화학공학소재연구정보센터
Energy & Fuels, Vol.12, No.3, 589-597, 1998
A kinetic scheme for catalytic coliquefaction of coal and waste tire
Catalytic liquefaction of two bituminous coals and one subbituminous coal was studied separately and with waste tire as solvent at different temperatures and tire/coal ratios. The tire sample represented a mixture of waste, recyclable tires. A; ferric-sulfide-based catalyst impregnated in situ in the coal was used as catalyst. Runs were made in a batch tubing-bomb reactor at 350-450 degrees C. The results indicate that the primary products of coal liquefaction are the asphaltenes, but a significant fraction of the subbituminous coal is also converted directly to oil and gas. The primary products of tire liquefaction are in the oil range. For all the coals, the addition of tire shows a synergistic effect on coal conversion, the synergism being mainly manifested in an increase in the yield of asphaltenes. The extent of synergism depends on process conditions and the coal type. The conversions of all coal types increase dramatically using the catalyst, the catalytic effect being mainly on the coal-to-asphaltenes reaction. The importance of retrogressive reactions is evident for all processes involving subbituminous coal. In the case of bituminous coals, the retrogressive reactions are important mainly at high temperatures. The data analysis suggests that the coliquefaction of different coals with waste tire may be described by essentially similar reaction schemes, although the relative significance of the various steps is different for different coals.