Supervisor：Chinese Academy of Sciences
Sponsors by：
Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
Editor-in-Chief：Fang yi tian
Email：rlhx@sxicc.ac.cn
ISSN 2097-213X
eISSN 1872-5813
CN 14-1410/TQ
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).
Preparation of the PdAg/CDs composite and its catalytic performance in the hydrogenolysis of glucose
, Available online ,
doi: 10.1016/S1872-5813(23)60340-8
Abstract:
2023, 51(8): 1035-1046.
doi: 10.19906/j.cnki.JFCT.2023019
Abstract:
In supercritical water (SCW) condition, the gasification of biomass to H2 or CH4 has been studied extensively and proves to be critical in realising the upgrading of carbonaceous fuels. Given the extreme conditions of water at high pressure and temperature, along with the complex structure of biomass, the development of such a process still remains a challenge. In order to realize the complete decomposition of biomass and a high yield of desired products, such as CH4 and H2 at relatively milder conditions, various catalysts were synthesized and practiced. Different metals (such as Cr, Ni, Zn, Ru and Rh) were incorporated into various supports, such as mineral compounds of Al2O3, SiO2, TiO2, ZrO2, MgO, Y2O3, CeO2, silica-alumina, zeolites and carbon based supports of carbon nanotube, activated carbon. As a result, the long term stability of catalys is critical in the gasification of carbonaceous fuel in supercritical water condition. Therefore, this work focused on the stability of various support materials and deactivation of active metal components in supercritical water conditions with the purpose of choosing robust catalysts. In supercritical water condition, the effect of catalyst on carbonaceous fuels cracking, methanation reaction and water gas shift reaction determines the gasification efficienty as a whole. Unfortunately, the mechanism of methanation reaction is still unclear. Therefore, the CH4 formation mechanism and the effect of catalyst on CH4 conversion are emphasized in this work.
In supercritical water (SCW) condition, the gasification of biomass to H2 or CH4 has been studied extensively and proves to be critical in realising the upgrading of carbonaceous fuels. Given the extreme conditions of water at high pressure and temperature, along with the complex structure of biomass, the development of such a process still remains a challenge. In order to realize the complete decomposition of biomass and a high yield of desired products, such as CH4 and H2 at relatively milder conditions, various catalysts were synthesized and practiced. Different metals (such as Cr, Ni, Zn, Ru and Rh) were incorporated into various supports, such as mineral compounds of Al2O3, SiO2, TiO2, ZrO2, MgO, Y2O3, CeO2, silica-alumina, zeolites and carbon based supports of carbon nanotube, activated carbon. As a result, the long term stability of catalys is critical in the gasification of carbonaceous fuel in supercritical water condition. Therefore, this work focused on the stability of various support materials and deactivation of active metal components in supercritical water conditions with the purpose of choosing robust catalysts. In supercritical water condition, the effect of catalyst on carbonaceous fuels cracking, methanation reaction and water gas shift reaction determines the gasification efficienty as a whole. Unfortunately, the mechanism of methanation reaction is still unclear. Therefore, the CH4 formation mechanism and the effect of catalyst on CH4 conversion are emphasized in this work.
2023, 51(8): 1047-1059.
doi: 10.19906/j.cnki.JFCT.2023025
Abstract:
Biomass can be converted into high-value nitrogen-containing chemicals and nitrogen-containing carbon materials by pyrolysis technique, which significantly increases the value of biomass and lowers the risk of environmental pollution by nitrogen-containing pollutants. Therefore, a good understanding of the migration and conversion mechanisms of nitrogen during pyrolysis is critical for the advancement of biomass pyrolysis technique. Herein, the forms and contents of nitrogen in biomass were first summarized. Afterward, the transformation process of nitrogen from biomass to pyrolysis products was discussed based on the distribution of nitrogen in the solid, liquid, and gaseous pyrolysis products. Finally, the effects of fuel properties, pretreatment methods and pyrolysis conditions on the migration and transformation of nitrogen were discussed carefully. In addition, an outlook for future research on nitrogen migration in biomass pyrolysis process was provided.
Biomass can be converted into high-value nitrogen-containing chemicals and nitrogen-containing carbon materials by pyrolysis technique, which significantly increases the value of biomass and lowers the risk of environmental pollution by nitrogen-containing pollutants. Therefore, a good understanding of the migration and conversion mechanisms of nitrogen during pyrolysis is critical for the advancement of biomass pyrolysis technique. Herein, the forms and contents of nitrogen in biomass were first summarized. Afterward, the transformation process of nitrogen from biomass to pyrolysis products was discussed based on the distribution of nitrogen in the solid, liquid, and gaseous pyrolysis products. Finally, the effects of fuel properties, pretreatment methods and pyrolysis conditions on the migration and transformation of nitrogen were discussed carefully. In addition, an outlook for future research on nitrogen migration in biomass pyrolysis process was provided.
2023, 51(8): 1060-1072.
doi: 10.19906/j.cnki.JFCT.2023007
Abstract:
Co-gasification of coal and biomass, as one of the means to achieve efficient and clean utilization of coal, has a positive contribution to achieving carbon neutrality and carbon peaking. Co-gasification not only helps to overcome a series of problems derived from coal gasification alone, reduces the emission of SOx, NOx and other harmful substances, and improves coal reactivity but also helps to overcome the problems of low energy density, poor gasification efficiency and high tar yield existing in biomass gasification alone. Based on this, the progress in the research of influencing factors and synergetic reaction mechanism is reviewed in this work. The effects of feedstock type and pretreatment method, process parameters and gasifier type on the co-gasification process are summarized, the catalytic synergistic mechanism in the co-gasification process of coal and biomass is systematically described, the synergistic mechanism of non-catalytic factors in the co-gasification process is briefly outlined, and new methods to study the co-gasification process are comprehensively discussed. The main concern of the co-gasification process is sorted out, and prospects are made for constructing the synergistic pathway with the help of the new in situ technique and revealing the reaction mechanism in coupling the chemical reaction system with the combination of density functional theory and gasification dynamics models.
Co-gasification of coal and biomass, as one of the means to achieve efficient and clean utilization of coal, has a positive contribution to achieving carbon neutrality and carbon peaking. Co-gasification not only helps to overcome a series of problems derived from coal gasification alone, reduces the emission of SOx, NOx and other harmful substances, and improves coal reactivity but also helps to overcome the problems of low energy density, poor gasification efficiency and high tar yield existing in biomass gasification alone. Based on this, the progress in the research of influencing factors and synergetic reaction mechanism is reviewed in this work. The effects of feedstock type and pretreatment method, process parameters and gasifier type on the co-gasification process are summarized, the catalytic synergistic mechanism in the co-gasification process of coal and biomass is systematically described, the synergistic mechanism of non-catalytic factors in the co-gasification process is briefly outlined, and new methods to study the co-gasification process are comprehensively discussed. The main concern of the co-gasification process is sorted out, and prospects are made for constructing the synergistic pathway with the help of the new in situ technique and revealing the reaction mechanism in coupling the chemical reaction system with the combination of density functional theory and gasification dynamics models.
2023, 51(8): 1073-1083.
doi: 10.19906/j.cnki.JFCT.2023041
Abstract:
Catalytic pyrolysis technology can convert waste plastics into high-quality carbon nanotubes (CNTs), achieving the recycling and high-value utilization of waste plastics. However, the process of plastic catalytic pyrolysis is complex, with numerous influencing factors, and the growth mechanism of carbon nanotubes is unclear. Therefore, this article elaborates on the influence of plastic structure and pyrolysis process on the growth process and structural characteristics of carbon nanotubes from the perspectives of plastic type, temperature, catalyst, etc., and analyzes the nucleation and growth mechanism of carbon nanotubes. It is found that the type and temperature of volatile matter will affect the structure of CNTs, while the performance of the catalyst will affect the diameter and growth mode of carbon nanotubes. The force between the catalyst and CNTs depends on the type of catalyst, and the carbon diffusion intensity at the boundary of CNTs is influenced by reaction conditions, catalyst and carbon source types. The relative size between the two determines the specific process of CNTs nucleation and growth.This review provides theoretical reference for the understanding of the process of preparing carbon nanotubes from waste plastic pyrolysis and the development of waste plastic resource utilization technologies.
Catalytic pyrolysis technology can convert waste plastics into high-quality carbon nanotubes (CNTs), achieving the recycling and high-value utilization of waste plastics. However, the process of plastic catalytic pyrolysis is complex, with numerous influencing factors, and the growth mechanism of carbon nanotubes is unclear. Therefore, this article elaborates on the influence of plastic structure and pyrolysis process on the growth process and structural characteristics of carbon nanotubes from the perspectives of plastic type, temperature, catalyst, etc., and analyzes the nucleation and growth mechanism of carbon nanotubes. It is found that the type and temperature of volatile matter will affect the structure of CNTs, while the performance of the catalyst will affect the diameter and growth mode of carbon nanotubes. The force between the catalyst and CNTs depends on the type of catalyst, and the carbon diffusion intensity at the boundary of CNTs is influenced by reaction conditions, catalyst and carbon source types. The relative size between the two determines the specific process of CNTs nucleation and growth.This review provides theoretical reference for the understanding of the process of preparing carbon nanotubes from waste plastic pyrolysis and the development of waste plastic resource utilization technologies.
2023, 51(8): 1084-1095.
doi: 10.1016/S1872-5813(23)60345-7
Abstract:
Lignin is a natural and renewable resource with aromatic structure. It can be converted into bio-oil by hydrothermal liquefaction. Due to the complex structure of wood fiber, the structural characteristics and reactivity of different kinds of lignin are different. Therefore, three typical lignin (kraft lignin (KL), enzymatic hydrolysis lignin (EHL) and ethanol lignin (OL)) were selected as raw materials. Firstly, physical and chemical properties of the raw materials were analyzed. Secondly, effects of reaction conditions on characteristics of their hydrothermal liquefaction bio-oil were investigated. Among them, EHL and OL are guaiacyl units. OL has the highest content of carbon and hydrogen elements, and its higher heating value reaches 23.54 MJ/kg. The aromatic characteristics are more obvious, and the phenolic hydroxyl content is relatively high. KL is mainly syringyl unit with less methoxy and phenolic hydroxyl groups. The results of liquefaction experiment show that when the reaction temperature was 300 ℃, yield and energy recovery rate of lignin bio-oil were the highest. The bio-oil yield ranked in the order of OL>KL>EHL. H/C ratio of bio-oil was concentrated within 1.0-1.4. Chemical composition of the three bio-oils was different. OL bio-oil contains 9.14% aromatic hydrocarbons, EHL bio-oil contains 41.34% phenolic species, and KL bio-oil has a higher acid content.
Lignin is a natural and renewable resource with aromatic structure. It can be converted into bio-oil by hydrothermal liquefaction. Due to the complex structure of wood fiber, the structural characteristics and reactivity of different kinds of lignin are different. Therefore, three typical lignin (kraft lignin (KL), enzymatic hydrolysis lignin (EHL) and ethanol lignin (OL)) were selected as raw materials. Firstly, physical and chemical properties of the raw materials were analyzed. Secondly, effects of reaction conditions on characteristics of their hydrothermal liquefaction bio-oil were investigated. Among them, EHL and OL are guaiacyl units. OL has the highest content of carbon and hydrogen elements, and its higher heating value reaches 23.54 MJ/kg. The aromatic characteristics are more obvious, and the phenolic hydroxyl content is relatively high. KL is mainly syringyl unit with less methoxy and phenolic hydroxyl groups. The results of liquefaction experiment show that when the reaction temperature was 300 ℃, yield and energy recovery rate of lignin bio-oil were the highest. The bio-oil yield ranked in the order of OL>KL>EHL. H/C ratio of bio-oil was concentrated within 1.0-1.4. Chemical composition of the three bio-oils was different. OL bio-oil contains 9.14% aromatic hydrocarbons, EHL bio-oil contains 41.34% phenolic species, and KL bio-oil has a higher acid content.
2023, 51(8): 1096-1105.
doi: 10.19906/j.cnki.JFCT.2023009
Abstract:
Mono-aromatic hydrocarbons (MAHs) are important basic raw materials for organic chemicals industry. Catalytic pyrolysis of lignin can produce MAHs. However, the complicated components of pyrolysis vapours can result in rapid coke deactivation of the catalyst and the lower yields of mono-aromatic hydrocarbons. The lignin pyrolysis vapours were upgraded to MAHs by Ni or Ga modified hierarchical zeolite (HZSM-5@Al-SBA-15). The distribution of catalytic pyrolysis products and the coke deposition behavior of catalysts were investigated in a fixed bed reactor. Results showed that the hierarchical zeolites had the developed pore structure, which could effectively improve the mass transfer and diffusion performance of lignin pyrolysis vapours. Moreover, the introduction of metal elements and mesoporous shell modulated the acidity distribution of the catalysts. Compared with the pure HZSM-5, the relative content of MAHs (78.63%), Ga/HS (77.15%) and Ni-Ga/HS (72.44%) were increased, and the content of poly-aromatic hydrocarbons was effectively inhibited. The content of CO2 in the gas products increased, indicating that the catalyst could promote the decarboxylation reaction. In addition, the content of coke deposition with supported hierarchical zeolite catalysts was significantly reduced, which were Ni/HS (7.79%), Ga/HS (6.37%) and Ni-Ga/HS (6.63%), respectively. This indicated that the introduction of metal components improved the anti-coke performance of the catalysts. Therefore, the supported hierarchical zeolite based on metal modification and pore optimization could upgrade the lignin pyrolysis vapours into high quality aromatic hydrocarbons. This study provides a basic reference for the high value utilization of lignin waste.
Mono-aromatic hydrocarbons (MAHs) are important basic raw materials for organic chemicals industry. Catalytic pyrolysis of lignin can produce MAHs. However, the complicated components of pyrolysis vapours can result in rapid coke deactivation of the catalyst and the lower yields of mono-aromatic hydrocarbons. The lignin pyrolysis vapours were upgraded to MAHs by Ni or Ga modified hierarchical zeolite (HZSM-5@Al-SBA-15). The distribution of catalytic pyrolysis products and the coke deposition behavior of catalysts were investigated in a fixed bed reactor. Results showed that the hierarchical zeolites had the developed pore structure, which could effectively improve the mass transfer and diffusion performance of lignin pyrolysis vapours. Moreover, the introduction of metal elements and mesoporous shell modulated the acidity distribution of the catalysts. Compared with the pure HZSM-5, the relative content of MAHs (78.63%), Ga/HS (77.15%) and Ni-Ga/HS (72.44%) were increased, and the content of poly-aromatic hydrocarbons was effectively inhibited. The content of CO2 in the gas products increased, indicating that the catalyst could promote the decarboxylation reaction. In addition, the content of coke deposition with supported hierarchical zeolite catalysts was significantly reduced, which were Ni/HS (7.79%), Ga/HS (6.37%) and Ni-Ga/HS (6.63%), respectively. This indicated that the introduction of metal components improved the anti-coke performance of the catalysts. Therefore, the supported hierarchical zeolite based on metal modification and pore optimization could upgrade the lignin pyrolysis vapours into high quality aromatic hydrocarbons. This study provides a basic reference for the high value utilization of lignin waste.
2023, 51(8): 1106-1113.
doi: 10.19906/j.cnki.JFCT.2023029
Abstract:
This study investigated the effects of decoupled temperature and pressure on lignin during the hydrothermal process. The effect of hydrothermal treatment on the lignin structure was evaluated, and the effects of decoupling temperature and pressure on the liquid products of the lignin were assessed under decoupling conditions. The results showed that lignin was composed almost entirely of the G-type monomer of coniferyl alcohol. After hydrothermal treatment, C–O bonds such as β–O–4 ester bonds in lignin were broken. Methoxy and aliphatic structures linked to oxygen-containing structures were converted into aliphatic carbon skeletons. The liquid phase products were initially vanillin and 3-(4-hydroxy-3-methoxyphenyl)-1-propanol, which were subsequently converted to guaiacol mainly by inter-monomer conversion and cleavage of the β–O–4 bond of the terminal guaiacyl unit of lignin. The decoupled high pressure inhibited the production of lignin liquid products and decreased the selectivity of isoeugenol in the products. The results of this paper are expected to provide more fundamental knowledge and understanding for the optimization of hydrothermal conversion process conditions of lignin.
This study investigated the effects of decoupled temperature and pressure on lignin during the hydrothermal process. The effect of hydrothermal treatment on the lignin structure was evaluated, and the effects of decoupling temperature and pressure on the liquid products of the lignin were assessed under decoupling conditions. The results showed that lignin was composed almost entirely of the G-type monomer of coniferyl alcohol. After hydrothermal treatment, C–O bonds such as β–O–4 ester bonds in lignin were broken. Methoxy and aliphatic structures linked to oxygen-containing structures were converted into aliphatic carbon skeletons. The liquid phase products were initially vanillin and 3-(4-hydroxy-3-methoxyphenyl)-1-propanol, which were subsequently converted to guaiacol mainly by inter-monomer conversion and cleavage of the β–O–4 bond of the terminal guaiacyl unit of lignin. The decoupled high pressure inhibited the production of lignin liquid products and decreased the selectivity of isoeugenol in the products. The results of this paper are expected to provide more fundamental knowledge and understanding for the optimization of hydrothermal conversion process conditions of lignin.
2023, 51(8): 1114-1125.
doi: 10.19906/j.cnki.JFCT.2023011
Abstract:
The effects of K2CO3 (PC) and K2FeO4 (PF) on the catalytic pyrolysis of herb residue were investigated by using a thermogravimetric analyser, online mass spectrometry and a fixed-bed reactor, using herb residue as the raw material and loaded with PF and PC catalysts respectively by impregnation. The results showed that both PC and PF lowered the pyrolysis reaction temperature of the herb, enhanced the water vapour reforming reaction and significantly increased the pyrolysis gas yield and H2 content. At 500 ℃, the catalyst promoted the production of H2 and increased the H2/CO ratio of the pyrolysis gas from 0 to 1.29 and 1.92, respectively; at 700 ℃, PC and PF can significantly reduce the liquid-phase yield and increase the H2/CO of the gas product, with PF being more effective, reducing the liquid-phase yield by 30.9% and increasing the H2/CO increased by 38.5%. However, PF will decompose and release oxygen during the pyrolysis process, which makes NO emissions increase.
The effects of K2CO3 (PC) and K2FeO4 (PF) on the catalytic pyrolysis of herb residue were investigated by using a thermogravimetric analyser, online mass spectrometry and a fixed-bed reactor, using herb residue as the raw material and loaded with PF and PC catalysts respectively by impregnation. The results showed that both PC and PF lowered the pyrolysis reaction temperature of the herb, enhanced the water vapour reforming reaction and significantly increased the pyrolysis gas yield and H2 content. At 500 ℃, the catalyst promoted the production of H2 and increased the H2/CO ratio of the pyrolysis gas from 0 to 1.29 and 1.92, respectively; at 700 ℃, PC and PF can significantly reduce the liquid-phase yield and increase the H2/CO of the gas product, with PF being more effective, reducing the liquid-phase yield by 30.9% and increasing the H2/CO increased by 38.5%. However, PF will decompose and release oxygen during the pyrolysis process, which makes NO emissions increase.
2023, 51(8): 1126-1136.
doi: 10.19906/j.cnki.JFCT.2023004
Abstract:
Light aromatics are extremely important building blocks in the chemical industry which can be produced from the catalytic fast pyrolysis (CFP) of biomass. In this work, wet torrefaction pretreatment (WTP) was employed to improve the quality of poplar wood (PW) in terms of the synergetic deoxygenation and demineralization. Then, metal-modified hierarchical HZSM-5 was prepared by the combined approach of NaOH desilication pretreatment and metal (Zn, Ga, and Fe) modification. At last, the CFP of torrefied PW was carried out by using the metal-modified hierarchical HZSM-5 as catalyst to produce light aromatics. Results showed that the deoxygenation and demineralization rates gradually increased with the increase of WTP temperature from 180 to 260 ℃, the maximum removal rates of oxygen, K, Mg, Ca, and Na were 47.96%, 90.99%, 86.65%, 66.09%, and 36.29%, respectively. NaOH desilication pretreatment and metal modification on HZSM-5 promoted the formation of light aromatics. The Zn-modified hierarchical HZSM-5 presented the highest yield of light aromatics. The yield of aromatics increased first with the raise of catalyst-to-torrefied PW ratio from 1:1 to 1∶3, then decreased slightly at the highest catalyst-to-torrefied PW ratio of 1∶5. At last, the operation parameter of WTP and CFP was optimized which the maximum yield of light aromatics was 7.83 × 107 p.a./mg at WTP temperature of 220 ℃, catalyst-to-biomass ratio of 3∶1, and CFP temperature of 850 ℃.
Light aromatics are extremely important building blocks in the chemical industry which can be produced from the catalytic fast pyrolysis (CFP) of biomass. In this work, wet torrefaction pretreatment (WTP) was employed to improve the quality of poplar wood (PW) in terms of the synergetic deoxygenation and demineralization. Then, metal-modified hierarchical HZSM-5 was prepared by the combined approach of NaOH desilication pretreatment and metal (Zn, Ga, and Fe) modification. At last, the CFP of torrefied PW was carried out by using the metal-modified hierarchical HZSM-5 as catalyst to produce light aromatics. Results showed that the deoxygenation and demineralization rates gradually increased with the increase of WTP temperature from 180 to 260 ℃, the maximum removal rates of oxygen, K, Mg, Ca, and Na were 47.96%, 90.99%, 86.65%, 66.09%, and 36.29%, respectively. NaOH desilication pretreatment and metal modification on HZSM-5 promoted the formation of light aromatics. The Zn-modified hierarchical HZSM-5 presented the highest yield of light aromatics. The yield of aromatics increased first with the raise of catalyst-to-torrefied PW ratio from 1:1 to 1∶3, then decreased slightly at the highest catalyst-to-torrefied PW ratio of 1∶5. At last, the operation parameter of WTP and CFP was optimized which the maximum yield of light aromatics was 7.83 × 107 p.a./mg at WTP temperature of 220 ℃, catalyst-to-biomass ratio of 3∶1, and CFP temperature of 850 ℃.
2016, 44(7): 777-783.
摘要：
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, La和Lc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, Lc和La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。
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, La和Lc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, Lc和La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。
2016, 44(4): 385-393.
摘要：
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。
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。
2016, 44(3): 263-272.
摘要：
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.
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.
2016, 44(3): 279-286.
摘要：
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.
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.
2016, 44(7): 801-814.
摘要：
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。
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。
2016, 44(9): 1034-1042.
摘要：
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。
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。
2016, 44(11): 1388-1393.
摘要：
分别以β、ZSM-5和USY分子筛为载体，采用浸渍法制备了锰铈催化剂，对其低温NH3-SCR反应性能进行了评价，并采用XRD、BET、NH3-TPD、H2-TPR以及XPS对催化剂进行了表征。结果表明，三种分子筛负载的锰铈催化剂均具有较好的低温NH3-SCR反应活性，其中，Mn-Ce/USY的催化性能最好，在107℃时NOx转化率可达到90%。负载锰铈后催化剂的比表面积和孔体积均有所下降；活性组分MnOx主要以无定型态分布于催化剂表面，且在ZSM-5上检测到聚集的CeO2。催化剂表面弱酸对低温NH3-SCR反应起主要作用，催化剂表面上活性组分的表面浓度和氧化态明显不同，较高的Mn4+/Mn3+原子比和吸附氧表面浓度对提高催化剂的低温NH3-SCR反应活性有利。
分别以β、ZSM-5和USY分子筛为载体，采用浸渍法制备了锰铈催化剂，对其低温NH3-SCR反应性能进行了评价，并采用XRD、BET、NH3-TPD、H2-TPR以及XPS对催化剂进行了表征。结果表明，三种分子筛负载的锰铈催化剂均具有较好的低温NH3-SCR反应活性，其中，Mn-Ce/USY的催化性能最好，在107℃时NOx转化率可达到90%。负载锰铈后催化剂的比表面积和孔体积均有所下降；活性组分MnOx主要以无定型态分布于催化剂表面，且在ZSM-5上检测到聚集的CeO2。催化剂表面弱酸对低温NH3-SCR反应起主要作用，催化剂表面上活性组分的表面浓度和氧化态明显不同，较高的Mn4+/Mn3+原子比和吸附氧表面浓度对提高催化剂的低温NH3-SCR反应活性有利。
2018, 46(2): 179-188.
摘要：
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M（M=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%。
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M（M=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%。
2018, 46(1): 92-98.
摘要：
通过建立具有更精确的SO3组分的实验室模拟烟气系统，同步研究了反应物浓度对硫酸氢铵和硫酸铵生成率和生成进度（生成速率）的影响。在实验浓度范围内，硫酸氢铵的开始生成温度为230-270℃，峰值温度为180-240℃，硫酸铵开始生成温度及峰值温度总体上比硫酸氢铵低40℃左右。硫酸氢铵的生成率明显高于硫酸铵，根据NH3和SO3浓度与物质的量比不同，烟温到120℃时，硫酸氢铵的生成率为64%-90%，硫酸铵的生成率为6%-15%，硫酸氢铵的生成率为硫酸铵的6-10倍。反应物浓度的增加会促进硫酸氢铵和硫酸铵的生成，且SO3较NH3更有利于硫酸氢铵的生成。硫酸氢铵和硫酸铵生成份额随温度的变化呈单峰状，且随着反应物浓度的增加，其峰值所在的温度区间逐渐升高。
通过建立具有更精确的SO3组分的实验室模拟烟气系统，同步研究了反应物浓度对硫酸氢铵和硫酸铵生成率和生成进度（生成速率）的影响。在实验浓度范围内，硫酸氢铵的开始生成温度为230-270℃，峰值温度为180-240℃，硫酸铵开始生成温度及峰值温度总体上比硫酸氢铵低40℃左右。硫酸氢铵的生成率明显高于硫酸铵，根据NH3和SO3浓度与物质的量比不同，烟温到120℃时，硫酸氢铵的生成率为64%-90%，硫酸铵的生成率为6%-15%，硫酸氢铵的生成率为硫酸铵的6-10倍。反应物浓度的增加会促进硫酸氢铵和硫酸铵的生成，且SO3较NH3更有利于硫酸氢铵的生成。硫酸氢铵和硫酸铵生成份额随温度的变化呈单峰状，且随着反应物浓度的增加，其峰值所在的温度区间逐渐升高。
2020, 48(11): 1281-1297.
摘要：
煤炭是中国重要的能源资源，而中国煤中重金属砷、硒、铅含量较高，燃煤电厂已经成为重要的砷、硒、铅排放源之一。针对电厂燃煤带来严峻的砷、硒、铅污染问题，本文首先介绍了燃煤释放的砷、硒、铅排放量大且危害性强，概述了世界各国关于重金属排放控制的相关政策法规，指出中国对燃煤重金属砷、硒、铅的排放控制势在必行；其次从煤中赋存形态、燃烧过程中的形态转化和质量分布三个方面阐释了燃煤过程中砷、硒、铅的迁移转化规律，重点描述了砷、硒、铅在颗粒物上的形态特征和尺度分布；最后综述了燃烧前、燃烧中和燃烧后对砷、硒、铅的排放控制技术，详述了吸附剂捕集和烟气净化装置协同脱除的研究进展，并论述了低低温除尘器和团聚技术对砷、硒、铅的强化脱除潜力。以期为燃煤电厂重金属砷、硒、铅超低排放的实现提供参考和指导。
煤炭是中国重要的能源资源，而中国煤中重金属砷、硒、铅含量较高，燃煤电厂已经成为重要的砷、硒、铅排放源之一。针对电厂燃煤带来严峻的砷、硒、铅污染问题，本文首先介绍了燃煤释放的砷、硒、铅排放量大且危害性强，概述了世界各国关于重金属排放控制的相关政策法规，指出中国对燃煤重金属砷、硒、铅的排放控制势在必行；其次从煤中赋存形态、燃烧过程中的形态转化和质量分布三个方面阐释了燃煤过程中砷、硒、铅的迁移转化规律，重点描述了砷、硒、铅在颗粒物上的形态特征和尺度分布；最后综述了燃烧前、燃烧中和燃烧后对砷、硒、铅的排放控制技术，详述了吸附剂捕集和烟气净化装置协同脱除的研究进展，并论述了低低温除尘器和团聚技术对砷、硒、铅的强化脱除潜力。以期为燃煤电厂重金属砷、硒、铅超低排放的实现提供参考和指导。
2013, 41(08): 1003-1009.
Abstract:
2009, 37(04): 501-505.
Abstract:
