387 Process Synthesis with Heat Integration of Decarbonised Coal Energy Systems Kok Siew Ng, Nan Zhang, Jhuma Sadhukhan* Centre for Process Integration, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom. Jhuma.Sadhukhan@manchester.ac.uk Development of clean coal technology is highly envisaged to mitigate the CO 2 emission level while 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 recycling and re-use of CO 2 from the flue gas of gas turbine into a secondary syngas processing route, proceeding with conversion of syngas into methanol. The system modification requires extensive mass and energy integration strategies to ensure that the efficiency and economics of the system are achieved to a considerably high level. The thermodynamic and economic feasibilities of the modified IGCC system were found to attain tremendous improvements. The thermal efficiency has been increased from 54% to 89.3%, whilst the economic potential has been enhanced from 48.1 M€/y to 377.4 M€/y. These results have shown good future prospects for employing CO 2 re-use technology into IGCC system, as an alternative to CCS system. 1. Introduction Currently, 40% of the global electricity is supplied from coal and it is expected to increase over the next few decades (World Coal Association, 2010). Coal-fired power plant is the predominant technology for generating electricity from coal, emitting approximately 2.9 Mt CO 2 per year to the atmosphere from 500 MW e plant (IPCC, 2005). The energy and industrial sectors, including power station, manufacturing and transportation contribute to 77.9% (2005) of the global CO 2 emission, and 54.8% (2008) of the CO 2 emission in the UK (Prime et al., 2009; World Resource Institute, 2010). The CO 2 emission from coal and other solid fuels shares 25.6% of the total CO 2 emission by fuel in the UK, i.e. 531.8 Mt CO 2 in year 2008 (Prime et al., 2009). IGCC has higher efficiency than conventional coal-fired power plant through the application of cogeneration concept. IGCC is also cleaner and has high potential in capturing CO 2 . Carbon capture technologies such as pre-combustion, post-combustion and oxy-fuel combustion are prominent. Other emerging technologies are undergoing rapid development including chemical looping and oxygen transport membrane. The inclusion of carbon capture facilities normally increases the overall capital investment