课题组在前期研究工作的基础上,以废弃生物质花椒枝为原料,采用水热辅助促进H3PO4深度渗透活化,以制备具高微孔率及甲苯吸附性能的废弃生物质活性炭。研究发现,在水热预处理辅助H3PO4活化法制备生物质基活性炭中,水热温度可有效调控所制得生物质活性炭的孔道结构。活性炭比表面积、微孔含量和孔容随辅助水热温度的升高而显著增加,180 °C水热辅助活化制得的生物质活性炭的比表面积可达1290.9 m2/g,微孔占比高达63.35 %,微孔孔容达0.56 cm3/g。同时,研究证实,微孔对甲苯的吸附起决定性作用,微孔含量及微孔孔容的增大为甲苯的吸附提供了有利条件,制得活性炭的甲苯吸附量高达532.89 mg/g。此外,制备的废弃生物质活性炭材料均表现出良好的可再生性能。
Lin Xie (谢琳), Yi Meng, Qiren Wang, Guizhi Zhang, Hongmei Xie*, Guilin Zhou*. Zanthoxylum bungeanum branches activated carbons with rich micropore structure prepared by low temperature H3PO4 hydrothermal pretreatment method for toluene adsorption [J]. Diamond and Related Materials, 2022, 130: 109474. (https://doi.org/10.1016/j.diamond.2022.109474)
Based on the previous research work, the waste biomass activated carbons with high porosity and toluene adsorption performance were prepared from waste biomass Zanthoxylum bungeanum branches by hydrothermal assisted to promote H3PO4 deep penetration and activation. The toluene adsorption capacity increased with the rising of hydrothermal pretreatment temperature. When hydrothermal pretreatment temperature increased from 100 °C to 180 °C, the specific surface area of the prepared activated carbons increased from 956.0 to 1290.9 m2/g. And the micropore ratio of the prepared activated carbons markedly increased from 30.55% to 63.35 %. Interestingly, the linear fitting results of toluene adsorption capacity and pore structures showed that the micropore volume and toluene adsorption capacity had maximum correlation. The micropore volume increased from 0.40 to 0.56 cm3/g, and the toluene adsorption capacity increased from 309.80 to 532.89 mg/g with the increase of hydrothermal pretreatment temperature. Toluene adsorption results were fitted by quasi-first, quasi-second, and Bangham models to analyse the toluene diffusion mechanism. The toluene adsorption process of all studied samples conformed to the Bangham kinetic model, which indicated that the diffusion mechanism of toluene adsorption process mainly followed intra-particle diffusion. Besides, the toluene adsorption capacity of the prepared biomass activated carbons could be regenerated at relatively low thermal desorption temperature (≤ 150 °C).