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Title: 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 foundmore » to be limited to 550{degree}C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.« less
Authors:
;
Publication Date:
OSTI Identifier:
10102249
Report Number(s):
DOE/MC/25006--3011
ON: DE91002090
DOE Contract Number:
AC21-88MC25006
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Jun 1991
Research Org:
Research Triangle Inst., Research Triangle Park, NC (United States)
Sponsoring Org:
USDOE, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 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