Decarbonisation Technology - August 2024 Issue

Transforming carbon and paving the way for a circular economy Carbon capture and utilisation could enable a new circular carbon economy where carbon is reused to generate value rather than wasted

Freya Burton and Kit McDonnell LanzaTech

T his summer is likely to see continued record-breaking heatwaves, reminding everyone that climate change is not a distant future threat but a pressing and immediate danger. Indisputably, the globe needs to aggressively stem both the flow (mitigate new emissions) and the stock (remove existing emissions) of anthropogenic carbon in the atmosphere to bend the carbon curve to a liveable level ( IPCC, 2023 ). Until now, the only option for carbon disposal has been in the atmosphere; unfortunately, the amount of CO 2 the planet can manage has now been exceeded. There is an urgent need for a new home for carbon waste. Luckily, we know today, at scale, how to transform that excess atmospheric carbon into valuable products by employing carbon capture and utilisation (CCU). CCU is often categorised with other carbon management means, such as carbon capture and storage (CCS). However, to date, CCUS has largely been synonymous with just CCS. This needs to change because the world deserves the additional benefits and value generated by efficient CCU operations, which both utilise waste carbon and generate value. Carbon is all around us Most people do not realise how deep carbon’s roots run into their lives. Carbon is the building block of all organic compounds, making up the essence of life on Earth, including humans. It is in the threads of clothes, the materials that build homes, and the fuel that powers vehicles. Yet, carbon, particularly in its gaseous form as carbon dioxide (CO₂), is a significant contributor to the planet’s most pressing environmental issues.

CO₂, a potent greenhouse gas, has been accumulating in the atmosphere mainly from industrial processes and petrochemical refining. These industries form the backbone of global supply chains, creating a carbon economy that thrives on non-renewable resources extracted from beneath the Earth. This extractive approach has led to the release of gigatons of CO₂, contributing to global warming and its accompanying catastrophes. Most people do not realise that many of the products they use daily are also made from virgin fossil carbon. It is a key ingredient in everything from clothes and cosmetics to household cleaners and medical supplies. Even if we managed to capture and store enough CO 2 to combat climate change, carbon- dependent global supply chains would still require the extraction of fossil carbon to make the things we need. That is why when talking about carbon storage as a decarbonisation tool, it is also important to talk about carbon utilisation, CCS’s lesser-known cousin. The reality is that barring a complete overhaul of the global economy, humans will always need carbon in some form. The good news is that there is already enough carbon above ground to make the products humans use without extracting more. What about plant- based carbon? That will also have a role to play. However, the scale of carbon use today is such that relying solely on biomass could pose challenges related to land use, deforestation, competition with food production, and other potential environmental impacts. So, a diversified carbon portfolio that does not have a negative impact on the planet is needed.