By Jeremy Williams

CO2 is a greenhouse gas and the main culprit in climate change, but it’s also a gas with industrial uses. As climate change sharpens our resolve to do something about emissions, all kinds of new uses for CO2 have been emerging. There are companies that are tapping waste gas streams to make building materials, fertiliser or plastic. Here’s another. Deep Branch is a biotech company that makes CO2 into protein.

The process uses gas fermentation. Microbes are fed a diet of CO2 and hydrogen from an electrolyser, and they produce a simple protein as waste material. This is harvested as a dry powder which is sold to manufacturers of animal feed.

There are multiple benefits to this. First, it turns waste CO2 into a resource that has value, which incentivises companies to capture it. Carbon emissions from industry are lowered while potentially increasing profits. At the same time, there are emissions savings from the livestock industry. The protein generated here, which is called Proton, would replace fish meal or soy used in animal feed, dramatically reducing the emissions, water and land use. Animal feed using Proton saves 60% of the emissions of normal feed.

There are companies doing similar things. FeedKind uses a methane stream to make their fish food, for example. What I liked about Deep Branch’s solution is that they have fitted the whole process into a container, making it easy to install on sites where CO2 is produced. Rather than ship the gas to them, the factory comes to you.

The company is based in Nottingham, UK, and is currently running an extensive trial involving a series of partners. CO2 is being captured at Drax, Britain’s largest power station. The protein from their container unit is then shipped to two feed manufacturers, one making fish food and one doing poultry feed. The new feeds will then be tested at the University of Sterling’s Institute of Aquaculture, and Nottingham Trent’s Poultry Research Unit. Finally, Sainsbury’s will advise on commercialising the end product and gauging consumer interest. The trial was one of several innovative farming projects to receive government grants earlier this month.

First published in The Earthbound Report.