Formation and growth of coal ash agglomerates

Conference · Wed Jun 01 04:00:00 EDT 1988 · Am. Chem. Soc., Div. Gas Fuel Chem., Prepr.; (United States)

OSTI ID:6596539

Carty, R H; Mason, D M; Kline, S D; Babu, S P ^[1]

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1. Institute of Gas Technology, 3424 South State Street, Chicago, IL (US)

The behavior of the mineral matter of coal and its reaction product, ash, is of concern in gasification processes because it governs deposition on gasifier and downstream surfaces as well as agglomeration in ash-agglomerating gasifiers. In general, fluidized-bed coal gasifiers operate under backmixed conditions. Consequently, the gasifier solids drain stream could carry with it some unconverted carbon. In contrast, in the KRW and U-GAS processes, the high-velocity jet in the gasifier effectively agglomerates the ash, thereby facilitating its selective removal from the fluidized-bed, and thus achieving carbon conversion in excess of 98%. For the ash-agglomerating fluidized-bed gasifier, the iron oxidation and iron aluminosilicate formation occur in the jet region of the reactor due to its oxidizing atmosphere and elevated temperature. The results of the gasification tests performed in this study indicate that in individual coal particles Fe/sub 2/O/sub 3/ concentrations between 15 and 80 weight percent of the ash promote the formation of ash agglomerates, whereas ash outside this range tends to form free ash rather than agglomerates. In the gasification of coals of low-iron-content ash, significant formation of ash agglomerates can occur by the joining of unmelted mineral matter with relatively small amounts of the iron aluminosilicate matrix material. Characterization of the composition and distribution of the coal ash using the techniques developed in this study could be of assistance in setting the operating conditions of fluidized-bed, ash-agglomerating gasifiers.

• OSTI ID: 6596539
• Report Number(s): CONF-8806136-
• Conference Information: Journal Name: Am. Chem. Soc., Div. Gas Fuel Chem., Prepr.; (United States) Journal Volume: 33:2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
010600* -- Coal
Lignite
& Peat-- Properties & Composition
011000 -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
AEROSOL WASTES
AGGLOMERATION
ALKALINE EARTH METAL COMPOUNDS
ASHES
BITUMINOUS COAL
BLACK COAL
CALCIUM COMPOUNDS
CALCIUM OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CLAYS
COAL
COAL GASIFICATION
COAL RANK
COMBUSTORS
DEPOSITION
ENERGY SOURCES
FEDERAL REGION IV
FEDERAL REGION V
FLUIDIZED-BED COMBUSTORS
FLY ASH
FOSSIL FUELS
FUELS
GASIFICATION
ILLINOIS
IRON COMPOUNDS
IRON OXIDES
IRON SULFIDES
KENTUCKY
KINETICS
MATERIALS
MINERALS
NORTH AMERICA
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PYRITE
QUARTZ
REACTION KINETICS
RESIDUES
SILICON COMPOUNDS
SILICON OXIDES
SUBBITUMINOUS COAL
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SULFUR CONTENT
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
USA
WASTES