Oxford University researchers have developed a method of converting plastic waste into hydrogen gas which can be used as clean fuel and high-value solid carbon.
Working in collaboration with colleagues at universities and institutions in the UK, China and Saudi Arabia, researchers in the Edwards/ Xiao group at Oxford’s Department of Chemistry achieved this with a new type of catalysis developed by the group which uses microwaves to activate catalyst particles to effectively ‘strip’ hydrogen from polymers.
The findings, published in Nature Catalysis, detail how the researchers mixed mechanically-pulverised plastic particles with a microwave-susceptor catalyst of iron oxide and aluminium oxide.
The mixture was subjected to microwave treatment and yielded a large volume of hydrogen gas and a residue of carbonaceous materials, the bulk of which were identified as carbon nanotubes.
This rapid one-step process for converting plastic to hydrogen and solid carbon significantly simplifies the usual processes of dealing with plastic waste and demonstrates that over 97% of hydrogen in plastic can be extracted in a very short time, in a low-cost method with no CO2 burden.
In a statement, Oxford University said the new method represents an attractive potential solution for the problem of plastic waste; instead of polluting our land and oceans, plastics could be used as a valuable feedstock for producing clean hydrogen fuel and value-added carbon products.
“This is not good applied science, but rather good science, applied,” said Professor Peter Edwards said.
“It opens up an entirely new area of catalysis in terms of selectivity and offers a potential route to the challenge of the plastic waste Armageddon, particularly in developing countries as one route to the hydrogen economy – effectively enabling them to leap-frog the sole use of fossil fuels.”
“Perhaps above all else – it is absolutely critical for a fundamental understanding of the chemistry, physics and electronic engineering of the mesoscale regime in catalysis that underpins any important applied advance in our quest for sustainable energy advances.”