We frequently speak about fossil carbon, biogenic carbon, captured carbon and atmospheric carbon as though they were fundamentally different materials.
At the atomic level, they are not.
A carbon atom in coal, natural gas, biomass, carbon dioxide or synthetic methane is still carbon. Nature does not attach a label saying “fossil” or “green” to the atom.
What changes is where that carbon came from, what molecule carries it, how energy is supplied to transform it, and where the carbon goes next.
That distinction is important.
When fossil fuels are extracted and combusted, carbon that has been isolated underground for millions of years is transferred into the active atmosphere–biosphere–ocean carbon cycle. If that CO₂ is continuously released, atmospheric carbon accumulates.
Biogenic carbon follows a shorter cycle. Plants remove CO₂ from the atmosphere, incorporate the carbon into biomass, and eventually much of that carbon returns to the atmosphere through decomposition or combustion.
But there is another possibility.
What if we stop treating carbon as a waste product?
Carbon can instead be regarded as a circulating material.
Consider methane:
CH₄ → energy + CO₂
Conventionally, the story ends with the CO₂ entering the atmosphere.
But suppose we capture that CO₂ and combine it with renewable hydrogen:
CO₂ + 4H₂ → CH₄ + 2H₂O
We have returned the carbon to methane.
The methane can again provide firm power or industrial heat. Its CO₂ can again be captured. And the cycle can repeat.
Carbon becomes the carrier. Hydrogen provides the renewable energy required to restore the fuel.
This is the philosophy behind Carbon Recycling Technology (CRT).
The real question is not simply: “Is this carbon fossil?”
A more useful engineering question may be:
Where does each carbon atom go after we use it?
If fossil carbon is continuously extracted, used once and discharged to the atmosphere, we have an open carbon pathway:
Geological carbon → fuel → CO₂ → atmosphere
If carbon is captured and repeatedly recycled, we begin to create a closed pathway:
Carbon → fuel → energy → CO₂ → fuel → energy → CO₂ → …
Once the circulating carbon inventory has been established, renewable hydrogen can provide the continuing energy input without requiring an equivalent continuing supply of fresh fossil carbon.
And if additional carbon is eventually required, it could potentially come from biomass, industrial CO₂ or ultimately directly from the atmosphere.
Two ledgers
I increasingly think energy systems should maintain two separate accounts.
The carbon ledger asks:
Where did the carbon come from, and where did every carbon atom go?
The energy ledger asks:
Where did the energy required to move and transform that carbon come from?
These are not the same question.
Carbon can circulate.
Energy must continually be supplied.
In a future CRT system, that energy would increasingly come from renewable electricity through hydrogen.
From carbon elimination to carbon management
Perhaps our objective should therefore not be to eliminate the element carbon from our energy and industrial systems.
Carbon is extraordinarily useful. It forms fuels, chemicals, materials and biological life itself.
The challenge is to stop continually transferring additional geological carbon into the atmosphere.
That suggests a different philosophy:
Do not discard carbon. Capture it. Account for it. Recycle it.
Every molecule should have a destination.
That is the foundation on which we are developing Carbon Recycling Technology at CEWT.
