The geological sequestration of bio-oil is an innovative approach for negative emissions. The process starts with cellulosic biomass. More that 100 Gt CO2 are already available for this. This is collected and heated to 500°C without oxygen. This biomass breaks down into bio-oil, which is rich in carbon similar to crude oil but has higher oxygen and lower energy content (i.e. it is not useful as a fuel). Bio-oil is prepared and injected into Class I industrial disposal wells or Class V salt caverns, where it is permanently stored. Bio-oil is denser than formation brine, meaning it naturally sinks and solidifies in place.

This technology is developed and operated by the venture-backed hardware startup Charm Industrial from San Francisco, California. With its mission to return the atmosphere to 280 PPM CO2, it is continuously improving the technology. The contribution to this carbon offset project enables scaling up and cost improvements.