Biomass Charcoal Co-Firing With Coal

Many biomass power plants operating today are small plants characterized by low efficiencies. The average biomass power plant is 20 MW with a biomass-to-electricity efficiency of about 20 percent. Small biomass power plants are also costly to build. Co-firing biomass with coal in existing large, low cost, base load pulverized coal (PC) power plants has been suggested as a cost-effective, near term opportunity for biomass power. However, co-firing of biomass in PC boilers requires addition of a separate biomass feed system. The proposed concept avoids a separate feed system by converting biomass to charcoal for co-firing with coal. Fuel supply reliability would be improved by producing and stockpiling charcoal at dedicated facilities located off the power plant site. With an energy density similar to coal, charcoal could be transported more economically than biomass. Overall costs for co-firing charcoal and coal would be lower than systems co-firing biomass. Investment in Clean Coal Technologies could also be leveraged for biomass energy use by co-firing charcoal with coal in Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluid Bed Combustion (PFBC) power systems.