Producing fuel from air and electricity

A University of Canterbury lecturer in New Zealand is researching the possibility of producing fuel from air and electricity. The technology removes carbon dioxide from the atmosphere and produces methanol, a liquid fuel similar to petrol. UC researcher Dr Aaron Marshall said efficient conversion of carbon dioxide into methanol would revolutionise energy technologies. He has received a Marsden Fund study grant to look into cutting-edge technology.

“We still need energy to carry out the process. Basically we make fuel (methanol) from carbon dioxide in the air and electricity. But in principle we would not need oil/petrol if this could be done efficiently on a large scale using renewable energy like wind or solar power. Methanol can be used in normal car engines,” Dr Marshall said.

“Theoretically not much energy is required. Most people think carbon dioxide is a very stable compound that would be really hard to turn back into fuel but actually only 1.2 V of electricity is required. Unfortunately, the reaction is complex which means we need to use much more energy than theory suggests.

“Imagine driving to Lyttelton from Christchurch. Both places are at a similar altitude so it shouldn’t require too much energy to get there. But if the only path is over the Port Hills, then you need lots of energy to climb the hill. We are basically looking for the Lyttelton tunnel.

“If we burn methanol, we get carbon dioxide, water and energy as products. We can produce methanol by making this ‘normal burning process’ go backwards on the surface of a catalyst by using electricity.

“We will use a combination of electrochemical and surface structure analysis tools to find out what the ‘sweet spot’ looks like on this catalyst to understand how to make the process better.”

Renewable energy (such as solar and wind power) is difficult to store, especially for use in transportation. One potential solution is to use this renewable energy to re-convert CO₂ from the atmosphere back into a fuel such as methanol.

This effectively results in carbon-neutral energy storage. At present only a fraction of the energy used in the process results in methanol production, with the majority of the energy wasted as heat or used up through the production of unwanted by-products.

This project aims to investigate how to make the process commercially and industrially feasible.

Dr Marshall will be collaborating with Professor David Harrington from the University of Victoria in Canada - an alumnus of UC who has expertise in this area.