The effect of limestone on ash behavior in fluidized-bed gasification of coal

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6022799

Kline, S D; Mason, D M; Carty, R H; Babu, S P

The behavior of coal mineral matter is of interest in fluidized-bed coal gasification and stage combustion because it governs the formation of ash agglomerates that facilitate ash removal from the reactor without excessive loss of carbon as well as deposition on reactor internals and downstream surfaces. The ultimate aim of this research program is to be able to predict quantitatively the behavior of the mineral matter in a fluidized-bed gasifier based on the operating conditions of the gasifier and a minimum analysis of the mineral matter present in the coal feed. In this work, the effects on ash behavior of using limestone as an in-bed sulfur capture agent and of recycling an SO{sub 2}-containing stream from the regeneration of a hot-gas cleanup system to the gasifier were investigated. The feed solids, ash discharge, and bed material from a pilot plant test in which limestone was used for sulfur capture were analyzed. Also, tests in a 2-in. ID reactor in which mixtures of limestone and coal char were gasified with steam and air, with and without the addition of SO{sub 2} to the feed gas, were studied. The results indicate that very few conventional coal ash agglomerates were formed, but instead the coal ash became attached to and penetrated the particles containing calcium oxide and calcium sulfide that were formed from the limestone. Sulfur dioxide recycled to the bed was reduced to hydrogen sulfide and absorbed as calcium sulfide with little, if any, other effect on ash behavior. 4 refs., 2 figs., 3 tabs.

• Research Organization: Institute of Gas Technology, Chicago, IL (USA)
• Sponsoring Organization: DOE/FE
• DOE Contract Number: AC21-87MC23283
• OSTI ID: 6022799
• Report Number(s): CONF-891130-6; ON: DE91008402
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
AGGLOMERATION
ASHES
CARBONATE ROCKS
CHALCOGENIDES
CHARS
COAL GASIFICATION
ELEMENTS
FLUIDIZED BEDS
GASIFICATION
IRON COMPOUNDS
IRON SULFIDES
LIMESTONE
MINERALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS PRODUCTS
REMOVAL
RESIDUES
ROCKS
SEDIMENTARY ROCKS
SORPTION
SORPTIVE PROPERTIES
SULFIDES
SULFUR
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS