Simultaneous removal of hydrogen sulfide and mercury from simulated syngas by iron-based sorbents

摘要

Two iron oxide based sorbents, TG-1 and TG-F, with high desulfurization efficiency, were selected for simultaneous removal of H_2S and Hg from simulated syngas. Our evaluation tests were carried out using a fixed bed reactor at different temperatures and in ambient atmosphere. The different activities for the simultaneous removal of H_2S and Hg between TG-1 and TG-F or TG-1 -S (denoted as such after uptake of H_2S) were compared. The results show that the two iron oxide based sorbents can capture Hg effectively from simulated syngas. The preferred temperature for Hg removal using the TG-F and TG-1 sorbents are 60-120 ℃ and 100-140 ℃, respectively. The Hg absorption capacity of TG-1 is higher than that of TG-F under the same conditions. CO and H_2 in the feed gas have negligible effect on the efficiency of Hg removal. H_2S is favoured for the removal of Hg over iron-based sorbents and it was found that the influence of H_2S concentration on the Hg capacity of the TG-1 and TG-F sorbents are different. It is found that the main active components of the two sorbents during the reaction are different. After several desulfurization cycles, the TG-l-S sorbent has a high efficiency for Hg removal from the simulated syngas.