Dr Hyungwoong Ahn has been awarded funding from the EPSRC in the First Grant Scheme for a project on "Carbon Capture in the Refining Process". This is the first proposal awarded by the EPSRC that looks at non-power plants.

In the refinery, CO₂ comes from two different sources - firstly by fuel combustion in the CHP boiler (around 35% of total CO₂ emissions) and from the process heater/furnace (around 45%), and secondly from the H₂ plant (around 20%). In the case of CO₂ emissions by fuel combustion, accounting for around 80% of total emissions, the sources are widely distributed throughout the complex and their flue gas has a relatively low CO₂ fraction (4-15%). Therefore, deploying and operating carbon capture units to these sources results in significant capital investment and running cost as well as operational difficulty. Unlike fuel combustion, the CO₂emissions from the H₂ plant are characterised by a single source having highly concentrated CO₂ (50-60%), which implies that it would be economically more feasible to capture CO₂ from the H₂ plant than from the other sources in the refinery. Moreover, it is likely that the H₂ demand in the refinery will increase rapidly with a change in crude oil slate from 'Sweet and Light' to 'Sour and Heavy'. As a result, the CO₂ emission at H₂ plants will become more and more significant in terms of abatement of carbon emission in the refinery.

The research aim of the project is to develop a Vacuum Swing Adsorption(VSA) process to capture CO₂ from a SMR-H₂ plant in the refining process. For post-combustion capture, the amine process is, to date, closest to commercialisation and ready to be deployed, but a cyclic adsorption process can be more energy-efficient than the amine process in this particular case due to the higher CO₂ fraction in the feed. The research will focus on finding an optimal configuration for a CO₂ VSA process using a commercially available adsorbent. The target is to achieve 90+% CO₂ recovery with 95+% purity from the H₂ PSA off-gas. A lab-scale multi-column VSA rig will be constructed in the adsorption labs at Edinburgh to demonstrate that the target is achievable with a well-designed cyclic adsorption process. The design and optimisation of the VSA process will be facilitated by a proper simulation work integrated with an optimiser. An overall process design of an example H₂ plant integrated with the VSA process will be implemented for the purpose of optimising its steam network.