What is 'Defossilisation'?

1. Cement manufacturing – potentially circular In cement production, the CO₂ released from limestone calcination originates from: CaCO3=> CaO + CO2 . If that CO₂ is later reacted back into calcium carbonate (or permanently incorporated into concrete), the calcium-carbon system is effectively being cycled. Depending on the overall process and energy source, this can approach a closed mineral loop. Here, the carbon is not continually introduced from new fossil fuel extraction; it is being managed within an industrial materials cycle. 2. Diesel engine emissions – a different situation If CO₂ is simply captured from a diesel engine and permanently stored or mineralised, the system still depends on continuously extracting and burning new fossil diesel. The cycle is: • extract crude oil, • refine diesel, • burn diesel, • capture some CO₂, • repeat. The economic driver remains fossil fuel production. That is fundamentally different from our concept of defossilisation. 3. Diesel CO₂ + renewable H₂ → renewable fuel Suppose instead you capture the diesel exhaust CO₂ and combine it with renewable hydrogen: CO 2 + H2=> synthetic hydrocarbon The resulting renewable diesel (or eSAF, e-methanol, e-methane, etc.) can then displace fossil fuel. Now the carbon itself is recycled. Over time, the dependence on extracting additional fossil carbon can decline. This is much closer to our CRT philosophy because the carbon becomes a circulating resource rather than a waste product. The key distinction One point I would refine is this statement: “Capturing CO₂ from diesel encourages diesel production.” That is not necessarily true in every case. It depends on the system boundary. For example: • Capturing CO₂ from an existing diesel fleet while renewable fuel capacity is being built could reduce emissions during a transition. • Capturing CO₂ to manufacture renewable fuels could help replace fossil diesel over time. The important question is whether the process ultimately reduces reliance on continual fossil carbon extraction. A principle that aligns with my philosophy I can express it this way: Carbon capture should not become an enabler for perpetual fossil carbon extraction. Its highest value is achieved when captured carbon is progressively integrated into renewable circular carbon systems that reduce dependence on geological carbon. I think that’s a powerful statement because it doesn’t dismiss carbon capture or utilisation. Instead, it establishes a clear systems objective: the end goal is to replace the continuous flow of geological carbon with renewable and recyclable carbon, which is exactly the essence of my defossilisation concept.