超临界水中钾对甲醛降解过程影响的研究

赵亮; 张军; 钟辉; 丁启忠; 陈孝武; 徐成威; 任宗党

超临界水中钾对甲醛降解过程影响的研究

东南大学能源热转换及其过程测控教育部重点实验室, 江苏南京 210096

基金项目: 国家重点基础研究发展规划(973计划,2009CB220007);动力工程多相流国家重点实验室开放基金。

详细信息

通讯作者:
张军,教授,主要研究方向为可再生能源转化与利用和电厂污染控制。E-mail:junzhang@seu.edu.cn。

中图分类号: TK6
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出版历程
- 收稿日期: 2012-09-02
- 修回日期: 2012-11-26
- 刊出日期: 2013-03-30

Influence of potassium salts on the decomposition of formaldehyde in supercritical water

Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China

摘要

摘要: 为掌握生物质中钾对生物质超临界水降解过程的影响,选择生物质气化转化过程中生成的重要小分子中间产物甲醛作为研究对象,研究不同工艺条件下(反应温度400～650℃、压力23～29 MPa、停留时间4～12 s),单一钾成分(KHCO₃/K₂CO₃/KCl)或混合钾成分(KHCO₃、K₂CO₃、KCl)对甲醛超临界水降解气体产物的影响。结果表明,KHCO₃、K₂CO₃、KCl、混合钾均降低了气体产物中CO的体积分数,提高了CO₂的体积分数,但KCl的影响程度弱于其他三种钾成分。此外,由于不同钾成分均不利于气体产物中CO和H₂体积分数的提高,从而使得气体产物的热值降低。KHCO₃、K₂CO₃、KCl、混合钾均降低了H₂、CO、CO₂的产率以及气化率,其对H₂产率以及气化率的抑制程度从大到小依次为:混合钾、KHCO₃、K₂CO₃、KCl,且提高反应温度、延长反应停留时间时抑制气体生成的作用相对越明显。而当反应压力改变时,钾成分对H₂产率及气化率的影响程度变化较小。较高反应温度、较高反应压力、较长停留时间时,混合钾中各成分出现协同作用,明显抑制了气体产物的生成。
- 钾成分 /
- 甲醛 /
- 超临界水气化 /
- 影响规律
Abstract: The influences of potassium salts on the decomposition of formaldehyde in supercritical water were investigated in a continuous reactor under 400～650℃, 23～29 MPa and a residence time of 4～12 s, as formaldehyde is one of the most important intermediate products for the gasification of biomass with supercritical water. The results showed that KHCO₃, K₂CO₃, KCl and mixed potassium salts are able to reduce the fraction CO in the gaseous product and increase the fraction of CO₂, which then depresses the heating value of the gaseous product. All these potassium ingredients exhibit an inhibitive effect on the formation of H₂, CO and CO₂ and the gasification efficiency; the inhibition strength of various potassium ingredients follows the order of mixed potassium salts > KHCO₃ > K₂CO₃ > KCl. The inhibitive effect on the formation of gaseous products is enhanced under high reaction temperature and long residence time, but is almost independent on the reaction pressure. Under high temperature, high pressure and long residence time, gas generation may be inhibited considerably by the mixed potassium salts, possibly due to a synergetic effect of different potassium salts.
- potassium salts /
- formaldehyde /
- supercritical water gasification /
- influencing rule

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参考文献(24)

于洁, 肖宏. 生物质制氢技术研究进展[J]. 中国生物工程, 2006, 26(5): 107-112. (YU Jie, XIAO Hong. Advance in technologies of hydrogen production from biomass[J]. China Biotechnology, 2006, 26(5): 107-112.)

GUO L J, LV Y J, ZHANG X M, JI C M, GUAN Y, PEI A X. Hydrogen production by biomass gasification in supercritical water: A systematic experimental and analytical study[J]. Catal Today, 2007, 129(3): 275-286.

KRUSE A. Supercritical water gasification[J]. Biofuel Bioprod Bior, 2008, 2(5): 415-437.

MADENO ?LU T G, KURT S, SAGLA?M M, YVKSEL M, GÖKKAYA D, BALLICE L. Hydrogen production from some agricultural residues by catalytic subcritical and supercritical water gasification[J]. J Supercrit Fluid, 2012, 76: 22-28.

D'JES ÚS P, BOUKIS N, CZARNETZKI B K, DINJUS E. Gasification of corn and clover grass in supercritical water[J]. Fuel, 2006, 85(7): 1032-1038.

AIDA T M, SHIRAISHI N, KUBO M, WATANABE M, SMITH R L. Reaction kinetics of D-xylose in sub- and supercritical water[J]. J Supercrit Fluid, 2010, 55(1): 208-216.

SINAG A, KRUSE A, SCHWARZKOPF V. Key compounds of the hydropyrolysis of glucose in supercritical water in the presence of K₂CO₃[J]. Ind Eng Chem Res, 2003, 45(5): 3516-3521.

WATANABE M, OSADA M, INOMATA H, ARAI K, KRUSE A. Acidity and basicity of metal oxide catalysts for formaldehyde reaction in supercritical water at 673K[J]. Appl Catal A-Gen, 2003, 245(2): 333-341.

OSADA M, WATANABE M, SUE K, ADSCHIRI T, ARAI K. Water density dependence of formaldehyde reaction in supercritical water[J]. J Supercrit Fluid, 2004, 28(2): 219-224.

张国妮, 张军, 徐益谦. 超临界水中甲醛气化的实验研究[J]. 西安交通大学学报, 2008, 42(3): 372-376. (ZHANG Guo-ni, ZHANG Jun, XU Yi-qian. Experimental research on formaldehyde gasification in supercritical water[J]. Journal of Xi'an Jiaotong University, 2008, 42(3): 372-376.)

OHNO K, MAEDA S. Global reaction route mapping on potential energy surfaces of formaldehyde, formic acid, and their metal-substituted analogues[J]. J Phys Chem A, 2006, 110(28): 8933-8941.

RAVEENDRAN K, GANESH A, KHILAR K C. Influence of mineral matter on biomass pyrolysis characteristics[J]. Fuel, 1995, 74(12): 1812-1822.

VAMVUKA D, TROULINOS S, KASTANAKI E. The effect of mineral matter on the physical and chemical activation of low rank coal and biomass materials[J]. Fuel, 2006, 85(12-13): 1763-1771.

BLASI C D, BRANCA C, D'ERRICO G. Degradation characteristics of straw and washed straw[J]. Thermochim Acta, 2000, 364(1-2): 133-142.

赵亮, 张军, 盛昌栋, 张永春, 丁启忠, 王坤, 刘杨先. 内在钾元素对玉米芯超临界水气化制氢过程的影响[J]. 西安交通大学学报, 2011, 45(7): 15-21. (ZHAO Liang, ZHANG Jun, SHENG Chang-dong, ZHANG Yong-chun, DING Qi-zhong, WANG Kun, LIU Yang-xian. Influence of inherent potassium in corncob on hydrogen production with supercritical water gasification [J]. Journal of Xi'an Jiaotong University, 2011, 45(7): 15-21.)

张国妮. 超临界水中甲醛气化制氢的微观机理研究. 南京: 东南大学, 2007. (ZHANG Guo-ni. Study on the mechanisms of formaldehyde decomposition in supercritical water. Nanjing: Southeast University, 2007.)

余春江. 生物质热解机理和工程应用研究. 杭州: 浙江大学, 2000. (YU Chun-jiang. Biomass pyrolysis mechanism and engineering application research. Hangzhou: Zhejiang University, 2000.)

WEI X L, SCHNELL U, HEIN K R G. Behaviour of gaseous chlorine and alkali metals during biomass thermal utilisation[J]. Fuel, 2005, 84(7-8): 841-848.

BRYGOO H B, VINAUGER M, COLCOMBET J, EPHRITIKHINE G, FRACHISSE J, MAUREL C. Anion channels in higher plants: functional characterization, molecular structure and physiological role[J]. BBA-Biomembranes, 2010, 1465(1-2): 199-218.

郭献军. 生物质燃烧氯的析出与控制研究. 武汉: 华中科技大学, 2009. (GUO Xian-jun. Study on release and control of chlorine during biomass combustion. Wuhan: Huazhong University of Science and Technology, 2009.)

BVHLER W, DINJUS E, EDERER H J, KRUSE A, MAS C. Ionic reactions and pyrolysis of glycerol as competing reaction pathways in near- and supercritical water[J]. J Supercrit Fluid, 2002, 22(1): 37-53.

李卫宏, 刘学武, 夏远景, 邓进军. 木质素在超临界水中气化制氢反应机理分析[J]. 中国农化机, 2011, (4): 60-63. (LI Wei-hong, LIU Xue-wu, XIA Yuan-jing, DENG Jin-jun. Reaction mechanism analysis on hydrogen production by gasification og lignin in supercritical water[J]. Chinese Agricultural Mechanization, 2011, (4): 60-63.)

HAO X H, GUO L J, MAO X, ZHANG X M, CHEN X J. Hydrogen production from glucose used as a model compound of biomass gasified in supercritical water[J]. Int J Hydrogen Energ, 2003, 28(1): 55-64.

ZHANG Y C, ZHANG J, ZHAO L, SHENG C D. Decomposition of formic acid in supercritical water[J]. Energ Fuel, 2009, 24(1): 95-99.

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