Correlation of tar yields from rapid pyrolysis with coal type and pressure

• Published in: Fuel (Guildford) 1987-08, Vol.66 (8), p.1118-1122
• Main Authors: Ko, Glen H., Peters, William A., Howard, Jack B.
• Format: Article
• Language: English
• Subjects: Applied sciences; coal; Energy; Exact sciences and technology; Fuel processing. Carbochemistry and petrochemistry; Fuels; rapid pyrolysis; Solid fuel processing (coal, coke, brown coal, peat, wood, etc.); tar yield
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(87)90310-3

A new correlation independently relating maximum tar yield from rapid pyrolysis (heating rate ≳ 100 K s − 1) to coal type and to total pressure is presented. Coal type effects are treated using only information on the elemental composition of the unpyrolysed coal. Pressure effects are correlated via empirical parameters obtained from best-fit analyses of existing data. The correlation is tested against experimental data for coals from the USA, France and W. Germany representing a wide range of rank, and for pressures from ‘Vacuum’ to 9 MPa. Satisfying results are obtained, with predictions of tar yield generally within ± 5 wt% (of dmmf coal) of observed values at all pressures for most coals. The correlation is most suited to predicting maximum tar yields under reaction conditions affording minimal opportunity for extra-particle secondary reactions of newly formed pyrolysis tars. It is also useful for predicting probable upper bounds on pyrolysis tar yields under other operating conditions.