97/05071 Development of advanced sorbents for hot gas desulfurization: Abbasian, J. et al. Proc. Annu. Int. Pittsburgh Coal Conf., 1996, 13, (1), 602–607

Abstract

Integrated Gasification Combined-Cycle (IGCC) processes are among the leading contenders for the production of electricity from coal. Coal gas desulfurization to sufficiently low levels at elevated temperatures (T > 350 C) is now recognized as crucial to efficient and economic coal utilization in advanced IGCC processes. The implementation of hot coal gas desulfurization relies heavily on the development of regenerable sorbent materials which can efficiently reduce H{sub 2}S from several thousand ppmv levels down to a few ppmv over many cycles of sulfidation/regeneration. Zinc-based sorbents, such as zinc titanate, are currently the leading candidate sorbents, however, they have been shown to suffer from zinc volatilization at elevated temperatures leading to sorbent deterioration, increasing sorbent replacement costs, and the overall cost of hot gas cleanup. This paper discusses the results obtained in an ongoing investigation geared towards developing advanced mixed-metal oxide sorbents for desulfurization of coal-derived fuel gases in the temperature range of 350 to 550 C. The paper focuses on the study related to the development of durable sorbents and addresses thermodynamic considerations, sulfidation kinetics, regenerability, and long term durability of a number of novel sorbents.