Enhanced durability of desulfurization sorbents for fluidized-bed applications
Advanced integrated gasification combined cycle (IGCC) power systems require the development of high-temperature desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier down to very low levels. The objective of this investigation was to identify and demonstrate methods for enhancing the long-term chemical reactivity and mechanical strength of zinc ferrite, a leading regenerable sorbent, for fluidized-bed applications. Fluidized sorbent beds offer significant potential in IGCC systems because of their ability to control the highly exothermic regeneration involved. However, fluidized beds require a durable, attrition-resistant sorbent in the 100--300 {mu}m size range. A bench-scale high-temperature, high- pressure (HTHP) fluidized-bed reactor (7.6-cm I.D.) system capable of operating up to 24 atm and 800{degree}C was designed, built and tested. A total of 175 sulfidation-regeneration cycles were carried out using KRW-type coal gas with various zinc ferrite formulations. A number of sorbent manufacturing techniques including spray drying, impregnation, crushing and screening, and granulation were investigated. While fluidizable sorbents prepared by crushing durable pellets and screening had acceptable sulfur capacity, they underwent excessive attrition during multicycle testing. The sorbent formulations prepared by a proprietary technique were found to have excellent attrition resistance and acceptable chemical reactivity during multicycle testing. However, zinc ferrite was found to be limited to 550{degree}C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.
- Research Organization:
- Research Triangle Inst., Research Triangle Park, NC (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC21-88MC25006
- OSTI ID:
- 10102249
- Report Number(s):
- DOE/MC/25006-3011; ON: DE91002090
- Resource Relation:
- Other Information: PBD: Jun 1991
- Country of Publication:
- United States
- Language:
- English
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Enhanced durability of desulfurization sorbents for fluidized-bed applications
Related Subjects
20 FOSSIL-FUELED POWER PLANTS
HYDROGEN SULFIDES
REMOVAL
ZINC COMPOUNDS
SORPTIVE PROPERTIES
IRON COMPOUNDS
SORBENT INJECTION PROCESSES
FLUIDIZED BEDS
HOT GAS CLEANUP
DESULFURIZATION
COAL GASIFICATION
FLUIDIZED-BED COMBUSTORS
BENCH-SCALE EXPERIMENTS
REGENERATION
010404
010402
200102
GASIFICATION
PURIFICATION AND UPGRADING
POWER CYCLES