Production of paraffinic fuels from renewable materials using a continuous hydrotreatment process

Abstract

A process for hydrotreating a feed originating from renewable sources such as vegetable oils to produce paraffinic hydrocarbons in the presence of hydrogen in excess over the theoretical hydrogen consumption and under hydrotreatment conditions in a fixed bed reactor having a plurality of catalytic zones disposed in series and comprising a hydrotreatment catalyst. The total feed flow is divided into a certain number of different part flows equal to the number of catalytic zones in the reactor; the various part flows are injected into the successive catalytic zones in increasing proportions to produce an effluent comprising paraffinic hydrocarbons. The effluent undergoes a separation step in order to separate a gas fraction and a liquid fraction containing the paraffinic hydrocarbons. At least a portion of said this liquid fraction is recycled to the first catalytic zone so that the weight ratio between said recycle and the part flow introduced into the first catalytic zone is 10 or more.