CAJ | 학술논문

生物甲烷路线在CO2减排和节能方面有很大的应用前景。而对生物沼气的分离是此路线的一个关键问题，特别是在60℃和0.1 MPa下。巨正则Monte Carlo（GCMC）和平衡分子动力学（EMD）的分子模拟方法研究CO2和CH4在不同管径的碳纳米管（CNT）中的吸附和扩散，可以从分子层面研究生物沼气的分离机理。分别计算了CO2/CH4二元混合物吸附量、吸附选择性、自扩散系数和渗透选择性等参数。模拟结果表明：由于碳管的受限空间和CO2与碳纳米管壁面分子之间强相互作用，导致二元等物质的量的混合物CO2/CH4的吸附量和扩散系数的差异。CO2的吸附量和自扩散系数都比CH4的大。渗透选择性在碳管管径达到最接近1 nm时达到最大值，此时混合物的分离过程是吸附控制，而非扩散控制。
생물갑완로선재CO2감배화절능방면유흔대적응용전경。이대생물소기적분리시차로선적일개관건문제，특별시재60℃화0.1 MPa하。거정칙Monte Carlo（GCMC）화평형분자동역학（EMD）적분자모의방법연구CO2화CH4재불동관경적탄납미관（CNT）중적흡부화확산，가이종분자층면연구생물소기적분리궤리。분별계산료CO2/CH4이원혼합물흡부량、흡부선택성、자확산계수화삼투선택성등삼수。모의결과표명：유우탄관적수한공간화CO2여탄납미관벽면분자지간강상호작용，도치이원등물질적량적혼합물CO2/CH4적흡부량화확산계수적차이。CO2적흡부량화자확산계수도비CH4적대。삼투선택성재탄관관경체도최접근1 nm시체도최대치，차시혼합물적분리과정시흡부공제，이비확산공제。
Biomethane route has large potential in emission reduction and energy saving. One of the key issues is separation of biogas in operating conditions of 333 K and 0.1 MPa. Grand canonical Monte Carlo (GCMC) and equilibrium molecular dynamics simulations (EMD) were used to compute adsorption loadings and self-diffusivities of CH4/CO2 at various diameters of carbon nanotube (CNT) bundles. Single component and equimolar gases were simulated. CO2 always had larger adsorption loading and diffusion coefficient than CH4 as the result of relatively strong interaction between CO2 molecules and tube walls, due to the confined capacity. The permselectivity reached a maximum in closely 1 nm, and under such conditions the separation process was controlled by adsorption rather than diffusion.