Burying CO2 in waste deep underground

Pumping organic matter underground helps to tackle the climate crisis

Spotted: Carbon dioxide removal (CDR) methods play a key role in the fight against climate change, removing over two billion metric tonnes of CO2 every year. But in order to meet 2050 climate goals, this figure needs to reach some seven to nine billion. US company Vaulted Deep believes its technology could help us get there.

A spin-out from waste management company Advantek, Vaulted Deep diverts carbon-filled organic waste that would otherwise eventually re-emit CO2 back into the atmosphere as it breaks down. The company takes this waste – which includes treated sewage, paper sludge, and farming or livestock waste – and processes it. This processed waste is then pumped deep underground using Vaulted Deep’s patented slurry injection technology – a system that’s verified by the carbon credit certification platform Isometric.

Once underground, the carbon within this waste gets locked away for over 10,000 years, and the company continues to monitor its wells to ensure the CO2 remains locked away. As well as preventing CO2 emissions, the technology also prevents the methane that would have been generated if the organic matter had decomposed above ground: according to the company, for every tonne of waste sequestered, 5.8 tonnes of CO2-equivalent emissions are avoided. Plus, it also offers an effective way to deal with waste that may otherwise pollute local environments and spread disease.

In May 2024, it was confirmed that Frontier – a consortium of tech giants that was established to manage advanced market commitments for carbon removal – had facilitated $58.3 million in offtake agreements with Vaulted Deep. As part of this agreement, the company will remove 152,480 metric tonnes of CO2 between 2024 and 2027 and has commissioned three new wells to help facilitate that.

Written By: Matilda Cox