Biochar from food waste could save 93,000 tonnes of CO2

Conducted as part of the Department for Energy Security and Net Zero (DESNZ) Phase 2 project in collaboration with Invica Industries, the study explores how converting food waste into biochar can help reduce greenhouse gas emissions and also improve soil quality.  Findings are detailed in Biochar.

The report demonstrates that converting food-waste digestate, a residue from biogas production, into biochar offers a low-cost, high-impact climate solution.  

Results from the study show that each tonne of biochar can sequester up to 1.2 tonnes of CO₂ equivalent, and co-locating production with anaerobic digestion plants, where food waste digestate is generated, could keep carbon removal costs below £100 per tonne.

The biochar produced is said to retain about 88 per cent of its carbon content, locking away approximately 1.15 to 1.20 tonnes of CO₂ per tonne of biochar, which is formed by heating biomass via pyrolysis at 400°C or higher. 

If implemented nationally, using 50 per cent of the UK’s projected available food-waste digestate, this approach could sequester around 93,000 tonnes of CO₂ annually by 2030.