NEW PARADIGMS IN EFFICIENCY, EMISSIONS AND POWER COST IN LANDFILL-GAS-FUELED GENERATORS

摘要

Technological refinements have continuously improved the performance and durability of gas-fueled engines in the landfill industry. Today, the benefits of an intensive national effort to increase gas-fueled reciprocating engine generation efficiency are reaching the landfill gas-toenergy market. The latest-generation gas engines, incorporating technologies developed with the U.S. Department of Energy Advanced Reciprocating Engine Systems (ARES) program, attained commercial status in 2002. These leanburn, electronically controlled units, designed for extended-duty service in distributed generation, deliver 1 to 2 MW of capacity and are capable of 43 percent mechanical efficiency, with Nox emissions rated as low as 0.5 g/bhp-hr without exhaust aftertreatment, and maintenance costs 40 percent lower per kWh than for traditional landfill gas engines. Now, enhancements for the special demands of LFG are bringing these technologies into the landfill industry. Landfill gas versions are designed to resist corrosion and to deliver the maximum performance from low-Btu fuels. Changes include the use of non-corrosive metals in strategic wear areas, elevated jacket water temperatures to prevent condensation of caustics, enhanced crankcase ventilation to remove caustics from the system, and modifications to enhance fuel flow and enable full rated power production on low- and variable-Btu gases. The benefits for operators include reduced unscheduled downtime with less hands-on attention, extended service intervals, lower parts-replacement costs, consistent power output, and emissions compliance. Those and other benefits add up to lower generating costs per kWh, greater kWh output from the available gas, and more profitable power production. Experience to date in commercial service in the United Kingdom and Canada, and in product-reliability verification units, demonstrate that these advanced gas generator sets deliver reliable electricity at highlycompetitive cost and in full compliance with applicable air-quality regulations.