Method for obtaining a composition containing alcohol and liquid hydrocarbons from a mixture of hydrogen and carbon monoxide gas

Abstract

The invention relates to the field of organic chemistry, in particular to a method for obtaining a product composition containing alcohols and liquid hydrocarbons in the presence of a Fischer-Tropsch synthesis catalyst containing cobalt-manganese. The claimed method is carried out in the following steps: a first gaseous feedstock containing carbon monoxide and hydrogen is contacted with a catalyst for at least 12 hours to obtain a first composition of a product containing C5+ hydrocarbons and one or more alcohols by Fischer-Tropsch synthesis, having a first selectivity with respect to alcohols and C5+ hydrocarbons; and then contacting the catalyst with a gas composition containing at least 35 vol. % H2 and having a H2:CO molar ratio of at least 2.0, at a pressure range of 10 bar to 40 bar and a temperature range of 150°C to 300°C, with modified selectivity; and then contacting the second gaseous feedstock containing carbon monoxide and hydrogen with the catalyst to obtain a second product composition containing C5+ hydrocarbons, having a second selectivity to alcohols of not more than 5% and / or a second selectivity to C5+ hydrocarbons of at least 80%, such that the second selectivity to alcohols is not more than 20% relative to the first selectivity to alcohols.