Coal Gasification/Repowering: A Means of Increasing Plant Capacity While Reducing Oil Consumption

An exploratory study was carried out by the United Technologies Research Center and Northeast Utilities Service Company to identify the performance characteristics of power plants based upon the repowering of several existing steam plants. In steam station repowering, an advanced, high temperature gas turbine fired by coal-derived, low-Btu fuel gas would generate power and exhaust to a new waste-heat recovery boiler that replaces the old oil-fired steam boiler. Steam from the new boiler drives the existing steam turbine. Computer models were assembled to simulate the integration of molten salt and Texaco coal gasification systems with combustion turbomachinery representative of the 1990 time frame. The results of this study indicated that either coal gasifier in a combined-cycle repowering application appears attractive as a means of replacing oil-fired systems with coal.