Simulation of Perovskite membrane for integration into a chemical looping air separation unit

摘要

The Chemical Looping Air Separation (CLAS) process was developed at the University of Newcastle for tonnage oxygen production. CLAS has a much lower energy intensity than conventional processes, requiring only 12 % of the specific power consumption; however, there are still some energy penalties associated with the CLAS process. The most significant being the large amounts of energy consumed in the steam generation and condensation processes. The aim of this study is to increase the energy efficiency of the CLAS process via membrane integration. If a high temperature oxygen transport membrane is introduced in the reduction reactor of the CLAS system, pure oxygen is produced without the need for a steam condenser. The most attractive oxygen transport membrane is Ba0.5Sr0.5Co0.8Fe0.2 (BSCF) owing to its high oxygen permeation flux. The BSCF membrane was utilised to study the oxygen permeation flux, oxygen recovery and energy saving of the integrated process compared to the typical CLAS process. A mathematical model was developed for the BSCF disk membrane to predict the oxygen permeation flux and oxygen recovery over a range of temperatures. Constants of the model were fitted using experimental data. The modelling results showed almost 10 % and 13 % energy savings in the low and high temperature membrane integrated CLAS processes over the typical CLAS, respectively.