硫酸铜浸渍球形活性炭的制备及脱硫性能

Preparation of spherical activated carbon impregnated with copper sulfate and its performance on desulfurization

将沥青基球形活性炭浸渍在一定浓度的CuSO_(4)溶液中,制备了一种高性能球形活性炭脱硫剂,研究了浸渍活性炭的脱硫性能及浸渍的最佳条件;利用SEM、N_(2)吸附-脱附、XPS、TG、XRD等分析方法对脱硫前后的活性炭进行了表征。实验结果表明,在CuSO_(4)含量为20%(w)、浸渍时间为48 h的条件下制备的浸渍活性炭脱硫性能最佳,穿透时间达212 min,穿透硫容达97.5 mg/mL,是初始活性炭的70倍;CuSO_(4)可以浸入活性炭的微孔和中大孔,但中大孔内的CuSO_(4)在脱硫过程中没有任何作用;浸渍活性炭的脱硫产物主要是单质硫、硫酸和亚硫酸,脱硫产物堵塞孔口或沉积在孔隙内会阻碍H_(2)S进入孔隙与活性位结合,使反应停止。浸渍剂不同活性炭的脱硫性能有较大差异,表明不同浸渍剂脱除H_(2)S的机理和转化H_(2)S的途径可能不同。

A high-performance spherical activated carbon desulfurizer was prepared by immersing pitch-based spherical activated carbon(SAC)with a certain concentration of CuSO_(4) solution.The desulfurization performance of impregnated activated carbon(IAC)and the optimal conditions of impregnation were studied.The activated carbon samples before and after desulfurization were characterized by SEM,N_(2) adsorption-desorption,XPS,TG,and XRD.The results indicate that SAC impregnated with 20%(w)CuSO_(4) solution and soaked for 48 h shows the best desulfurization performance,with breakthrough time of 212 min and breakthrough capacity of 97.5 mg/mL,which is 70 times as much as that of unmodified SAC.CuSO_(4) can be immersed into the microspores and medium-large pores of activated carbon,while CuSO_(4) in the medium-large pores has no contribution to desulfurization.The desulfurization products after using IAC are mainly elemental sulfur,sulfuric acid and sulfurous acid.The desulfurization products would block the pores or deposit in the pores,which will prevent H_(2)S from entering the pores and combining with the active sites,eventually stop the reaction.IAC containing different impregnants exhibits quite different desulfurization performance,and different impregnants may have different H_(2)S removal and conversion mechanisms.