Technical Economic and Environmental analysis of Chemical Looping versus oxyfuel combustion for NGCC power plant

Abstract

The Power Sector is undergoing a rapid technological change with respect to implementation of low carbon technologies. The IEA Energy Outlook 2017 shows that the investments in Renewables for the first time are equal to those on the fossil sources. It is likely that the conventional gas turbines and internal combustion engines will need to be integrated in systems employing biofuels and/or CCUS (Carbon Capture Usage and Storage). Also, the European Union is moving rapidly towards low carbon technologies (i.e. Energy Efficiency, Smart Grids, Renewables and CCUS), see the Energy Union Strategy. Currently 28% of the installed power capacity in Europe is based on natural gas plants. Gas-based power capacity has reached 418 GW in 2016 and is likely to continue to grow in the future. To efficiently capture the carbon dioxide emissions generated by the combustion of natural gas in the combustion chamber a possible solution could be to adopt new combustion processes, like Chemical Looping Combustion. The combination of CLC and GTs can decrease the efficiency of a combined cycle power plant from 60% to about 40.34%. These performances influence costs and environmental burdens and this is also the same for oxyfuel combustion, which is a competing technology to realize CCS. This paper, starting from literature mass and energy balances of a conventional combined cycle, a combined cycle coupled with chemical looping combustor and a combined cycle coupled with oxyfuel combustion, calculates the reduction of CO2 emissions which can be achieved during the whole life cycle of the power plant and then identifies the value of the carbon credit which is needed to have an interesting payback period for such kind of investment.