改性蓝藻基活性炭的制备及常压下对CO_2的捕集性能

Preparation and Evaluation of Modified Cyanobacteria-derived Activated Carbon for CO_2 Adsorption

以蓝藻为前驱体,采用KOH活化法制备了一系列蓝藻基活性炭;探讨了活化时间、活化温度以及碱炭比等活化参数对其孔结构的影响;进一步分别用HNO_3,HPO_4和NH_3·H_2O进行二次改性,制备了N或P原子掺杂的改性蓝藻基活性炭,研究了不同改性活性炭在25℃和1.01×10~5Pa条件下对CO_2的吸附捕集性能.结果表明,KOH活化的最佳活化时间为2 h,活化温度800℃,碱炭比为2.样品ACK-2-8在该条件下对CO_2的吸附量达到3.85 mmol/g.二次改性后的样品ACK-2-8-1,ACK-2-8-2和ACK-2-8-3对CO_2的吸附量分别高达4.41,3.97和4.63 mmol/g.N的掺杂有利于CO_2的吸附捕集.多批次重复再生实验结果表明,本材料对CO_2吸附再生具有较稳定的重复利用性.

A series of porous carbon sorbents obtained through carbonization and KOH activation of the abundant waste materials cyanobacteria or further modified by HNO_3,HPO_4 or NH_3·H_2O was utilized for CO_2 adsorption.During the optimal activation parameters experiments,the activation time,activation temperature and the KOH/C mass ratio were 2 h,800℃and 2,respectively.Sample ACK-2-8 was capable of uptake CO_2 capacities near 3.85 mmol/g at 25℃and 1.01×10~5 Pa.At the same time,the secondary modification samples of ACK-2-8-1,ACK-2-8-2 and ACK-2-8-3 exhibited CO_2uptake capacities up to 4.41,3.97 and 4.63 mmol/g in turn.It was notable that the N-doping enhanced CO_2uptake from samples ACK-2-8-1 or ACK-2-8-3.It could be reused for five batches of continuous operation without a significant loss of CO_2uptake capacity and thus has a great potential of real-world applications.