Solvothermal liquefaction of carbonaceous materials

Abstract

The invention relates to a method for producing a low carbon intensity oil comprising the steps of: a. providing a feed mixture comprising a carbonaceous material and an organic solvent selected from methanol, ethanol, propanol, isopropanol, buthanol, isobuthanol, pentanol, hexanol butanediol, benzene diol, benzene triol, glycerol, ethylene glycol, polyethylene glycol, propylene glycol, acetone, methyl ethyl ketone (MEK), toluene, benzene, hydroxy methyl furfural (HMF), phenols, alkoxyphenols, alkylphenols, creosol, vanillin, formic acid, acetic acid, citric acid or a combination thereof in a concentration of at least 5 % by weight; b. converting the feed mixture at pressures in the range 20 bar to 150 bar and at temperatures in the range 250 °C to 430 °C thereby producing a converted feed mixture; c. passing the converted feed mixture to a first separator operating at pressures in the range 20 to 150 bar and temperatures in the range 250 to 430 °C thereby producing a first gas stream and a first liquid stream; d. cooling the first gas stream to temperature in the range 120 °C to 180 °C and feeding it to a second separator operating at a pressure in the range 20 to 80 bar thereby producing a second gas stream with a reduced content of condensable and second liquid stream comprising recovered condensables; e. cooling the first liquid stream to a temperature in the range 150 °C to 300 °C and feeding it to a third separator operating at a pressure of 1 to 20 bar thereby producing a third gas stream and third liquid stream comprising the crude low carbon intensity oil with a minimum moisture content and a fourth liquid stream comprising water and optionally suspended solids.

Description

[0001] Solvothermal liquefaction of carbonaceous materials

[0002] Field of the invention

[0003] The present invention relates to the area of producing low carbon intensity liquid fuels and chemicals from carbonaceous materials such as biomass and more specifically to the area of solvothermal conversion of carbonaceous materials to low carbon intensity oil and chemicals in the presence of an organic solvent.

[0004] Background of the invention

[0005] Advanced liquid biofuels and chemicals produced from carbonaceous materials such as biomass and residue streams have become a central focus to mitigate global climate change arising from greenhouse gas emissions to develop sustainable circular economies.

[0006] Several processes to convert biomass into advanced biofuels are being applied and developed including biological decomposition to produce liquids (e.g., ethanol) and gases (e.g., methane), and thermochemical conversion processes to produce advanced liquid biofuels. The thermochemical processes use temperature and pressure to break biomass at the cellular level. Thermochemical conversion processes include gasification, pyrolysis, and solvothermal and hydrothermal techniques.

[0007] The present invention is generally related to solvothermal conversion processes for conversion of carbonaceous materials in the presence of an organic solvent. Despite extensive studies of several promising pathways, none has progressed to a commercial state. Hence, there are still several requirements for improvements of the technologies including improvement of yields, improvement of carbon intensity, improved product characteristics such as more stable oil products, higher process efficiency e.g., by using less severe process conditions, easier controllable processes, increased on-stream factor e.g. by reduced charring, fouling and / or clogging in processes. Further, product separation is often challenging and may not result in products ready for use or further processing e.g. having a too high moisture content or a too high ash content and / or requires extensive amounts solvents for separation. Hence, there are a need for improved processes mitigating the challenges of the prior art processes.

[0008] Objective of the invention

[0009] Hence, the object of the present invention is therefore to provide an improved method for producing oil from carbonaceous materials that are more efficient and have lower carbon intensity than the prior art methods.

[0010] The improvements may, dependent on certain additional parameters related to preferred embodiments, be one or more of the following: higher oil yield, less char production, easier controllable process, easier downstream product separation, less severe operating conditions meaning cheaper / more cost- effective operations and other additional beneficial effects.

[0011] The improved process may further lead to an improved product meaning one or more of the following: a more stable oil product, e.g., less corrosive (lower acid number) due to fewer ketones and aldehyde groups in oil and carboxylic acids esterified, valuable by-products meaning a more cost-effective process, better resource utilization meaning increased circularity, lower energy consumption for heating due to lower heat capacity, which again means an advantage in the process due to processing in organic solvents.

[0012] Due to a complex composition of the converted carbonaceous feedstock, the separation process becomes particularly demanding and a further objective of the invention is therefore to achieve a higher efficiency of the separation and hence the overall yield of the process, hereby contributing to the lowering of the carbon intensity. Description of the invention

[0013] According to one aspect of the present invention the objective of the invention is achieved through a method for producing a low carbon intensity oil comprising the steps of a. providing a feed mixture comprising: i. a carbonaceous material, ii. an organic solvent selected from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol butanediol, benzene diol, benzene triol, glycerol, ethylene glycol, polyethylene glycol, propylene glycol, catechol’s, acetone, methyl ethyl ketone (MEK), toluene, benzene, hydroxy methyl furfural (HMF), phenols, alkoxyphenols, alkylphenols, creosol, formic acid, acetic acid, or a combination thereof in a concentration of at least 5 % by weight, iii. Water in an amount of less than 40 % by weight, b. converting the feed mixture at pressures in the range 20 bar to 150 bar and at temperatures in the range 280 °C to 430 °C thereby producing a converted feed mixture; c. passing the converted feed mixture to a first separator operating at pressures in the range 20 to 150 bar and temperatures in the range 250 to 430 °C thereby producing a first gas stream and a first liquid stream; d. cooling the first gas stream to temperature in the range 120 °C to 180 °C and feeding it to a second separator operating at a pressure in the range 20 to 80 bar thereby producing a second gas stream with a reduced content of condensables and second liquid stream; e. cooling the first liquid stream to a temperature in the range 150 °C to 300 °C and feeding it to a third separator operating at a pressure of 1 to 20 bar thereby producing a third gas stream and third liquid stream comprising the crude low carbon intensity oil and optionally a fourth liquid stream comprising water.

[0014] A carbonaceous material according to the present invention is generally a carbon containing material e.g. organic matter such as biomass and / or waste materials. Carbonaceous materials according to the invention are further described in the detailed description. In contrast to hydrothermal liquefaction processes, the water content of the feed mixture provided according to the present invention is generally low. In an embodiment according to the present invention the water may constitute less than 40 % by weight such as less than 30 % by weight of the feed mixture. In many advantageous embodiments the water content of the feed mixture is less than 20 % by weight such as less than 15 or less than 10 % by weight of the feed mixture.

[0015] Due to the composition of the feed mixture, which is comprising a significant amount of organic solvent(s), there is a motivation in separating the solvent in an efficient manner to be able to reutilize the solvent in the upstream feed mixture preparation process or as a downstream separate product. The efficiency in the separation process will have significant impact on the overall viability of a plant utilizing the technology according to the invention. The method according to the invention provides a very efficient separation contributing to the overall efficiency of the conversion process.

[0016] In advantageous embodiment of the invention the solvent in the feed mixture comprises low carbon intensity methanol and / or low carbon intensity ethanol such as renewable methanol and / or renewable ethanol.

[0017] In one embodiment, the concentration of renewable methanol and / or renewable ethanol is at least 10 % by weight such as at least 15 % by weight. In other preferred embodiments the concentration of renewable methanol and / or renewable ethanol is at least 20 % by weight, at least 25 % by weight, at least 30 % by weight, at least 35 % by weight, at least 40 % by weight.

[0018] Preferably, the ratio of the weight of renewable methanol and / or renewable ethanol to the dry ash free weight of the carbonaceous material is at least 0,5 such as at least 1. In other preferred embodiments the ratio of the weight of renewable methanol and / or renewable ethanol to the dry ash free weight of the carbonaceous material is at least 1 ,5, at least 2,0, at least 2,5, at least 3,0.

[0019] Advantageously the solvent comprises renewable methanol produced from the gas generated by conversion of the feed mixture. The production of methanol from the gas generated by conversion of the feed mixture is further described in the detailed description.

[0020] The operating temperature and operating pressure of the first separator are in many embodiments close to the conversion pressure and temperature with some allowance for pressure drop and heat losses such as an operating pressure of in the range 20 to 150 bar and an operating temperature of 280 to 430 °C. In an advantageous embodiment the first separator operates at a temperature of 300 to 400 °C and a pressure of 60 to 120 bar.

[0021] The operating temperature and operating pressure of separator 2 are selected so as maximize the recovery of condensables (e.g. solvent for recycling to the feed mixture) from the first liquid stream while maximizing the heat recovery from the first gas stream and while minimizing the pressure reduction so as to minimize recompression costs. In many embodiments this is obtained by cooling the first gas stream to a temperature in the range 120 to 180 °C and by reducing the pressure to a pressure in the range 20 to 80 bar. In an advantageous embodiment the first gas stream is cooled to a temperature in the range 140 to 160 °C and the pressure reduced to a pressure in the range 30 to 50 bar. The operating temperature and operating pressure of separator 3 are selected so as maximize the dehydration and solvent recovery from the second liquid stream. In many embodiments this is obtained by cooling the liquid stream to a temperature in the range 150 to 300 °C and by reducing the pressure to a pressure in the range 1 to 20 bar. In an advantageous embodiment the second liquid stream is cooled to a temperature in the range 200 to 300 °C and the pressure reduced to a pressure in the range 2 to 15 bar such as a temperature of 270 °C and a pressure 10 bar.

[0022] An advantageous embodiment comprises a solids removal step prior to the first separator. The solids removal step may in many embodiments according to the invention comprise a filtration step, a gravimetric separation step, a hydro-cyclone step or a combination thereof. By removing such solids at elevated temperatures and pressures prior to the first separator the tendency to form emulsions is minimized and separation efficiencies improved.

[0023] Advantageously the third liquid stream from the third separator comprising the crude low carbon intensity crude oil is flashed to a pressure in the range 1 to 5 bar such as 2 bar and fed to a fourth separator where it is it is separated into a fourth gas stream comprising condensables in the form of light organic compounds rich in phenolics and a fifth liquid stream comprising the crude low carbon intensity crude oil.

[0024] Further the fourth liquid stream from the fourth separator may advantageously be cooled to a temperature of 30-70 °C and expanded to a pressure of 1 to 10 bar such as 5 bar and fed to a fifth separator for separation into a water rich stream and a solids stream.

[0025] In one embodiment heat is recovered from the cooling and condensation of various process streams in the separation system and used to at least partly heat the feed mixture to the conversion temperature. In an advantageous embodiment this is performed by transferring the heat recovered to a heat transfer fluid selected among a heat transfer oil, a molten salt, steam or high pressure water. The heat transfer fluid is generally further heated prior being heat exchanged with the feed mixture.

[0026] Conversion of the feed mixture is generally performed at pressures in the range 20 bar to 150 bar such as at pressure in the range 60 to 120 bar or 80 to 100 bar.

[0027] In many embodiments the pressure during the conversion of the feed mixture is maintained in the range 20 bar below to 20 bar above the critical pressure of the fluid mixture.

[0028] Advantageously the pressure during the conversion of the feed mixture is maintained above the boiling point pressure of the fluid mixture so as to maintain the fluid mixture in a liquid or supercritical state. It should be noted that the latter is ensured when the pressure is higher than the critical pressure, when the temperature of the fluid mixture is in the supercritical temperature range.

[0029] In many embodiments the conversion of the feed mixture is performed at a temperature of at least 280 °C such as at least 350 °C.

[0030] In a preferred embodiment the conversion of the feed mixture is performed at a temperature of less than 400 °C.

[0031] In one embodiment the feed mixture (step a) comprises phenolics such as phenols, alkoxy phenols, alkyl phenols, creosols, benzene diols, benzene triols or combinations thereof. In a preferred embodiment the concentration of phenolics is at least 3 % by weight. Advantageously the phenolics are produced by process e.g. the phenolics rich stream from separator 4 may be at least partly recycled to the feed mixture.

[0032] The conversion of the carbonaceous material in the presence of e.g alcohols such as methanol and ethanol and / or phenolics improves the yield and quality of the oil by as the solvents are acting as hydrogen donors for the conversion of the biomass, provide increased solubility of oily products, favor deoxygenation and hydrogenolysis reactions, and stabilize the reactive intermediate products e.g. by forming acetals with carbonyl groups such as ketones and aldehydes and esters with carboxylic acids. Thereby the solvent composition retards repolymerization reactions that may lead to high molecular weight products often called solid residues or char formation and lower oil quality. Further the solvents used facilitates the separation of the products.

[0033] By at least partly producing the methanol from the carbon oxide containing process gas from the conversion process the oil yield and the overall process efficacy is improved. By using low carbon intensity hydrogen such as produced by electrolysis using electricity from wind, solar, hydro, geothermal, nuclear energy or combinations thereof the carbon footprint and carbon intensity of the produced oil are further reduced.

[0034] Brief description of the drawings

[0035] The invention will be described in more detail in the following detailed description, with reference to embodiments shown in the drawings where:

[0036] FIG. 1 shows a schematic overview of a process according to the invention for converting carbonaceous material into a low carbon intensity crude oil, a carbon oxide rich gaseous product, a water product and a solid product; FIG. 2 shows a schematic overview of an preferred embodiment of a process according to the invention, where organic solvent is recovered from the product separation and recycled to the feed mixture preparation step;

[0037] FIG. 3 shows a schematic drawing of another preferred embodiment of a process, where the solvent comprises methanol and phenolics and methanol and phenolics is recovered in the separation system and recycled to the feed mixture;

[0038] FIG 4 shows a schematic overview of an advantageous embodiment of a process comprising a preferred separation system;

[0039] FIG. 5 shows a schematic overview of another advantageous embodiment of a system for producing renewable methanol from the gas produced in the conversion process according to the invention further comprising using electricity produced by renewable electricity such as electricity produced from wind, solar and / or geothermal energy.

[0040] Description of a preferred embodiment

[0041] FIG. 1 shows an embodiment of a production process for conversion of carbonaceous material such as biomass and waste to 1 . a low carbon intensity crude oil product, 2. a gaseous product comprising carbon oxides such as carbon mono oxide and carbon dioxide, 3. a solid product, and 4. a water product.

[0042] A feed mixture comprising a carbonaceous material comprising moisture and a solvent is provided as the first step. In contrast to hydrothermal liquefaction processes, the water content of the feed mixture provided according to the present invention is generally low. In an embodiment according to the present invention the water may constitute less than 40 % by weight such as less than 30 % by weight of the feed mixture. In many advantageous embodiments the water content of the feed mixture is less than 20 % by weight such as less than 15 or less than 10 % by weight of the feed mixture.

[0043] A carbonaceous material according to the present invention is generally a carbon containing material e.g. organic matter such as biomass and / or waste materials.

[0044] Nonlimiting examples of carbonaceous materials according to the present invention include lignin, cellulose, hemicellulose, lignocellulosics, proteins, starch, saccharides, lipids, woody biomass such as residues from forestry or pulp and paper operations e.g. wood chips, hog fuel, sawdust, prunings, thinnings and waste, bark, leaves, park and garden waste and weeds, road cuttings, wine trash etc.; Residues, byproducts and waste streams from agricultural production such as grasses, straw, stems, stover, husk, cobs, hulls, shells, kernels, leaves, pulp from e.g. wheat, barley, oat, rye, corn, rice, sunflowers, rapeseed, flax, nut shells, cotton; empty fruit bunches from palm oil production, oil manufacturers effluent (e.g. Palm Oil Manufacturers Effluent (POME) from palm oil manufacturing), pressing residues from vegetable oil production, manures and beddings from animal production, green / organic household wastes, greenhouse waste etc.; energy crops like short rotation coppice, willow, jatropha, sorghum, switchgrass and miscanthus; such as aquatic biomass such as water hyacinth, duck weed, azoIla, water fem; such as red, green and brown macroalgae / seaweed such as sargassum, genus, caulerpaf, euglena, ucus, gracelaria, laminaria, macrocystis, monostroma, porphyra, pleurochrysis etc.; microalgae such as ankistrodemus, botryococcus, chlorella, chlorophyta, cryptophyte, dictyophaerium, dinophyta, chlorophyta, cryptophyte, crypthecodinum, cyclotella, dunaliella, glaucophyta, haematococus, hydrodictyon, hantzschia, microcystis, nannochloris, nannochloropsis, neochloris, nitsschia, nodularia, oscillatoria, phaeophyta, phaedactylum, rhodophyta, scenedesmus, spirogyra, spirulina, scenedesmus, schizacytrium, stichococcus, tetraselmis, thalassiosira, tribophyta; bacteria such as cyanobacteria, industrial waste, residues and by-products such as residues, byproducts and waste streams from vegetable oil production, residues and byproducts from juice production, residue from wine production, residues, byproducts and waste streams from vegetable oil production; residues, byproducts and waste from food production such as brewers spent grains and yeast; residues and byproducts from fruit and vegetable processing such as pulp; residues, by-products and waste streams from coffee production, residues, byproducts and waste stream from cocoa production, residues and by products sugar production such as bagasse, molasses, vinasses, residues and byproducts from fermentation processes such as distillers grains, brewers grains, residues and waste streams paper production such as paper sludges, black liquor, green liquor, white liquor; digestate from aerobic and anaerobic digestion; primary and / or secondary sludge from wastewater cleaning, leachate, clarifier sludges, paper waste, organic fraction of household waste, restaurant wastes, slaughter house wastes, municipal solid waste, pulped household and / or municipal solid wastes, used and recycle cooking oils, fats, glycerine, plastic and polymers, and combinations thereof.

[0045] The dry ash free weight of the carbonaceous material may in many embodiments constitute at least 10 % by weight of the feed mixture such as at least 15 % by weight of the feed mixture. In some embodiments the dry ash free weight of the carbonaceous material constitute at least 17,5 % by weight of the feed mixture such as at least 20 % by weight, at least 22,5 % by weight, at least 25 % by weight or at least 30 % by weight of the feed mixture.

[0046] In contrast to thermochemical conversion routes the carbonaceous material can in many embodiments be added to the feed mixture without the need for predrying. In many embodiments the moisture content in the feed mixture is less than 50 % by weight of the feed mixture such as less than 40 % by weight, less than 30 % by weight, less than 20 % by weight and even less than 10 % by weight of the feed mixture.

[0047] In many applications of the invention the carbonaceous material comprises lignin in a concentration of at least 5 % of the dry ash free weight of the carbonaceous material such as at least 10 %, at least 15 %, at least 20 % of the dry ash free weight of the carbonaceous material.

[0048] In one embodiment of the present invention, the carbonaceous material comprises lignin in a concentration of up 60 % of the dry ash free weight of the carbonaceous material such as up to 50 %, up to 40 %, up to 30 % of the dry ash free weight of the carbonaceous material.

[0049] In one preferred embodiment according to the present invention, the carbonaceous material comprises a combination of a lignocellulosic material and a plastic material. The plastic material constitutes in some embodiments up to 50 % of the dry ash free weight of the carbonaceous material such as up to 40 %, whereas in other applications of the invention the plastic material may constitute up to 35 %, up to 30 %, up to 25 %, up 20 %, up to 15 % by weight of the dry ash free carbonaceous material.

[0050] The carbonaceous material may according to the present invention be in a solid form and / or liquid form or a combination thereof, and may be contained in one or more feedstock. Further the carbonaceous material(-s) may be received in various sizes and shapes.

[0051] In many embodiments according to the present invention the step of providing the feed mixture include a pretreatment step prior to further processing.

[0052] In a preferred embodiment according to the present invention, the pretreatment step includes a size reduction step for homogenization and / or mixing of the carbonaceous material. The specific size reduction depends on the character of the specific feedstock and may comprise one or more cutting, crushing, grinding, attriting and / or milling operations. Non limiting examples of size of suitable size reduction techniques according to the present invention include chippers, macerators, shredders, hammer mills, knife mills, shear mills, roller mills, disc mills, pin mills, ball mills, colloidal mills, stone mills and combinations thereof.

[0053] In many embodiments according to the present invention the carbonaceous material is size reduced to a maximum particle size of 30 mm, 15 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 ,5 mm, 1 mm, 0,5 mm or 0,1 mm.

[0054] In a preferred embodiment according to the present invention the carbonaceous material is sized reduced to an average particle size of less than 2 mm, 1 ,5 mm, 1 ,25 mm, 1 ,0 mm, 0,75 mm, 0,5 mm, 0,25 mm, 0,1 mm or 0,05 mm.

[0055] Advantageously the carbonaceous material has a bimodal size distribution i.e. is comprised of two particle size distributions each having an average particle size.

[0056] In a preferred embodiment the first particle size distribution of the carbonaceous material has an average particle size of less than 200 micron (0,1 mm) with a standard deviation of up to 50 micron such as an average particle size of less than 100 micron with a standard deviation of up to 30 micron, and the second particle size distribution of the carbonaceous material has an average particle size of up to 1500 micron (1 ,5 mm) with a standard deviation of up to 500 micron (0,5 mm) such as an average particle size of up to 1200 micron with an average particle size distribution of up to 300 micron (0,3 mm). Control of maximum particle size, average particle size and particle size distribution of the carbonaceous material is important for the rheological properties of the feed mixture as well as for the mass- and heat transfer within the particles during the conversion step.

[0057] The pretreatment of the step of providing the carbonaceous material may according to many applications of the present invention further comprise measures for removal of contaminants from the carbonaceous material prior to processing. Such contaminant removal may comprise means removal of surface dirt, metallic and non-metallic contaminants by washing, magnetic separators, Eddy current separators and combinations thereof. By the removal of such contaminants in the pretreatment step of wear of equipment and pipes such as by erosion is reduced. A further effect may be easier down-stream processing such as easier product separation and purification, and a higher overall yield of desired product.

[0058] The solvent is generally selected so as to provide rheological properties of the feed mixture, to provide hydrogen donor capability, to provide increased solubility of the oily reaction intermediates and to provide increased stability of the reaction intermediates e.g. by inhibiting polymerization of reactive intermediates, and to favor deoxygenation and hydrogenolysis reactions.

[0059] The solvent provided for preparation of the feed mixture is generally selected from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol butanediol, benzene diols, benzene triols, glycerol, ethylene glycol, polyethylene glycol, propylene glycol, acetone, methyl ethyl ketone (MEK), toluene, benzene, hydroxy methyl furfural (HMF), phenols, alkoxy phenols, alkyl phenols, creosol, formic acid, acetic acid, citric acid or a combination thereof and are present in a concentration of at least 5 % by weight in the feed mixture. The concentration of the solvent(-s) may in one application be at least 10 % by weight such as 15 % by weight. Preferably the solvent constitutes at least 20 % by weight of the feed mixture such as at least 25 % by weight. More preferably the solvent constitutes at least 30 % by weight of the feed mixture such as at least 40 % by weight of the feed mixture.

[0060] The solvent concentration may in many embodiments be in the range 5 % by weight to 95 % by weight of the feed mixture such as in the range 10 to 90 % by weight, in the range 20 to 90 % by weight, in the range 30 to 85 % by weight, 40 to 85 % by weight of the feed mixture.

[0061] Advantageously the solvent has a low carbon footprint e.g. by being produced from a renewable source.

[0062] In an advantageous embodiment the solvent comprises renewable methanol and / or renewable ethanol. In a particular advantageous embodiment, the solvent comprises renewable methanol produced from the carbon oxide rich gas generated as further described in relation to FIG 5. In another advantageous embodiment the solvent comprises recycled oil product or a fraction thereof. In a further advantageous embodiment, the solvent comprises or further comprises renewable phenolics produced by the process, recovered and recycled to the feed mixture step as further described in relation to FIG 4. The pressure during the conversion of the feed mixture is often at least 20 bar such as at least 40 bar; preferably the pressure during the conversion of the feed mixture is at least 60 bar such as at least 70 bar; more preferably the pressure during the conversion of the feed mixture is at least 80 bar such as at least 90 bar; even more preferably the pressure during the conversion of the feed mixture is at least 100 bar such as at least 110 bar.

[0063] In many applications the pressure during the conversion of the feed mixture is maintained below 150 bar such as below 130 bar. Often the pressure during the conversion of the feed mixture is maintained below 120 bars such as below 110 bar. In some embodiments the pressure during the conversion of the feed mixture is below 100 bars such as below 90 bar.

[0064] In many embodiments the pressure during the conversion process is maintained in the range from 20 bar below to 20 bar above the critical pressure of the fluid mixture.

[0065] Advantageously the pressure during the conversion of the feed mixture is maintained above the boiling point pressure of the fluid mixture so as to maintain the fluid mixture in a liquid or supercritical state. It should be noted that at temperatures above the critical temperature the pressure should be maintained above the critical pressure to ensure that the fluid mixture is in a supercritical state.

[0066] The conversion of the feed mixture is often performed at temperatures of at least 250 °C such as temperatures of at least 280 0 °C. In some embodiments the conversion of the feed mixture is performed at temperatures of at least 300 °C such as at temperatures of at least 310 °C. In other embodiments the conversion of the feed mixture is performed at temperatures of at least 320 °C such as temperatures of at least 330 °C. In further embodiments the conversion of the feed mixture is performed at temperatures of at least 340 °C such as temperatures of at least 350 °C.

[0067] Preferred embodiments include converting the feed mixture at temperatures of less than 430 °C such as temperatures of less than 410 °C. Often the conversion of the feed mixture is performed at temperatures of less than 400 °C such as at a temperature of less than 385 °C. In some embodiments the conversion of the feed mixture is performed at temperatures of less than 374 °C such as at a temperature of less than 365 °C. The residence time at conversion temperature and pressure is generally at least 2 minutes such as at least 5 minutes. In some embodiments the residence time at the conversion temperature and pressure is at least 7,5 minutes such as at least 10 minutes. In other embodiments the residence time at the conversion temperature and pressure is at least 12,5 minutes such as at least 15 minutes.

[0068] Often the residence time at the conversion temperature and pressure is below 90 minutes such as below 60 minutes. In some embodiments the residence time at the conversion temperature and pressure is below 45 minutes such as below 30 minutes. In other embodiments the residence time at the conversion temperature and pressure is below 15 minutes such as below 10 minutes.

[0069] The residence time at conversion conditions may in an embodiment of the invention be performed by pressurizing the feed mixture and heating the feed mixture to the conversion temperature and maintaining the feed mixture at the conversion pressure and temperature for the residence time e.g. in a reactor. The pressure may in one embodiment be at least partly autogeneously generated i.e. the pressure may be at least partly generated by heating the feed mixture e.g. in a batch reactor.

[0070] A preferred embodiment according to the invention is, where the process is continuously fed to a heating device for heating to the conversion temperature. Preferably the heating device is a heat exchanger, where the feed mixture is at least partly heated by heat recovered from the cooling of converted feed mixture.

[0071] The converted feed mixture is fed to a separation system where 1. a low carbon intensity crude oil product, 2. a carbon oxide rich gaseous product, 3. a solid product, and 4. a water effluent are recovered. The separation system comprises a first separator (shown in FIG 4) operating at pressure in the range 20 to 150 bar and temperatures in the range 280 to 430 °C thereby producing a first gas stream and a first liquid stream.

[0072] The first gas stream is cooled to a temperature of 120 to 180 °C in a cooler (shown in FIG. 4) and fed to a second separator operating at pressures in the range 20 to 80 bar whereby a second gas stream with a reduced content of condensables and a second liquid stream comprising recovered condensables.

[0073] The first liquid stream is cooled in a second cooler (shown in FIG 4) to a temperature in the range 150 to 300 °C and fed to a third separator (show in FIG 4) typically operating at a pressure in range of 1 to 20 bar, thereby producing a third gas stream and a third liquid stream.

[0074] In an advantageous embodiment the second liquid stream is cooled to a temperature in the range of 200 to 300 °C and the pressure in the third separator (shown in FIG 4) is controlled to a pressure in the range 2 to 15 bar.

[0075] The separation system is further illustrated and described in relation to FIG 4.

[0076] FIG. 2 shows a schematic overview of a preferred embodiment according to the invention, where the feed mixture is at least partly heated by heat recovered from the converted product mixture in the separation system. The heat is recovered In the separation system by heat transfer to a heat transfer fluid such as a heat transfer oil, a molten salt, high pressure water or steam which is further heated prior to being fed to the heater.

[0077] In addition to means for separating the converted feed mixture into the low carbon intensity crude oil product, the carbon oxide rich gaseous product, the solid product (biochar), and the water effluent product described above, the separation system may comprise means for recovering and recycling solvent to the feed mixture as shown in the FIG 2.

[0078] FIG. 3 shows a schematic drawing of another preferred embodiment of a process, where the solvent comprises methanol and phenolics and the methanol and phenolics are recovered in the separation system and recycled to the feed mixture.

[0079] Conversion of the carbonaceous material in the presence of methanol and phenolics such as phenols, creosols, alkoxy phenols, alkyl phenols, benzene diols, benzene triols and combinations thereof in a total concentration of at least 5 % by weight such as at least 10 % by by weight is advantageous. It improves the yield and quality of the low carbon intensity crude oil. The methanol and phenolics are believed to act as hydrogen donors during the conversion of the biomass, provide increased solubility of oily products, favor deoxygenation and hydrogenolysis reactions, stabilize reactive intermediate products e.g. by forming acetals with carbonyl groups such as ketones and aldehydes and esters with carboxylic acids. Thereby the solvent combination retards repolymerization reacrions that may lead to high molecular weight products often called solid residues or char and poorer quality of the low carbon intensity crude oil. Further the solvents used facilitates the separation of the products.

[0080] As illustrated in the figure phenolics is produced from the conversion of the carbonaceous material and recovered from the crude oil fraction and at least partly recycled to the feed mixture fraction as further described under FIG. 4. The phenolics are produced by the conversion of the carbonaceous material, hence they are renewable and thereby assist in reducing the carbon footprint of the produced crude oil in addition to the benefits mentioned above. As shown in FIG.3 methanol is also recovered in the separation system and recycled to the providing the feed mixture step. The recovery of methanol and other condensables is further illustrated and described in relation to FIG. 4.

[0081] As also shown in FIG.3 a carbon oxide rich gas is recovered in the separation system. In an advantageous embodiment the carbon oxide rich gas is catalytically reacted with green hydrogen to produce methanol with water as a by-product as further illustrated and described in relation to FIG. 5. At least part of the methanol produced is recycled to the providing feed mixture step. As the methanol is produced from biogenic carbon and hydrogen is produced using low carbon intensity electricity, the methanol produced is renewable methanol. Hence, at least partly using the renewable methanol produced will further reduce the carbon footprint of the produced crude oil. Further in addition to the other benefits described above, the overall oil yield and carbon efficiency are increased as carbon oxides in the gas stream now converted would otherwise have been lost.

[0082] FIG. 4 shows a schematic overview of an advantageous embodiment of an advantageous process comprising a preferred separation system.

[0083] As shown in the FIG. 4 the converted feed mixture from the conversion step is in one embodiment first fed to solids removal step (solids trap) for removal of solids prior to the first separator. The solids removal step may in many embodiments comprise one or more filtration steps, gravimetric separation steps, hydro-cyclone steps or a combination thereof. The solids removal is operating at elevated temperature and pressure such as a temperature in the range 250 to 430 °C, and a pressure in the range 20 to 150 bar. By removing such solids at elevated temperature and pressures prior to the first separator the tendency to form emulsions is minimized and separation efficiencies improved. The separated solids may be subjected to further processing such as purification steps such as washing, drying and / or other stabilization steps such as thermal treatment. In one application the solids may be further processed to obtain biochar that may be used as for soil amendment and / or as a fertilizer product, while sequestering recovered carbon in the solid product thereby contributing in reducing the carbon intensity of the produced liquid fuels and / or chemicals.

[0084] The separation system further comprises a first separator typically operating at pressures and temperatures close to the conversion pressure and temperatures with some allowance for pressure drops and heat losses. Typically operating at pressure in the range 20 to 150 bar and temperatures in the range 250 to 430 °C thereby producing a first gas stream and a first liquid stream. In an advantageous embodiment the first separator operates at a temperature in the range 300 to 400 °C and at a pressure in the range 60 to 120 bar. In many embodiments the first separator comprises a gravimetric phase separator such as a two-phase separator.

[0085] By operating the first separator at hot high-pressure conditions according to the present invention it is obtained that the majority of the gas can be recovered at high pressure and that the majority of lighter compounds such as the solvent and water are separated into the first gas stream.

[0086] The first gas stream is cooled to a temperature of 120 to 180 °C in a first cooler and fed to a second separator operating at a pressure in the range 20 to 80 bar, whereby a second gas stream with a reduced content of condensables and a second liquid stream comprising recovered condensables. The operating temperature and operating pressure of separator 2 are selected so as to maximize the recovery of condensables (e.g. solvent for reuse) from the first liquid stream while maximizing the heat recovery from the first gas stream and while minimizing the pressure reduction so as to minimize recompression costs. Typical the condensables in the second liquid stream comprises recovered solvent such as exemplified as methanol and water in the figure. The second liquid stream may in many applications be further separated to a solvent rich stream for and a water rich stream. Suitable techniques for such separation include distillation, multiple flashing, membrane techniques or combinations thereof. The recovered methanol is typically at least partly recycled to the providing the feed mixture step as indicated in FIG 4.

[0087] In a preferred embodiment the first gas stream is cooled to a temperature in the range 140 to 160 °C and the pressure reduced to a pressure in the range 30 to 50 bar.

[0088] The operating temperature and operating pressure of separator 3 are selected so as to maximize the dehydration and solvent recovery from the second liquid stream. In many embodiments this is obtained by cooling the first liquid stream to a temperature in the range 150 to 300 °C in a second cooler and by reducing the pressure to a pressure in the range 1 to 20 bar, thereby producing a third gas stream, a third liquid stream and optionally a fourth liquid stream comprising residual water and residual solids. The fourth liquid stream may be expanded to a pressure of 1 to 7 bar such as a pressure of 5 bar and cooled to a temperature of 20-80 °C such as 50 °C in a third cooler.

[0089] In an advantageous embodiment the second liquid stream is cooled to a temperature in the range 200 to 300 °C and the pressure is reduced to a pressure in the range 2 to 15 bar such as a temperature of 270 °C and a pressure 10 bar.

[0090] Advantageously the third liquid stream from the third separator comprising the crude low carbon intensity crude oil is expanded to a pressure in the range 1 to 5 bar such as 2 bar and separated in fourth separator where it is it is separated into a fourth gas stream comprising phenolics rich condensables and a fifth liquid stream comprising the crude low carbon intensity crude oil. In a preferred embodiment, the phenolics rich stream fourth gas stream is cooled to a temperature of 60 to 150 °C such as 80 °C in a fourth cooler, whereby the phenolics rich gas is condensed. In an advantageous embodiment the condensed phenolics rich stream is at least partly recycled to the step of providing the feed mixture. In another embodiment the fifth liquid stream comprising the crude oil produced is cooled to a temperature of 60 to 150 °C.

[0091] Further the fourth liquid stream from the third separator may advantageously be cooled to a temperature of 30-70 °C in a fifth cooler and expanded to a pressure of 1 to 10 bar such as 5 bar and fed to a fifth separator for separation into a water rich stream and a solids stream.

[0092] In one embodiment heat is recovered from the cooling and condensation of various process streams in the separation system and at least partly used to heat the feed mixture to the conversion temperature. In an advantageous embodiment this is performed by transferring the heat recovered to one or more heat transfer fluid(-s) selected among heat transfer oils, molten salts, steam or high pressure water. The heat transfer fluid is generally further heated prior to being heat exchanged with the feed mixture.

[0093] Some of the advantages of the separation system described comprise production of low moisture and ash content low carbon intensity crude oil without the use of extraction solvents, comprise recovery of large part of the gas at high pressure, comprise that solvents e.g. methanol are recovered in liquid stream two and can be at least partly recycled to the step of providing the feed mixture. Further hot low pressure gas stream may also be recovered. In addition, phenolics recovered in a phenolic rich fraction can be recycled to the step of providing the feed mixture. Furthermore, aqueous streams are recovered. Still further the pressure let down of the converted feed mixture may be integrated with the separation system, which results in a simpler and an easier controllable process. Even further recovery of heat from cooling of the converted feed mixture may be integrated with the separation system, which further results in a simpler, more controllable and more cost effective solution.

[0094] FIG. 5 comprises an advantageous system for producing renewable methanol(-s) from the carbon oxide rich gas produced in the conversion of the carbonaceous material, and at least partly recycling the alcohol produced to the step of providing the feed mixture of the conversion process.

[0095] The carbon oxide rich gas produced from the conversion the carbonaceous material comprises carbon oxides such carbon dioxide and carbon mono oxide as the main compounds. The amount of process gas and the composition of the gas depend on the specific operating conditions, and carbonaceous material(-s) being converted, but often further comprises Ci to C4 hydrocarbons, and hydrogen.

[0096] The carbon oxide rich gas may be recovered from the separation system shown in FIG. 4 e.g. the high pressure second gas stream from separator 2 and / or the low pressure gas stream from separator 3.

[0097] In an advantageous embodiment the two gas streams from separator 1 and separator 3 are combined and catalytically reacted with hydrogen to produce methanol with water as a by-product.

[0098] The first step of the methanol production is a syngas production step as shown in FIG. 5.

[0099] The first step of the syngas preparation step typically comprises a purification step for removal of at least sulphur compounds and nitrogen compounds such as ammonia. The purification may comprise adsorption methods such as adsorption to metal oxide sorbents such as ZnO, zeolites or activated carbon, chemical and physical absorption techniques as well as membrane separation. A preferred embodiment for sulphur removal comprises adsorption to a mixed oxide sorbent comprising ZnO. The sorbent may be regenerated by steam treatment or reaction with hydrogen.

[0100] Another preferred embodiment for sulphur removal comprises pressure swing adsorption to an activated carbon sorbent or a zeolite sorbent.

[0101] A preferred embodiment for nitrogen removal comprises pressure swing adsorption such as adsorption to an activated carbon and / or a zeolite sorbent.

[0102] The syngas production step further comprises means for adjusting the H2 / CO- ratio to a molar ratio in the range 1 ,8 to 2,5 or in the range 1 ,8 to 2,2 such as a molar Fb / CO-ratio of 2 by addition of hydrogen to the syngas production step.

[0103] In a preferred embodiment the adjustment of the Fb / CO-ratio in the syngas preparation step is be performed by a thermochemical, electrochemical or biological conversion processes and combinations thereof.

[0104] In an advantageous embodiment, the means for adjusting the Fb / CO-ratio include adding hydrogen preferably electrolytic hydrogen at least partly produced by low carbon intensity electricity such as electricity from wind, solar, hydro, geothermal, nuclear or combinations thereof to the syngas preparation unit as shown in FIG 5. Thereby the methanol produced is renewable methanol and the overall carbon footprint of the process is reduced.

[0105] In another embodiment, the means for adjusting the Fb / CO-ratio include performing a reverse water gas shift reaction (RWGS), where CO2 and F are reacted to produce CO and water vapor (H2O). The means for adjusting the Fb / CO-ratio by RWGS reaction may be performed by conventional means such as by reaction in a catalytic reactor. Suitable catalysts for the RWGS reaction include supported bimetallic catalysts combining two or more different transition metals such as Fe, Co, Ni, Cr, Zn, Co, Cu, Ce on a high surface area porous supporting material such as alumina, silica, zeolites or carbon supports.

[0106] The reaction temperature depends on the specific catalyst and process configuration.

[0107] One embodiment of the present invention comprises a syngas preparation unit where a reverse water gas shift reaction of the process gas operating at temperatures in the range 300 to 500°C such 300 to 400 °C and pressures in the range 10-50 bar such as 30 to 40 bar.

[0108] Another preferred embodiment is where the syngas preparation unit comprises an electrochemical reverse water gas shift (eRWGS) process where carbon oxide (CO, CO2) containing process gas from the conversion process of the carbonaceous material is converted to syngas in an electrochemical cell.

[0109] The electrochemical cell may comprise one or more catalyst(-s) to promote the reverse gas reaction. Often the operating temperature of the electrochemical cell is at least 400 °C, 500°C, 600 °C, 700 °C, 800 °C, 900 °C or even at least 1000 °C.

[0110] In a preferred embodiment heat from the syngas preparation and / or methanol is transferred to the conversion process of the carbonaceous material e.g. by heat transfer to a heat transfer fluid such as a heat transfer oil, high pressure water, steam or a molten salt.

[0111] Typically, the methanol synthesis step according to the present invention involves at least one catalytic reaction step for reacting the syngas to methanol in the presence of one or more metal catalyst(-s). The catalytic reaction step is often performed at pressures in the range 30 to 150 bar, and temperatures in the range 200 to 450 °C such as pressures of 50 to 100 bar and temperatures in the range 200 to 300 °C. An advantageous embodiment comprises performing the catalytic reaction step at a pressure of 50 bar and a temperature of 250 °C.

[0112] Suitable metal catalysts according to the invention include copper zinc oxide catalysts, copper zinc chromium oxide catalysts, copper mixed oxides catalysts, and iron oxide catalysts on an alumina, zirconia carrier or zeolite carrier material. Other metal promotors and modifications may be added to the catalyst structure for activity and selectivity enhancement.

[0113] In one embodiment, the catalytic reaction step is arranged as a fixed-bed reaction system comprising one or more fixed beds comprising the metal catalyst(-s).

[0114] Another configuration of the catalytic reaction step according to the present invention is as a fluidized-bed reactor system containing the metal catalyst(-s) fluidized by the gas feedstock.

[0115] The conversion per pass in the catalytic reaction step is often relatively low e.g. in the range 10-40 % such as in the range 20 to 30 %. Hence, an advantageous embodiment is where the unreacted carbon oxides and hydrogen are at least partly recycled back into the catalytic reactor after intermediate separation of produced alcohol and water as shown in FIG. 5. Hereby the overall conversion is increased.

[0116] As also shown in the FIG. 5 the methanol produced from the process gas is at least partly recycled to the conversion process. Hereby, the overall oil yield and efficiency of the conversion process for carbonaceous material and the resulting carbon footprint of the oil produced are reduced.

[0117] As illustrated the methanol and water produced in the methanol synthesis may be separated from unreacted gases by flashing and may be at least partly recycled and mixed with the incoming process gas to the methanol to achieve a higher overall conversion. The liquid fraction from the flash separation (5) may further separated (6) into a methanol stream and water stream by conventional means such as by distillation. As illustrated the separated water may be at least partly be recycled to the electrolysis unit (3), and the methanol produced may be at least partly recycled to the conversion process thereby increasing the overall process efficiency, and reducing the chemical consumption as well as the carbon footprint of the oil produced from carbonaceous material.

Claims

CLAIMS1 . Method for producing a low carbon intensity oil comprising the steps of a. providing a feed mixture comprising: i. a carbonaceous material ii. an organic solvent selected from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol butanediol, benzene diol, benzene triol, glycerol, ethylene glycol, polyethylene glycol, propylene glycol, acetone, methyl ethyl ketone (MEK), toluene, benzene, hydroxy methyl furfural (HMF), phenols, alkoxyphenols, alkylphenols, creosol, formic acid, acetic acid, citric acid or a combination thereof in a concentration of at least 5 % by weight iii. water in an amount less than 40 % by weight b. converting the feed mixture at pressures in the range 20 bar to 150 bar and at temperatures in the range 250 °C to 430 °C thereby producing a converted feed mixture; c. passing the converted feed mixture to a first separator operating at pressures in the range 20 to 150 bar and temperatures in the range 250 to 430 °C thereby producing a first gas stream and a first liquid stream; d. cooling the first gas stream to temperature in the range 120 °C to 180 °C and feeding it to a second separator operating at a pressure in the range 20 to 80 bar thereby producing a second gas stream with a reduced content of condensables and second liquid stream comprising recovered condensables; e. cooling the first liquid stream to a temperature in the range 150 °C to 300 °C and feeding it to a third separator operating at a pressure of 1 to 20 bar thereby producing a third gas stream andthird liquid stream comprising the crude low carbon intensity oil and optionally a fourth liquid stream comprising water.

2. Method according to claim 1, where the solvent in the feed mixture comprises low carbon intensity methanol and / or low carbon intensity ethanol.

3. Method according to claim 2, where the low carbon intensity methanol and / or low carbon intensity ethanol in the feed mixture is at least partly recovered from the second liquid stream and recycled to the feed mixture step.

4. Method according to any of the claims 1 to 3, comprising a solids removal step prior to the first separator.

5. Method according to claim 4, where the solids removal step comprises a filtration step, a gravimetric separation step, a hydrocyclone step or a combination thereof.

6. Method according to any of the preceding claims, where the third liquid stream comprising the crude low carbon intensity oil is expanded to a pressure of 1 to 5 bar and fed to a fourth separator operating at a temperature in the range 200 to 300 °C where it is it is separated into a fourth gas stream comprising light organic compounds rich in phenolics and a fifth liquid stream comprising low carbon intensity crude oil. Method according to claim 5, where the fourth gas stream rich in phenolics is condensed, and at least partly recycled to the step of providing the feed mixture.

7. Method according to any of the preceding claims, where the fourth liquid stream is cooled to 30-70 °C and expanded to a pressure in the range1 to 10 bar such as 5 bar and fed to a fifth separator where it is separated into a water rich stream and a solids rich stream.

8. Method according to any of the preceding claims, where heat is recovered from the separated gas and / or liquid streams in the separation system and transferred to one or more heat transfer fluid(-s) and at least partly used heat the feed mixture to conversion temperature.

9. Method according to claim 8, where the heat transfer fluid is selected among heat transfer oils, molten salts, steam, pressurized water or a combination thereof.

10. Method according to claim 9, where the heat transfer fluid is further heated prior to being heat exchanged with the feed mixture.

11. Method according to any of the preceding claims, where the first separator operates at a temperature of 300 to 400 °C and a pressure of 60 to 120 bar.

12. Method according to any of the preceding claims, where the second separator operates at a temperature of 140 to 160 °C and a pressure of 30 to 50 bar.

13. Method according to any of the preceding claims, where the third separator operates at a temperature of 200 to 280 °C and a pressure of2 to 15 bar.

14. Method according to any of the preceding claims, where the pressure during the conversion of the feed mixture is maintained in the range 20bar below to 20 bar above the critical pressure of the fluid mixture.

15. Method according to any of the preceding claims, where the conversion of the feed mixture is performed at a temperature of at least 280 °C or at least 350 °C.

16. Method according to any of the preceding claims, where the conversion of the feed mixture is performed at a temperature of less than 400 °C.

17. Method according to any of the preceding claims, where the conversion of the feed mixture is performed at pressures in the range 80 to 120 bar.

18. Method according to any of the preceding claims, where the feed mixture comprises low carbon intensity methanol and / or low carbon intensity ethanol in a concentration of at least 10 % by weight such as at least 20 % by weight, at least 30 % by weight, or at least 40 % by weight.

19. Method according to any of the preceding claims, where the low carbon intensity methanol in the feed mixture is at least partly produced from the gas produced by conversion of the feed mixture.

20. Method according to any of the preceding claims, where the feed mixture (step a) comprises or further comprises phenolics such as phenols, alkoxy phenols, alkyl phenols, or creosols.

21. Method according to claim 20, where the concentration of phenolics is at least 3 % by weight such as at least 5 % by weight, at least 10 % by weight or at least 20 % by weight.

22. Method according to any of the claims 20 and 21 , where the phenolics are produced by the process.

23. Method according to any of the preceding claims, where the total concentration of the organic solvents is at least 30 % by weight such as at least 40 % by weight.

24. Method according to any of the claims 1-23, where the water content of the feed mixture is less than 30 % by weight, such as less than 20 % by weight, or more preferred less than 15 % by weight or less than 10% by weight of the feed mixture.

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