Novel design of chemical looping air separation process for generating electricity and oxygen

Abstract

The continuous- and batch-types chemical looping air separation (CLAS) processes are developed by using Aspen Plus® software. Through the heat integration of CLAS systems and oxy-fuel combustion of methane (OCM), new continuous- and batch-types of stand-alone electricity/oxygen production systems are denoted as Designs 1 and 2, respectively. The redox performances of both CLAS processes regarding Cu-, Mn-, and Co-based oxygen carriers with different ratios of inert binders are evaluated in terms of power/oxygen production ratios and specific CO2 emissions. A few comparisons show that (i) Design 1 using Cu- or Mn-based oxygen carriers at prescribed temperatures and normal pressures of oxidation and reduction can ensure almost zero CO2 emissions if the outlet 97 vol% of CO2 can be captured, (ii) Design 2 using Cu-based oxygen carrier with 83 wt% MgAl2O4 at a pressure of 8 atm and a temperature of 1070 °C during oxidation ensures almost zero CO2 emissions as well as the highest power production ratio, and (iii) Design 2 using Mn-based oxygen carrier with 37 wt% MgAl2O4 at a pressure of 15 atm and a temperature of 930 °C during oxidation ensures almost zero CO2 emissions as well as the largest oxygen production ratio.