New Zno-Based Regenerable Sulfur Sorbents for Fluid-Bed/Transport Reactor Applications

• Published in: Industrial & engineering chemistry research Vol. 41; no. 23; pp. 5676 - 5685
• Main Authors: Slimane, Rachid B, Williams, Brett E
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.11.2002
• Subjects: Adsorbents; Air pollution caused by fuel industries; Applied sciences; Atmospheric pollution; Chemistry; Combustion and energy production; Energy; Energy. Thermal use of fuels; Exact sciences and technology; General and physical chemistry; Pollution; Pollution reduction; Prevention and purification methods; Stack gas and industrial effluent processing; Surface physical chemistry; Desulfurization; Hydrogen Sulfides; Transition metal Compounds; Sulfurization; Zinc Oxides; Inorganic adsorbent; Attrition; Titanium Oxides; Characterization; Gas solid adsorption; Regeneration; Sol gel process; Preparation; Physicochemical purification; Kinetics; Performance; Chemical reactivity; Flue gas purification; Breakthrough curve
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie011019t

A new sorbent synthesis technique has been developed at GTI, based on sol−gel processing of inorganic and organic precursors, for the preparation of ZnO-based regenerable sulfur sorbents with unique properties that could not be attained with “conventional” sorbent preparation methods such as coprecipitation or solid-oxide mixing followed by extrusion, granulation, or spray drying. Unlike these techniques, which require very high calcination temperatures to impart physical strength to sorbents, sol−gel processing offers the unique capability of producing sintering at exceptionally low temperatures. As a result, materials with high surface areas, small pore sizes, and very high resistance to attrition can be synthesized. Sorbents prepared with this new technique demonstrated attrition indices that are well below the stringent requirement of the transport reactor of ≈4% and effective capacity for sulfur absorption exceeding 8 g of S/100 g of sorbent. In addition, these sorbents demonstrated regenerability at temperatures that are lower than those required by typical zinc titanates. On the basis of chemical analysis, physical characterization, attrition resistance determination, and evaluation of chemical reactivity and regenerability, the exceptional characteristics of this new class of zinc-based sorbents are demonstrated in this paper.