FIELD: chemistry.
SUBSTANCE: invention relates to a method of starting the process, in stationary state, for producing usually gaseous, usually liquid and optionally usually solid hydrocarbons from synthetic gas, where the said process is a Fischer-Tropsch process involving the following steps: (i) feeding synthetic gas; (ii) catalytic conversion of the synthetic gas by carrying a Fischer-Tropsch reaction in one or more conversion reactors at high temperature and pressure to obtain usually gaseous, usually liquid and optionally usually solid hydrocarbons; and (iii) using at least a portion of the gaseous hydrocarbons obtained at step (ii) as a recycled stream which is repeatedly fed into the conversion reactor(s) at step (ii); the method involves mixing a stream of hydrogen with the recycled stream from step (iii), which is carried out before recycling the said stream into the conversion reactor(s) at step (ii), where as the activity of the synthetic gas conversion catalyst approaches a stationary value, the amount of the recycled stream is reduced; the initial partial pressure of the synthetic gas in the conversion reactor is 30-80% of the stationary value of partial pressure of the synthetic gas, preferably 40-60%; the flow rate of the synthetic gas kept constant and temperature in the conversion reactor at the beginning is the same as temperature in the stationary state or 0-30°C lower than temperature in the stationary state. The invention also relates to a version of the Fischer-Tropsch process which involves the above described method.
EFFECT: invention enables compensation for the initial high catalyst activity, which leads to formation of a high quality stream and prevents water condensation in the reactor.
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