The advent of near-zero sulphur emission legislation for diesel fuels, combined with the need to develop better ways of handling heavier hydrocarbon feedstocks, means that creating more effective hydrodesulphurisation (HDS) catalysts is more important than ever. A new approach to catalyst preparation being developed by Oxford Catalysts could provide the key to providing the improvements needed.
Experiments carried out at Oxford Catalysts suggest that it is the preparation method – rather than the identity or combination of metals used – that has the greatest influence on the performance of HDS catalysts.
In a talk to be presented on 9 April at the 235th American Chemical Society Meeting in New Orleans, Louisiana, US, Dr Tiancun Xiao will discuss studies carried out in collaboration with his Oxford Catalyst colleagues, Doctors Sergio Gonzáles-Cortés and Sreekala Rugmini, that demonstrate the improved performance in HDS catalysts created using Oxford Catalysts' patented organic matrix combustion preparation method compared to those containing the same metals but produced using standard impregnation methods.
The group's experiments reveal that monometallic, bimetallic and trimetallic HDS catalysts prepared using organic matrix combustion perform better than HDS catalysts of similar compositions prepared using impregnation methods. But that is not the end of the story.
When comparing the performance of different types of HDS catalysts prepared using the organic matrix method the group found – as expected – that the bimetallic performed better than the monometallic catalysts. However, the performance of the trimetallic catalysts – though still better than that of catalysts prepared via impregnation – was worse than that of the bimetallic catalysts.
Dr Sergio Gonzáles-Cortés, Research Scientist, Oxford Catalysts says:
"This result was a surprise. We don't yet understand why this happens, but we think that it may be due to the strong interaction between cobalt and nickel. This is an exciting area of research for our company!"
Posted April 9th,2008