电化学强化无烟煤瓦斯解吸特性及其机理
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摘要
介绍自主研制的电化学强化煤岩气解吸试验装置,该装置主要由高压注气系统、真空脱气系统、电化学作用系统、环境温度测控系统和数据采集系统等5部分组成。该装置的创新性如下:特殊研制了一种耐酸碱腐蚀且绝缘的吸附解吸罐,内设电解液腔与电极定位环,实现了电化学作用场的施加;吸附解吸罐的两端盖均有出气孔和注液孔,配合电化学作用系统可研究电解液在煤岩孔裂隙中定向移动并驱替气体的过程,是建立煤岩流体电动力学这一新理论较为关键的试验装置。采用该装置进行不同酸碱度电解液的电化学强化无烟煤瓦斯解吸试验,结果表明:在酸性电解液中,阳极侧的瓦斯解吸率较阴极侧高,而在中性或碱性电解液中,阳极侧解吸率较低;随电解液p H的升高,瓦斯最终解吸率增大,由61.84%增至87.26%,平均解吸速率提高5.59倍。这是由于电化学方法提高了煤瓦斯扩散系数,主要基于以下3方面作用:电渗作用驱动煤体孔裂隙中的电解液运移,并洗刷、携带煤基质表面吸附瓦斯,提供了瓦斯运移动力;电解反应产生的H+溶蚀碳酸盐和黄铁矿等矿物以及电泳作用迁移煤粒与黏土矿物等带电颗粒,疏通了孔裂隙,缩短了瓦斯扩散距离;热效应增强了甲烷气体分子的活性。
An experimental device of intensifying gas desorption from coal and rock by electrochemical method has been independently developed.It is composed of gas injection system,degassing system,temperature measurement and control system,data acquisition system,and electrochemical treatment system.The innovations of the device are as follows: the adsorption-desorption vessel with acid-alkali corrosion and good insulation property,including electrolyte chamber and electrode-located rings,is designed to ensure the infliction of electrochemical field; and by setting the air outlet and liquid inlet in each end cap of vessel,so that the process of motion-oriented of electrolyte and gas in pores and fractures of anthracite under electrochemical treatment can be researched. The device can be used to establish a new theory of electro-hydrodynamic of coal and rock.Experiments on intensifying gas desorption from anthracite in different electrolytes were conducted using this device.The results are as follows: the desorption ratio of gas in the side of anode is higher than in the side of cathode when the electrolyte is acid,however,the situation changes when the elec-trolyte is neutral or alkaline; the ultimate desorption ratio of gas increase( from 61.84% to 87.26%) with increasing p H and the average desorption rate increases by 5.59 times,since the electrochemical treatment improves the diffusion coefficient of anthracite through the following three functions: the adsorbed gas can be separated from coal surface and driven in the action of electro-osmosis,which provides impetus for gas migration; the pores and fractures increase with the treatment of electrolytic dissolution of minerals and electrophoresis migration of charged particles such as coal powder and clay,which shorten gas diffusion distance; the temperature of anthracite increases,which enhance the activity of gas molecules.
An experimental device of intensifying gas desorption from coal and rock by electrochemical method has been independently developed.It is composed of gas injection system,degassing system,temperature measurement and control system,data acquisition system,and electrochemical treatment system.The innovations of the device are as follows: the adsorption-desorption vessel with acid-alkali corrosion and good insulation property,including electrolyte chamber and electrode-located rings,is designed to ensure the infliction of electrochemical field; and by setting the air outlet and liquid inlet in each end cap of vessel,so that the process of motion-oriented of electrolyte and gas in pores and fractures of anthracite under electrochemical treatment can be researched. The device can be used to establish a new theory of electro-hydrodynamic of coal and rock.Experiments on intensifying gas desorption from anthracite in different electrolytes were conducted using this device.The results are as follows: the desorption ratio of gas in the side of anode is higher than in the side of cathode when the electrolyte is acid,however,the situation changes when the elec-trolyte is neutral or alkaline; the ultimate desorption ratio of gas increase( from 61.84% to 87.26%) with increasing p H and the average desorption rate increases by 5.59 times,since the electrochemical treatment improves the diffusion coefficient of anthracite through the following three functions: the adsorbed gas can be separated from coal surface and driven in the action of electro-osmosis,which provides impetus for gas migration; the pores and fractures increase with the treatment of electrolytic dissolution of minerals and electrophoresis migration of charged particles such as coal powder and clay,which shorten gas diffusion distance; the temperature of anthracite increases,which enhance the activity of gas molecules.
引文
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[11]卢义玉,丁红,葛兆龙,等.空化水射流热效应影响煤体渗透率试验研究[J].岩土力学,2014,35(5):1247-1254.LU Yiyu,DING Hong,GE Zhaolong,et al.Experiment study of effect of coal permeability under thermal effect of cavitation water jets[J].Rock and Soil Mechanics,2014,35(5):1247-1254.
[12]李志强,王登科,宋党育.新扩散模型下温度对煤粒瓦斯动态扩散系数的影响[J].煤炭学报,2015,40(5):1055-1064.LI Zhiqiang,WANG Dengke,SONG Dangyu.Influence of temperature on dynamic diffusion coefficient of CH4into coal particles by new diffusion model[J].Journal of China Coal Society,2015,40(5):1055-1064.
[13]SHI J Q,MAZUMDER S,WOLF K H,et al.Competitive methane desorption by supercritical CO2injection in coa[J].Transport in Porous Medial,2008(75):35-54.
[14]易俊,鲜学福,姜永东,等.煤储层瓦斯激励开采技术及其适应性[J].中国矿业,2005,14(12):26-29.YI Jun,XIAN Xuefu,JIANG Yongdong,et al.The adaptability study and technologies of prompting exploitation in coal-bed methane seams[J].China Mining Magazine,2005,14(12):26-29.
[15]FAIZ M,SAGHAF A,SHERWOOD N,et al.The influence of petrological properties and burial history on coal seam methane reservoir characterisation,Sydney Basin,Australia[J].International Journal of Coal Geology,2007(70):193-208.
[16]姜永东,熊令,阳兴洋,等.声场促进煤中甲烷解吸的机理研究[J].煤炭学报,2010,35(10):1649-1653.JIANG Yongdong,XIONG Ling,YANG Xingyang,et al.Mechanism research on sound field promoting the coal bed methane desorption[J].Journal of China Coal Society,2010,35(10):1649-1653.
[17]何学秋,张力.外加电磁场对瓦斯吸附解吸的影响规律及作用机理的研究[J].煤炭学报,2000,26(6):614-618.HE Xueqiu,ZHANG Li.Study on the effects of electromagnetic fields on gas adsorption and emission and its mechanism[J].Journal of China Coal Society,2000,26(6):614-618.
[18]康天合.一种电化学强化煤瓦斯解吸渗流的方法[P].中国专利:ZL201110130935.8,2013-05-08.
[19]GUO J,KANG T,KANG J,et al.Accelerating methane desorption in lump anthracite modified by electrochemical treatment[J].International Journal of Coal Geology,2014,131:392-399.
[20]LALVANI S,PATO M,COUGHLIN R W.Sulphur removal from coal by electrolysis[J].Fuel,1983(62):427-437.
[21]LOCKHART N C.Electra-osmotic dewatering of coal froth flotation concentrates[J].Fuel,1982(61):780-781.
[22]AMBA S A,CHILINGAR G V,BEESON C M.Use of direct electrical current for increasing the flow rate of reservoir fluids during petroleum recovery[J].Journal of Canadian Petroleum Technology,1964,3(1):8-14.
[23]CHILINGAR G V,ENASSIR A,STEVENS R G.Effect of direct electrical current on permeability of sandstone cores[J].Journal of Petroleum Technology,1970,22(7):830-836.
[24]FUERSTENAU D W,ROSENBAUM J M,YOU Y S.Electrokinetic behavior of coal[J].Energy and Fuels,1987,2(3):241-245.
[25]陈宗淇.胶体与界面化学[M].北京:高等教育出版社,2001.
[26]张国华,梁冰,毕业武.水锁对含瓦斯煤体的瓦斯解吸的影响[J].煤炭学报,2012,37(2):253-258.ZHANG Guohua,LIANG Bing,BI Yewu.Impact of water lock on gas desorption of coal with gas[J].Journal of China Coal Society,2012,37(2):253-258.
[27]赵东,冯增朝,赵阳升.高压注水对煤体瓦斯解吸特性影响的试验研究[J].岩石力学与工程学报,2011,30(3):547-555.ZHAO Dong,FENG Zengchao,ZHAO Yangsheng.Experimental study of effects of high pressure water injection on desorption characteristic of coal bed methane[J].Chinese Journal of rock Mechanics and Engineering,2011,30(3):547-555.
[28]AIREY E M.Gas emission from broken coal:An experimental and theoretical investigation[J].International Journal of Rock Mechanics and Mining Sciences,1968(5):475-494.
[29]魏建平,秦恒洁,王登科,等.含瓦斯煤渗透率动态演化模型[J].煤炭学报,2015,40(7):1555-1561.WEI Jianping,QIN Hengjie,WANG Dengke,et al.Dynamic permeability model for coal containing gas[J].Journal of China Coal Society,2015,40(7):1555-1561.
[30]SAMI S,DAVIS P K,SMITH J G,et al.Electoosmostically enhanced dewatering/deliquoring of fine-partical coal[R].U.S.Department of Energy,1990.
[31]LI S X.Experimental studies of electrokinetic phenomena in brinesaturated porous materials[D].University of Massachusetts Amherst,1996:36-30.
[32]PODDER J,MAJUMDER S.A study on thermal and electrical characterization of Barapukuria coal of northwestern Bangladesh[J].Thermochimica Acta,2001(372):113-118.
[33]CROSDALE P J,BEAMISH B B,VALIX M.Coalbed methane sorption related to coal composition[J].International Journal of Coal Geology,1998,35(1-4):147-158.
[2]孟召平,刘翠丽,纪懿明.煤层气/页岩气开发地质条件及其对比分析[J].煤炭学报,2013,38(5):728-736.MENG Zhaoping,LIU Cuili,JI Yiming.Geological conditions of coalbed methane and shale gas exploitation and their comparison analysis[J].Journal of China Coal Society,2013,38(5):728-736.
[3]MASSZI D.Cavity stress-relief method for recovering methane from coal seams[J].Rocky Mountain Association of Geologists,1991:149-154.
[4]冯杰,刘杰修,陈杰.洗煤厂精煤仓瓦斯燃烧浅析[J].煤矿安全,2006,37(3):52-53.FENG Jie,LIU Jiexiu,CHEN Jie.The analysis of gas buring in bunker of coal preparatoin plant[J].Coal Mine Safety,2006,37(3):52-53.
[5]侯振坤,杨春和,王磊,等.大尺寸真三轴页岩水平井水力压裂物理模拟试验与裂缝延伸规律分析[J].岩土力学,2016,37(2):407-414.HOU Zhenkun,YANG Chunhe,WANG Lei,et al.Hydraulic fracture propagation of shale horizontal well by large-scale true triaxial physical simulation test[J].Rock and Soil Mechanics,2016,37(2):407-414.
[6]ZHANG Jingcheng.Numerical simulation of hydraulic fracturing coalbed methane reservoir[J].Fuel,2014,136:57-61.
[7]LIN Baiquan,LI He,YUAN Desheng,et al.Development and application of an efficient gas extraction model for low-rank high-gas coal beds[J].International Journal of Coal Science&Technology,2015,2(1):76-83.
[8]穆朝民,王海露,黄文尧,等.高瓦斯低透气性煤体定向聚能爆破增透机制[J].岩土力学,2013,34(9):2496-2500.MU Chaomin,WANG Hailu,HUANG Wenyao,et al.Increasing permeability mechanism using directional cumulative blasting in coal seams with high concentration of gas and low permeability[J].Rock and Soil Mechanics,2013,34(9):2496-2500.
[9]KUMAR H,LESTER E,KINGMAN S,et al.Inducing fractures and increasing cleat apertures in a bituminous coal under isotropic stress via application of microwave energy[J].International Journal of Coal Geology,2011(88):75-82.
[10]赵阳升,杨栋,胡耀青,等.低渗透煤储层煤层气开采有效技术途径的研究[J].煤炭学报,2001,26(5):455-458.ZHAO Yangsheng,YANG Dong,HU Yaoqing,et al.Study on the effective technology way for mining methane in low permeability coal seamseam[J].Journal of China Coal Society,2001,26(5):455-458.
[11]卢义玉,丁红,葛兆龙,等.空化水射流热效应影响煤体渗透率试验研究[J].岩土力学,2014,35(5):1247-1254.LU Yiyu,DING Hong,GE Zhaolong,et al.Experiment study of effect of coal permeability under thermal effect of cavitation water jets[J].Rock and Soil Mechanics,2014,35(5):1247-1254.
[12]李志强,王登科,宋党育.新扩散模型下温度对煤粒瓦斯动态扩散系数的影响[J].煤炭学报,2015,40(5):1055-1064.LI Zhiqiang,WANG Dengke,SONG Dangyu.Influence of temperature on dynamic diffusion coefficient of CH4into coal particles by new diffusion model[J].Journal of China Coal Society,2015,40(5):1055-1064.
[13]SHI J Q,MAZUMDER S,WOLF K H,et al.Competitive methane desorption by supercritical CO2injection in coa[J].Transport in Porous Medial,2008(75):35-54.
[14]易俊,鲜学福,姜永东,等.煤储层瓦斯激励开采技术及其适应性[J].中国矿业,2005,14(12):26-29.YI Jun,XIAN Xuefu,JIANG Yongdong,et al.The adaptability study and technologies of prompting exploitation in coal-bed methane seams[J].China Mining Magazine,2005,14(12):26-29.
[15]FAIZ M,SAGHAF A,SHERWOOD N,et al.The influence of petrological properties and burial history on coal seam methane reservoir characterisation,Sydney Basin,Australia[J].International Journal of Coal Geology,2007(70):193-208.
[16]姜永东,熊令,阳兴洋,等.声场促进煤中甲烷解吸的机理研究[J].煤炭学报,2010,35(10):1649-1653.JIANG Yongdong,XIONG Ling,YANG Xingyang,et al.Mechanism research on sound field promoting the coal bed methane desorption[J].Journal of China Coal Society,2010,35(10):1649-1653.
[17]何学秋,张力.外加电磁场对瓦斯吸附解吸的影响规律及作用机理的研究[J].煤炭学报,2000,26(6):614-618.HE Xueqiu,ZHANG Li.Study on the effects of electromagnetic fields on gas adsorption and emission and its mechanism[J].Journal of China Coal Society,2000,26(6):614-618.
[18]康天合.一种电化学强化煤瓦斯解吸渗流的方法[P].中国专利:ZL201110130935.8,2013-05-08.
[19]GUO J,KANG T,KANG J,et al.Accelerating methane desorption in lump anthracite modified by electrochemical treatment[J].International Journal of Coal Geology,2014,131:392-399.
[20]LALVANI S,PATO M,COUGHLIN R W.Sulphur removal from coal by electrolysis[J].Fuel,1983(62):427-437.
[21]LOCKHART N C.Electra-osmotic dewatering of coal froth flotation concentrates[J].Fuel,1982(61):780-781.
[22]AMBA S A,CHILINGAR G V,BEESON C M.Use of direct electrical current for increasing the flow rate of reservoir fluids during petroleum recovery[J].Journal of Canadian Petroleum Technology,1964,3(1):8-14.
[23]CHILINGAR G V,ENASSIR A,STEVENS R G.Effect of direct electrical current on permeability of sandstone cores[J].Journal of Petroleum Technology,1970,22(7):830-836.
[24]FUERSTENAU D W,ROSENBAUM J M,YOU Y S.Electrokinetic behavior of coal[J].Energy and Fuels,1987,2(3):241-245.
[25]陈宗淇.胶体与界面化学[M].北京:高等教育出版社,2001.
[26]张国华,梁冰,毕业武.水锁对含瓦斯煤体的瓦斯解吸的影响[J].煤炭学报,2012,37(2):253-258.ZHANG Guohua,LIANG Bing,BI Yewu.Impact of water lock on gas desorption of coal with gas[J].Journal of China Coal Society,2012,37(2):253-258.
[27]赵东,冯增朝,赵阳升.高压注水对煤体瓦斯解吸特性影响的试验研究[J].岩石力学与工程学报,2011,30(3):547-555.ZHAO Dong,FENG Zengchao,ZHAO Yangsheng.Experimental study of effects of high pressure water injection on desorption characteristic of coal bed methane[J].Chinese Journal of rock Mechanics and Engineering,2011,30(3):547-555.
[28]AIREY E M.Gas emission from broken coal:An experimental and theoretical investigation[J].International Journal of Rock Mechanics and Mining Sciences,1968(5):475-494.
[29]魏建平,秦恒洁,王登科,等.含瓦斯煤渗透率动态演化模型[J].煤炭学报,2015,40(7):1555-1561.WEI Jianping,QIN Hengjie,WANG Dengke,et al.Dynamic permeability model for coal containing gas[J].Journal of China Coal Society,2015,40(7):1555-1561.
[30]SAMI S,DAVIS P K,SMITH J G,et al.Electoosmostically enhanced dewatering/deliquoring of fine-partical coal[R].U.S.Department of Energy,1990.
[31]LI S X.Experimental studies of electrokinetic phenomena in brinesaturated porous materials[D].University of Massachusetts Amherst,1996:36-30.
[32]PODDER J,MAJUMDER S.A study on thermal and electrical characterization of Barapukuria coal of northwestern Bangladesh[J].Thermochimica Acta,2001(372):113-118.
[33]CROSDALE P J,BEAMISH B B,VALIX M.Coalbed methane sorption related to coal composition[J].International Journal of Coal Geology,1998,35(1-4):147-158.