Co-Disposal of Dry FGD By-product with Coal Gasification Ash and Inorganic Brines

Abstract

A B S T R A C TThere is a growing pressure from the environmental authorities and public bodies to reduce anthropogenic pollution. Stringent environmental legislation is being implemented for industries around the world, even more so for coal consuming industries. Control of gaseous emissions is one of the areas that are receiving considerable attention towards sustainable development. Coal combustion in coal-fired power utilities emits SO x to the atmosphere. Dry flue gas desulphurisation (FGD) is a well known technology often used to mitigate sulphur emissions in coal-fired power utilities. It traditionally uses lime to neutralise SO x , and forms a mixture of anhydrite (CaSO 4 ), and calcium sulphite (CaSO 3 ). Several options are reported in literature for the utilisation and management of FGD by-product. However, this paper reports on the preliminary findings of the option where excess FGD by-product is co-disposed with gasification/bottom ash and brines. The study examined the influence of moisture content, chemistry of the liquid medium, and ratio of FGD by-product to gasification ash on the physical and chemical properties of the cured mix. The results demonstrate that the chemistry of raw materials influences the final properties of the resultant product.