COPPER-BASED SORBENTS FOR HOT COAL GAS DESULFURIZATION SYSTEMS

摘要

High-temperature coal gas desulfurization has been recognized as essential in the development of emerging power generation technologies such as the Integrated Gasification Combined Cycle (IGCC), aiming to improve both the efficiency and environmental performance of power generation from coal. Hot gas desulfurization may be accomplished by using regenerable mixed metal oxides sorbents which can reduce the H_2S content of the coal gas to a few ppmv over many sulfidation/regeneration cycles.The focus of much of the current research on hot gas desulfurization has been on the use of zinc-based sorbents. Although these sorbents have been the subject of extensive pilot-scale and process development work, zinc-based sorbents have been shown to suffer from sulfate formation and zinc volatilization, leading to sorbent degradation over multicycle use, increasing sorbent replacement costs and the overall cost of hot gas desulfurization processes. Copper-based sorbents do not suffer from this problem, and when they are effectively stabilized against reduction, can offer superior desulfurization efficiencies, making them logical alternative candidates for hot coal gas desulfurization processes.