Substandard carbon-containing raw materials and methods of their thermochemical processing

Abstract

The analysis of the structure of consumption of primary energy resources in the world and in Ukraine are carried out. It is shown that in recent decades the share of coal is stable at 25–30 % and does not show a tendency to decrease. Similar patterns are observed in Ukraine too. It is established that in Ukraine the energy potential of reserves of substandard carbon-containing raw materials is commensurate with the deposits of conditioned coal and can be used to increase the country's energy security. At the same time, the deterioration of environmental indicators in the world and in Ukraine requires an increase in the level of environmental safety in the use of carbon-containing raw materials and appropriate environmental modernization of its thermochemical conversion methods. The paper reviews the methods of thermochemical processing of substandard carbon-containing raw materials (pyrolysis and coking, hydrogenation, gasification) and shows that the gasification process, which allows processing of various substandard fuel resources in terrestrial and underground conditions, is the most promising for environmental safety use. It is shown that developed terrestrial gasification methods are characterized by insufficient productivity of gas generators, significant capital costs for their installation and negative impact on the environment. In addition, terrestrial processing of low-quality coal is not a waste-free technology and does not solve the problem of “secondary” gasification residues recycling. Some of these shortcomings can be eliminated by using the method of underground gasification, in which there is no need to extract coal to the surface, and secondary waste remains underground.