double the amount of solid waste compared with IGCC systems. As suggested above, IGCC is also less risky than indirectly fired cycles (EFCC and HIPPS), which require significant technological development of high-temperature heat exchange components.

Gasification-based power generation systems offer the highest efficiencies for advanced systems, with IGFC efficiencies projected by DOE to be about 60 percent. Potential advantages of coal gasification combined-cycle systems include the high efficiencies obtained with a combined-cycle configuration, superior environmental performance, and the capability to replace natural gas combined-cycle systems in existing power plants. Thus, a strong incentive has been established for the development of high-efficiency coal gasification technologies optimized for power generation. The committee notes that gasification is also an important first step in the production of clean gaseous and liquid fuels from coal, as discussed below. Given the high cost of developing advanced power generation systems, the committee does not consider large-scale demonstration of numerous technology options with significant DOE cost sharing to be justified.

The committee recommends that second- and third-generation gasification-based systems be given the highest priority for new plant applications. Work on all the advanced systems should focus on acquiring the cost, emissions control, and efficiency information needed to select the most promising systems for further development. The limitations of critical components, such as heat exchangers, turbines, and fuel cells, and the timing and probability of technological success should be taken into account. This process should begin before FY 1996 and should include a rigorous comparative study of the design options.

The proposed FY 1995 budget supporting advanced combined-cycle systems in the FE R&D program is $173 million, split between the natural gas program ($113 million for fuel cells and advanced turbines) and the coal program ($60 million for IGCC, PFBC, and indirectly fired cycle [IFC]). In contrast, the proposed FY 1995 budget is $8 million for advanced pulverized coal. Within the coal program, DOE accords the highest funding level proposed for FY 1995 to the gasification combined-cycle systems ($28 million).

The Advanced Turbine Systems program, funded under the natural gas component of the FE R&D program, is charged with considering alternative fuels to natural gas, including coal-derived gas. In the opinion of the committee, advanced turbine materials alone will not be capable of resisting the corrosive effects of impurities in coal-derived gas, and a high level of gas cleanup will be needed. While cold gas cleanup can meet the necessary requirements for IGCC systems, hot gas cleanup has the potential for a simpler and lower cost approach and is an important part of the program to achieve DOE's efficiency goals for advanced technologies. Thus, hot gas cleanup is a high-priority area for both the



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