1.Introduction
India faces a peak electric generating shortage of over 20 % and an energy shortage of 12 % India is the world’s largest producer of sugar, with over 430 sugar mills producing an estimated 12 million tons of sugar annually. The rapidly changing markets for sugar and energy provide an excellent opportunity to develop innovative methods to optimize the cogenerated power form the sugar plants that can reduce the energy shortage faced by the country. Market studies have indicated that an additional power of 3500 MW can be generated through the use of cogeneration in the sugar industry. This paper builds up an energy balance for an operating plant and estimates the magnitude of the optimum power that can be cogenerated form the plant.
Sugar can be produced either form sugar beet or sugar cane. In India, sugar is mainly produced from sugar cane. The sugar extraction process can be broadly classified into the following steps. The juice that is extracted from the sugar cane contains 80 % by weight of water that requires to be evaporated . The juice is heated. After which it is treated with various chemical reagents like lime, sulphuric acid, phosphoric acid, carbonic acid, magnesia etc to remove the impurities. It is then passed through a set of evaporators, in which the water is evaporated and syrup is formed in the end. The syrup is then heat in a vacuum pan before being sent into a centrifugal machine, in which the white sugar crystals are separated out. The fuel that is used in the boilers is bagasse, which is a by- product of the sugar extraction process.