Properties Of Hydrogen Sulfide Removal And Regeneration Of The New Iron-based Composite System

The harm caused by the odour on the human body is in the second place after the noisein the seven environmental hazards,. H₂S is one of the main component of the odorousgases, not only will cause corrosion of equipment and pipelines, catalyst poisoning, butalso can endanger human health, even life-threatening. The desulfurization technologiesare mainly dry, wet and biological method, but mostly there are disadvantages, such ashigh operating costs, low purification, complexprocess. Therefore, the improvement anddevelopment of the desulfurization technologies have become the focus of attention andthe problems to be solved.In this paper, the properties of wet desulfurization and regeneration were firstlyexamined in the three kinds composite systems of Fe（Ⅲ）/Fe（Ⅱ）, Fe（Ⅲ）/Cu（Ⅱ） andFe（Ⅲ）/Cu（Ⅱ）/EDTA, and then the mechanism of desulfurization and regeneration werepreliminarily studied, next the activated carbon fibers （ACF） were selected as carrier, theFe（Ⅲ）/Cu（Ⅱ）/EDTA-ACF composite materials were prepared by the volume impregnationmethod. The composites were characterized by the BET, SEM and other means, and thewet desulfurization and regeneration properties were studied. The results show that theFe（Ⅲ）/Fe（Ⅱ） system was applicable for removing the high concentrations of H₂S gas, theremoval efficiency was from35%to75%for the4000ppm of H₂S gas, but theeffectively absorption time was short, and the regeneration efficiency was only10%⁴0%; the Fe（Ⅲ）/Cu（Ⅱ） system was applicable for removing the low concentrations of H₂Sgas, when the ratio of Fe（Ⅲ）/Cu（Ⅱ） was4:1, the removal efficiency was from75%to90%for the800ppm of H₂S gas, and the regeneration efficiency was15%⁶0%; the Fe（Ⅲ）/Cu（Ⅱ）/EDTA system was applicable for removing the1000⁴000ppm of H₂S gas,when the ratio of Fe（Ⅲ）/Cu（Ⅱ）/EDTA was4:1:1, the removal efficiency was from92%to99%, and the regeneration efficiency was up to70%or more. The SEM results showthat the active substance were more evenly distributed on the ACF surface, when the ratioof Fe（Ⅲ）/Cu（Ⅱ）/EDTA was4:1:1and the pretreatment time was4h. The specific surfacearea （BET） of the composites had increased than the original ACF, this effectivelyextended the residence time of H₂S in the carrier of ACF. The removal efficiency of H₂Swas better in the Fe（Ⅲ）/Cu（Ⅱ）/EDTA-ACF composite system, the desulfurization ratewas up to more than90%.