Decarbonised coal energy system advancement through CO2 utilisation and polygeneration

Abstract

Development of clean coal technology is highly envisaged to mitigate the CO2 emission level whilst meeting the rising global energy demands which require highly efficient and economically compelling technology. Integrated gasification combined cycle (IGCC) with carbon capture and storage (CCS) system is highly efficient and cleaner compared to the conventional coal-fired power plant. In this study, an alternative process scheme for IGCC system has been proposed, which encompasses the reuse of CO2 from the flue gas of gas turbine into syngas generation, followed by methanol synthesis. The thermodynamic efficiency and economic potential are evaluated and compared for these two systems. The performances of the systems have been enhanced through systematic energy integration strategies. It has been found that the thermodynamic and economic feasibilities have attained significant improvement through the realisation of a suitably balanced polygeneration scheme. The economic potential can be enhanced from negative impact to 317 M€/y (3.6 €/GJ). The results have demonstrated promising prospects of employing CO2 reuse technology into IGCC system, as an alternative to CCS system.