The Fischer-Tropsch process
The Fischer-Tropsch (FT) process was developed in Germany in the early part of the last century as a way to produce liquid fuels, such as diesel, from coal. Initially, the availability of cheap oil meant that the FT process was only used when political expediency required it. It was used, for example, in Germany during the second world war, and in South Africa during the apartheid era.
In the FT process, a synthesis gas (syngas) consisting of a mixture of carbon monoxide and hydrogen, is converted into hydrocarbons over a catalyst. Oxford Catalysts' patented technology allows the typically cobalt catalysts to be produced with a reduced need for precious metal promoters, without any loss of performance and in fact with superior activity, selectivity and stability to conventional catalysts.
It is now possible to use feedstocks such as natural gas and biogas, as well as coal, for the production of synthetic fuels. The range of products produced is broad and includes diesel, jet fuel, naphtha and bases for synthetic lubricants. Generally these are of higher quality than those derived by conventional means, having no sulphur or aromatics.
FT microchannel reactors
Microchannel reactors are designed for economic production on smaller scales. FT microchannel reactors are compact and have channels with diameters in the millimetre range. Conventional reactors are many times larger and have channel diameters in the centimetre range. Because the smaller diameter channels in microchannel reactors dissipate heat more quickly than those in conventional reactors, more active catalysts can be used to achieve superior conversion rates.
When used with superactive FT catalysts developed by Oxford Catalysts, the Velocys microchannel FT reactor operates economically at 1,000 bpd (or more) and exhibits conversion efficiencies in the range of 70% per pass.
In contrast, conventional FT plants typically exhibit conversion efficiencies in the range of 50% or less per pass. They are designed to work at minimum capacities of 5,000 bpd, and function well and economically only at capacities of 30,000 bpd or higher.