Biomass integrated gasification combined cogeneration with or without CO2 capture – A comparative thermodynamic study

Fossil fuels presently cater to majority of energy demand of the world. However, due to the climate change problem capture of CO2 emitted from the use of fossil fuels is emerging as a necessity. Alternately, developing technology with CO2 neutral fuels may reduce green house gas emission. Possible even better solution may be combining both of these options, i.e., employing CO2 capture process for energy efficient system using CO2 neutral fuels, say biomass. In this paper, such cogeneration system with CO2 capture using amine solution has been proposed. Thermodynamic modeling for the detail process has been implemented using ASPEN Plus®. Comparative study of performance relative to a similar base case plant without carbon capture has been presented. Results show post combustion CO2 capture process is better than pre-combustion CO2 capture process for such plants with net negative CO2 emission. Also degree of CO2 capture has to be optimized on the basis of the overall performance of the plant as higher CO2 capture affects thermodynamic and economic performance of the plant, specifically beyond certain value. In a net CO2 negative emission plant extent of CO2 capture is quite flexible and may be decided for optimum performance.