Ionic liquids could be the key to a commercial process for converting natural gas to methanol.

Using remote reserves of natural gas, whose main component is methane, is currently a challenge. By converting the gas to a liquid, such as methanol, it becomes much easier to store and transport.

Platinum based catalysts are known to be effective for direct methane to methanol conversion. Now, Yongchun Tang and colleagues at the California Institute of Technology's Power, Environmental and Energy Research Center in Covina, California, US, have come up with an improvement on previous catalytic methods. The researchers used platinum salts, such as platinum chloride, dissolved in ionic liquids and concentrated sulfuric acid to selectively convert methane to methanol. 

Tang's system is relatively high yielding, and the catalyst is not inhibited by the water produced during the reaction - a problem for previous methods like the Catalytica system, developed by catalyst company Catalytica Advanced Technologies, California, US.

'We hope that this work will lead to a cost effective and field-deployable commercial process converting gas to liquid in the near future,' said Tang. 'But first we must improve the performance of the current systems.' 

Roy Periana, at the University of Southern California, US, is one of the inventors of the Catalytica system. 'I am always very intrigued by possible improvements to that system. If ionic liquids could be used to minimize water inhibition as well as increase catalyst rates, this could be a substantial improvement that could eventually push us closer to developing commercial catalysts,' he said.

Susan Batten