Adsorption of low-concentration H2S on manganese dioxide-loaded activated carbon

摘要

Manganese dioxide-loaded activated carbon (AC) absorbents (MnO2/AC) were prepared and characterized by XRD, N-2 adsorption-desorption, BET, and SEM. A mixture of H2S and N-2 was used to evaluate the performance of absorbents in a fixed adsorption bed for H2S removal. Results show that the specific surface area decreased from 580.4 to 390.9 m(2) g(-1) with modification of manganese dioxide and the topography changed significantly. A suitable H2S removal activity was obtained with a manganese dioxide-to-AC ratio of 1: 1, drying temperature of 393 K, and drying time of 24 h. At the adsorption temperature of 313 K and a flow rate of 20 ml min(-1), the H2S breakthrough capacity of 110.7 mg g(-1) was observed. Comparing with the unmodified AC, H2S breakthrough capacity increased by 96.9 mg g(-1). The kinetics of adsorptive removal of H2S over the MnO2/AC adsorbent followed the Bangham model, ln 0.1181/0.1181-q = 3.002t(1.352).