Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

Technical Report · Sun Feb 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/6574419· OSTI ID:6574419

Schrodt, J T

Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

• Research Organization: Kentucky Univ., Lexington (USA). Dept. of Chemical Engineering
• DOE Contract Number: AS05-76ET10463
• OSTI ID: 6574419
• Report Number(s): DOE/ET/10463-T1(Vol.2)
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010402* -- Coal
Lignite
& Peat-- Purification & Upgrading
ASHES
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL GASIFICATION
DATA
DESULFURIZATION
ELEMENTS
EXPERIMENTAL DATA
FLUIDIZED BED
FLUIDS
FUEL GAS
FUELS
GAS FUELS
GASES
GASIFICATION
HIGH TEMPERATURE
HOT GAS CLEANUP
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
INFORMATION
IRON COMPOUNDS
IRON OXIDES
KINETICS
LOW BTU GAS
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PARTICLE SIZE
PURIFICATION
REACTION KINETICS
REMOVAL
RESIDUES
SIZE
SORPTION
SORPTIVE PROPERTIES
SULFIDES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE PROPERTIES
SYNTHETIC FUELS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS