Process for the production of bio-oil and biogas from biomass

A process for the production of liquid fuel, and of a gaseous fuel, from biomass, which comprises the following steps:

• a. send biomass to a pre-treatment section to form a homogeneous phase that can be moved and/or pumped, in which the following operations are carried out:
• inert parts are separated from the biomass, and
• the biomass is shredded and/or ground to reduce the size thereof and make it moveable and/or pumpable, forming the homogeneous phase;
• b. the homogeneous phase obtained by pre-treatment is subsequently subjected to subcritical hydrothermal liquefaction at a temperature between 240° C. and 310° C. and at a pressure between 40 bar and 110 bar to form a liquefied phase;
• c. the liquefied phase coming out of the liquefaction (b) is subsequently subjected to either
• I. a physical separation by different density or dynamics, obtaining a first aqueous phase, a gaseous phase, and an oily phase, wherein the gaseous phase is sent into the atmosphere after treatment, and wherein the oily phase is subsequently separated into a bio-oil and a solid residue, classifiable as secondary solid fuel (SSF);
• or
• II. a separation by different size so as to remove a solid residue from a mixed phase, which contains a gaseous fraction, an aqueous fraction and an oily fraction;
• d. after separation, the process continues in two alternative and mutually exclusive ways as follows:
• a.1 in a first mode
• the first aqueous phase obtained in (I) is subjected to a multiple-stage anaerobic reaction of four to six stages in series from which a biogas, an anaerobic sludge and a second aqueous phase are produced, wherein the four to six stages are maintained at decreasing temperatures, wherein the four to six stages are maintained at decreasing temperatures, wherein a penultimate stage is a methanogenic stage, wherein the dwell time in each stage is from 2 to 8 days;
• and
• after the anaerobic reaction, the second aqueous phase is subsequently subjected to an aerobic reaction to obtain a purified aqueous phase, wherein a part of the purified aqueous phase is recirculated and admixed with the first aqueous phase in a ratio of 1:2 to 1:10 w/w forming a current entering the first stage and a part of the purified aqueous phase is recirculated and admixed with a stream entering the methanogenic stage, wherein the current entering the first stage is preheated to at least 60° C.;
• or
• b.1 in a second mode
• the mixed phase obtained in (II) is subsequently subjected to a separation by different density or dynamics, obtaining a first aqueous phase, a bio-oil and a gaseous phase, which is sent into the atmosphere after treatment;
• the first aqueous phase is subjected to a multiple-stage anaerobic reaction of four to six stages in series from which a biogas, an anaerobic sludge and a second aqueous phase are produced, wherein the four to six stages are maintained at decreasing temperatures, wherein the four to six stages are maintained at decreasing temperatures, wherein a penultimate stage is a methanogenic stage;
• and
• the second aqueous phase is subsequently subjected to an aerobic reaction to obtain a purified aqueous phase, wherein a part of the purified aqueous phase is recirculated and admixed with the first aqueous phase in a ratio of 1:22 to 1:10 w/w forming a current entering the first stage and a part of the purified aqueous phase is recirculated and admixed with a stream entering the methanogenic stage, wherein the current entering the first stage is preheated to at least 60° C.