China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. The paper studies supercritical methanol treatment of lignite with a device at high temperature and pressure. Experiments mainly focus on the effects of temperature, pressure, catalysts and pretreatment ways on the extraction rate. Results indicate that the extraction rate increases with raising of temperature and pressure below 330 ℃,10 MPa. When temperature exceeds 330 ℃, extraction rate decreases slightly. After swelling pretreatment in methanol for 8 h, the lignite is treated for 60 min at 330 ℃，8.2 MPa with NaOH as catalyst(1%wt). The weight ratio of methanol/ Xilinhaote lignite is 5/1. Under these conditions, the extraction rate can reach 22.88%.
Cite this paper
H. Luan, A. Wang, Q. Zhang and F. Chen, "Research on Supercritical Methanol Treatment of Lignite," Advances in Materials Physics and Chemistry, Vol. 2 No. 4, 2012, pp. 158-161. doi: 10.4236/ampc.2012.24B041.
 H. Dai, K. Xie, Technology and Use of Lignite, Peking: Coal Industry,1999, pp. 1-9
 M. Satoru，H. Masahiro, K. Koh, Analysis of oxygen-functional groups in brown coals.Fuel Processing Technology, vol. 67, pp. 231-243, 2000.
 Z. Shi, Study on Thermal Extraction of Coal and Hydrogenation Liqucfaetion Behavior of Extract, April 2009.
 C. Li，T. Takanohashi，T. Yoshida, Effect of acid treatment on thermal extraction yield in ashless coal production, Fuel，vol. 83(3), pp. 727—732, 2004.
 O. Yunus, C. Kadim, Low temperature extractability and solvent swelling of Turkish liginites, Fuel Processing Technology, vol. 53(1-2), pp. 81-97, 1997.
 H Hu, S. Guo, K. Hedden. Extraction of lignite with water in sub- and supercritical states, Fuel Processing Technology, vol. 53(3), pp. 269-277, 1997.
 K. Xie, Coal Structure And Its Reactivity, Peking: 2002, pp.68-90
 C. Chen, J. Gao, X. Wei, Solvent Extraction And Coal Cleaning, Coal Conversion, vol. 18(2), pp. 14-20, 1995.
 Y. Tian, S. Shen, Y. Tian, Coal Unfreezing Extraction and Coal Chemical Group Composition, Journal of Taiyuan University of Technology, vol. 32(6), pp. 555-558, 2001.
 F Czechowski, M Stolarski, R. Bernd, Supercritical fluid extracts from brown coal litho types and their group components-molecular composition of non-polar compounds, Fuel，vol. 81, pp. 1933-1944, 2002.
 T. Yoshida，T. Takanohashi，K. Sakanishi, The effect of extraction condition on “hypercoal” production(Ⅰ)：Under room-temperature filtration, Fuel， vol. 81(10), pp. 1463-1469, 2002.
 J. Shen, X. Li, G. Zou, Extraction yield of different rank coals in CS2-NMP and their relation w ith coals property, Coal Conversion，vol. 28(3), pp. 1-4, 2005.
 W. Liu , T. Xia, S. Zhang , X. Wei, Z. Zong , C. Li, Factors influencing supercritical methanolysis of lignite, Journal of Wuhan University of Science and Technology, vol. 33(1), pp. 95-98, 2010.
 Z. B. Zhao, S. S. Chen, Z. F. Zhang, Study on Suprcritical Gas Extraction of Coal, Coal Conversion，vol. 19(1), pp. 88-95, 1996.
 C. H. Chen, Supercritical Extraction Features Of Some Coals, Coal Conversion，vol. 18(4), pp. 68-74, 1995.
 X. Zhu, Z. B. Zhu, C. J. Han, C. F. Zhang, Quantitative Determination Of Oxygen- Containing Functional Groups In Coal By Ftir Spectroscopy, Journal of Fuel Chemistry and Technology, vol. 27(4), pp.335-339, 1999.
 M. Li, Research On Oxygen-Containing Functional Groups On Coal Surface, May, 2004.
 P. Zhao, S. D. Shi, Research on Forms of Organic Oxygen in Shengli Lignite with XPS, Coal Science and Technology, vol. 32(7), pp. 51-52, 2004.
 Y. Chen, J. S. Gao, J. Yan, Extraction of Coal with Cyclohexanone, Journal of Fuel Chemistry and Technology, vol. 25(1), pp. 60-64, 1997.
 H. M. Li, Study on the Effect of Pretreatments on coal liquefaction reactivity, May 2010.
 H. Q. Hu, H. Qian, S. C. Guo, Solvent Swelling of Coal for Improved Supercritical Extraction, Journal of Fuel Chemistry and Technology, vol. 25(3), pp. 223-226, 1997.