It’s a distressing image. A sea turtle lies dead among plastic debris on a beach, seemingly a victim of our global pollution crisis.
If the pictures are stark, so are the figures. An estimated 10m tonnes of plastic ends up in the oceans each year. Almost 5bn tonnes has gone to landfill since the post-war boom in production. It takes around 500 years for a plastic bottle to biodegrade. And less than 10% of plastic is recycled.
With marine life facing ‘irreparable damage’ according to the UN’s oceans director, and recent research emphasising the impact of land-based plastic pollution, solutions are urgently needed.
Last year, one of those potential solutions was turned into a company spun out from Oxford research. Oxford Sustainable Fuels (OSF) is developing technology that can turn end-of-life plastic into high-quality transportation fuel, unlocking the potential of a substance known as pyrolysis oil.
Pyrolysis is the process of decomposing plastic at moderately high temperatures, in the absence of oxygen, to produce an oil-like substance. So far, this pyrolysis oil has found few uses – in part because of its instability. But the academics behind OSF have developed efficient ways of purifying and upgrading this viscous, highly reactive substance to produce gasoline, diesel and jet fuels. Significantly, the process is able to handle mixed plastics, negating the need for sorting and separation.
It’s a novel use for plastics that would otherwise have found their way into landfill, our oceans, or the atmosphere via incineration. And, as company co-founder Professor Peter Edwards notes, it’s a quirk of science that Nobel Prize-winning research into the synthesis of polymers – the molecules that make up plastics – is essentially now being reversed.
‘Proposed solutions to the plastic waste crisis, such as plastic-free aisles in supermarkets or the banning of all consumer-use, non-biodegradable plastics, are most laudable,’ says Professor Edwards, from Oxford’s Department of Inorganic Chemistry. ‘However, it will take considerable time and effort to wean a global society off plastic.
‘Given the extraordinary scale and rate of expansion of plastic waste, we urgently need complementary strategies. Catalytic chemical recycling techniques such as ours offer substantial environmental and economic benefits.’
OSF was spun out with the help of Oxford University Innovation – the University’s research commercialisation arm – and attracted £1m in seed funding before progressing to the current scale-up phase. The company hopes to have opened a waste-to-fuel plant capable of handling 10,000-20,000 tonnes of plastic within the next couple of years, creating numerous jobs in the process. Past and present Oxford PhD students have played key roles in the research advances that have brought the science and the technology to this point – notably the company’s chief technology officer, Dr Zhaoxi Zhang.
Co-founder Dr Tiancun Xiao, also of Oxford’s Department of Inorganic Chemistry, says: ‘Our aim is to become a key part of the circular economy by enabling the transformation of waste into valuable and needed products. To be a part of the solution in helping our global and local environment is a huge motivation for us. We believe our technology will be an important element in the fight against plastic waste ending up in the oceans.’
Professor Edwards adds: ‘What’s important about OSF is that it is founded on new ways of thinking about plastic waste as a global resource for responsible recycling. My generation of chemists have spent their careers focusing on making plastics more efficiently, with better properties. Now we must turn our attention to dealing with the legacy of plastic waste material.’