EDITORIAL: Clean Coal Technology Needed
Coal is number one when it comes to the U.S. power-generation industry-more than 50% of electricity produced in the U.S. is generated by coal-fired power plants. The plants are less costly to build than nuclear power plants and there's less safety risk involved. And with an estimated 250 years of coal reserves in the U.S., it's likely than new plants will be coal fired. This is good news except that the contribution of CO2 emissions from fossil fuels to global warming has the U.S. Environmental Protection Agency continually increasing restrictions on emissions from power plants. We need to find ways to overcome this dilemma, and there are signs of moving in that direction.
For example, the Department of Energy's National Energy Technology Laboratory, in keeping with our National Energy Policy calling for a new commitment to clean-coal innovations, selected five research projects in a nationwide competition for ideas on ways to use the nation's abundant coal reserves while meeting environmental requirements. The projects total about $5 million with $3.5 million coming from DOE.
Four projects focus on improving environmental performance and fuel efficiency of coal-burning power plants, and one involves new approaches to reducing CO2 emissions.
Sensor Research & Development Corp. (Orono, Maine) will develop an ultrasensitive continuous emissions monitor to detect and help control trace amounts of mercury from coal-fired plants.
Iowa State University (Ames, Iowa) together with Energy Systems Associates will develop a microwave-based monitor to analyze during plant operation the chemical composition of fly ash from coal-fired plants. Unburned carbon in the ash is a key indicator of a plant's combustion efficiency.
Alstom Power Inc. (Windsor, Conn.) will build and evaluate a new type of coal furnace called a circulating moving bed combustor. The advanced combustor could be as much as 30% less expensive and 60% more efficient than conventional pulverized-coal and fluidized-bed boilers now on the market. A 3-MW pilot-scale furnace will be used for field-testing. Project collaborators include University of Massachusetts and Massachusetts Institute of Technology.
Alstom Power Inc. also will evaluate the feasibility and economics of a dozen advanced power-plant concepts based on pulverized coal, circulating fluidized-bed and circulating moving bed coal combustors. The goal is to increase the efficiency of future coal plants that use these combustors up to 50% from the 35% efficiency of today's average coal-fired plant. Ohio-based utility American Electric Power will participate.
SRI International (Menlo Park, Calif.) will investigate two concepts to convert CO2 emissions into fuel. One approach involves a new process that uses solar energy in a photochemical reaction together with common iron minerals and water to convert CO2 into methanol and other products. A second approach involves ways to use heat to convert CO2 into fuel-grade chemicals using iron-containing minerals.
These projects, if successful, could make tomorrow's coal plants cleaner and more efficient.