Assessment of copper-based chemical looping air separation system for energy efficiency improvements of oxy-combustion and gasification power plants

Chemical Looping Air Separation (CLAS) is a promising solution for energy efficient large scale oxygen production in comparison to the existing technologies (e.g. cryogenic air separation). This paper is evaluating the copper-based CLAS system used in conjunction with two power generation technologies based on coal oxy-combustion and gasification processes. Since the power generation sector is facing significant environmental constraints in term of reducing greenhouse gas emissions, the evaluated power plant concepts are equipped with carbon capture. As benchmark cases used to quantify the efficiency improvements as well as the CO2 capture energy penalty, similar power generation schemes with and without carbon capture were considered using cryogenic air separation as oxygen production method. Firstly, the assessment was concentrating on a CLAS system with 100 t/h oxygen output to assess the main issues (conceptual design, ancillary mass & energy consumptions, thermal integration) and then the system was scaled-up to match the oxygen consumption of large scale power plants with 400-500 MW net power output and 90% carbon capture rate. As the evaluations show, the CLAS system is increasing the net power efficiency by about 3 percentage points for the oxy-combustion plant and about 1.4 percentage points for the gasification plant.