Abstract

India is a predominantly agricultural country that produces a total biomass about 600 Mt annually, of which 150–200 Mt is regarded as waste (UNDP 2011). However, about 85 Mt of this unused biomass, especially agricultural residues such as straw and stubble, are burned in open fields by farmers. This surplus biomass could be used as feedstock for animals and as an energy source for domestic and industrial. The wasted biomass could also be used to generate biofuel by way of thermochemical conversion. Of the various thermochemical conversion technologies for biomass, pyrolysis is one of the more economically feasible. It primarily produces raw biochar, bio-oil, and syngases. The produced biochar contain a higher percentage of organic carbon and can be further modified by two activation methods (physical and chemical) to produce activated biochar. Activated biochar has a larger surface area, greater porosity, more surface functional groups, and greater cation-exchange capacity, all of which play an important role in wastewater treatment.