The search for fuels without contaminant components

To convert a gaseous fuel into a clean liquid one is the target of the research project being undertaken by the School of Industrial Engineering and Telecommunications Engineers of Bilbao in the Basque Country. It involves, in the final analysis, obtaining fuels which do not have contaminant components, i.e. sulphur, nitrogen or aromatic components.

Participating in this project, financed by the MARCO programme of the European Union, are nine groups from different European countries, under the co-ordination of the School of Engineering. All of them are researching ways of obtaining clean fuels from natural gas.

The process basically consists of two stages: the first involves converting natural gas into synthesised gas, a mixture of carbon monoxide with carbon dioxide and hydrogen. In the second phase, this synthesised gas produces carbohydrates, from which petrol is subsequently produced.

The tasks corresponding to this first stage are being undertaken in a pilot plant at the University of the Basque Country (EHU/UPV). To this end, the EHU/UPV has a small reactor for such experiments. Fundamentally, work is being carried out to obtain catalysts for the conversion of the natural gas into that synthesised gas. These are necessary for the subsequent manufacture of hydrocarbons and what is being sought are catalysts where reactions can take place at lower temperatures, with greater criteria of selection, technically more efficient and economically more viable as well – in other words, reactions which are cheaper than those conventional catalysts. These catalysts, once prepared with these modifications and innovations and characterised, they have to be tested, i.e. they have to be made to react. Making the natural gas react with oxygen and also with water vapour in order to produce this synthesised gas, comparing how the different catalysts behave and selecting those showing the greatest advantages.

The process is very simple. The gas is introduced into the reactor, which is full of an inert material. The catalyst is introduced into the mix and the reaction initiated. This is the moment of transformation: the methane and oxygen converts into hydrogen and carbon monoxide. These gases go through a condenser, in which the water is drawn off and the gas is taken to the gas chromatograph.

In this machine the parts that have not reacted are analysed, as well as the yield (i.e. the level of conversion), etc. Aapart from testing the behaviour of various catalysts, researchers at the EHU/UPV experiment with the temperature, pressure, capacities, etc. All these parameters are controlled by computer.

Researchers have developed catalyst prototypes that notably enhance the behaviour of commercial products, as well as achieving the possibility of carrying out conversions at lower temperatures. Industrial application of the mentioned improvements considerably lower the production costs.

Researchers at the EHU/UPV are quite aware that natural gas reserves will one day dry up: This is why they are studying the possibilities of getting similar results from, for example, the gasification of the biomass. The research project is to finish in December of next year.