BIOREFINERY AND METHOD FOR REVAMPING A CONVENTIONAL REFINERY OF MINERAL OILS INTO SAID BIOREFINERY

摘要

The invention relates to a method for revamping a conventional refinery of mineral oils into a new biorefinery, wherein said biorefinery is characterized by a production scheme which enables the treatment of raw materials of a biological origin for the production of biofuels with a high productivity and reduced hydrogen consumption. Said method allows the re-use of existing plants, enabling, in particular, the revamping of a refinery containing a system comprising two hydrodesulfurization units, U1 and U2, into a biorefinery comprising a unit for the production of hydrocarbon fractions from mixtures of a biological origin, containing fatty acid esters, by hydrolysis of the same (ID), hydrodeoxygenation and isomerization. Each of said hydrodesulfurization units U1 and U2 comprises: a hydrodesulfurization reactor, (Al) for the unit U1, and (A2) for the unit U2, wherein said reactor contains a hydrodesulfurization catalyst, one or more heat exchangers between the feedstock and effluent of the reactor, a heating system of the feedstock upstream of the reactor, a treatment unit of acid gases downstream of the reactor, containing an absorber (B) for H₂S, said unit called Tl in the unit U1 and T2 in the unit U2, and the method of the present invention comprises: installing a unit ID, comprising a hydrolysis reactor R_id, upstream of the unit U1, installing a connection line LD between the unit ID and the unit U1, installing a line L between the units U1 and U2 which connects them in series, possibly installing a product recycling line for the unit U1 and possibly installing a recycling line for the unit U2, substituting the hydrodesulfurization catalyst, in the reactor A1, with a hydrodeoxygenation catalyst, substituting, the hydrodesulfurization catalyst, in the reactor A2, with a hydroisomerization catalyst, installing a by-pass line X of the treatment unit of acid gases T2 of the unit U2, substituting the absorber (B), in the unit for the treatment of acid gases T1, with a specific absorber for CO₂ and H₂S. The new operational configuration, obtained with the method object of the present invention, allows materials of a biological origin to be converted to biofuels, controlling the corrosion phenomena, reducing the hydrogen consumption, increasing the productivity and recovering glycerine, as by-product, that can be commercially exploited.