页岩气绝对吸附量转化新方法
|
摘要
为了弄清引起基于过剩吸附量的气-固超临界实验吸附等温线表现出极大值后下降现象的原因,在分子动力学原理的基础上,应用分子模拟方法,模拟了超临界甲烷在不同温度下0~50 MPa压力范围的分子密度,并结合单分子吸附理论对"过剩吸附量"和"绝对吸附量"进行了转换,并提出适用于临界前后大压力范围的转化方法。结果表明:分子模拟的密度结果与美国国家标准局(NIST)的数据一致,在甲烷超临界压力以下,"过剩吸附量"与"绝对吸附量"差异不大,但随着压力升高差异逐渐增大,在甲烷储层压力下,两者的差异可达到150%以上。该方法的转化具有较高精度,且突破了现有转化方法的低压条件限制。
In order to find out the reason why the adsorption isotherm obtained by gas-solid supercritical adsorption experiment based on the excess adsorption amount shows declining after the maximum value,the density of supercritical methane in the pressure range of 0 ~50 MPa at different temperature is obtained using molecular simulation based on the principle of molecular dynamics,the excess adsorption capacity is transformed into absolute adsorption capacity according to single molecular adsorption theory,and a new method for transforming the excess adsorption capacity into absolute adsorption capacity is put forward. It is shown that,the molecular simulation density results are in accordance with the data in National Institute of Standards and Technology( NIST); when pressure is lower than supercritical pressure,the difference between the excess adsorption capacity and absolute adsorption is not so much,but the difference increases with the increase of pressure,and it reaches to above 150% under reservoir pressure. This method has high precision and breaks through the restriction of low pressure condition of the existing transformation method.
In order to find out the reason why the adsorption isotherm obtained by gas-solid supercritical adsorption experiment based on the excess adsorption amount shows declining after the maximum value,the density of supercritical methane in the pressure range of 0 ~50 MPa at different temperature is obtained using molecular simulation based on the principle of molecular dynamics,the excess adsorption capacity is transformed into absolute adsorption capacity according to single molecular adsorption theory,and a new method for transforming the excess adsorption capacity into absolute adsorption capacity is put forward. It is shown that,the molecular simulation density results are in accordance with the data in National Institute of Standards and Technology( NIST); when pressure is lower than supercritical pressure,the difference between the excess adsorption capacity and absolute adsorption is not so much,but the difference increases with the increase of pressure,and it reaches to above 150% under reservoir pressure. This method has high precision and breaks through the restriction of low pressure condition of the existing transformation method.
引文
[1]何余生,李忠,奚红霞,等.气固吸附等温线的研究进展[J].离子交换与吸附,2004,20(4):376-381.HE Yusheng,LI Zhong,XI Hongxia,et al.Research process of gas-solid adsorption isotherms[J].Ion Exchange and Adsorption.2004,20(4):376-381.
[2]李武广,杨胜来,徐晶,等.考虑地层温度和压力的页岩吸附气含量计算新模型[J].天然气地球科学,2012,23(4):791-796.LI Wuguang,YANG Shenglai,XU Jing,et al.A new model for shale adsorptive gas amount under a certain geological conditions of temperature and pressure[J].Natural Gas Geoscience,2012,23(4):791-796.
[3]张志英,杨盛波.页岩气吸附解吸规律研究[J].实验力学,2012,27(4):492-496.ZHANG Zhiying,YANG Shengbo.On the adsorption and desorption trend of shale gas[J].Journal of Experimental Mechanics,2012,27(4):492-496.
[4]郭为,熊伟,高树生,等.页岩气等温吸附/解吸特征[J].中南大学学报(自然科学版),2013,44(7):2836-2840.GUO Wei,XIONG Wei,GAO Shusheng,et al.Isothermal adsorption/desorption characteristics of shalegas[J].Journal of Central South University(Science and Technology),2013,44(7):2836-2840.
[5]YANG R T.吸附法气体分离[M].王树森,曾美云,胡竞民,译.北京:化学工业出版社,1991.
[6]盛茂,李根生,陈立强,等.页岩气超临界吸附机理分析及等温吸附模型的建立[J].煤炭学报,2014,39(s1):179-183.SHENG Mao,LI Gensheng,CHEN Liqiang,et al.Mechanisms analysis of shale-gas supercritical adsorption and modeling of isorptionadsorption[J].Journal of China Coal Society2014,39(s1):179-183.
[7]周亚平,周理.超临界氢在活性炭上的吸附等温线研究[J].物理化学学报,1997,13(2):119-127.ZHOU Yaping,ZHOU Li.Study on the adsorption isotherms of supercritical hydrogen on activatedcarbon[J].Acta Physico-Chimica Sinica,1997,13(2):119-127.
[8]OZAWA Sentaro,KUSUMI Senchiro,OGINO Yoshibdda.Physical adsorption of gases at high pressure[J].Journal of Colloid&Interface Science,1976,56(1):83-91.
[9]DUBININ MM.The potential theory of adsorption of gases and vapors for adsorbents with energetically nonuniform surfaces[J].Chem Rev 1960,60(2):235-41.
[10]LI M,GU A,LU X,et al.Determination of the adsorbate density from supercritical gas adsorption equilibrium data[J].Carbon,2003,41(3):585-588.
[11]杨晓东,林文胜,郑青榕,等.超临界温度甲烷吸附的晶格理论及实验[J].上海交通大学学报,2003,37(7):11.YANG Xiaodong,LIN Wensheng,ZHENG Qingrong,et al.Lattice theory and experimental study of methane adsorption above the critical temperature[J].Jounal of Shanghai Jiao Tong University,2003,37(7):11.
[12]熊健,刘向君,梁利喜,等.页岩气超临界吸附的Dubibin-Astakhov改进模型[J].石油学报,2015,36(7):849-856.XIONG Jian,LIU Xiangjun,LIANG Lixi,et al.Improved Dubibin-Astakhov model for shale-gas supercritical adsorption[J].Acta Petrolei Sinaica,2015,36(7):849-856.
[13]孙艳,周理,苏伟,等.单分子层吸附机理对储氢材料研究的冲击[J].科学通报,2007,52(3):361-365.SUN Yan,ZHOU Li,SU Wei,et al.Impact of monolayer adsorption mechanism on hydrogen storage material[J].Chinese Science Bulletin.2007,52(3):361-365.
[14]周理.超临界吸附研究:疑惑、问题与分析[C].第四届全国氢能学术会议,2002.
[15]周理,周亚平,孙艳,等.超临界吸附及气体代油燃料技术研究进展[J].自然科学进展,2004,14(6):615-623.ZHOU Li,ZHOU Yaping,SUN Yan,et al.The research of supercritical adsorption and gas oil alternative fuel technology[J].Progress in Natural Science,2004,14(6):615-623.
[16]钟永林.超临界二氧化碳流体在岩石中吸附行为的分子模拟[D].青岛:中国石油大学(华东),2013.
[17]曹涛涛,宋之光,王思波,等.不同页岩及干酪根比表面积和孔隙结构的比较研究[J].中国科学:地球科学,2015,45(2):139-151.CAO Taotao,SONG Zhiguang,WANG Sibo,et al.A comparative study of the specific surface area and pore structure of different shales and theirkerogens[J].Science China:Earth Sciences,2015,45(2):139-151.
[2]李武广,杨胜来,徐晶,等.考虑地层温度和压力的页岩吸附气含量计算新模型[J].天然气地球科学,2012,23(4):791-796.LI Wuguang,YANG Shenglai,XU Jing,et al.A new model for shale adsorptive gas amount under a certain geological conditions of temperature and pressure[J].Natural Gas Geoscience,2012,23(4):791-796.
[3]张志英,杨盛波.页岩气吸附解吸规律研究[J].实验力学,2012,27(4):492-496.ZHANG Zhiying,YANG Shengbo.On the adsorption and desorption trend of shale gas[J].Journal of Experimental Mechanics,2012,27(4):492-496.
[4]郭为,熊伟,高树生,等.页岩气等温吸附/解吸特征[J].中南大学学报(自然科学版),2013,44(7):2836-2840.GUO Wei,XIONG Wei,GAO Shusheng,et al.Isothermal adsorption/desorption characteristics of shalegas[J].Journal of Central South University(Science and Technology),2013,44(7):2836-2840.
[5]YANG R T.吸附法气体分离[M].王树森,曾美云,胡竞民,译.北京:化学工业出版社,1991.
[6]盛茂,李根生,陈立强,等.页岩气超临界吸附机理分析及等温吸附模型的建立[J].煤炭学报,2014,39(s1):179-183.SHENG Mao,LI Gensheng,CHEN Liqiang,et al.Mechanisms analysis of shale-gas supercritical adsorption and modeling of isorptionadsorption[J].Journal of China Coal Society2014,39(s1):179-183.
[7]周亚平,周理.超临界氢在活性炭上的吸附等温线研究[J].物理化学学报,1997,13(2):119-127.ZHOU Yaping,ZHOU Li.Study on the adsorption isotherms of supercritical hydrogen on activatedcarbon[J].Acta Physico-Chimica Sinica,1997,13(2):119-127.
[8]OZAWA Sentaro,KUSUMI Senchiro,OGINO Yoshibdda.Physical adsorption of gases at high pressure[J].Journal of Colloid&Interface Science,1976,56(1):83-91.
[9]DUBININ MM.The potential theory of adsorption of gases and vapors for adsorbents with energetically nonuniform surfaces[J].Chem Rev 1960,60(2):235-41.
[10]LI M,GU A,LU X,et al.Determination of the adsorbate density from supercritical gas adsorption equilibrium data[J].Carbon,2003,41(3):585-588.
[11]杨晓东,林文胜,郑青榕,等.超临界温度甲烷吸附的晶格理论及实验[J].上海交通大学学报,2003,37(7):11.YANG Xiaodong,LIN Wensheng,ZHENG Qingrong,et al.Lattice theory and experimental study of methane adsorption above the critical temperature[J].Jounal of Shanghai Jiao Tong University,2003,37(7):11.
[12]熊健,刘向君,梁利喜,等.页岩气超临界吸附的Dubibin-Astakhov改进模型[J].石油学报,2015,36(7):849-856.XIONG Jian,LIU Xiangjun,LIANG Lixi,et al.Improved Dubibin-Astakhov model for shale-gas supercritical adsorption[J].Acta Petrolei Sinaica,2015,36(7):849-856.
[13]孙艳,周理,苏伟,等.单分子层吸附机理对储氢材料研究的冲击[J].科学通报,2007,52(3):361-365.SUN Yan,ZHOU Li,SU Wei,et al.Impact of monolayer adsorption mechanism on hydrogen storage material[J].Chinese Science Bulletin.2007,52(3):361-365.
[14]周理.超临界吸附研究:疑惑、问题与分析[C].第四届全国氢能学术会议,2002.
[15]周理,周亚平,孙艳,等.超临界吸附及气体代油燃料技术研究进展[J].自然科学进展,2004,14(6):615-623.ZHOU Li,ZHOU Yaping,SUN Yan,et al.The research of supercritical adsorption and gas oil alternative fuel technology[J].Progress in Natural Science,2004,14(6):615-623.
[16]钟永林.超临界二氧化碳流体在岩石中吸附行为的分子模拟[D].青岛:中国石油大学(华东),2013.
[17]曹涛涛,宋之光,王思波,等.不同页岩及干酪根比表面积和孔隙结构的比较研究[J].中国科学:地球科学,2015,45(2):139-151.CAO Taotao,SONG Zhiguang,WANG Sibo,et al.A comparative study of the specific surface area and pore structure of different shales and theirkerogens[J].Science China:Earth Sciences,2015,45(2):139-151.