Close to where the college rowing teams of Britain’s second-oldest university practise their strokes along the River Cam, a grey shipping container sits outside a business unit waiting to be dispatched to Abu Dhabi. Inside is a piece of equipment devised by a firm called Levidian Nanosystems. In a deal announced on May 16th with Zero Carbon Ventures, a firm in the United Arab Emirates, Levidian will ship 500 more such units to the region over the next five years. They will take methane emitted from landfill or being flared off at oil-production sites, and turn it into cleaner-burning hydrogen, along with a pile of fluffy black powder called graphene.
Graphene, which consists of monolayers of carbon atoms bonded in a repeating hexagonal pattern, is the thinnest known material. It was isolated in 2004 at the University of Manchester by Andre Geim and Konstantin Novoselov, who went on to win a Nobel prize for their discovery.
At the time, amid much hype, graphene was said to offer astonishing possibilities. It certainly has many interesting properties. For a start, it is 200 times stronger than steel. Yet it is extremely lightweight and flexible. It is also an excellent conductor of heat and electricity, and exhibits interesting light-absorbing abilities. Researchers are still finding ways to tune it to obtain other features. Recently, for example, it has been shown that by arranging several sheets of graphene at particular angles, a superconducting version of the material (that is, one which lets electricity pass without resistance) can be created.
Levidian Nanosystems employs yet another approach, which it calls loop. This process uses microwaves to turn methane (a molecule composed of a carbon atom and four hydrogens) into a plasma by stripping electrons from its molecules. This causes the chemical bonds holding the molecule together to break, thus creating hydrogen (which is extracted from the top of the reaction chamber) and high-quality graphene (which collects at the bottom). The process does not rely on any catalysts.
The idea is that loop can be used to strip carbon from methane gas flows, such as those found in various industrial processes, water-treatment plants and biogas reactors, as well as oil wells and landfill sites. That gets rid of methane, a potent pollutant, without generating CO2—which would be an inevitable outcome if the methane were, instead, burned. The hydrogen that is made can then be burned as fuel without producing any greenhouse gases and the graphene sold for other applications, such as an additive to toughen anti-corrosion paint—in exactly the same way that the grey paint used to protect Levidian’s shipping container from the elements has been treated.
Although Levidian began as a graphene producer, it now sees its role as providing a decarbonisation service. The loop system is being tested by Britain’s National Grid, which is responsible for the distribution of the country’s gas and electricity, to boost the amount of hydrogen in the gas supply. The main ingredient of natural gas is methane, and decarbonising it in this way can produce up to a 40% reduction in CO2 emissions when the gas is subsequently burnt, according to John Hartley, Levidian’s boss. As for the graphene, National Grid plans to use that to reinforce its pipelines so that they can carry more hydrogen.