Technical and Economic Evaluation of Retrofitting and Repowering Oil-Fired Boilers with Gas from Coal. Final Report

摘要

Fluor studied the feasibility of substituting fuel gas produced from coal for oil fuel at a modern oil-fired boiler plant and of repowering the same boiler plant using fuel gas from coal as the combustion turbine fuel as well as boiler fuel in some cases. Several cases were investigated, including cases with the fuel gas plant connected to the boiler plant with a 50-mile gas delivery pipeline. The Texaco, Inc., coal gasifier was used for the fuel gas production. This gasifier is still under development, and the study results are highly dependent on development of the gasifier to the commercial configuration and cost used in the study. It appears that some savings might be universally available since fuel price differentials of the magnitudes tabulated can be expected in most areas of the United States. When a boiler plant is repowered, a considerable additional quantity of electricity can be produced at relatively low cost through the conversion of the boiler plant to a more efficient combined-cycle type of operation. If the boiler plant is repowered with fuel gas, plant capacity can be increased by up to 73%, and levelized cost of total electricity can be reduced by up to 7.2 mills per kWh (1980 $) below the cost when gas is simply substituted for oil. The boiler plant could be replaced with a new conventional coal-fired plant of the same capacity or a new conventional coal-fired plant of the same capacity as a repowered boiler plant could be installed. In either case, no clear advantage was found with respect to either new capital requirements or cost of electricity if a gas-from-coal system were to be employed. However, a fuel gas system does present an opportunity to reduce capital requirements considerably because fuel gas could be purchased over-the-fence from a second party. Capital requirements for fuel gas substitution would amount to only about $5/kW. (ERA citation 08:023416)