APPLICATION OF METAL SULFATES FOR REMOVING HYDROGEN SULFIDE FROM GAS STREAMS

摘要

Reactive absorption of hydrogen sulfide into aqueous ferric sulfate solution is a direct process for H2S removal and Sulfur recovery. A distinct advantage of the process is that the reaction of H2S with is so rapid and complete that there remains no danger of discharging toxic waste gas. In this study, the reactive absorption of hydrogen sulfide into aqueous ferric sulfate solution has been studied and design calculations for equipments have been done. Subsequently, diameter and height of absorption tower are 3.6 ft and 12.5 ft and pressure drop is 0.35 inH2O/ft packing, oxidizer's height and diameter are 2.45 ft and 4.9 ft, for known gas flow rate (100000 kg/day sour gas, contain≈4% v/v H2S). Effective operation parameters on this process considered. Results show that low temperature and high pressure are suitable for absorption reaction. Variation of hydrogen sulfide concentration and Fe3+ concentration with time in absorption reaction shown that the reaction of ferric sulfate and hydrogen sulfide is first order with respect to the both reactant. At low Fe2(SO4)3 concentration the absorption rate of H2S increase with increasing the Fe2(SO4)3 concentration. At higher concentration, a decrease in the absorption rate was found as shown in figure 2. At higher concentration of Fe2(SO4)3, the ionic strength and viscosity of solution increase remarkably resulting in a decrease of solubility, diffusivity and hence absorption rate.^