Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications
Chemical reactivity was determined at GECRD by measuring sorbent sulfur loading (defined as grams of sulfur absorbed per 100 g of fresh sorbent) in fresh and in cycled samples from a bench-scale reactor. Only formulations that exhibited a good balance of chemical and mechanical performance as fresh pellets were selected for further cyclic testing in the benchscale reactor system. Details of the bench-scale reactor and procedures have been given before (Ayala, 1991). The important aspect of the benchscale testing is that both absorption and regeneration were conducted in a packed-bed reactor simulating the time/temperature environment to which the sorbent would be exposed in a typical cycle of the full-scale moving-bed system. Absorption was carried out at 1000[degrees]F using any of three gas compositions, all having a deliberately high H[sub 2]S concentration (1 %) to accelerate testing. The oxidative regeneration was carried out between 1000 and 1250[degrees]F and 1--21% oxygen during the early phases of regeneration, and at 1400[degrees]F during the final phase simulating the temperature rise of the sorbent bed. Sixteen zinc titanate formulations were prepared as cylindrical extrudates. For all formulations, the calcination time was held constant at 2 hours. The following results were obtained: Formulations containing a 0.8 Zn:Ti ratio produced mixtures of several stoichiometric titanates: Zn[sub 2]Ti[sub 3]O[sub 8], ZnTiO[sub 3], and Zn[sub 2]TiO[sub 4], with the relative amount of each depending on temperature. Formulations containing a 2.0 Zn:Ti ratio exhibited exclusively the Zn[sub 2]TiO[sub 4] structure. The higher calcination temperature of 1800[degrees]F significantly reduced the porosity available for chemical reactivity, while the lower calcination temperature of 1400[degrees]F produced, in some cases, formulations with traces of residual unreacted zinc oxide and anatase titanium dioxide.
- Research Organization:
- General Electric Co., Schenectady, NY (United States). Corporate Research and Development Center
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC21-88MC25003
- OSTI ID:
- 6887151
- Report Number(s):
- DOE/MC/25003-93/C0090; CONF-920951-29; ON: DE93002612
- Resource Relation:
- Conference: US Department of Energy contractors review meeting on gasification and gas stream cleanup systems, Morgantown, WV (United States), 15-17 Sep 1992
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of durable mixed-metal oxide sorbents for high-temperature desulfurization of coal gases in moving-bed reactors
ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS
Related Subjects
FUEL GAS
DESULFURIZATION
HOT GAS CLEANUP
ADSORBENTS
CALCINATION
CHEMICAL REACTION KINETICS
COAL GASIFICATION
COMBINED-CYCLE POWER PLANTS
EXTRUSION
FERRITES
HYDROGEN SULFIDES
PELLETIZING
REGENERATION
REMOVAL
STABILITY
TEMPERATURE DEPENDENCE
TITANATES
ZINC COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
FABRICATION
FERRIMAGNETIC MATERIALS
FLUIDS
FUELS
GAS FUELS
GASES
GASIFICATION
HYDROGEN COMPOUNDS
IRON COMPOUNDS
KINETICS
MAGNETIC MATERIALS
MATERIALS
MATERIALS WORKING
MOLDING
OXYGEN COMPOUNDS
POWER PLANTS
PURIFICATION
PYROLYSIS
REACTION KINETICS
SULFIDES
SULFUR COMPOUNDS
THERMAL POWER PLANTS
THERMOCHEMICAL PROCESSES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
010402* - Coal
Lignite
& Peat- Purification & Upgrading
010404 - Coal
Lignite
& Peat- Gasification