ORACLE: Odorant RemovAl by Chemical Looping dEsulphurisation

Work in this grant will look at the uses of oxygen carriers in processes to assist in the removal of odorant compounds from natural gas. The odorants are added so that leaks of gas can be detected by the smell, however, they pose problems for any use the natural gas which is not tolerant of sulphur. in particular fuel cells use catalysts which are deactivated by sulphur. It is therefore necessary to remove the odorants before the natural gas can be used in these systems. An oxygen carrier uses oxygen held within the solid material to burn a substance, and can then be regenerated itself with air. We will
look at the selectivity and efficiency of various oxygen carrier materials towards the combustion of sulphur containing compounds. This process, if found to be suitable can then be used in a system which first combusts the sulphur compounds to sulphur dioxide so that it can be removed by standard methods.

This project will work closely with the lead SME (GR2L) and Johnson Matthey (JM), one of the world's leading catalyst manufacturers. Chemical looping combustion was originally proposed as a way of increasing the efficiency of powerstations, reducing NOx and performing carbon capture. However, any large scale industrial use in the power sector is many years from application, largely owing to the massive capital outlay and the risk involved with this technology. Early adoption of chemical looping technology is therefore likely to be at a much smaller scale and in niche areas. One such application is gas clean up and recovery. GR2L already exploit this technology in their Argon0 system. A key way to achieve impact is therefore to find alternative applications for chemical looping technology and to work with industrial partners who have an unmet need. Working closely with GR2L and JM in this project means that the results will have immediate impact, and be directly applicable to industrial applications.

The particular application of the chemical looping technology in this work, is to assist in the removal of contaminates from methane. At present many processes which can be used to convert natural gas are inhibited by the sulphur compounds used to add odour. Thus, a cost effective and more generic way of removing these compounds safely will enable natural gas to be used more efficiently in point of use processes (e.g. small fuel cells, whose catalysts are poisoned by sulphur). This will have wider benefits to society at large, since the proposed methods of removing the sulphur are environmentally
benign and safe, and their implementation will remove one of the barriers to wider adoption of e.g. efficient, small scale fuel cell system for combined heat and power.