URS and the Ljungström Division of Arvos Group have signed an exclusive agreement to jointly develop, demonstrate and market technology to improve the energy efficiency of coal-fired power plants by 1 percent to 3 percent, with a corresponding reduction in carbon dioxide emissions.
The approach involves combining URS’ SBS Injection sorbent injection technology for sulfur trioxide control with Ljungström’s air preheater technology. Sulfuric acid and other acidic compounds found in coal combustion gas cause fouling and corrosion of the air preheater equipment. By eliminating these acids, the thermal performance and efficiency of a coal-fired power plant can be improved.
Long-term testing of the combined technologies at the Ljungström Division research facilities in Wellsville, New York, has shown recovery of thermal energy from combustion flue gases to temperatures as low as 220 degrees Fahrenheit — an improvement in overall plant efficiency of as much as 3 percent, or about a 300 Btu/kW-hr heat rate reduction. Similar efficiency gains can be achieved at most power plants with relatively simple modifications to the air preheater, the companies say.
Additionally, lowering the flue gas temperature exiting the air preheater can increase the capture of mercury in existing air pollution control equipment, thereby reducing mercury emissions from the power plant.
Earlier this month URS introduced a mercury control technology, HBS Injection, to help US power plants comply with the Mercury and Air Toxics Standard regulation issued by the EPA.
Photo Credit: coal power plant via Shutterstock