Alkali attack of coal gasifier refractory linings

Thermodynamic calculations are used to study the alkali reactions in coal gasifier atmospheres. The reactive alkali and sulfur species released from coal are first calculated at temperatures from 800 K to 1900 K and pressures from 1 atm to 100 atm. Four P-T diagrams are constructed for the stable alkali and/or alkali-sulfur species at differ-ent temperatures and pressures. Alkali vapors are generated by the reactions Na₂CO₃_(s) + 2C_(s) = 2Na_(g) + 3CO_(g) Na₂CO₃_(s) + H₂O_(g) + C_(s) = 2NaOH_(g) + 2CO_(g) or K₂CO₃_(s) + 2C_(s) = 2K_(g) + 3CO_(g) K₂CO₃_(s) + H₂O_(g) + C_(s) = 2KOH_(g) + 2CO_(g) The phases formed from alkali-cement, and alkali-sulfur-cement reaction are also predicted. For both 53% and 72% alumina cement, calcium aluminate (CaO•Al₂O₃) is decomposed by the reactions CaO•Al₂O₃ + 2Na + 1/20₂ = Na₂O•Al₂O₃ + CaO CaO•Al₂O₃ + 2K + 1/20₂ = K₂O•Al₂O₃ + CaO or CaO•Al₂O₃ + 2Na + l/2S₂ = Na₂0•Al₂O₃ + CaS CaO•Al₂O₃ + 2K + 1/2S₂ = K₂•Al₂O₃ + CaS

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Engineering

Department dc:contributor.department

Materials Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1986

Author dc:creator

• Sun, Tawei

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/94471

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/94471