. In contrast, the DP-Fe/Ag/CM catalyst prepared using the DI method shows rather poor dispersion of Fe and Ag due to the absence of the secondary support of Al2O3; in fact, individual Ag2O and Fe3O4 agglomerate on the catalyst surface and no AgFeO2 species is detected. Therefore, the DP-Fe/Ag/CM catalyst, with the surface area of only 1/4 of that for Fe-Ag/Al2O3/CM-SGI, exhibits the poorest activity in the SCR of NO by propene.
Electrochemical properties of coal pitch-based three-dimensional porous carbon as electrode materials for supercapacitors
GUO Ming-cong, LIU Shu-lin,  HE  Feng-xiang, SONG Tian-yong, LI Qiang-sheng, CAI Xin-hui, HU Bo
 doi: 10.19906/j.cnki.JFCT.2021080
Abstract(62) HTML(13) PDF 1070KB(9)
Using cheap coal pitch as raw material and adding pore-forming agent, the carbon material with three-dimensional skeleton structure was obtained by mixing process, air oxidation stabilization process and carbonization process successively, and then the porous carbon material with high specific surface area was obtained by water vapor activation. Thermogravimetric and elemental analysis were used to study the thermal reaction characteristics and structural changes of the samples after oxidation stabilization and carbonization. The surface morphology, pore structure and electrochemical properties of the activated samples were characterized by scanning electron microscope, BET method and electrochemical workstation. After water vapor activation, BET of porous carbon can reach 1638 m2/g. The water-based double layer capacitors prepared with this porous carbon as the electrode material of supercapacitors have good cyclic performance, and the specific capacitance can reach 252 F/g at 1 A/g current density. After 10000 cycles, the specific capacity can still maintain 97.3%. Therefore, the porous carbon materials prepared by this method have low cost and good chemical stability, and can be used as an ideal electrode material for supercapacitors.
Performance of Pt-doped Ni/NiAlOx catalysts for phenanthrene hydrogenation saturation
LIU Dao-cheng, JING Jie-ying, WANG Jiu-zhan, FENG Jie, LI Wen-ying
 doi: 10.1016/S1872-5813(21)60128-7
Abstract(44) HTML(9) PDF 2099KB(7)
Limited by the steric hindrance, hydrogenation of the final unsaturated ring in polycyclic aromatic hydrocarbons remains a challenge. In this work, we prepared a series of Pt-Ni/NiAlOx catalysts by impregnation method to improve the adsorption of aromatics, and phenanthrene was served as the model compound. The effects of Pt content on the structure and saturation performance of Pt-Ni/NiAlOx catalysts were investigated systematically. When the saturation reaction was performed at 300 ℃, 5 MPa and a weight hourly space velocity of 52 h−1, the selectivity of perhydrophenanthrene could be improved from 40% over Ni/NiAlOx catalysts to 67% over 0.5Pt-Ni/NiAlOx catalysts with 0.5 wt% Pt loading. Meanwhile, the obvious reaction rate and turnover frequency were also improved from 1.53 × 10−3 mol/kg/s and 14.64 × 10−3 s−1 to 1.81 × 10−3 mol/kg/s and 22.16 × 10−3 s−1 respectively. This is related to the modified stability of metallic electron−deficient structure of Ni by Pt introduction in phenanthrene hydrogenation, which can promote the adsorption of aromatic hydrocarbons as well as the hydrogenation activity.
Effect of calcination temperature on the structure and performance of molybdenum-tin catalyst for DME oxidation
XIONG Pan, GAO Xiu-juan, WANG Wen-xiu, ZHANG Jun-feng, SONG Fa-en, ZHANG Qing-de, HAN Yi-zhuo, TAN Yi-sheng
 doi: 10.1016/S1872-5813(21)60120-2
Abstract(49) HTML(19) PDF 1351KB(5)
The Mo1Sn2 catalyst with a Mo/Sn molar ratio of 1∶2 was prepared by hydrothermal method, and the structure of molybdenum-tin catalysts was regulated by changing the calcination temperature (400−700 ℃), the effect of catalyst structure changes on the performance of selective oxidation of dimethyl ether (DME) to methyl formate (MF) was studied. The Mo1Sn2 catalyst calcinated at 400 ℃ was found to have good performance in the catalytic oxidation of DME to methyl formate, with the conversion of DME of 9.2% and the selectivity of MF up to 86.9% at 110 ℃ under atmospheric pressure, and no COx was generated. The structure and surface properties of the catalysts were systematically investigated by XRD, Raman, XPS, TPD, H2-TPR and in-situ IR. The results showed that low-temperature calcination was more favorable for the formation of more MoOx structures and Mo5+ species on the surface of the molybdenum-tin catalysts, and the resulting enhanced acidity, redox properties and increase of medium to strong basic sites of the catalysts could significantly promote the enhancement of the catalyst activity and methyl formate production.
The behavior of the different catalysts for model carbon hydrogasification
QU Xuan, WANG Qin-fen, YAN Shuai, FENG Jun, ZHANG Jian-shu, ZHANG Rong, BI Ji-cheng
 doi: 10.1016/S1872-5813(21)60136-6
Abstract(37) HTML(6) PDF 1270KB(5)
The characteristics of the catalytic hydrogasification of activated carbon/bituminous char/anthracite char with the different catalysts were studied in a pressurized thermogravimetry analysis (PTGA). The GC, BET were used to characterize the physical structure and chemical reaction process of carbon, and the function principle of Co to the carbon-hydrogen reaction was preliminarily obtained. The results show that the catalytic activity of transition metals (Fe, Co, Ni) is significantly higher than that of alkali metals and alkaline earth metals in CCHG process. Transition metal CCHG process exists in low temperature (600−750 ℃) and high temperature (> 800 ℃), the emergence of the low temperature catalytic zone can be attributed to the interaction between the transition metal oxide and carbon, then part of carbon structure is activated. The transition metal is embedded in carbon layer structure, the effects of breaking C-C bond and proving the active hydrogen are more effective. Under the conditions of Co catalyst above 850 ℃ and 1 MPa hydrogen pressure, the hydrogen supply of the catalyst can reach saturation, and the catalytic hydrogasification process of carbon is mainly the catalytic bond breaking reaction induced by temperature. The model carbon with high specific surface area and low density has high CCHG activity with the low catalyst load.
Study on regioselectivity in cobalt catalyzed hydroformylation of α-hexene
HE Xiao-fei, GUO Jing, XIA Hong-qiang, ZHAO Tian-sheng
 doi: 10.1016/S1872-5813(21)60131-7
Abstract(39) HTML(7) PDF 1367KB(2)
Regioselective effects of electron and steric hindrance of catalytically active intermediate HCO(CO)2L by phosphine ligands on α-hexene hydroformylation were studied based on density functional theory. Strongly electron-attractive phosphine ligands raise the stability of HCo(CO)2L. PPh3 with large steric hindrance suppresses the adsorptive coordination of α-hexene to HCo(CO)2L, and the addition reaction of the C=C with the Co–H via the branched chain pathway. The difference in the energy barrier (ΔΔE) between B-TS1 for the branched chain alkyl Co intermediate transition state and L-TS1 for the linear chain one is 2.73 kcal/mol, indicating that the addition via the branched chain path is relatively difficult whereas that via the linear chain path advantage. The electron and steric hindrance of phosphine ligands both affect pathway of the addition reaction and are favor in the linear chain addition, with the linear chain aldehydes as main products.
Effect of halogen atoms on photocatalytic activity of bismuth oxyhalide (BIOX, X = Cl, Br, I)
ZHAO Li-ye, LI Heng, WANG Liang, LI Chun-hu
 doi: 10.19906/j.cnki.JFCT.2021067
Abstract(33) HTML(31) PDF 1136KB(7)
BiOCl, BiOBr and BiOI were prepared by hydrothermal and solvothermal methods. XRD, SEM, photocurrent density curve and UV-vis were used to characterize the crystal structure, surface morphology and photoelectric properties. The band structure and density of states of BiOX were calculated by DFT, with the atomic number of halogen increased, the dispersion of the fermi level near the semiconductor conduction band decreased, the band gap becomes smaller. The photocatalytic activity of BiOCl, BiOBr and BiOI was evaluated by photocatalytic degradation of RhB, the degradation rate of RhB in 60 min for BiOI could reach 100%. Meanwhile, the main active groups in the process of photocatalytic degradation of Rhodamine B were explored by radical trapping experiment.
Thermodynamic study of uranium in the process of coal thermal utilization
WANG Jiang, ZHAO Yong-chun, ZHANG Jun-ying
 doi: 10.19906/j.cnki.JFCT.2021058
Abstract(28) HTML(35) PDF 1214KB(1)
Uranium is a kind of radionuclide and also an important strategic resource. In some areas of China, the content of U in coal is extremely enriched. After high temperature transformation, U in coal would be enriched in solid products, which may cause radioactivity risk. In order to control the release of U and transform U in coal products into resource, it is necessary to investigate the migration law of uranium during thermal utilization of coal. Based on the thermodynamic equilibrium principle, this paper calculated and analyzed the morphology distribution of uranium in the pyrolysis, gasification and combustion processes of Ganhe coal, Xiao Longtan coal and Shengli coal. Also the influence of calcium based additives on U migration was analyzed, to provide theoretical guidance for subsequent experimental studies. The results show that: uranium has different forms under different thermal techniques; UO3(g) is the only gas phase product produced under different working conditions, and higher temperature, lower pressure and stronger oxidation environment will increase the amount of UO3(g); volatilization of uranium has been significantly week, since the fixation of uranium in calcium uranate. Especially, the amount of calcium uranate in Ganhe coal during combustion is increased obviously after the use of calcium based additives and the effect of CaO is the most significant.
The characteristics of maceral in Huangling coal and its in-situ pyrolysis
WANG Yue, DING Hua, WU Lin-lin, ZHANG Yun-peng, ZHOU Qi, QU Si-jian
 doi: 10.1016/S1872-5813(21)60102-0
Abstract(37) HTML(11) PDF 33390KB(4)
In order to reveal the pyrolysis and coking characteristics of different components in coal, the macerals in Huangling coal were enriched by centrifugation, and the pyrolysis characteristics of macerals were studied. The transformation characteristics of macerals during pyrolysis were observed in-situ by heating stage microscope. The purities of vitrinite and inertinite are more than 90% and 80%, respectively, while the purity of liptinite is nearly 70%. The initial pyrolysis temperature of liptinite is about 385 ℃, and those of the other macerals are all about 410 ℃. The maximum pyrolysis temperatures are between 470−480 ℃ for all macerals studied. The maximum weight loss rate and the total weight loss rate decrease in the order of liptinite, vitrinite, semi-vitrinite and inertinite. The softening temperature of the liptinite (including sapropelic groundmass) is 350−370 ℃, while that of vitrinite is about 410−420 ℃ as shown by the in-situ pyrolysis in a heating stage microscope. The pyrolysis process of vitrinite goes through the stages of edge shrinking, pore formation, surface softening, the formation of liquid phase, and solidification. Only slight morphological changes are observed in semi-vitrinite, while no changes are observed in inertinite. The active components in Huangling coal are vitrinite and liptinite, and the liptinite can promote the softening and melting characteristics of the adjacent vitrinite.
Theoretical study of methanol synthesis from CO2 hydrogenation on the surface of NiO supported In2O3(110) catalyst
ZHANG Ke-wen, CHEN Yi-fei, HU Ting-ping, LV Xi-mei
 doi: 10.1016/S1872-5813(21)60139-1
Abstract(43) HTML(15) PDF 845KB(8)
In this paper, the influence of NiO support on the synthesis of methanol from CO2 hydrogenation on In2O3(110) defect surface was studied with density functional theory (DFT). Two methanol synthesis pathways, namely HCOO pathway and reverse water gas (RWGS) pathway, were analyzed. The reaction energy and activation energy barrier of each elementary reaction involved in the HCOO and RWGS pathways were calculated. The results show that the NiO support can enhance the adsorption performance of In2O3 catalyst for CO2 and promote the generation of methanol through the HCOO reaction path. In the HCOO path, the hydrogenation of HCOO to H2COO is the rate-determining step for the HCOO reaction path, and the activation energy barrier is 1.66 eV. The NiO-supported In2O3(110) defect surface has a promoting effect on the hydrogenation of CO2, which is conducive to the synthesis of methanol from CO2 along the HCOO pathway, thus improving the efficiency of methanol synthesis from CO2 hydrogenation.
Growth of high performance coal tar-based carbon film and its application in Joule heating
DU Zhi-ming, LEI Zhi-ping, YU Wen-hao, YAN Jing-chong, LI Zhan-ku, SHUI Heng-fu, REN Shi-biao, WANG Zhi-cai, KANG Shi-gang
 doi: 10.1016/S1872-5813(21)60162-7
Abstract(25) HTML(6) PDF 976KB(3)
Conductive carbon film has a wide range of application prospects, especially in the fields of electric heating devices, energy storage devices, and solar cells. Coal tar is an ideal precursor for preparing carbon film. In order to improve the performance of coal tar-based carbon film, it is necessary to study the influence of tar composition on the structure and performance of carbon film. In this paper, a carbon film is prepared using aromatic compounds, heteroatom compounds and tar as carbon sources. It is found that the carrier concentration of aromatic hydrocarbon-based carbon films is higher than 1022/cm3, but the mobility of the carrier is lower than 1 cm2/Vs. The resistivity and sheet resistance of the aromatic hydrocarbon-based carbon film are lower than that of the coal tar-based carbon film. Naphthalene-based carbon film has the best electrical and thermal properties. The maximum heating temperature of naphthalene-based carbon film at 30 V exceeds 300 °C. The thickness of the carbon film has a decisive influence on the sheet resistance of the carbon film. The performance of the heteroatom compound-based carbon film is significantly lower than that of aromatic compound-based film.
Pretreating Co/SiO2 to generate highly active Fischer-Tropsch synthesis catalyst with low CH4 selectivity
MU Shi-fang, SHANG Ru-jing, ZHANG Jian-li, CHEN Jian-gang
 doi: 10.1016/S1872-5813(21)60163-9
Abstract(26) HTML(3) PDF 465KB(4)
The effects of pretreatment methods (DR, R, ROR) on the microstructure of Co/SiO2 catalysts and the activity for Fischer-Tropsch synthesis (FTS) were investigated. The pretreated catalysts were characterized by TEM, HRTEM, XRD, XPS, H2-TPD, TG and TPR. The results showed that after the pretreatments, specific morphological of the Co species changed, forming new Co active surface species. The Co particles redispersed and the Co species was facile to be re-reduced. The Co/SiO2 catalysts pretreated by different method showed different catalytic performance. The catalyst treated by the reduction-passivation had higher activity and ${\rm{C}}_{5}^ {+} $ selectivity for FTS.
Study on the adsorption and oxidation mechanism of mercury by HCl over γ-Fe2O3 catalyst
ZHOU Wen-bo, NIU Sheng-li, WANG Jun, LI Ying, HAN Kui-hua, WANG Yong-zheng, LU Chun-mei, ZHU Ying
 doi: 10.1016/S1872-5813(21)60098-1
Abstract(72) HTML(12) PDF 1561KB(12)
The mechanism of adsorption and oxidation of Hg0 by HCl on γ-Fe2O3 surface was investigated by density functional theory (DFT) calculation. The adsorption models of Hg0, HCl, HgCl and HgCl2 on γ-Fe2O3 (001) surface were constructed, and the reaction mechanism of catalytic oxidation of Hg0 by HCl on γ-Fe2O3 surface was analyzed. The results illustrate that the Hg0 tends to chemically adsorb at Feoct site. HCl can be dissociated and adsorbed on the surface of the catalyst to form adsorbed Cl and hydroxyl groups, and promote the adsorption of Hg0. HgCl can be molecularly chemisorbed upon γ-Fe2O3 (001) and act as intermediate. HgCl2 tends to adsorb in parallel on the surface of γ-Fe2O3.HCl oxidizes Hg0 on γ-Fe2O3 (001) according to the L-H mechanism: chemically adsorbed Hg0 reacts with dissociatively adsorbed HCl. By measuring the energy distribution of the reaction path, the oxidation process of Hg0 on the surface of γ-Fe2O3 was studied. The heterogeneous oxidation of Hg0 by HCl proceeds through a two-step reaction pathway: Hg0 (ads)→HgCl(ads)→HgCl2(ads).
Efficient separation of phenols from phenols-containing oil mixtures via forming hydrogen bonds
JI You-an, ZHAO Xiao-sheng, LIU Qing, YANG Yu-feng, HAN Jiang-ze
 doi: 10.1016/S1872-5813(21)60137-8
Abstract(57) HTML(10) PDF 1175KB(4)
In this work, the separation of phenol from oil mixtures was proposed by using mildronate (THP), Girard's Reagent T, and Girard's Reagent P. The results showed that the mentioned separation agents could form deep eutectic solvent (DES) with phenol and then separate phenol. The highest separation efficiency of phenol was 96.5% by THP, and the residual phenol content in oil was as low as 1.3 g/L; it was enough to finish separation in 10 min; the initial phenol content had no effect on the minimum residual phenol content (about 8.8 g/L) in oil after separation. An n-hexane washing method was used to remove the neutral oil entrained in DES. The results showed that the neutral oil to phenol mass ratio in DES was reduced to 0.04, which indicated that the purity of phenol product was greatly improved. THP was renewable and reused for 5 times, and its properties remained unchanged. Finally, FT-IR spectra showed that there was hydrogen bonds formed between THP and phenol.
Study on structure and combustion performance of Daliuta coal pyrolysis char by Raman spectroscopy
XU Yan-mei, PAN Zhi-yan, HU Hao-quan
 doi: 10.19906/j.cnki.JFCT.2021059
Abstract(53) HTML(20) PDF 1457KB(6)
In this study, the structure and combustion performance of pyrolysis chars from Daliuta raw coal, vitrinite-rich sample, inertinite-rich sample and demineralized coal sample were studied by Raman spectroscopy. The results showed that under the same pyrolysis conditions, compared with the pyrolysis char from Daliuta raw coal sample, the pyrolysis char from the demineralized coal sample has more large aromatic ring systems (≥ 6 rings), higher ignition temperature and much low combustion performance. The combustion performance of pyrolysis char from inertinite-rich sample is lower than that from vitrinite-rich sample, and the burnout capacity of pyrolysis char from inertinite-rich sample is far lower than that from vitrinite-rich sample. The ignition temperature (ti), the combustion reactivity index (tindex) and the wavenumber of D band (WD) in the Raman spectrum of Daliuta coal char has a good correlation, the correlation coefficients R2 obtained by the quadratic curve fitting are 0.9159 and 0.7133, respectively. There is no obvious correlation between burn-out temperature and WD of Daliuta coal char, indicating that the carbon structure of Daliuta coal char has a significant impact on the ignition temperature and combustion reactivity index of the char, but is no regular effect on the burn-out ability of the char.
Co-pyrolysis kinetics and pyrolysis product distribution of various tannery wastes
ZHANG Jie-han, KANG Guo-jun, YANG Hang, LIU Zhou-en, YU Jian, GAO Shi-qiu
 doi: 10.1016/S1872-5813(21)60133-0
Abstract(50) HTML(14) PDF 1399KB(5)
Tanning sludge, chrome tanned buffing dust and chrome shavings were selected as experimental materials. The non-isothermal distributed activation energy model (DAEM) was used to study the pyrolysis kinetic parameters. The effects of particle size and temperature on the distribution of co-pyrolysis products of various tanning wastes were investigated in a fixed-bed pyrolysis reactor, which provided a new approach for comprehensive thermal treatment of various tannery wastes. The results showed that the total activation energy required for the co-pyrolysis decreased and then increased in the range of conversion rate of 0.1 to 0.8. The tar yield decreased with raising particle size, while the yields of gas and char increased. With the increase of pyrolysis temperature, the tar yield increased rapidly to a peak value of 17% at 600 ℃, and then decreased, correspondingly the char yield decreased while the gas yield increased. When the pyrolysis temperature was 600 ℃ and the particle size of the material was 1.6–2.5 mm, the specific surface area of char was larger, and the light fractions in tar was higher. Thus the co-pyrolysis was conducive to the clean treatment of tannery wastes.
2021, 49(10): 1-8.  
Abstract(31) HTML(15) PDF 8395KB(11)
Composition and structure characteristics of soluble organic matter from Naomaohu lignite by sequential extraction and thermal conversion performance of the corresponding residue
MAO Kai-min, MO Wen-long, MA Feng-yun, MA Ya-ya, WANG Yue, WEI Xian-yong, FAN Xing
2021, 49(10): 1389-1401.   doi: 10.1016/S1872-5813(21)60117-2
Abstract(101) HTML(24) PDF 1458KB(34)
Carbon disulfide (CDS), methanol, acetone and isometric carbon disulfide/acetone mixture (IMCDSAM) were used as solvents to sequentially extract Naomaohu lignite (NL) via ultrasonic-assisted extraction to obtain extracts (E1−E4) and final extraction residue (ER). Composition and structure of E1−E4 were analyzed by GC-MS. It is found that the main compounds in E1 are alkanes, aromatics, alcohols and esters. Alkanes, alcohols and esters are the main compounds in E2. Alcohols, phenolics and esters are the main components in E3, and esters are mainly phthalic diester compounds. Affected by synergistic effect of the two solvents CDS and acetone, the relative content of alkenes in E4 is relatively high. FT-IR was used to characterize functional groups in NL, E1−E4 and ER. The results show that the ultrasonic extraction process only extracts free small compounds from macromolecular skeleton of the NL and some other molecules, which connect the macromolecular skeleton by weak covalent bonds, and the process does not destroy the macromolecular skeleton structure. In addition, peak fitting results from FT-IR show that types of infrared absorption peaks in ER do not change after ultrasonic extraction, while intensity of the peaks varies. TG-DTG profiles of NL and ER indicate that after ultrasonic extraction weight loss of NL increases from 47.09% to 51.04%, and peak of the maximum weight loss rate is advanced from 450 to 430 ℃. Pyrolysis kinetic analyses of NL and ER based on Coats-Redfern model show that after ultrasonic extraction activation energy of ER in rapid pyrolysis stage is lower than that of NL, and the pyrolysis process is easier to proceed.
Nitrogen-doped porous carbon supported nickel nanoparticles as catalyst for catalytic hydroconversion of high-temperature coal tar
XIE Rui-lun, ZHANG Xia, TIAN Yu-jiao, LEI Zhao, CAO En-de
2021, 49(10): 1402-1411.   doi: 10.1016/S1872-5813(21)60156-1
Abstract(62) HTML(6) PDF 1170KB(9)
A novel and highly active nitrogen-doped porous carbon-supported nickel catalyst Ni@N-PC was successfully developed by a thermolysis of nickel-based zeolitic imidazolate frameworks growing on both sides of graphitic carbon nitride and used for catalyzing hydroconversion of isopropanol soluble portion from ultrasonic extraction of high-temperature coal tar (ISPHTCT). The active nickel nanoparticles were mainly encapsulated on the top of carbon nanotubes and partially dispersed on the surface of carbon nanosheets. Naphthalen-1-ol was used as a model compound to investigate the catalytic hydroconversion activity under different reaction conditions and reveal the mechanism for catalytic hydroconversion. The ISPHTCT and catalytic hydroconversion products of ISPHTCT (ISPCHCP) were analyzed with gas chromatograph/mass spectrometer. The results show that 70% of naphthalen-1-ol was converted at 160 °C and completely converted at 200 °C for 120 min, and the ISPHTCT was greatly upgraded. A total of 180 organic compounds including 33 nitrogen-containing organic compounds, 11 sulfur-containing organic compounds and 39 oxygenates were identified in ISPHTCT, while no obvious nitrogen-containing organic compounds, sulfur-containing organic compounds and oxygenates were detected in ISPCHCP, indicating the excellent performance of Ni@N-PC for heteroatom removal. All the alkenes, cyclenes and alkynes were saturated and the majority of arenes were converted to cyclanes by catalytic hydroconversion over Ni@N-PC, which exhibited high catalytic hydrogenation activity.
Preparation and characterization of pitch-based mosaic coke from heavy-phase coal pitch: Effects of quinoline insoluble
ZHANG Chun-yang, ZHU Ya-ming, XU Yun-liang, HU Chao-shuai, LAI Shi-quan, GAO Li-juan, ZHAO Xue-fei
2021, 49(10): 1412-1420.   doi: 10.19906/j.cnki.JFCT.2021057
Abstract(96) HTML(38) PDF 1399KB(27)
Mosaic coke is a kind of special artificial carbon material, which is usually used as the raw material to produce high-quality nuclear graphite. The quality of graphite has been usually focused on the properties of mosaic cokes. In order to investigate the influence of the quinoline insoluble (QI) content of heavy-phase pitch on the micro-structure and properties of mosaic coke, 9 kinds of heavy-phase pitches with varied QI contents were used as the raw materials to produce series of mosaic cokes in this study. Optical micro-scope, scanning electronic micro-scope, X-ray diffraction, Raman spectrum and curve-fitted methods were used to judge the micro-structure of 9 kinds of mosaic cokes. Also, the micro-strength of mosaic cokes was determined. The results show that the higher content of QI in heavy-phase pitch has the mosaic structure easier to be produced during the liquid-phase carbonization process. What’s more, with the increase of QI content, the content of regular carbon microcrystals decreases, but the content of amorphous carbon and micro-strength are improved. When the QI contents in the heavy-phase are higher than 7%, the derived mosaic cokes have the total contents of mosaic structure (the sum of fine mosaic structure, medium mosaic and coarse mosaic) higher than 82% and the micro-strength higher than 85%. In other words, the heavy-phase pitch with the content of QI higher than 7% is a promised raw material to produce high-quality mosaic coke.
Catalytic pyrolysis of sugarcane bagasse by zeolite catalyst for the production of multi-walled carbon nanotubes
2021, 49(10): 1421-1434.   doi: 10.1016/S1872-5813(21)60127-5
Abstract(174) HTML(46) PDF 1861KB(13)
Recently, the disposal of waste by beneficial and environmentally friendly methods has attracted great attention. In this work, we have studied the production of high-value carbon nanotubes (CNTs) which have remarkable applications by catalytic pyrolysis of sugarcane bagasse (SCB) as an agricultural waste using a two-stage process. Various reaction factors including the effects of zeolite types (HZSM-5, HMOR, and HY), pyrolysis temperatures (450−700 °C), and SCB/ZSM-5 ratios (3−12) on SCB pyrolysis were investigated to generate CNTs from pyrolysis products. A Co-Mo/MgO catalyst was used for growing CNTs via the decomposition of pyrolysis products. The morphological structure and quality of CNTs were characterized using TEM and Raman spectroscopy, while the fresh Co-Mo/MgO catalyst was characterized by XRD and TPR analyses. The results showed that zeolite type, pyrolysis temperature, and SCB/ZSM-5 ratio had significant effects on the CNTs yield. The optimum carbon yield (24.9%) was achieved using the HZSM-5 catalyst at the pyrolysis temperature of 500 °C and with the SCB/ZSM-5 ratio of 6. TEM observations confirmed the growth of bamboo-like carbon nanotubes (BCNTs) and carbon nano-onions (CNOs) in different proportions according to the reaction parameters. Also, CNTs with the largest diameter distribution range (7−76 nm) were produced using the SCB/ZSM-5 ratio of 6. Raman spectra demonstrated the production of high-quality CNTs under all studied conditions.
Mechanism of N2O reduction by biomass gasification gas reburning
LI Ying, NIU Sheng-li, WANG Yong-zheng, HAN Kui-hua, ZHOU Wen-bo, WANG Jun
2021, 49(10): 1435-1443.   doi: 10.1016/S1872-5813(21)60092-0
Abstract(118) HTML(19) PDF 1240KB(31)
A molecular modeling based on the density functional theory (DFT) and the transition state theory (TST) was performed to investigate the influence of biomass gas CO on the N2O decomposition catalyzed by CaO during reburning in the circulating fluidized bed boiler. The model for N2O adsorption onto the CaO(100) surfaces were constructed; and the processes of the N2O decomposition on the CaO(100) surface and the surface recovery of CaO(100) were investigated. The results illustrate that the energy barrier of N2O decomposition on the CaO(100) surface is much lower than that in homogeneous case, and CaO is therefore able to catalyze the N2O decomposition. The atomic O from N2O decomposition can poison the active sites O atom on the CaO(100) surface, while biomass gas CO can promote the regeneration of the active sites on the surface of CaO(100), which is beneficial for CaO to catalyze the N2O removal.
Application of metal-organic frameworks in CO2 hydrogenation
ZHOU Cheng, NAN Yong-yong, ZHA Fei, TIAN Hai-feng, TANG Xiao-hua, CHANG Yue
2021, 49(10): 1444-1457.   doi: 10.1016/S1872-5813(21)60097-X
Abstract(136) HTML(50) PDF 1829KB(36)
The dramatic increase in atmospheric CO2 concentrations has attracted people's attention, and many strategies have been developed to convert CO2 into high-value chemicals. Metal-organic frameworks (MOFs), as a class of versatile materials, can be used in the CO2 capture and conversion because of their unique porosity, large specific surface area, rich pore structure, multiple active centers, good stability and recyclability. Various functional nanomaterials have been designed and synthesized based on metal organic framework (MOF) of crystalline porous materials to meet these challenges. Herein, in this review, the latest processes of MOFs in field the of CO2 hydrogenation to carbon monoxide, methane, formic acid, methanol and olefins are summarized, and the synthesis methods of catalysts based on MOFs and the reasons for their high catalytic activity are analyzed. Besides, a brief introduction to improve the catalytic activity of the new MOF material and explore the feasible strategies for CO2 conversion are advised. Finally, the paper discusses the main challenges and opportunities of MOF-type catalysts in CO2 chemical conversion, and presents a brief outlook on further developments in this research area.
Performance of Zn-Al co-doped La2O3 catalysts in the oxidative coupling of methane
LI Ying-tao, NIU Peng-yu, WANG Qiang, JIA Li-tao, LIN Ming-gui, LI De-bao
2021, 49(10): 1458-1467.   doi: 10.1016/S1872-5813(21)60100-7
Abstract(105) HTML(27) PDF 1377KB(18)
Zn-doped and Zn-Al co-doped La2O3 catalysts were prepared by citric acid sol-gel method and characterized by a series of in situ technologies, to investigate the structure-activity relationship of La2O3-based catalysts in the oxidative coupling of methane (OCM). The in situ XRD results reveal a thermal expansion of the La2O3 crystal along the c-axis at high temperature. The H2-TPR results show two types of oxygen species on the La2O3-based catalysts, viz., the strong-binding oxygen species and weak-binding oxygen species; in addition, the XPS results indicate that the strong-binding oxygen species is probably attributed to anion radical O. The doping with Zn can significantly increase the number of oxygen vacancies in the Zn-doped La2O3 catalysts, which can promote the activation of oxygen and generate more strong-binding oxygen species; as a result, the Zn-doped La2O3 catalyst shows better performance in OCM in comparison with the unmodified La2O3 catalyst. Moreover, the co-doping with Al can promote the dispersion of Zn in La2O3 and further raise the number of strong-binding oxygen species in the Zn-Al co-doped La2O3 catalysts, which is beneficial to enhance the selectivity to C2+ hydrocarbons in the OCM reaction
Effects of Ca content on the activity of HZSM-5 nanoparticles in the conversion of methanol to olefins and coke formation
2021, 49(10): 1468-1486.   doi: 10.1016/S1872-5813(21)60130-5
Abstract(56) HTML(10) PDF 1104KB(6)
Effects of calcium content on the performance of HZSM-5 nanoparticles of 150 nm with Si/Al ratio = 230 in the methanol to olefin conversion were investigated. The parent and modified catalysts showed their largest yields of ethylene and propylene at 490 °C and lower WHSV (= 3.3 h−1). The selectivity for propylene over HZSM-5 was 0.45 at 490 °C whereas it was promoted to 0.51 over Ca27-HZSM-5 (Ca/Al = 27). With decreasing temperature from 490 to 440, and 390 °C, the yield of propylene and ethylene remained nearly constant at 0.13−0.14 and 0.10−0.11 over Ca27-HZSM-5, respectively; more narrow than the corresponding range of yields for HZSM-5 (0.10−0.14 and 0.08−0.12). FT-IR results confirmed the formation of oxygenated and poly alkyl aromatic species in the carbon deposits. TG results indicated that oxygenate coke was formed and converted to heavier poly aromatic coke species with time. Increasing Ca in the porous structure of HZSM-5 may lead to heavier aromatic carbonaceous deposits. In general, Ca content positively affected activity through modification of the density, strength, and accessibility of Brønsted and Lewis acid sites. Long-term MTO activity test of HZSM-5 with Ca/Al = 27 showed stable performance over 100 h, although with an oscillatory feature.
Low-temperature oxidation of methanol to dimethoxymethane over Mo-Sn catalyst
WANG Wen-xiu, GAO Xiu-juan, XIONG Pan, ZHANG Jun-feng, SONG Fa-en, ZHANG Qing-de, HAN Yi-zhuo, TAN Yi-sheng
2021, 49(10): 1487-1494.   doi: 10.1016/S1872-5813(21)60094-4
Abstract(154) HTML(16) PDF 1250KB(26)
A new Mo-Sn catalyst prepared by hydrothermal method was used for the synthesis of dimethoxymethane (DMM) from methanol oxidation. The catalyst with low Mo content can achieve low-temperature oxidation of methanol to DMM with high selectivity. The influence of Mo content on the structure and the catalytic performance of the catalyst was investigated. It was found that Mo1Sn10 catalyst showed the best catalytic performance under the conditions of 140 °C and atmospheric pressure, the methanol conversion was 14.2%, and the selectivity of DMM reached 88.9% without the formation of COx during the reaction process. The catalysts were characterized by XRD, Raman, FT-IR, XPS, NH3-TPD and H2-TPR. The results showed that the catalysts with different Mo content had obvious differences in structure and performance. Lower Mo content was more conducive to the formation of Mo5+ and MoOx, and the resulting changes in acidity and redox properties were the important reasons for the excellent performance of the catalysts.
Structural analysis of functional group and mechanism investigation of caking property of coking coal
LI Xiang, QIN Zhi-hong, BU Liang-hui, YANG Zhuang, SHEN Chen-yang
2016, 44(4): 385-393.  
[Abstract](120) [FullText HTML](83) [PDF 1138KB](9)
以11种炼焦煤为研究对象,分别进行FT-IR和黏结指数G测试。采用PeakFit软件对FT-IR谱峰进行分峰拟合和定量计算,研究炼焦煤特征官能团含量与其黏结性间的关系。结果表明,煤黏结性大小与其FT-IR吸收峰密切相关,特别是3 000-2 800和3 700-3 000 cm-1两个吸收带;脂肪族结构是煤黏结性形成的主要决定因素,通常脂肪链越短或支链化程度越高,越有利于煤的黏结性形成;含-OH(或-NH)的氢键缔合结构可以与脂肪链协同作用,共同决定煤的黏结性能。不论煤分子有多大,只要是结构单元缩合度较小而作为桥键的脂肪链较多的结构形式,在热解过程中就会生成大量适度分子量、以结构单元为基元的液相物质。氢键是煤中主要的分子间作用形式,当若干形成氢键的官能团聚集缔合时,其相互作用会更强,甚至会形成类似超分子的结构;在形成胶质体阶段,这类氢键缔合的结构也会被打破,并形成以胶质体液相为主的物质。这些液相物质的存在,有利于胶质体的流动、黏连和固化成为半焦,从而最终获得优越的黏结性。
XRD characterization of structural evolution in low-middle rank coals
LI Xia, ZENG Fan-gui, WANG Wei, DONG Kui
2016, 44(7): 777-783.  
[Abstract](133) [FullText HTML](53) [PDF 2169KB](4)
通过对28个最大镜质组反射率0.30%-2.05%镜煤样品的X射线衍射(XRD) 分析, 获得XRD结构参数, 得到这些参数随反射率增大呈现的阶段性规律。在镜质组反射率小于1.0%阶段, LaLc急剧增加, d002迅速减小, 含氧官能团的脱落和脂肪长度支链化程度减小占主导; 在1.0%-1.6%阶段, La持续增加, d002先增加后减小, Lc先减小然后趋于平稳, 芳香体系脱氢和调整空间位阻同时进行; 在1.6%-2.0%阶段, d002持续减小, LcLa的增大, 煤结构演化以芳构化为主。XRD结构参数演化与第一、二次煤化作用跃变关系密切。
Effect of Na2O on mineral transformation of coal ash under high temperature gasification condition
CHEN Xiao-dong, KONG Ling-xue, BAI Jin, BAI Zong-qing, LI Wen
2016, 44(3): 263-272.  
[Abstract](56) [FullText HTML](61) [PDF 1275KB](4)
利用XRD和FT-IR考察了高温弱还原气氛下Na2O对两种硅铝含量不同的煤灰中矿物质组成的影响, 揭示了Na2O影响煤灰熔融特性的本质.通过FactSage计算了高温下矿物质反应的ΔG, 探讨了Na2O影响煤灰中矿物质组成的机理.结果表明, Na2O对煤灰矿物质组成的影响与原煤灰的硅铝含量密切相关.硅铝总含量82.89%的煤灰, Na2O含量为5%-20%时, 钠长石和霞石的生成是煤灰熔融温度降低的主要原因; 当Na2O含量大于20%时, 导致煤灰熔融温度降低的原因是霞石的生成.硅铝总含量47.85%的煤灰, Na2O含量小于10%时, 没有含钠矿物质生成; 当Na2O含量大于10%时, 主要生成菱硅钙钠石、青金石和含钠的硅铝酸盐矿物, 导致煤灰熔融温度降低.FactSage计算表明生成含Na矿物质反应的ΔG较小, 其在高温下更容易发生.
Research progress in the direct conversion of syngas to lower olefins
YU Fei, LI Zheng-jia, AN Yun-lei, GAO Peng, ZHONG Liang-shu, SUN Yu-han
2016, 44(7): 801-814.  
[Abstract](148) [FullText HTML](75) [PDF 8665KB](19)
合成气直接催化转化制备低碳烯烃是C1化学与化工领域中一个极具挑战性的研究课题, 具有流程短、能耗低等优势, 已成为非石油路径生产烯烃的新途径。直接转化方式主要包括经由OX-ZEO双功能催化剂直接制低碳烯烃的双功能催化路线以及经由费托反应直接制备低碳烯烃的FTO路线。综述简述了近年来在合成气直接制备低碳烯烃方面的研究进展, 重点讨论了低碳烯烃的形成机理、新型催化剂的研发及助剂对其催化性能的影响, 并对合成气直接制烯烃的未来进行了展望。
Performance of Mn-Ce catalysts supported on different zeolites in the NH3-SCR of NOx
HUANG Zeng-bin, LI Cui-qing, WANG Zhen, XU Sheng-mei, FENG Ling-bo, WANG Hong, SONG Yong-ji, ZHANG Wei
2016, 44(11): 1388-1393.  
[Abstract](94) [FullText HTML](59) [PDF 780KB](4)
High resolution TEM image analysis of coals with different metamorphic degrees
LI Xia, ZENG Fan-gui, SI Jia-kang, WANG Wei, DONG Kui, CHENG Li-yuan
2016, 44(3): 279-286.  
[Abstract](95) [FullText HTML](55) [PDF 12189KB](4)
利用高分辨率透射电子显微镜(HRTEM) 分析了三种不同变质程度煤样的结构特征.基于傅里叶-反傅里叶变换方法, 并结合Matlab、Arcgis和AutoCAD软件, 通过图像分析技术, 获得了HRTEM照片的晶格条纹参数.结果表明, 三种煤样的晶格条纹呈现不同特征, 按条纹长度分别归属于1×1-8×8共计八个类型.以3×3为临界点, 在1×1和2×2中, ML-8中芳香层片的比例高于DP-4和XM-3;在3×3-8×8中, ML-8中芳香层片的比例低于DP-4和XM-3.对比HRTEM和XRD参数d002发现, 随着镜质组反射率的增加d002都呈现递减趋势.
Effects of acid-alkali treatment on properties and reactivity of ZSM-5 catalyst
LV Jiang-jiang, HUANG Xing-liang, ZHAO Lei-lei, SUN Ren-shan, HU Long-wang, GONG Yan
2016, 44(6): 732-737.  
[Abstract](77) [FullText HTML](39) [PDF 2776KB](3)
考察了碱处理、先碱后两步酸处理对HZSM-5分子筛物化性质以及苯与甲醇烷基化反应性能的影响。结果表明, 碱处理在脱除分子筛中非骨架硅的同时, 提高了晶孔的利用率, 也中和了分子筛的强酸中心, 使催化剂活化甲醇的能力减弱, 苯与甲醇反应活性降低; 先碱后两步酸处理既脱除了分子筛中的非骨架铝, 也恢复了一部分强酸中心, 提高了苯与甲醇的反应活性。进一步考察了先碱后两步酸处理中不同碱浓度的影响, 结果表明, 适宜浓度的碱处理后再两步酸处理, 一方面, 能脱除分子筛的非骨架硅铝物种, 使分子筛的颗粒粒径更加均匀; 另一方面, 分子筛的强酸中心有所减少, 降低了催化剂的积炭失活速率, 苯转化率提高15%以上。
Relationship between coal ash fusibility and ash composition in terms of mineral changes
WANG Yang, LI Hui, WANG Dong-xu, DONG Chang-qing, LU Qiang, LI Wen-yan
2016, 44(9): 1034-1042.  
[Abstract](106) [FullText HTML](49) [PDF 809KB](2)
通过在一种真实煤灰中添加不同的氧化物或直接用氧化物配制合成灰,探究了不同灰成分对灰熔融特性的影响规律。利用FactSage 7.0对不同灰分的熔融过程进行了热力学模拟,通过熔融过程中的矿物质变化为各种灰成分对熔融特性的影响规律提供理论依据。结果表明,氧化钠对灰熔点的降低作用源于钠长石和霞石对钙长石的取代;氧化镁含量的增加对灰熔点起先降低后升高的作用,当氧化镁含量超过一定时,产生的镁橄榄石能够升高灰熔点;硫对灰熔点的升高作用源于镁橄榄石和硫酸钙对透辉石的取代;氧化钙含量的增加对灰熔点起到先降低后升高的作用,当氧化钙含量超过一定时,硅从熔点较低的矿物质迁移到熔点较高的矿物质中,升高了灰熔点。在与硅氧单元体结合的过程中,氧化钠优先于氧化钙;与氧化钙和硅氧单元体结合的氧化物的优先级为:氧化铝>氧化镁>氧化铁。
Effect of rare-earth element modification on the performance of Cu/ZnAl catalysts derived from hydrotalcite precursor in methanol steam reforming
YANG Shu-qian, HE Jian-ping, ZHANG Na, SUI Xiao-wei, ZHANG Lei, YANG Zhan-xu
2018, 46(2): 179-188.  
[Abstract](72) [FullText HTML](33) [PDF 7028KB](5)
采用原位合成法在γ-Al2O3表面合成了锌铝水滑石,再通过顺次浸渍法制备了一系列掺杂稀土改性的MM=Y、La、Ce、Sm、Gd)/Cu/ZnAl催化材料,并将其应用于甲醇水蒸气重整制氢反应。探讨了稀土掺杂改性对Cu/ZnAl催化剂催化性能的影响,并采用XRD、SEM-EDS、BET、H2-TPR、XPS和N2O滴定等手段对催化剂进行了表征。结果表明,催化剂的活性与Cu比表面积和催化剂的还原性质密切相关,Cu比表面积越大,还原温度越低,催化活性越高。稀土Ce、Sm、Gd的引入能改善活性组分Cu的分散度、Cu比表面积以及催化剂的还原性质,进而提高催化剂的催化活性。其中,Ce/Cu/ZnAl催化剂表现出最佳的催化活性,在反应温度为250 ℃时,甲醇转化率达到100%,CO含量为0.39%,相比Cu/ZnAl催化剂,甲醇转化率提高了近40%。
Research on the middle-low temperature denitration and anti-poisoning properties of plate V2O5-MoO3/TiO2 SCR catalysts
LIN Zhuo-wei, LU Qiang, TANG Hao, LI Hui, DONG Chang-qing, YANG Yong-ping
2017, 45(1): 113-122.  
[Abstract](76) [FullText HTML](43) [PDF 1085KB](4)
针对中低温锅炉烟气脱硝技术需求的特点,采用等体积浸渍法,以V2O5为活性组分、MoO3为助剂,制备了高钒高钼含量的V2O5-MoO3/TiO2型粉末和平板式SCR脱硝催化剂,考察了活性组分和助剂含量对催化剂活性以及抗SO2和H2O中毒性能的影响,对反应前后的催化剂进行了微观表征,并针对最优催化剂研究了其在不同烟气工况下催化剂的脱硝性能。结果表明,提升V2O5负载量可以有效提高催化剂的脱硝活性;MoO3助剂的添加也可以提高催化剂的脱硝活性。XPS、XRF、FT-IR等表征结果表明,MoO3的含量会影响催化剂中V4+/V5+的比值,其相对含量的增加有利于催化剂中非化学计量钒物种的形成以及化学吸附氧比例的增加,钼与钒物种间的交互作用是抑制SO2和H2O对催化剂的毒化作用的关键。3V2O5-10MoO3/TiO2平板式催化剂在温度为200℃、空速为3 500 h-1含SO2和H2O烟气条件下,经30 d连续反应,脱硝效率稳定维持在82%左右,该催化剂在中低温下具有优异的抗SO2和H2O中毒性能以及稳定性。
Preparation of core-shell catalysts for one-step synthesis of dimethyl ether from syngas
WANG Wen-li, WANG Yan, CHEN Yue-xian, ZHAO Wen-chao, LI Rui-feng
2013, 41(08): 1003-1009.  
[Abstract](2054) [PDF 13334KB](2)
A core-shell catalyst CuO-ZnO-Al2O3@Al2O3 for one-step synthesis of dimethyl ether from synthesis gas was prepared using glucose, sucrose or starch as template, and characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The thickness of the Al2O3 shell in the catalyst was altered by controlling the synthesis condition, such as temperature and time. The catalytic performance of dimethyl ether (DME) synthesized from CO hydrogenation on the catalysts were investigated. The conversion of CO and the selectivity of DME on CuO-ZnO-Al2O3@Al2O3 achieved 35.2% and 61.1% at 260 ℃, 5.0 MPa and 1 500 mL/(h·gcat), respectively.
Effect of wastewater treatment processes on thermal treatment properties of sewage sludge
JIE Li-Beng, Zheng-Shi-Mei, LI Chao
2009, 37(04): 501-505.  
[Abstract](1518) [PDF 0KB](8)
The properties of pyrolysis and combustion for five different sewage sludges are studied by thermal gravimetric analysis at a heating rate of 10℃/min in the atomosphere of nitrogen and oxygen, respectively. The results show that both of the “anaerobic” wastewater treatment and the sludge anaerobic digestion make the organic compounds in sludge so complicated that the organic compounds decomposition and release temperature becomes higher during pyrolyzing, and the “aerobic + anaerobic” process makes the organic compounds in sludge more complicated than the “anaerobic +aerobic” process. There is no influence on the combustion process and the burnout point, but can make the combustion temperature of sludge higher. The thermal reaction mechanisms have been studied with šatava-šesták equation. It shows that the pyrolysis mechanism of these sludges is a process of volatile diffusion at first and then the chemical reaction function, while the combustion mechanism of them is a process of chemical reaction and diffusion function.