TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Process: The process comprises at least partly expanding the converted feed mixture in a flash separation step, where the converted feed mixture is separated into a gas phase and a liquid phase, liquid carbon dioxide is recovered from the gas phase, and at least part of the liquid carbon dioxide recovered is fed into the bioreactor. The process further comprises recovery of substances from the residual fraction remaining after separation of the fraction comprising a liquid hydrocarbon product, where the recovery is performed in one or more evaporators and condensers, and leaving a water fraction, and feeding the water fraction into a bioreactor for the production of biomass such as algae and/or bacteria such as cyano bacteria. The process comprises upgrading the liquid hydrocarbon product from the separation is heated to a temperature of 350- 600 degrees C, at a pressure of 0.5-30 bar, thus producing at least one liquid hydrocarbon fraction and/or at least one solid residue fraction and/or at least one gas fraction and/or at least one aqueous fraction. The fraction is not condensed in the one or more condensing steps comprise a combustible gas, where the gas is combusted to produce heat for heating in the process. The pretreatment apparatus comprises a device adapted to divide particles in the feedstock and to mixture the feedstock and the water and the liquid organic compound to a feed mixture with the specified feed mixture properties for the process. The algae and/or bacteria in the recovery step are concentrated and recycled to the feed mixture. The step of expanding and cooling comprises first cooling the converted feed mixture at process pressure to a temperature of 100-200 degrees C by heat exchange with the incoming feed mixture and subsequently expanding the cooled product stream in one or more steps at least one of the expansion steps comprising an expansion in a flash separator to a pressure of 50-70 bar, thus producing a gas phase and a liquid phase, and subsequently cooling the gas phase in a first condenser to a temperature of 35-80 degrees C, and cooling the gas phase from the first condenser to a temperature of 12-30 degrees C, thus producing a condensate comprising liquid carbon dioxide. The converting feed mixture is subject to a further flash expansion at a pressure higher than 70 bar, preferably higher than 200 bar, and at a temperature of at least 300 degrees C. The first of the evaporators is adapted to perform a vapor recompression technique, including mechanical vapor recompression and/or thermal recompression. The evaporators are heated by steam and the steam is at least partly produced by the process. The first evaporator comprises at least two condensers operating decreasing condensation temperatures. The condensation temperature of first condenser is 85-110 degrees C, preferably 90-105 degrees C, where the temperature of the last condenser is preselected so as to condense compounds having a boiling point lower than water, such as a condensation temperature of 20-80 degrees C, preferably 40-60 degrees C. The substances are recovered comprise water soluble organics and/or homogeneous catalyst in the form of potassium and/or sodium, and the recovered substances are at least partly recirculated in a concentrated form and introduced into the feed mixture. The concentration factor, as defined as the mass ratio of the residual fraction fed to the recovery step to the mass of concentrate, is at least 4, preferably at least 7. The recovery of liquid carbon dioxide includes an expansion to a pressure of 50-70 bar and a first step of cooling of the gas phase in to a temperature of 35-80 degrees C, and second step of cooling the gas phase to a temperature of 12-30 degrees C. The concentration of the at least one liquid organic compound contained in the feed mixture is at least 5 wt.%, preferably at least 20 wt.%. The pressure during the conversion step is 275-350 (preferably 300-325) bar. The temperature during the conversion step is 380-430 degrees C, preferably 400-430 degrees C. The feed mixture at entry temperature is pressurized essentially to the desired process pressure before heating to process temperature is initiated. The pH during the conversion is above 7, preferably 8-10, where the pH of the feed mixture is measured during and/or after the conversion and when the pH measurement is outside the preferred range, and the composition of the feed mixture is altered to correct the pH in the conversion. The heating of the feed mixture is taking place at a rate of at least 50 degrees C/minutes, preferably 150 degrees C/minutes in the temperature of 140-300 degrees C. The average flow velocity in pipes in the process and/or at the entry of the conversion zone/reactor, is at least 0.2 (preferably 0.5-3) m/s. The heating for the conversion is at least partly performed by introducing one or more supercritical fluids, such as a superheated supercritical fluid, into the feed mixture. The heating performed for the conversion is at least partly performed by introducing an oxidizing agent into the feed mixture. The introducing the one or more supercritical fluids and/or oxidizing agent is performed in vertically positioned cyclone shaped mixing chamber, where the feed mixture is introduced in the center from top with a ratio of the average linear velocity in the inlet pipe to the minimum average linear velocity of the mixed fluids in the mixing chamber of at least 2, the superheated supercritical fluid and/or oxidizing agent is introduced into the chamber substantially tangentially to the mixing chamber at a velocity ratio of at least 4, and the partially or fully converted feed mixture is withdrawn from the cyclone shaped mixing chamber from the bottom. The introducing the one or more supercritical fluids and/or oxidizing agent is performed in a mixing chamber having a conically shaped inlet and a conically shaped outlet, the walls of conical shaped inlet and outlet having angle to the centerline of the mixing chamber of maximum 60 degrees , where the feed mixture is introduced from the top with a ratio of the average linear velocity in the inlet pipe to the minimum average linear velocity of the mixed fluids in the mixing chamber of at least 2, the superheated supercritical fluid and/or oxidizing agent is introduced into the mixing chamber with an angle, in the flow direction of at least 20 degrees , the average linear velocity ratio of the superheated supercritical fluid and/or oxidizing agent is at least 4 and the partially or fully converted feed mixture is withdrawn from the mixing chamber from the bottom. The aqueous fraction is recycled to the recovery step and mixed with the residual fraction from the separation. The upgrading by heating is performed in at least 2 steps. The temperature in the first heating step of heating is maintained below 200 degrees C, preferably 100-140 degrees C. The heating for the first evaporation step is recovered from the cooling and expanding the converted feed mixture. The residual fraction comprising liquid hydrocarbons and/or solids are withdrawn from the first heating step and fed to a second heating step, where it is heated to a temperature of up to 600 degrees C, preferably 425-500 degrees C. At least a fraction of the heated residual fraction comprising liquid hydrocarbons and/or is fed to a fractionator. The evaporated fraction is condensed and fractionated in two or more condensing steps having predefined and decreasing condensation temperatures. The outlet temperature of the non-condensed liquid hydrocarbons in the first condensation step is at 340-400 degrees C, preferably 360-380 degrees C. The outlet temperature from the second condensation step is at 120-300 degrees C, preferably 150-250 degrees C. The cooling medium is used in the condensation, and the heat transferred to the cooling medium is used for at least partly supplying the heat required in the conversion. The second heating step comprises two or more vessels or drums operating in a sequential cycle, where the solid residue is allowed to accumulate within the vessels or drums for a predefined period. The pretreatment further comprises division of the particles in the feedstock, to obtain the desired maximum particle size. The first step of pre-treating further comprises chemical pulping. The pretreatment further comprises heating of the feed mixture to a temperature of 50-200 degrees C, preferably 90-160 degrees C, at a pressure of 1-20 bar, preferably 4-20 bar to avoid boiling. The pretreatment apparatus is provided prior to the feed pump. The vertically positioned cyclone shaped mixing chamber is provided for the introduction of the one or more supercritical fluids and/or oxidizing agent is performed in, where an inlet tangential to the mixing chamber is provided for introducing the superheated supercritical fluid and/or oxidizing agent into the chamber and a bottom outlet is provided for withdrawing the fully converted feed mixture from the cyclone shaped mixing chamber. The mixing chamber having a conically shaped inlet and a conically shaped outlet is provided for the introduction of the one or more supercritical fluids and/or oxidizing agent, the walls of conical shaped inlet and outlet having angle to the centerline of the mixing chamber of maximum 60 degrees , where an inlet is provided with an angle, in the flow direction of at least 20 degrees for the introduction of the superheated supercritical fluid and/or oxidizing agent into the mixing chamber, and an outlet is provided at the bottom for withdrawing the partially or fully converted feed mixture from the mixing chamber. The feed mixture comprising at least a feedstock containing algae and/or cyano bacteria produced by the process, water and at least one liquid organic compound, where the concentration of the at least one liquid organic compound contained in the feed mixture is at least 1 wt.%. The mixing chamber having a conically shaped inlet is provided for the introduction of the one or more supercritical fluids and/or oxidizing agent, and a conically shaped outlet, the walls of conical shaped inlet and outlet having angle to the centerline of the mixing chamber of maximum 60 degrees , where an inlet is provided with an angle, in the flow direction of at least 20 degrees for the introduction of the superheated supercritical fluid and/or oxidizing agent into the mixing chamber, and an outlet is provided at the bottom for withdrawing the partially or fully converted feed mixture from the mixing chamber. Preferred Components: The conversion device comprises a vertically oriented reactor having a conically shaped inlet for introducing the feed mixture in the top and a conically shaped outlet in the bottom, where the angle of the walls of the conical inlet to the centerline of the reactor is below 60 degrees , and the angle of the walls of the conical outlet to the centerline of the reactor is below 30 degrees .    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The feed mixture provided contains at least one homogeneous catalyst in the form of a compound of potassium and/or sodium so as to ensure a total concentration of potassium and sodium of at least 1-10 wt.%, preferably 2-5 wt.%. The ratio of weight of the one or more liquid organic compounds to the dry weight of carbonaceous material in the feed mixture is 0.1- 2, preferably 0.2-0.5. The residence time in the reactor is 10-40 minutes, preferably 10-25 minutes. The pressure is maintained at 2.5-10 bar. The feedstock material added has a maximum particle size of 15 mm, preferably 0.5 mm. The liquid organic compound is added in amount of at least 5 wt.%, preferably at least 20 wt.%. At least one homogeneous catalyst is added in the form of a compound of potassium and/or sodium so as to ensure a total concentration of potassium and/or sodium of at least 0.5 wt.%, preferably 2-5 wt.%. The pretreatment has duration of 5 minutes to 24 hours, preferably 20 minutes to 3 hours. The dry solid content of the carbonaceous material is 20-70 wt.%, preferably 30-60 wt.%. The feed mixture provided contains at least one homogeneous catalyst in the form of a compound of potassium and/or sodium so as to ensure a total concentration of potassium and sodium of at least 0.5 wt.%, preferably 2-5 wt.%. The feed mixture comprising a dry solid content of carbonaceous material is 20-70 wt.%, preferably 30-60 wt.%. The feed mixture comprises particles with a maximum diameter of 30 mm, preferably 0.5 mm. The concentration of the at least one liquid organic compound contained in the feed mixture is at least 5 wt.%, preferably at least 20 wt.%. EXAMPLE - No suitable example given.