Graphene at Glastonbury
At Worthy Farm, home to the Glastonbury festival, a company is showcasing new tech that will strip the carbon from the methane to create clean hydrogen and graphene. The farm currently produces biofuel via anaerobic digestion of tens of thousands of tonnes of cow slurry and silage – this famously helps power the festival.
The new tech will allow the farm to capture carbon from some of the biomethane produced and turn it into graphene, for use in industry, and clean hydrogen, which will be used to generate electricity via an existing heat and power plant. This is a system that can work anywhere with a source of methane, says Levidian – the start-up behind the LOOP technology – which has teamed up with clean hydrogen producer Hexla. This trial will save the equivalent of 25 tonnes of CO2 each year, and if plans to expand globally are successful, the company says the process could save hundreds of thousands of tonnes of CO2 emissions each year.
Building on cement
For years the construction industry has sought ways to clean up emissions caused by the use of cement, which accounts for some 8% of global emissions. One breakthrough initiative adds biochar (carbonised organic material) rinsed with wastewater from concrete production to the mix. Research from the US showed that the treated biochar could absorb nearly a quarter (23%) of its weight in CO2 while allowing the cement to retain its strength.
Heated at temperatures reaching up to 1,000°C, biochar becomes a stable, solid form of carbon that endures for thousands of years. But previous attempts to add even small quantities of biochar to cement had resulted in much weaker concrete. Researchers used the alkaline wastewater to engineer the surface of the biochar, and were able to add up to 30% of biochar to the cement mix, which proved as strong as ordinary cement in the lab.
Negative-emission coal
Negative-emission coal sounds counterintuitive. But a Swiss start-up says it has discovered the most efficient method of removing carbon from that atmosphere to date – by accelerating processes that took 50 million years in the natural world to a matter of hours – and then burying the resultant coal-like hydrochar in secured underground bunkers.
RECOAL, a spin-out founded last year from Swiss and Dutch universities and engineering companies, proposes using residual biomass from biogas plants, and from other sources such as algae, to produce the hydrochar by heating it to high temperatures and pressurising it in the presence of water. The company aims to build a pilot plant in Switzerland to produce the coal and the large underground vaults in which to store it by 2025. The process will initially remove 1,000 tonnes of CO2 a year.
