EVENDALE, Ohio - GE Marine & Industrial Engines (M&I) has completed tests on its popular LM2500 aeroderivative gas turbine and has verified that the engine is capable of burning biomass and other low Btu-content fuels made from the gasification of bio materials.
These findings are the reason the LM2500 is being considered for several biomass projects worldwide, including those in Brazil and The Netherlands.Two component tests were conducted by M&I to support the Biomass Integrated Gasification-Gas Turbine (BIG-GT) project, whose participants include the Brazilian government, CHESF, Eletrobras, Shell Brazil, and a Scandinavian company, TPS Termiska Processor. The Global Environment Facility (GEF), an organization within the World Bank, is also providing funding.
Biomass Testing
The LM2500, which is designed for liquid, gaseous, or dual fuel operation, already has a substantial capability for low-Btu gas operation. In general, however, the LM2500 will require only limited modifications for operation on a biomass fuel. During an atmospheric component test conducted, M&I evaluated key features of the LM2500 combustor at atmospheric conditions for reduced complexity. Features included in this test were combustor light-off and blow-out, low speed efficiency, temperature profile and flammability limits. The second analysis -- a sector test -- used a five-cup portion of a standard annular combustor. M&I's sector high pressure test facility has the capability to achieve 40 bar of pressure at 250 pps mass flow and 1400oF temperature. The key objectives of the sector test were to obtain flammability, efficiency and emissions information on biomass fuels as simulated in an installed, operating environment. A fuel system control specification also was defined so the gas turbine can operate on the low Btu biomass fuel. Biomass fuel has approximately one-seventh the heating value of natural gas and may be supplied at temperatures as high as 450C (842F). Both tests were successfully completed, and demonstrated that the LM2500 combustor and fuel nozzle designs are acceptable and within the expected operational envelope as compared to common fuel parameters such as on natural gas or distillates.
BIG-GT Project
The BIG-GT project was initially divided into three phases: preliminary investigation, equipment development, and implementation. Phase I was completed in September 1992 and Phase II will be finished in June 1997. Phase III will be initiated in mid-1997. Once these have concluded, a fourth phase will provide for debugging and pre-commercial operation, and the fifth phase for actual commercial operation of a BIG-GT facility. Phase II activity includes the modification and component testing of the LM2500 combustor and fuel nozzles affected by the fuel change. These changes will be accomplished within the time and budgetary constraints of the project's Phase II. Two independent project teams were established for Phase II of the project to work in parallel to develop distinct technology packages for possible implementation in Phase III. Each team was led by a gasifier system manufacturer, which was responsible for the performance of the gasifier/gas clean-up train, integration of the gas turbine and steam bottoming cycle, the overall system control, and the provision of process guarantees. GE worked with both project teams. The final package was decided in late 1995, and TPS Termiska Processor was selected for the gasification technology. This integrated low-pressure BIG-GT design will have a net combined-cycle output around 30 megawatts for a fully-fired LM2500. Successful implementation of the BIG-GT demonstration facility would open the door for worldwide commercial application of sustainable biomass power generation. The increased usage of biomass could provide a basis for rural development and employment in developing countries and for utilization of excess crop lands in the industrial world.