Integration options for novel chemical looping air separation (ICLAS) process for oxygen production in oxy-fuel coal fired power plants

Oxygen is commonly produced at industrial scales by air separation using cryogenic air separation units (CASU). Despite being the most matured technology, CASU is highly energy intensive. Approximately, 3-4% energy penalty is expected to be arising for oxygen production using CASU in the oxy-fuel process. As an alternative to CASU, this paper demonstrates the integrated chemical looping air separation (ICLAS) process for oxy-fuel thermal power plant which is expected to offset the energy penalty associated with CASU. In our recent comprehensive thermodynamic study, three metal oxide systems (Mn, Co and Cu) were found most suitable for chemical looping air separation (CLAS). The objective of this work is to find out the possible integration modes of the CLAS process with oxy-fuel coal-fired power plants. Thermodynamic process simulations were carried out for ICLAS in oxy-fuel using Fact-sage 6.1 database for all selected oxygen carriers and process kinetics have not been considered. The effect of several process parameters such as operating temperature, heat recovery, actual partial pressure in the reactors and chemical conversion of the oxygen carriers on the operating cost of the ICLAS process were investigated in detail. The results indicate that for acceptable process kinetics ICLAS can potentially run at much lower operating costs compared to an advanced CASU based system by 2020. Crown Copyright (c) 2013 Published by Elsevier Ltd. All rights reserved.