A liquid fuel production system includes: a liquid fuel-synthesizing portion configured to advance a conversion reaction from a raw material gas containing at least hydrogen and a carbon oxide to a liquid fuel; a raw material gas-supplying portion configured to supply the raw material gas to the liquid fuel-synthesizing portion; and a raw material gas-circulating portion configured to resupply a remaining raw material gas, which contains the hydrogen and the carbon oxide that are unreacted, and an acidic by-product of the conversion reaction, from the liquid fuel-synthesizing portion to the raw material gas-supplying portion, wherein the raw material gas-supplying portion includes a mixing portion configured to mix an amine compound and the remaining raw material gas in the presence of water vapor, and a moisture-removing portion configured to remove a neutralized product of the amine compound and the acidic by-product together with condensed water of the water vapor.

A method for controlling a process comprising a steam system coupled to a reactor system, wherein the steam system comprises a steam vessel that feeds a stream of liquid water under pressure to the reactor system to cool the reactor system, thereby generating a steam stream, and receives the steam stream from the reactor system, the method comprising the steps of (i) obtaining a first total liquid level measurement in the steam vessel using an inferred level device, (ii) obtaining a second total liquid level measurement in the steam vessel using a direct level measurement device, (iii) calculating a difference between the first and second total liquid level measurements using a control system, and (iv) initiating an alarm using the control system when the difference between the first and second total liquid level measurements is 1% of the lower of the first and second total liquid level measurements.

A method is described for shutting down a Fischer-Tropsch reactor fed with a reactant gas mixture comprising a synthesis gas and a recycle gas recovered from the Fischer-Tropsch reactor in a synthesis loop, said Fischer-Tropsch reactor containing a Fischer-Tropsch catalyst cooled indirectly by a coolant under pressure, comprising the steps of: (a) depressurising the coolant to cool the reactant gas mixture to quench Fischer-Tropsch reactions taking place in the Fischer-Tropsch reactor, (b) stopping the synthesis gas feed to the Fischer-Tropsch reactor, and (c) maintaining circulation of the recycle gas through the Fischer-Tropsch reactor during steps (a) and (b) to remove heat from the Fischer-Tropsch reactor. The method safely facilitates a more rapid return to operating conditions than a full shut-down.