An Analysis of Technologies for Electricity and Synthetic Liquid Fuel Co-production from the Gas of Underground Coal Gasification

Abstract

The relevance of the study is stemming from a growing interest in underground coal gasification technologies (UCG). This follows from exhaustion of the world oil and gas reserves, availability of a significant amount of coal deposits in various countries around the world, a growing demand for energy, and the threat of global climate change. Recent years have seen a drastically grown interest in UCG. In contrast to all major programs of the 20th century, this interest is stimulated by private capital in response to record high prices for oil and energy carriers. In addition, UCG studies have been resumed: more than 30 tests are conducted or planned in Australia, China, India, South Africa, New Zealand, Canada and the United States. The aim of the study is to develop competitive UCG gas-based technologies for producing electricity and synthetic liquid fuels. A promising line of using UCG gas for combined production of synthetic liquid fuel (methanol) and electricity is studied. A detailed mathematical model of the relevant plant has been developed by using an efficient computation system elaborated at the Melentiev Energy Systems Institute of the Siberian Branch of the Russian Academy of Sciences (ESI SB RAS), called a computer aided software development system (CASDS). By using the model, a technical and economic optimization of schemes and parameters was carried out, which made it possible to estimate the proposed coal processing method competitiveness conditions. The sensitivity of the plant economic indicators to changes in external conditions has been analyzed. The cost of diesel fuel in the eastern regions of Russia was analyzed, and it has been concluded from the obtained analysis results that the methanol produced by the energy-and-processing plant is competitive with expensive commercial diesel fuel, and that the introduction of such systems is economically expedient.