The process
How coal becomes diesel.
Coal-to-liquids is gasification followed by Fischer–Tropsch
synthesis: coal is reacted with oxygen and steam to make synthesis
gas, the gas is cleaned and conditioned, and a catalyst then
assembles it into liquid hydrocarbons that refine into finished
fuels.
The chemistry is not new — it has run at commercial scale in
South Africa for decades. What determines whether a programme is
fundable is the feedstock position, the water and power balance, the
emissions treatment and the offtake agreements around it.
Coal supply and preparation
Run-of-mine coal crushed, screened and sized to a consistent feed specification.
Gasification
Coal reacted with oxygen and steam under pressure to produce raw synthesis gas.
Gas conditioning
Sulphur, particulates and carbon dioxide removed, and the hydrogen to carbon monoxide ratio adjusted.
Fischer–Tropsch synthesis
Synthesis gas passed over a catalyst and assembled into long-chain liquid hydrocarbons.
Product upgrading
Hydrocracking and distillation into finished, on-specification fuel grades.
Product slate
Diesel, naphtha, kerosene and LPG into certified storage ahead of release.
Distribution
Into the national supply through licensed wholesale, metered logistics and monitored retail.
Parallel streams Power island and steam raising ·
Water treatment and recycle · Carbon dioxide capture and handling
· Ash and slag to beneficiation or disposal
The sequence above describes coal-to-liquids in general terms. It is not a
design for either proposed facility; configuration, capacity and emissions
treatment would be settled through feasibility work.