Heat and Power Production Using Integrated Oxygen Blown Biomass Gasifier Prepared for Future Co-production of Transportation Fuels - Technical, economic and environmental analysis

Paper i proceeding, 2004

This study evaluates integration of an oxygen-blown biofuel gasifier to a natural gas combined cycle combined heat and power (CHP) plant. The CHP plant and gasifier are assumed to be designed for future co-production of CO2 neutral heat, electricity and transportation fuels (energy combine plant). The paper investigates the consequences of substituting natural gas with gasified biofuel for conventional CHP plant operation. Results are for a gasifier integrated to a large size CHP plant producing electricity and district heat. The power plant simulation program GateCycle is used for plant performance evaluation. The study investigates the technical and economic performance of the CHP plant and the consequences for global fossil CO2 emissions. Costs and/or income associated with anticipated energy policy instruments are included. The results show that integrating an oxygen-blown gasifier to the CHP plant can be an attractive option if policy instruments favouring production of transportation fuels from biomass are expected in the future. The assumed value for costs associated with emitting CO2 is 250 SEK/tonne. A price premium of 200 SEK/MWh for electricity based upon renewable energy sources is also assumed. The resulting cost of electricity (COE) for a NGCC CHP plant co-fired with oxygen-blown gasified biofuel is 367 SEK/MWh compared to 354 SEK/MWh if the gasifier is air-blown. The corresponding reference power market price is 384 SEK/MWh. The relative differences between COE values for the different configurations considered are very dependent on the assumed values of energy policy instruments.