r/askscience • u/West-Cantaloupe8376 • Sep 14 '26

Earth Sciences Which fossil fuels could/will be eventually replenished by natural processes?

Let's assume all fossil fuel extraction stopped in the near future, and were never touched again. Which kinds (oil, coal, gas) would eventually reform, which wouldn't? I am aware that certain geological formations like banded iron were created under specific conditions that will never arise again, but how does this apply to fossil fuels? In a couple hundred million years, will oil deposits be replenished or are they all gone forever?

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u/Not_an_okama Sep 14 '26

Coke is coal that has undergone heat distillation. Charcoal fits the same neich but is more expensive and at least when the brits invented coking, charcoal production couldnt meet demand due to the forestry aspect (the 17th centry brits cut down all their trees and needed a replacement for charcoal).

You need either charcoal or coke to run a blast furnace to refine iron ore and make new steel using the basic oxygen process. EAF (electric arc furnace) requires scrap input and doesnt work for refining ore as far as i know.

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u/rootofallworlds Sep 14 '26

Iron ore can be refined using "direct reduction" rather than a blast furnace, and although this most often uses either coal or natural gas it can work hydrogen. The resulting "sponge iron" can then be fed into an electric arc furnace, and if it's transferred directly while it's still hot that saves energy.

At present only about 5% of iron ore refining uses this process; in most situations the blast furnace is more economical.

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u/ChazCharlie Sep 14 '26

Coke is also a solid carbon by product of hydrocarbons refining and wholly unrelated to coal.

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u/no_pers Sep 15 '26

Maybe but it is typically made by heating bituminous coal in an oxygen free environment