Flash Pyrolysis of Coal with Reactive and Non-Reactive Gases. Progress Report, October 1, 1981-September 30, 1982 (Yields in Various Gases and Conditions)

摘要

This report presents the results of the first year's work. The purpose of the program is to develop a data base for the process chemistry of the flash pyrolysis of coal with both reactive gases (H sub 2 , CH sub 4 , CO and CO sub 2 ) and non-reactive gases (He, N sub 2 and Ar). The yields and distribution of products are presented as a function of the reaction variables. A 1 in. ID by 8 ft long downflow entrained tubular reactor was used to obtain product yields and distribution as a function of the process variables. The pyrolysis of New Mexico sub-bituminous coal was performed at temperatures ranging from 825 to 1000 exp 0 C and at gas pressures ranging from 20 to 1000 psi. Residence time of the coal particles at reactor conditions ranged from 0.5 to 8 sec. Pyrolysis in reactive gases caused higher conversion of coal than that in non-reactive gases. The total carbon conversion to gaseous and liquid products correlated in the following order: H sub 2 > CH sub 4 > He > CO > N sub 2 > Ar. For the reactive gases, H sub 2 , CH sub 4 and CO at 900 exp 0 C and 200 psi, the total carbon conversion to gaseous and liquid products was 37.6%, 30.4% and 17.5, respectively. For the non-reactive gases, He, N sub 2 and Ar, the yields were 16.6%, 15.3% and 9.3%. A correlation appears to exist between the yields and heat-up rate of the coal particles for the inert gases in the order of He > N sub 2 > Ar. The flash pyrolysis in methane was characterized by a high yield of ethylene, reaching 10.5% at 825 exp 0 C and 50 psi, which was approximately two times higher than with inert helium gas under similar conditions. Phenols, if any, were present only in trace amounts in the light oil fraction of the liquid products. The yield of tar increased with increase in the pressure of helium but decreased with increase in the pressure of hydrogen. The composition of tar depended on the nature of the pyrolyzing gas. 43 figures, 13 tables. (ERA citation 08:032946)