The oil reserves stored in the Earth are an enormous energy resource, but the carbon dioxide and particulate pollution caused by burning petroleum products are major environmental concerns. KACST researcher Hamid Al-Megren is among a team of researchers that has found a potentially transformative solution.
They use microwaves and metal catalysts to convert the hydrocarbons in crude oil into hydrogen gas and solid carbon. Hydrogen can be used as a fuel that releases only harmless water as an end product. The new procedure could allow oil to continue to power the planet, while turning off the major cause of increasing carbon dioxide levels in the atmosphere.
Al-Megren is based at the KACST Petrochemical Research Institute, and worked on the project with scientists at the University of Oxford, University of Cambridge, and the University of Cardiff in the UK.
“Hydrogen offers the prospect of a highly effective fuel for future sustainable energy [and] promises a sustainable energy revolution,” the researchers write in the journal Angewandte Chemie, explaining the potential of their discovery.
Earlier work has shown that hydrogen can be released from hydrocarbons using heat, but the new research suggests that microwaves can trigger a much more efficient and effective procedure.
The other key to releasing the hydrogen fuel is a metal catalyst. Crucially, the researchers have found effective candidates composed of the abundant and inexpensive metals, nickel and iron.
In their proof-of-concept trials, they demonstrated that a range of liquid hydrocarbons, similar to those in vehicle fuels, could generate very high purity hydrogen at an efficiency of 96%. The molecules that initially had tightly bonded carbon and hydrogen atoms were split into carbon and hydrogen with only tiny percentages of undesirable products. These included only around 0.2% of carbon dioxide and as little as 0.5% carbon monoxide.
“We believe these findings offer a new and attractive path towards a decarbonized fossil fuels economy,” the researchers say. They point out that the carbon that is also released from the hydrocarbons can readily be recycled into other materials through a variety of established chemical processes.
The economic and political significance of being able to extract oil while avoiding the major environmental problems associated with its use can hardly be overstated. New oil reserves are still being found worldwide and using it to generate hydrogen, rather than burning it, could meet the needs of the oil industry, the global economy and the environment all at the same time.
Xiangyu, J., Gonzales-Cortes, S., Xiao, T., Wang, J., Yao, B. et al. Rapid production of high-purity hydrogen fuel through microwave-promoted deep catalytic dehydrogenation of liquid alkanes with abundant metals. Angewandte Chemie International Edition 56, 10170-10173 (2017). | article