Application of Mesoporous Silica as Catalyst Support in Sulfur Dioxide Removal: Metal and Amine Sorbent Modifications

Abstract

Emission of hazardous SO2 into the atmosphere due to the burning of fossil fuels in various industries is detrimental not only to the environment but also to human beings. Various mitigation techniques have been implemented to overcome this problem, with flue gas desulfurization (FGD) method being the most commonly used. Dry FGD does not typically perform as good as wet method and requires new type of sorbent to be tested. Mesoporous silica (MS), a sorbent with porosity in the range of 2-50 nm is considered as attractive alternative due to its high specific surface area, ordered pore structures and wide array of morphologies. Due to relatively weak interaction between MS and SO2 adsorbate during dry FGD process, additives are introduced to overcome this problem. These MS are modified with basic additives which are deemed more favorable for SO2 adsorption. Metal and amine-based additives are commonly employed where the latter are reported to obtain higher adsorption capacity. Increasing additive loading is beneficial up to an optimal value depending on the types of additives.