【摘要】 活性炭微球是一种储存及净化天然气的新型碳材料.采用高精度的重力分析仪(IGA003,HIDEN)对天然气主要成分CH4和CO2杂质在活性炭微球材料内的扩散性质进行了研究.运用Fick扩散模型关联得到了CH4及CO2在活性炭微球内的扩散系数.研究结果表明,CH4与CO2在活性炭微球内的扩散属于晶体扩散,二者的扩散系数处于10-13m2·s-1数量级上.同时,CH4与CO2在介孔活性炭微球内的扩散速率均随着温度的增加而增加,随着体系平衡压力的增加而减小,而且CH4的扩散速率要略大于CO2的扩散速率.研究结果可用于活性炭微球吸附剂应用中传质性质的计算.更多还原

【Abstract】 Activated meso-carbon microbeads (a-MCMBs) as a kind of new carbon materials can store and purify natural gas.The diffusion of methane and carbon dioxide in a-MCMB prepared by the authors, was investigated by using the intelligent gravimetric analyzer apparatus (IGA-003, HIDEN) at 298 K and 258 K.The diffusion coefficients of methane and carbon dioxide were correlated in terms of the Fick diffusion model.The results indicated that the diffusion of methane and carbon dioxide in a-MCMB was intra-crystalline diffusion and the diffusion coefficients were of the order of magnitude 10~ -13 m~2·s~ -1.Moreover, the diffusion coefficients of methane and carbon dioxide in a-MCMB all increased with temperature and decreased with pressure.In addition, the diffusion coefficients of methane were larger than those of carbon dioxide in a-MCMB at the same temperature and pressure.This conclusion is useful in studying the mass transfer process in the applications of a-MCMB as the adsorbent.更多还原