03/01793 Increased power generation from sugarcane biomass - the results of a technical and economic evaluation of the benefits of using advanced gasification technology in a typical Brazilian sugar mill: Morris, M. et al. International Sugar Journal, 2002, 104, (1242), 243–244, 244–248

Abstract

A huge potential for power generation from waste fuels exists within the sugar cane industry. 1 200 million tonnes of sugar cane is harvested annually, which corresponds to a worldwide electricity production potential of 40 000 MW or 300 TWh/annum in the eighty countries where sugar cane is grown on a significant basis. This paper outlines work on the cultivation and recovery of sugar cane by-product fuels and provides an overview of the evaluation and development work on an advanced gasification system applied to these fuels. Integration of such a system with a sugar mill in Brazil, and conceptual engineering and costing of a large-scale demonstration plant is also described. Availability of future agricultural residues from the main producing areas of Brazil was showed to be approximately 40 million dry tonnes, most of it nowadays being burned before harvesting. Based on the assumption that the majority of the sugar cane production will be harvested in the future without burning and, taking into account the recovery factors of cane trash, approximately 20 million tonnes of biomass will be available. This is in addition to the 40 million dry tonnes of bagasse available. Tests in a 2 MW gasification pilot plant showed that bagasse and cane trash could be used as feedstock to the gasification process. On the basis pf these tests, conceptual engineering of a bagasse and cane trash-fuelled combined-cycle power plant integrated into a typical sugar mill in Brazil was performed. It was shown that when a gasification plant, based on a General Electric LM 2500 gas turbine, is integrated with a typical mill in Brazil, the net exported power will be 28 MW (or more than 160 kWh/tonne cane), and when a gasification plant twice the size is integrated, the net exported power will be 290 kWh/tonne. As a result of the increased amount of agricultural residues available for power production, the higher efficiencies in conversion and, to a lesser extent, the avoided emissions as a result of less sugar cane burning, the emissions of CO 2 , greenhouse gases and particulates will be significantly reduced.