CH4 Gas Extraction by CO2: Substitution in Clathrate Hydrate through Bimolecular Iteration  

作　　者：Xiao-Hui Yu Yuan Liu San-Ya Du Xu Zheng Jin-Long Zhu Hong-Wu Xu Jian-Zhong Zhang Shi-Yu Du Xiao-Cheng Zeng J.S.Francisco Chang-Qing Jin Yu-Sheng Zhao Hui Li 于晓辉;刘源;杜三亚;郑旭;朱金龙;徐洪武;张建中;都时禹;曾晓成;J.S.Francisco;靳常青;赵予生;李晖(National Lab for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190;LANSCE Division,Los Alamos National Laboratory,Los Alamos,New Mexico 87545,USA;Beijing Advanced Innovation Center for Soft Matter Science and Engineering,Beijing University of Chemical Technology,Beijing 100029;Department of Chemistry,University of Nebraska-Lincoln,Lincoln,Nebraska 68588,USA;Department of Physics,Southern University of Science and Technology(SUSTech),Shenzhen 518055;Center for High Pressure Science and Technology Advanced Research(HPSTAR),Beijing 100094;Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials,Ningbo Institute of Industrial Technology,Chinese Academy of Sciences,Ningbo 315201)

机构地区：[1]National Lab for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190 [2]LANSCE Division,Los Alamos National Laboratory,Los Alamos,New Mexico 87545,USA [3]Beijing Advanced Innovation Center for Soft Matter Science and Engineering,Beijing University of Chemical Technology,Beijing 100029 [4]Department of Chemistry,University of Nebraska-Lincoln,Lincoln,Nebraska 68588,USA [5]Department of Physics,Southern University of Science and Technology(SUSTech),Shenzhen 518055 [6]Center for High Pressure Science and Technology Advanced Research(HPSTAR),Beijing 100094 [7]Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials,Ningbo Institute of Industrial Technology,Chinese Academy of Sciences,Ningbo 315201

出　　处：《Chinese Physics Letters》2020年第4期140-144,共5页中国物理快报（英文版）

基　　金：Supported by the National Key R&D Program of China under Grant Nos 2016YFA0401503 and 2018YFA0305700;the National Natural Science Foundation of China under Grant Nos 11575288,11775011,21703006,21773005;the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016006.J.Zhu was supported by the National Thousand-Young-Talents Program and the National Science Associated Funding Grant U1530402;The experimental work has benefited from the use of the neutron source at Los Alamos Neutron Science Center(LANSCE),which is funded by the U.S.Department of Energy’s Office of Basic Energy Sciences.

摘　　要：Methane clathrate hydrate(MCH)is a promising energy resource,but controllable extraction of CH4 from MCH remains a challenge.Gradually replacing CH4 in MCH with CO2 is an attractive scheme,as it is cost efficient and mitigates the environmentally harmful effects of CO2 by sequestration.However,the practicable implementation of this method has not yet been achieved.In this study,using in situ neutron diffraction,we confirm that CH4 in the 51262 cages of bulk structure-I(si)MCH can be substituted by gaseous CO2 under high pressure and low temperature with a high substitution ratio(~44%)while conserving the structure of the hydrate framework.First-principles calculations indicate that CO2 binds more strongly to the 51262 cages than methane does,and that the diffusion barrier for CH4 is significantly lowered by an intermediate state in which one hydrate cage is doubly occupied by CH4 and CO2.Therefore,exchange of CO2 for CH4 in MCH is not only energetically favorable but also kinetically feasible.Experimental and theoretical studies of CH4/CO2 substitution elucidate a method to harness energy from these combustible ice resources.

关 键 词：SUBSTITUTION SUBSTITUTED ATTRACTIVE 

分 类 号：TQ221.11[化学工程—有机化工]