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 Rid, 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.