indirect liquefaction

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June 29, 2026

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Indirect liquefaction is a method of converting solid coal into liquid fuels. This process involves breaking down coal into a synthesis gas, which is a mixture of carbon monoxide and hydrogen. This synthesis gas is then used as a building block to create the desired liquid hydrocarbon molecules.1

This contrasts with direct liquefaction, where the coal's macromolecular structure is broken down to maximize the yield of specific liquid molecules. Indirect liquefaction requires adding hydrogen to coal, as coal has a lower hydrogen content compared to petroleum. The synthesis gas produced can also be converted into methanol, which is then further processed into various liquid hydrocarbons.21

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coal utilization
Liquefaction reactions
…or it can be done indirectly, through an intermediate series of compounds. In direct liquefaction, the macromolecular structure of the coal is broken down in such a manner that the yield of the correct size of molecules is maximized and the production of the very small molecules that constitute fuel…
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…or it can be done indirectly, through an intermediate series of compounds. In direct liquefaction, the macromolecular structure of the coal is broken down in such a manner that the yield of the correct size of molecules is maximized and the production of the very small molecules that constitute fuel…
Read More