INCREASING ENERGETIC EFFICIENCY IN SUGAR, ETHANOL, AND ELECTRICITY PRODUCING PLANTS

Abstract

The sugar-alcohol industry has been one of the most important activities in the Brazilian economy, producing sugar and ethanol for both domestic and foreign markets. This industry has been historically characterized by its low energy efficiency, consuming a considerable part of the bagasse produced as fuel in its co-generation systems, to supply the energy needs of the process. A new scenario, with the possibility of selling surplus electricity to the distribution network, or else, to use bagasse as a raw material for other processes, has motivated several plants into investing in more efficient co-generation systems, as well as in higher process energetic integration. This chapter discusses the improvement of sugar-alcohol mills co-generation systems by increasing boiler efficiency through the use of bagasse dryers, as well as other design approaches, to these systems. Energy process integration is also included, showing that available thermal energy exploitation may lead to a significant reduction in plant steam intake, thus improving the energy efficiency of the production process.