North American gas companies have asked odour experts at Cardiff University to solve the potentially lethal problem of shale gas losing its smell.
Gas companies in the US are legally obliged to mix chemicals with shale gas to create a distinctive bad egg smell, gas companies perform the same process on natural gas from other sources as well. The odour allows gas customers to detect leaks early before the gas builds up to explosive levels. However, there are reports in the US that the gas sometimes loses its smell, potentially placing customers at risk.
Shale gas is used more widely in the US than in the UK. However, as debate continues about using shale gas deposits in Britain, including deposits in South Wales, the Cardiff research could soon be relevant here.
The research contract was awarded to Cardiff by NYSEARCH, a voluntary Research and Development organisation representing twenty gas companies in North America and administered by the Northeast Gas Association (NGA).
A mixture of chemicals called mercaptans is added to the gas to give it an odour capable of being detected at below the lower explosion limit in air. Cardiff University has been asked to explain why the gas can lose its odour en route to the customer in the US, even though the mercaptans can be detected by gas chromatography and are still present at the appropriate levels.
The University’s Olfactory Lab in the School of Biosciences, led by Professor Tim Jacob, a world-leading authority on smell, will address the problem by examining the mechanisms of ‘odour masking’.
Professor Jacob said, “It is not fully understood how gas can lose its odour. We suspect there is organic material present in the gas which can bind to the mercaptans or their receptors and make them lose their odour. Our project aims to discover those compounds which most effectively mask mercaptans and how these compounds achieve this masking. This knowledge will enable the US gas industry to avoid the problem of odour masking and develop new strategies for the odorisation of natural gas.
“This is a pressing issue in the US, where use of shale gas is widespread. However, if we see greater use of shale gas in Wales and the rest of the UK, our research could be very useful to British gas suppliers as well.”