By Kawser Abdulahi
Alcohol made from thin air seems to be the kind of stuff students dream of, but that’s exactly what researchers here at Cardiff University have done – although it’s not the drinking kind, yet.
Scientists at the Cardiff Catalysis Institute have found a cleaner, greener and cheaper way of producing methanol, the simplest form of alcohol, from methane using oxygen in the air. Professor Hutchings, a pioneer of gold-catalysis, and his team have, using gold-palladium nanoparticles, developed a novel way of forming methanol via a chemical reaction oxidising methane with oxygen(O2) and hydrogen peroxide(H2O2) at lower temperatures (50ºC).
Professor Graham Hutchings, Director of Cardiff Catalysis Institute, said: “We have already shown that gold nanoparticles supported by titanium oxide could convert methane to methanol, but we simplified the chemistry further and took away the titanium oxide powder. The results have been outstanding…”
Currently, in industry, methanol is produced from the breakdown of natural gas (methane) into carbon monoxide(CO) and hydrogen gas(H2) at high temperatures (200ºC to 500ºC) before being reassembled in another, highly pressurised process of the two-stage ‘steam reforming’ and ‘methanol synthesis’ systems. This is a highly expensive and energy consuming, whereas the new method can be done in a single step at a considerably lower temperature no higher than 50ºC.
At the moment, after the conversion of natural gas into a liquid state, it is transported in pressurised containers for the next step. This new technique introduces the possibility of methanol manufacture in a single site, converting natural gas into methanol, simplifying the industrial processes of chemical and plastic production. Since methanol is more reactive than methane, it is key in industrial manufacture and can be easily converted into a variety of fuels and chemicals.
Professor Hutchings, added: “The quest to find a more efficient way of producing methanol is a hundred years old. Our process uses oxygen – effectively a ‘free’ product in the air around us – and combines it with hydrogen peroxide at mild temperatures which require less energy.”
Prof Hutchings was recently recognized for his contribution in the field of energy. He was the recipient of the prestigious ENI award, an international prize for excellence awarded to the most advanced scientific breakthroughs in the fields of energy, sustainability and the environment.
The award was for the ground-breaking research that led to the development of a gold catalyst, that replaced the extremely toxic mercury catalyst previously in use. This catalyst is now being used in the mass production of vinyl chloride, the main ingredient in PVC, which is a key component in the manufacture of everything from doors to drinking bottles.
With depleting fossil fuel stores and the negative effects of climate change increasingly evident, research into alternative, greener methods of methanol production are vital.
Dr James J. Spivey, Professor of Chemical Engineering at Louisiana State University and Editor-in-Chief of Catalysis Today, said: “This research is of significant value to the scientific and industrial communities. The conversion of our shale resources into higher value intermediates like methanol provide new routes for chemical intermediate.”
If produced in sufficient quantities, methanol, which is currently used in the manufacture of biodiesel, can be used as an alternative to petrol.
Regarding the future, Prof Hutchings said: “Commercialisation will take time, but our science has major implications for the preservation of natural gas reserves as fossil fuel stocks dwindle across the world.”
He added: “At present global natural gas production is ca. 2.4 billion tons per annum and 4% of this is flared into the atmosphere – roughly 100 million tons. Cardiff Catalysis Institute’s approach to using natural gas could use this “waste” gas saving CO2 emissions. In the US there is now a switch to shale gas, and our approach is well suited to using this gas as it can enable it to be liquefied so it can be readily transported.”
Albeit still in its infancy, the research by Prof Hutchings and his team, using gold nanoparticles to form methanol using oxygen in the air has significant implications for both industrial and scientific communities.
Read the full article ‘Aqueous Au-Pd colloids catalyze selective CH4 oxidation to CH3OH with O2 under mild conditions’ published in the journal Science.