Pellets processing and co-firing in a thermal power plant

Abstract

Majority of power plants of India are running on coal. To reduce the greenhouse gas emitted from these coal-based power plants, the power generating stations intends to utilize agriculture residue-based pellets. Agro residue-based pellets combustion is renewable source of energy. The use of agro based briquettes in densified form reduces air pollution which is mainly due burning of stubble. Apart from generation of smog in winter season, stubble burning in fields also reduces soil fertility. Central Electricity Authority, Ministry of Power (MoP) issued an Advisory for utilization of agro remains or residue-based pellets for power generation. Co-firing in a coal fired thermal power plants states to promote the use of the biomass pellets. All pulverized based coal units of electrical power generating units shall make efforts for using 5-10% blend of biomass-based pellets. These pellets must be primarily from residual agriculture waste. The generating units must keep in account of all the technical feasibility, safety aspects etc.In line of these directives, I intended to study pellet firing aspects in a thermal power plant and the parameter which will affect the behavior of thermal plant as compared to their normal operation with coal as raw material. Therefore, a pilot projects was carried out to replace 7% coal with agro based biomass pellets/ torrefied/non-torrefied (density) biomass pellets in thermal power plants. The boiler operating procedures and technical modification required were studied thoroughly, and it was deduced that co-firing can come out as a potential high-efficient energy solution to all the energy problems with added benefits of safer and cleaner substitute to fossil fuels. In addition to that, it will help reducing emissions of greenhouse gases and improve the economic condition of farmers which is a win situation.