Influence of acid treatment on the structure and extraction performance of Xinjiang Hefeng low-rank coal

MA Ya-ya; MA Feng-yun; MO Wen-long; FAN Xing

Volume 47 Issue 6

Jun. 2019

Turn off MathJax

Article Contents

Article Navigation > Journal of Fuel Chemistry and Technology > 2019 > 47(6): 649-660

MA Ya-ya, MA Feng-yun, MO Wen-long, FAN Xing. Influence of acid treatment on the structure and extraction performance of Xinjiang Hefeng low-rank coal[J]. Journal of Fuel Chemistry and Technology, 2019, 47(6): 649-660.

Citation:

MA Ya-ya, MA Feng-yun, MO Wen-long, FAN Xing. Influence of acid treatment on the structure and extraction performance of Xinjiang Hefeng low-rank coal[J]. Journal of Fuel Chemistry and Technology, 2019, 47(6): 649-660.

Citation:

PDF( 2954 KB)

Influence of acid treatment on the structure and extraction performance of Xinjiang Hefeng low-rank coal

Key Laboratory of Coal Clean Conversion & Chemical Engineering Process(Xinjiang Uyghur Autonomous Region), College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, China

Funds:

the National Natural Science Foundation of China-Key Project of Xinjiang Joint Fundation U1503293

the National Natural Science Foundation of China 21276219

More Information

Corresponding author: MA Feng-yun, E-mail: ma_fy@126.com; MO Wen-long, mowenlong@xju.edu.cn
Received Date: 2018-12-28
Rev Recd Date: 2019-03-24

Available Online: 2021-01-23

Publish Date: 2019-06-10

Abstract

Abstract

The acid treatment experiment to remove the inorganic minerals in Xinjiang Hefeng low-rank coal was conducted, and the effects of deashing treatment on the main structure of coal sample and its extraction performance by petroleum ether and CS₂ were analyzed by instrumental characterizations. The FT-IR results show that the main structure of the treated coal changes slightly compared with the untreated one. And the acid-washed coal sample (AC) presents a very weak absorption peak at 1712 cm^-1 attributed to carboxylic acid (C=O), which could not be observed in the raw coal sample (RC). It can also be seen from TG-DTG characterization that the process of acid treatment results in a cleavage of small molecular bonds in the coal without destroying the macromolecular network structure. The performance of two-stage ultrasonic extraction of RC and AC samples with petroleum ether (PE) and CS₂ as solvents proposes that the extraction proportions of PE and CS₂ of AC sample are higher than that of RC sample, from 0.16% and 0.53% (RC) to 0.17% and 0.64%, respectively, and the extraction rate of AC sample is larger than that of RC sample, reducing the number of solvent extraction operation significantly.FT-IR and GC-MS analysis of the extracts shows that the acid treatment not only effectively removes the heteroatoms in the coal sample, but also increases the type of CS₂ extracts. In addition, from the results of TG-DTG for the residues, it can be noted that the ultrasonic extraction is a physical swelling process, and does not destroy the macromolecular structure of the coal sample.
- Hefeng coal,
- acid treatment,
- coal structure,
- extraction performance

FullText(HTML)

References(24)

References

[1]	MARZEC A. Towards an understanding of the coal structure:A review[J]. Fuel Process Technol, 2002, 77:25-32. doi: 10.1016-S0378-3820(02)00045-0/
[2]	ASHIDA R, MORIMOTO M, MAKINO Y, UMEMOTO S, NAKAGAWA H, MIURA K. Fractionation of brown coal by sequential high temperature solvent extraction[J]. Fuel, 2009, 88(8):1485-1490. doi: 10.1016/j.fuel.2008.12.003
[3]	TAHMASEBI A, YU J, HAN Y, YIN F, BHATTACHARYA S, STOKIE D. Study of chemical structure changes of Chinese lignite upon drying in superheated steam, microwave, and hot air[J]. Energy Fuels, 2012, 26(6):3651-3660. doi: 10.1021/ef300559b
[4]	ZHENG A L, FAN X, WANG S Z, LIU F J, WEI X Y, ZHAO Y P. Analysis of the products from the oxidation of Geting bituminous coal by atmospheric pressure photoionization-mass spectrometry[J]. Anal Lett, 2014, 47(6):958-969. doi: 10.1080/00032719.2013.860541
[5]	IINO M. Network structure of coals and association behavior of coal-derived materials[J]. Fuel Process Technol, 2000, 62(2):89-101. http://www.sciencedirect.com/science/article/pii/S0378382099001204
[6]	WANG J, TAKARADA T. Characterization of high-temperature coal tar and supercritical-water extracts of coal by laser desorption ionization-mass spectrometry[J]. Fuel Process Technol, 2003, 81(3):247-258. doi: 10.1016/S0378-3820(03)00025-0
[7]	WANG S Q, TANG Y G, SCHOBERT H H, GUO Y N, GAO W C, LU X K. FTIR and simultaneous TG/MS/FTIR study of Late Permian coals from Southern China[J]. J Anal Appl Pyrolysis, 2013, 100:75-80. doi: 10.1016/j.jaap.2012.11.021
[8]	MAO J D, SCHIMMELMANN A, MASTALERZ M, HATCHER P, LI Y. Structural features of a bituminous coal and their changes during low-temperature oxidation and loss of volatiles investigated by advanced solid-state NMR spectroscopy[J]. Energy Fuels, 2010, 24(4):2536-2544. doi: 10.1021/ef9015069
[9]	FAN X, JIANG J, CHEN L, ZHOU C C, ZHU J L, ZHU T G, WEI X Y. Identification of organic fluorides and distribution of organic species in an anthracite with high content of fluorine[J]. Fuel Process Technol, 2016, 142:54-58. doi: 10.1016/j.fuproc.2015.09.024
[10]	GRYGLEWICZ G, RUTKOWSKI P, YPERMAN J. Characterization of sulfur compounds in supercritical coal extracts by gas chromatography-mass spectrometry[J]. Fuel Process Technol, 2002, 77:167-172. https://www.sciencedirect.com/science/article/pii/S0378382002000462
[11]	YU X Y, WEI X Y, LI Z K, CHEN Y, ZONG Z M, MA F Y. Comparison of three methods for extracting Liuhuanggou bituminous coal[J]. Fuel, 2017, 210:290-297. doi: 10.1016/j.fuel.2017.08.071
[12]	IINO M, TAKANOHASHI T, OHSUGA H, TODA K. Extraction of coals with CS₂-N-methyl-2-pyrrolidinone mixed solvent at room temperature[J]. Fuel, 1988, 67(12):1639-1647. doi: 10.1016/0016-2361(88)90208-6
[13]	WEI X Y, SHEN J L, TAKANOHASHI T, IINO M. Effect of extractable substances on coal dissolution. Use of CS₂-N-methyl-2-pyrrolidinone mixed solvent for dissolution re-action products[J]. Energy Fuels, 1989, 3(5):575-579. doi: 10.1021/ef00017a008
[14]	TAKANOHASHI T, XIAO F, TAKAHIRO YOSHIDA A, SAITO I. Difference in extraction yields between CS₂/NMP and NMP for upper freeport coal[J]. Energy Fuels, 2003, 17(1):255-256. doi: 10.1021/ef020141h
[15]	TAKANOHASHI T, TAKAYUKI YANAGIDA A, IINO M, MAINWARING D E. Extraction and swelling of low-rank coals with various solvents at room temperature[J]. Energy Fuels, 1996, 10(5):1128-1132. doi: 10.1021/ef960033t
[16]	LU H Y, WEI X Y, YU R, PENG Y L, QI X Z, QIE L M. Sequential thermal dissolution of Huolinguole lignite in methanol and in ethanol[J]. Energy Fuels, 2011, 25(6):2741-2745. doi: 10.1021/ef101734f
[17]	ISHIZUKA T, TAKANOHASHI T, ITO O, LINO M. Effects of additives and oxygen on ex-traction yield with CS₂-NMP mixed solvent for argonne premium coal samples[J]. Fuel, 1993, 72(4):579-580. doi: 10.1016/0016-2361(93)90120-Q
[18]	NISHIOKA M. Multistep extraction of coal[J]. Fuel, 1991, 70(12):1413-1419. doi: 10.1016/0016-2361(91)90007-W
[19]	LI Q C, TAKANOHASHI T, YOSHIDA T, SAITO I, AOKI H, MASHIMO K. Effect of acid treatment on thermal extraction yield in ashless coal production[J]. Fuel, 2004, 83(6):727-732. doi: 10.1016/j.fuel.2003.06.002
[20]	LIU L L, YUAN Y, KUMAR S, WANG Z H, HE Y, LV Y, LIU J Z, GUL-E-RANA J, CEN K F. Catalytic effect of metal chlorides on coal pyrolysis and gasification part Ⅱ. Effects of acid washing on coal characteristics[J]. Thermochim Acta, 2018, 666:41-50. doi: 10.1016/j.tca.2018.06.001
[21]	GENG W, NAKAJIMA T, TAKANASHI H, OHKI A. Analysis of carboxyl group in coal and coal aromaticity by Fourier transform infrared (FT-IR) spectrometry[J]. Fuel, 2009, 88(1):139-144. doi: 10.1016/j.fuel.2008.07.027
[22]	WIJAYA N, ZHANG L. A critical review of coal demineralization and its implication on understanding the speciation of organically bound metals and submicrometer mineral grains in coal[J]. Energy Fuels, 2011, 25(1):1-16. https://www.researchgate.net/publication/231272542_A_Critical_Review_of_Coal_Demineralization_and_Its_Implication_on_Understanding_the_Speciation_of_Organically_Bound_Metals_and_Submicrometer_Mineral_Grains_in_Coal
[23]	LIU X P, WU X T, WANG J. Substantial upgrading of a high-ash lignite by hydrothermal treatment followed by Ca(OH)₂ digestion/acid leaching[J]. Fuel, 2018, 222:269-277. doi: 10.1016/j.fuel.2018.02.034
[24]	TANG L F, CHEN S J, WANG S W, TAO X X, HE H, FENG L, ZHENG L, MA C Y, ZHAO Y D. Exploration on the action mechanism of microwave with peroxyacetic acid in the process of coal desulfurization[J]. Fuel, 2018, 214:554-560. doi: 10.1016/j.fuel.2017.10.087