Gas desulfurization

Common methods for dry desulfurization of gas include the iron oxide method, zinc oxide method, manganese oxide method, activated carbon method, and molecular sieve method. The operating conditions in urban coal-based gas plants are generally at normal temperature and pressure. Moreover, the desulfurization agents used in the normal-temperature iron oxide method are abundant, inexpensive, and easily available; therefore, this method is the most widely used for desulfurization in urban coal-based gas plants. When gas containing hydrogen sulfide passes through a desulfurization agent, hydrogen sulfide comes into contact with active iron oxide, resulting in the formation of iron sulfide and ferrous sulfide. The desulfurization agent containing these iron sulfides then comes into contact with oxygen in the air; under humid conditions, the iron sulfides are converted back into iron oxide and elemental sulfur, thereby enabling a process of both desulfurization and regeneration to proceed, until the surface of the iron oxide is largely covered by sulfur or other impurities and loses its activity. Reference: http://www.meijiaohua.com/ArticleContent.asp?id=12781