Comparison of Heat Treatment Processes for Barzas Sapromixite and Brown Coal in Various Gas Media
M. L. Shchipko1, A. V. Rudkovskiy2, V. I. Sharypov3, B. N. Kuznetsov4
1 Institute of Chemistry and Chemical Technology
2 Institute of Chemistry and Chemical Technology
3 Institute of Chemistry and Chemical Technology
4 Institute of Chemistry and Chemical Technology, bnk@icct.ru
Abstract
Thermal conversions of sapromixite from Barzas deposit in an inert medium, hydrogen medium, and that of synthesis gas have been studied in a flow-through reactor under atmospheric pressure and in an autoclave under a pressure of up to 7 MPa. A higher conversion level of brown coal as compared with sapromixite is determined by a low metamorphic degree of brown coal and by its high content of highly reactive oxygen-bearing fragments. However, the yield of resins from sapromixite in a temperature range of 450-850 oC is 3-4 times higher when compared to the yield from brown coal. It has been found that an increased yield of resins under variations in heat treatment conditions is caused for the most part by a decrease in the formation of gases and water. The yield of semicoke has no any significant changes. The process flow diagram has been suggested that explains the observed effects. It has been demonstrated that unlike heat treatment in an autoclave, when employing a flow-through reactor and atmospheric pressure, the composition of the gas medium has no tangible effect on the conversion level of combustible. Meanwhile, the liquid yield at a temperature of devolatilization of coal, 650 oC, in a current of hydrogen and synthesis gas is at least 1.5 times higher by comparison to the yield in devolatilization of coal in an inert medium. A procedure of devolatilization of sapromixite has been suggested that affords an enhanced liquid yield as compared with the conventional process by way of using the products of gasification of a fixed residue of the process as the gas heat carrier.
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