Hamburg: Chocolate-making and its best friend...carbon-capturing

A new facility in the city will produce biochar, trap CO2 and generate sustainable energy

Last week, the company Circular Carbon opened its first German facility in Hamburg. The company produces biochar – a substance that can capture CO2 from organic materials with the main ingredient in the facility being cocoa shells – a waste product from chocolate-making.

The substance has a wide range of uses, but Circular Carbon has specialised in producing a biochar that imitates peat, perfect as a type of fertiliser or animal feed. Additionally, the waste heat generated during the production process is pumped into a nearby industrial facility and recycled.

Biochar

Biochar is a substance produced by putting carbon and organic waste through a process known as pyrolysis – applying heat in an inert atmosphere. This produces a coal-like substance that is very resistant to decomposition, birthing the concept of pyrogenic carbon capture and storage.

In the case of Circular Carbon and their Hamburg facility, the main raw material used to produce biochar is cocoa shells, a byproduct in the making of chocolate. The material is processed with heat, which lets out a byproduct in the form of steam. The steam is then channelled into a nearby industrial facility, replacing their need for fossil fuel heat.  

Improving the soil with processed waste

The resulting biochar has a lot of properties resembling peat because it is produced with nutritious nutrient-rich food waste. This makes it perfect as a sort of fertiliser, able to increase the productivity of acidic and depleted soils, improving agriculture. It can also be used as an animal feed or building material, as well as a moisture sponge for trees in urban environments.

According to an official statement, there are a lot of nutrient-rich materials suitable for producing biochar, including oat husks, fruit stones, straw and green waste in general. In this way, organic residues can be contained in a non-reactive, slow-decomposing form, instead of rotting away, releasing all their carbon into the atmosphere.