Improved Fischer-Tropsch synthesis method by controlling the partial water pressure in the reaction zone

摘要

Process for synthesis of hydrocarbon from a charge of synthesis gas type, comprises contacting the synthesis gas with a catalyst in a reactor in Fischer-Tropsch synthesis condition and controlling partial pressure of water to maintain its critical value. Process for synthesis of hydrocarbon from a charge of synthesis gas type, comprises contacting the synthesis gas with a catalyst in a reactor in Fischer-Tropsch synthesis condition and controlling partial pressure of water to maintain their critical value (ppH 2O-limit) defined by a formula (ppH 2O-limit = exp (-7751/d p.T).P s(T)), in which T is a reaction temperature in K, d pis average diameter of pores of the catalyst in nm, determined by adsorption-desorption of nitrogen (Barrett, Joyner and Halenda method), and P s(T) is vapor pressure saturating of water to the temperature T, in bar, where the partial pressure of the water is controlled by a implementation of the following actions: determination of the critical value in the reaction conditions, comprising counting the temperature of the reaction zone and the property of the catalyses used in the Fischer-Tropsch synthesis step (average diameter of porous), and measuring the partial pressure of water vapor, comparison with the critical value and optionally adjusting the partial pressure in the Fischer-Tropsch synthesis reactor using at least one selective medium to verify the condition of (ppH 2O-react is less than ppH 2O-limit) comprising decreasing the total pressure, introducing the inert diluents in the charge of Fischer-Tropsch reactor, increasing the charge, increasing the recycling rate in the case where the reaction or reactor is equipped with a recycling unconverted gas, continuously eliminating all or part of the water by the reactor, and decreasing the operator temperature.