竹质中孔活性炭甲烷吸附分离及存储性能研究

实验以毛竹废料为原料采用磷酸活化法制备了既有较高比表面积又含有大量中孔的活性炭,测定了干燥活性炭的CH4、CO2、N2及O2吸附等温线及预吸附水活性炭的CH4吸附等温线,以考察其对甲烷的吸附分离及存储性能。实验结果表明:干燥活性炭对甲烷的吸附性能与其它气体存在较大差异,可应用于吸附分离CH4/CO2、CH4/N2、CH4/O2及CH4/空气气体混合物中的甲烷气体。在275K条件下(水炭比为2.43),预吸附水的活性炭在3.49MPa下的甲烷储量达10.58mmol/g,是同温同压条件下干燥活性炭甲烷储量的1.72倍,并远远大于同温同压条件下其它预吸附水活性炭的甲烷储量,可在较低压力条件下(<4MPa)实现甲烷的高效存储。

The application study of mesopore-enriched bamboo activated carbon in methane adsorptive separation and storage

The activated carbons with high specific surface and considerable mesopores were prepared from bamboo waste with phosphoric acid activation. In order to determine the properties of the prepared activated carbons for methane adsorptive separation and storage, the adsorption isotherms of CH4, CO2, N2 and O2 on dry carbons and the adsorption isotherms of CH4 on the carbons with preadsorbed water were measured. The considerable difference in the adsorption capacity between CH4 and the other gases was observed on dry carbon, which is of interest for the adsorptive separation/purification of CH4 from its mixtures with CO2 or N2 or O2 or both N2 and O2. As high as 10.58mmol methane could be stored in one gram prepared activated carbon at 275 K and 3.49MPa in the presence of 2.43 times water, which was 1.72 times that in the prepared dry carbons without the presence of water and even much more than that in the other carbons with preadsorbed water at the same temperature and pressure. These bamboo activated carbons can be used for methane storage due to their high methane storage capacity at a lower pressure (<4MPa).