Biomass power generation: sugar cane bagasse and trash.

I I The main objective of this project is to evaluate and develop the technology required in the complete fuel-to-electricity chain; starting with the cultivation and recovery of sugar cane by-product fuels, and ending with electric power generation with an advanced gasification system integrated with the sugar mill. Pilot plant gasification tests have been performed on bagasse and cane trash. Studies have also been made on the integration of a BIG-GT (Biomass Integrated Gasification-Gas Turbine) plant in a sugar mill and optimisation of the overall mill facilities. Introduction Development in the sugar cane industry is driven by the wish to convert the fuel value of bagasse and cane trash (comprising tops and leaves separated at harvest) to electric power. To realise this vast agrofuel potential, research and development of the entire system from the fuel supply chain, the thermal process, its integration in the sugar mill's combined heat and power system to export to the grid must be carried out and demonstrated at full scale. The Global Environment Facility (GEF) cofunded the project and, for the activities which began in the year 2000, the European Union (EU) and the Swedish National Energy Administration also provided financial support. TPS is a Swedish company that has developed a proprietary gasification process that can be used in conjunction with a gas turbine. This process will be demonstrated on wood fuel in the 8 MW ARBRE plant in the UK (Pitcher and Weekes, 2000), which is presently undergoing commissioning. Gasification of sugar cane bagasse and trash I Work contracted to TPS included tests in a 2 MW i I atmospheric pressure circulating fluidised bed (CFB) gasification pilot plant (Figure 1 ; Rensfelt, 1997). Three tests on bagasse pellets were performed during 1998 and 1999 and tests on loo'se cane trash were performed during 2000 and 2001. In the tests on pelletised bagasse, no tendencies of ash agglomeration were observed when the gasifier was operated at normal operating temperatures of up to 900°C. The high chemical reactivity of bagasse resulted in a high carbon conversion to gas. A reasonably low tar content of the product gas was achieved at this operating temperature. The conversion of nitrogen to ammonia was high. The results of the pilot plant tests on cane trash are still to be analysed fully, but once again there was no tendency for the fuel to agglomerate and the process data appear to be in line with expectations.