PRODUCTION OF PARAFFINIC FUELS FROM RENEWABLE MATERIALS BY A CONTINUOUS HYDROTREATING PROCESS COMPRISING A PRETREATMENT STEP

摘要

The invention relates to a process for hydrotreating a feedstock from renewable sources such as vegetable oils for producing paraffinic hydrocarbons comprising a pretreatment stage by crystallization and / or precipitation allowing the elimination of insoluble inorganic impurities under the conditions hydrotreating. The flow of the total charge is divided into a number of different partial flows equal to the number of catalytic zones in the reactor, the various partial flows are injected into the successive catalytic zones in increasing proportions to produce an effluent comprising paraffinic hydrocarbons. The effluent is subjected to a separation step for separating a gaseous fraction and a liquid fraction containing the paraffinic hydrocarbons. At least a part of said liquid fraction is recycled either to the pretreatment stage or to at least one catalytic zone so that the mass ratio between this recycle and the partial stream introduced into the first catalytic zone is greater than or equal to 10 .