Call it the ultimate conjuring trick: British engineers have created petrol literally from thin air. Air Fuel Synthesis (AFS), a company in Stockton-on-Tees, UK, has created a plant in two shipping containers which produces half a litre of purified petrol every day.
The idea of producing petrol from air first came into vogue with the fuel crisis of the 1970s, but as oil prices dropped, interest in the idea- as with interest in so many novel fuel technologies- moved to the back-burner. With oil prices once more rising, and the threat of climate change galvanising people to explore alternative fuel sources, air-derived petrol seems once more to be a very attractive prospect.
The basic concept entails extracting water and carbon dioxide (CO2) from air, then using the constituent carbon, oxygen and hydrogen in these compounds to create petroleum. Because the CO2 produced by burning air-derived petrol would already have come from the air in the first place, using air petrol in our vehicles would be a carbon-neutral process. Thus, as long as the energy used to create the petrol in the first place came from renewable sources- for instance, from wind farms or solar power- air petrol would be a totally “green” product.
As yet, however, AFS’s petrol is not green. In fact, AFS has not yet established that the process is even energy-efficient; that is to say, that producing the petrol requires less energy than will be gained from burning it. The plant is intended solely to prove the viability of the process, and not, in the company’s words, “to prove its net efficiency or energy balances”. Proof of efficiency, they say, must wait for a proposed larger plant: AFS plans to build a plant which fits in three shipping containers, and produces 1200 litres of petrol per day. This plant will hopefully demonstrate efficiency. Ultimately, AFS wants to build plants on the scale of refineries, which would cost around £10 billion each; but government funding for such plants, of course, will be contingent on proof of efficiency.
In the meantime, the company deserves credit for proving that the idea is workable at all. Peter Edwards, an inorganic chemist at the University of Oxford who is working on a similar with a Saudi firm, notes that AFS has “taken a concept that has been around for 35 years and gotten the process going.” He notes that even if the process can be proven efficient, though, it must compete with other emissions-reducing technologies: “The efficiency of this process would also have to balanced against the cost of alternative measures like burying or dumping CO2 underground.”
The technology, then, has a while to go in proving itself, but the idea is highly attractive. Air-derived petrol would allow humanity to reduce emissions drastically while still using an established technology. It would be a lot easier to persuade people to “go green” if they could participate by simply filling their cars the same way they always had, but from a different source. AFS has a lot to prove; but if they manage, our world will change forever.