Experimental and Modeling Studies of Coal Pyrolysis and Hydrogenation

摘要

Research objectives were to study experimentally the product distribution of various coals in a broad range of conditions and to develop a comprehensive mathematical model of coal structure and coal pyrolysis. Experimentally, a pyrolysis reactor system is described and illustrated which yielded products for characterization by pressure gel permeation chromatography, NMR, and elemental analysis. Kinetics of gaseous product formation was studied indicating that (1) product distribution is highly sensitive to pyrolysis temperatures, (2) particle size is a minor factor, and (3) pressure has a significant effect. A chemically based model of coal pyrolysis was developed that incorporates several features. First, coal is regarded as a collection of functional groups by which each coal is characterized. Second, chemical reactions selected on the basis of organic chemical theory and thermochemistry include bond dissociation and recombination, hydrogen abstraction, and free radical addition to aromatic rings. Third, mass transfer has been taken into account within both the microporous structure and transitional pores and macropores. A new computer code is being developed.