Emissions Control Technologies
- Overall, DOE can make an important contribution to reducing the costs and improving the performance of emissions control technologies by careful selection of critical problems for research in conjunction with industry.
- Hot gas particulate cleanup is an especially critical technology at this time, since it will be an essential element in the success of high-performance PFBC and could improve the efficiency of gasification-based systems.
- Hot gas cleanup for sulfur removal is another critical development needed for advanced PFBC systems where high-efficiency sulfur removal still needs to be demonstrated at acceptable reagent stoichiometries. There would also be efficiency benefits for advanced IGCC systems.
- A thorough understanding is needed of options for the control of hazardous air pollutants, especially volatile air toxics, such as mercury and chlorine, across the set of advanced combustion and gasification-based technologies.
- NOx control measures meeting DOE's performance targets for advanced power systems with hot gas cleanup and high-temperature turbines remain to be fully specified and demonstrated. Selective catalytic reduction or other add-on technologies could well be required in addition to the combustion-based NOx controls now envisioned.
- Solid waste reduction is needed for all coal-based systems. Waste minimization, by-product recovery, and reuse options will become increasingly important and merit additional attention.
- Currently, the primary focus of DOE's coal R&D to reduce CO2 emissions is improving power plant efficiency. Should future policy measures require an accelerated rate of CO2 reductions, additional measures to remove and dispose of CO2 from gas streams, to avoid CO2 emissions to the atmosphere, could also be warranted.
Power Generation Systems
- DOE's quantitative performance and cost objectives for advanced power systems should be reviewed in light of the committee's discussion and conclusions. In particular, a more realistic goal for advanced power systems would be to achieve significant efficiency improvements at an overall cost comparable to new plants today. For environmental R&D goals, an alternative long-term vision is to benchmark air emissions from coal plants relative to cleaner but more costly competing fuels, particularly natural gas. The long-term challenge would be to achieve greater emissions reductions economically while substantially reducing solid wastes.