GT2004-54194 CO-UTILIZATION OF FOSSIL AND RENEWABLE FUEL: BIOMASS GAS/NATURAL GAS

ABSTRACT Recently natural gas prices have increased very substantially and USA's imports have reached 19% of consumption. These trends are due, in part, to the growing number of low capital cost natural gas combined cycle (CC) electrical generating systems. A way of alleviating high NG prices would be to convert local biomass into a biomass gas (BG) for co-utilization with NG. Essentially, construct a biomass integrated gasifier (BIG) CC system or co-generator system (CG) to matched the nearby biomass supply to deliver supplementary BG to an existing NGCC system or an old steam plant to be repowered. If the combustion turbine is robust, retrofitting costs of the NGCC should be modest. The BG might also be used as a supplementary fuel for the heat recovery steam generator (HRSG) and provide added electrical capacity. We consider the technological and economic circumstances required for these forms of co-use to benefit all participants and serve as a sensible use of biomass as a CO 2 neutral fuel. As an illustrative case we consider an adaptation of the Kelly plant in Gainesville Florida that has already been partially re-powered with a NGCC system. We conclude that in rural areas with nearby access to good biomass supplies BG-NG-CC or BG-NG-CG can produce cost competitive electricity particularly when NG prices exceed $4/MBU