Fibrous Ion Exchanger as a Carrier of the Fe-EDTA Catalyst for H_2S Emission Control

摘要

The paper deals with a method of hydrogen sulphide removal from the air by its selective catalytic oxidation with the use of Fe-EDTA complex. The techniques based on this catalytic system are briefly described and discussed in many scientific papers. Except of many advantages the system has one very important drawback. The catalyst is active in strong alkaline environment which causes serious corrosivity problems. It was shown that the problem could be solved with the help of Fiban fibrous ion exchangers as carriers of the catalyst. The base of these materials is fibrous ion exchanger with Fe(Ⅲ)-EDTA complex immobilized on their functional groups. The role of fibrous package is improving the mass-transfer between the gas and liquid, buffering the pH of absorbing solution and, probably, catalyzing the reactions of oxidation of sulphur and iron ions. The data presented show that the filtering layers with anion exchange package are much more active in the catalytic processes of hydrogen sulphide removal than cation exchanger and inert materials. The main parameters affecting the process of catalytic oxidation are: concentration of hydrogen sulphide in the air, relative humidity of the purified air and the process time. It was shown that application of the Fe(Ⅲ)-EDTA/Fiban S system, under appropriate conditions, leaded to nearly complete conversion of H_2S to elemental sulphur.