玉米芯活性炭的制备及储气性能

天然气、氢气、二氧化碳等气体的吸附研究在洁净气体代油燃料的强化存储、温室气体减排、大气治理等方面具有重要意义，其重点内容是高效吸附材料的开发．以玉米芯为原料，采用磷酸活化法制备了含有较高中孔比例的活性炭，其比表面积达到1,610,m2/g，孔容为1.72,cm3/g，中孔体积达到1.14,cm3/g，占孔容的66％．测定了H2、N2、CH4和 CO2在该吸附剂上的吸附等温线．在0.4,MPa 时，CO2对 CH4的选择性达到2.76，对 N2的选择性达到7.63，对 H2的选择性达到42.31，具有良好的分离应用前景．测定了水存在条件下甲烷在该活性炭上的吸附等温线，由于孔尺寸有利于甲烷水合物的生成，因此甲烷吸入量较在干燥吸附剂上提高了82％．根据克劳修斯-克拉佩龙方程计算了甲烷水合物的生成焓为-64.37,kJ/mol．

Preparation of Corncob Activated Carbon and Its Gas Storage

The research of gas adsorption is extremely important in gas storage, the emission reduction of greenhouse gas, the control of atmospheric pollution and so on. Corncob was used as raw material to prepare activated carbon with a high content of mesopores using phosphoric acid activation. Its specific surface area reached 1,610 m2/g, and the pore volume was 1.72 cm3/g, with the pore volume of mesopores reaching 1.14 cm3/g, accounting for 66%of the total pore volume. The adsorption isotherms of H2, N2, CH4 and CO2 were measured, respectively, which indicated that there were obvious differences in adsorption capacity between CO2 and other gases. The adsorption selectivity be-tween CO2 and CH4,N2,H2 at 0.4 MPa was 2.76,7.63,42.31, respectively. Therefore, this activated carbon is beneficial to carbon dioxide separation. In addition, the sorption isotherms of CH4 on this activated carbon were stud-ied in the presence of water. As pore size was conducive to the formation of methane hydrate, the amount of methane sorption increased by 82% compared with that of dried sample. The enthalpy of formation of methane hydrate was calculated to be-64.37 kJ/mol by Clausius-Clapeyron equation.