Dr Paula Carey, Co-Founder & Chief Scientific Officer, Carbon8 explains the impact of carbon capture technology at Carbon8 on the productivity, efficiency and circular economy of cement plants.

Tell us about your carbon capture technology.
Carbon8’s carbon capture utilisation and storage (CCUS) technology is known as Accelerated Carbonation (ACT). In the process, carbon dioxide derived directly from flue gas generated by a cement plant is reacted with calcium minerals within the cement by-pass or kiln dust produced by the same plant without the need for purification.

The reaction occurs at atmospheric temperatures and pressures over 20-30 minutes and can be engineered so that a carbon negative lightweight aggregate is produced, through granulation of the fine grained dusts.

The technology is delivered in a containerised plant (known as the CO2ntainer) with a small footprint that is plugged directly into the flue stack of the cement plant without affecting the cement manufacturing process.

What role can your technology play when implemented in a carbon intensive industry like the cement industry?
The amount of carbon dioxide that is captured is limited by the amount of residue available, but the economics of our system means that a profit can be made for every tonne of CO2 captured without the need for subsidies, or large energy penalties or the use of expensive toxic chemicals such as amines. The process results in the sustainable management of an industrial residue that might otherwise be destined for landfill and produces a low carbon product for the construction industry reducing the need for the extraction of natural aggregate.

What is the impact of your technology on the productivity and cost of cement manufacturing?
The installation of our technology has no effect on the productivity of the cement plant, it has a low energy requirement and its installation adds to the bottom line of the cement production.

How does your technology impact the energy efficiency of a cement plant?
Because our technology operates at atmospheric temperatures and pressures, it has a low energy demand and does not have an impact on the efficiency of the cement plant.

How does your tech support the circular economy?
Carbon8’s technology produces a carbon negative, lightweight aggregate from an industrial residue, breaking the route to landfill disposal and producing a sustainable product for the construction industry that replaces the need for the extraction of natural virgin aggregate. On our website – www.carbon8.co.uk – we describe ourselves as a “circular impact company

What are the major challenges in implementation and execution of your technology?
Because the amount of CO2 captured is relatively small compared with large-scale, expensive carbon capture projects, it has been more challenging to demonstrate the economic and environmental benefits of deploying and operating our technology within the global cement industry. A Vicat cement plant in France has been using our CO2tainer since 2020, after successful trials with CRH in Canada and Hanson (now part of Heidelberg Cement Group) in the UK.

The variability of the waste streams that are available to Carbon8 also raises a challenge; every cement works is slightly different and demands a unique solution in terms of mix design for our process.

What innovations can the world expect from Carbon8 in the near future?
We are using AI to develop our process control to overcome the variability of the residues that are generated by the different hard-to-abate industries, and so facilitate the deployment of ACT solutions into other sectors, like Energy From Waste, biomass and steel.