Alkali attack of coal gasifier refractor linings

Technical Report · Thu Dec 15 04:00:00 EST 1988

OSTI ID:6780218

Brown, Jr, J J

This investigation examines the alkali-refractory corrosion in non-slagging coal gasifiers and in the non-slagging portions of slagging gasifiers. The alkali species in a typical gasifier atmosphere were calculated using the SOLGASMIX-PV computer program. Reactions between alkali and refractory castables, fireclay refractories, and alumina-chromia brick were first computed theoretically and then selectively confirmed experimentally. Alkali-alumino silicate compounds were synthesized and their thermal expansion properties and water solubilities were measured. Below 20 atm pressure, alkali is present in gasifiers as solid or liquid oxides, hydroxides, carbonates, or sulfides up to about 1400K; above this temperature most of the compounds exist as vapor species, including alkali metal vapor. At 1400K and above, the specific alkali phases are quite pressure sensitive. Alkali corrosion of calcium aluminate castables refractories is primarily confined to the cement phase. The results of alkali corrosion of alumina-chromia refractories, both experimental and theoretical, show formation of alkali-aluminate (Na/sub 2/O/center dot/Al/sub 2/O/sub 3/, K/sub 2/O/center dot/Al/sub 2/O/sub 3/) and ..beta..-alumina (Na/sub 2/O/center dot/11Al/sub 2/O/sub 3/, K/sub 2/O/center dot/11Al/sub 2/O/sub 3/) compounds with formation of several metastable alkali compounds. Sulfur did not appear to affect the reaction products. 50 refs., 32 figs., 26 tabs.

• Research Organization: Oak Ridge National Lab., TN (USA); Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Materials Engineering
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6780218
• Report Number(s): ORNL/Sub-85-43397/02; ON: DE89005673
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALUMINATES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COAL GASIFICATION
COHERENT SCATTERING
COMPUTER CODES
CORROSION
CORROSION PRODUCTS
CRYSTAL STRUCTURE
DIAGRAMS
DIFFRACTION
EXPANSION
GASIFICATION
HYDROGEN COMPOUNDS
HYDROXIDES
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE STUDIES
POTASSIUM COMPOUNDS
PRESSURE DEPENDENCE
REFRACTORIES
S CODES
SCATTERING
SILICON COMPOUNDS
SILICON OXIDES
SODIUM COMPOUNDS
SOLUBILITY
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE DEPENDENCE
THERMAL EXPANSION
THERMOCHEMICAL PROCESSES
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION