Turning plastic waste into hydrogen and high-value carbons

The ever-increasing production and use of plastics over the last half century has created a huge environmental problem for the world. Currently, most of the 4.9 billion tonnes of plastics ever produced will end up in landfills or the natural environment, and this number is expected to increase to around 12 billion tonnes by 2050. In collaboration with colleagues at universities in the UK, China and the Kingdom of Saudi Arabia, researchers in the Edwards / Xiao group at Oxford's Department of Chemistry have developed a method of converting plastic waste into and hydrogen gas which can be used as a clean fuel, and high-value solid carbon. This was achieved with a new type of catalysis developed by the Edwards group which uses microwaves on catalyst particles to effectively 'strip' hydrogen from polymers. The findings 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 opens up an entirely new area of great potential in terms of selectivity and offers a potential route to the use of plastic waste Armageddon 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.