Rice straw biomass to high energy yield biocoal by torrefaction: Indian perspective

India is an agriculture based country and generates more than 600 million tonnes of biomass waste from different crops and produces 140 million tonnes of rice straw alone annually. To dispose the rice straw for making field ready for next crop, farmers are burning it in the fields. Burning of rice straw in agriculture fields poses lot of environmental, health and economic issues in various parts of the country. On one hand, rice straw is a good source of renewable energy but on the other hand it has some inherent problems. Therefore, to mitigate problems due to the burning of rice straw, in this study, an effort is made to convert rice straw into an useful product by torrefaction process, i.e. biocoal. The biocoal which has the calorific value equivalent to that of bituminous coal is used in thermal power plants. By optimizing the processing parameters of torrefaction process, desired calorific value of torrefied product has been archived. The 10% use of torrefied product with coal can consume 140 million tonnes of rice straw and as a consequence, it reduces the consumption of fossil fuels. This can greatly solve problems arising due to burning of rice straw and reduce greenhouse gas emission significantly.