Method for stabilizing nitrogen-rich oils

Abstract

The present invention relates to a process for hydrotreating a nitrogen rich liquid oil stream by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.

Description

TECHNICAL FIELD

[0001] The present invention relates to a process for hydrotreating a nitrogen rich liquid oil stream by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.BACKGROUND

[0002] The field of renewable feedstocks has been attracting a great deal of attention, not only in Europe, but also US and China. Using renewable feedstocks enables a sustainable approach to the production of hydrocarbon products for use as transportation fuel, in particular any of marine fuel, diesel, jet fuel and naphtha as well as for use as petrochemical raw materials, such as steam cracker feeds.

[0003] Oils derived from nitrogen rich feedstocks such as sewage sludge, algae or other nitrogen-rich renewable sources have a higher propensity for polymerization than oils derived from wood or straw.

[0004] If the oils derived from nitrogen rich feedstocks are not stabilized they may quickly coke and plug catalyst bed. If they are stabilized using the same method as used for pyrolysis oil derived from woody biomass, then an unnecessary high pressure, low LHSV and very expensive catalyst is used, leading to a very high CAPEX.

[0005] WO 2022 / 152900 describes a method for low temperature stabilization of liquid oils.

[0006] Zacher et al “Technology advancements in hydroprocessing of bio-oils”, Biomass and Bioenergy, 125 (2019) 151-168 teaches that oils with a carbonyl content of 1.3 mmol / g should be sufficiently stable for hydrotreatment to take place at 400° C. Since a step of low temperature stabilization is adding cost and complexity to a process, this teaching implies avoiding such a step.

[0007] However, it has been found that this is not the case if the feed oil has a high N content. A feed with high N content, and with a carbonyl content between <0.5-1.13 mmol / g, may cause plugging in a reactor at an operating temperature of 300° C.

[0008] The present technology provides the discovery of a new problem—that for feeds with low carbonyl numbers, such as above the detection limit, but below 1.13 mmol / g, but high concentrations of nitrogen, plugging of the reactor is a risk. It is an object to provide a stable renewable crude, and a process for the formation thereof, that can be further hydroprocessed using more traditional hydroprocessing conditions.SUMMARY

[0009] It has been found by the present inventor(s) that plugging of a hydroprocessing reactor by a feed with high N content, yet low carbonyl content, can be reduced, and even avoided, if the feed is first stabilised.

[0010] So, in a first aspect the present invention relates to a process for hydrotreating a nitrogen rich liquid oil stream by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.DETAILED DISCLOSURE

[0011] The unit “barg” denotes pressure above atmospheric (atmospheric pressure: about 1 bar).

[0012] A process is provided for hydrotreating a nitrogen rich liquid oil stream, comprising at least 0.5 wt % nitrogen and a carbonyl content from 0.5 mmol / g to 1.13 mmol / g by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream. The combination of features recited above, enables stabilization of the liquid oil.

[0013] In preferred embodiments, the temperature is in the range 180-220° C., e.g. 190-200° C. In another embodiment, the pressure is 80-175 barg, e.g. 150 barg. In another embodiment LHSV is 0.2-4.0 h−1, such as 0.2-0.2 h−1, or 0.8-1.0 h−1, e.g. 0.9 h−1.

[0014] In a further embodiment, the temperature is in the range 180-220° C., e.g. 190-200° C. In another embodiment, the pressure is 15-80 barg, e.g. 50 barg. In another embodiment, LHSV is 0.2-4.0 h−1, such as 0.2-0.2 h−1, or 0.8-1.0 h−1, e.g. 0.9 h−1.

[0015] The temperature range 80-250° C. encompasses the inlet temperature of the liquid oil stream and the outlet temperature of stabilized liquid oil stream. Preferred temperature ranges include 100-250° C., 120-250° C., and 150-250° C. The process is exothermic thus a raise in temperature of about 100° C. or more may occur. The higher the inlet temperature e.g. 80° C., the easier the ignition of the process to initiate the exotherm. The outlet temperature can for instance be 150 or 200 or 240° C. More generally, the temperature in a given step or reactor (unit) thereof, means the inlet temperature in an adiabatic step, or the reaction temperature in an isothermal step.

[0016] By the present invention, a continuous operation process is used, since contrary to a batch operation, there is no dependency on the outcoming product (stabilized liquid oil) being fluid at all times. The term continuous operation, as is well known in the art, means that the incoming stream of liquid oil during a given production cycle is continuous, as also is the stabilized liquid oil stream being withdrawn as the outcoming product. This is in contrast to a batch operation i.e. discontinuous operation, as is also well known in the art, in which the total amount of liquid oil and catalyst is introduced at the beginning of the process, and the outcoming product is withdrawn after a certain period of time.

[0017] The process suitably has a hydrogen to liquid oil ratio, defined as the volume ratio of hydrogen to the flow of the liquid oil stream, of 100-8000 NL / L, such as 2000-5000 NL / L. By the invention, the process is also conducted at a hydrogen to liquid oil ratio of 1000-6000 NL / L, such as 2000-5000 NL / L, for instance 2500, 3000, 3500, 4000 or 4500 NL / L. As used herein, the term “hydrogen to liquid oil ratio” or “H2 / Oil ratio” means the volume ratio of hydrogen to the flow of the liquid oil stream. It should be understood that the unit NL means “normal” liter, i.e. the amount of gas taken up this volume at 0° C. and 1 atmosphere. The volume of liquid oil is in line with the practice in the field determined at 15° C. and 1 atmosphere.

[0018] In an embodiment, the liquid oil stream contains at least 2 wt % N, or at least 5 wt % N. The liquid oil stream may contain 10 wt % nitrogen (N), such as at least 2 wt % N, or at least 5 wt % N. The nitrogen content is suitably determined by standard elemental analysis.

[0019] In an embodiment, the liquid oil stream contains at least 0.5 wt % oxygen (O), such as at least 2 wt % 0, or at least 4 wt % 0. The oxygen content is suitably determined by standard elemental analysis.

[0020] In one aspect the micro carbon residue (MCR) of the liquid oil stream, before hydrotreating, as determined by ASTM D 4530, is between 5-20 wt %, such as between 5-15 wt %, as such elevated MCR values indicate an inclination for coke depositing. After hydrotreating, the micro carbon residue (MCR) of the stabilized liquid oil stream, as determined by ASTM D 4530, is suitably below 5 wt %, such as below 4.5 wt %, which indicates lower inclination for coke depositing.

[0021] In an embodiment, the liquid oil stream is a pyrolysis oil stream or a hydrothermal liquefaction oil (HTL oil) stream. In an embodiment, the liquid oil stream is a stream of oil originating from a thermochemical decomposition process, such as pyrolysis or hydrothermal liquefaction, being part of the same process plant or a separate process plant. In an embodiment the liquid oil stream is a pyrolysis oil stream which comprises at least 0.5 mol / kg of one or more of: aldehyde compounds, ketones, alcohols, furfural, as determined by ASTM E3146-20. In an embodiment the liquid oil stream may be characterized by it's elemental composition being from 50 wt % to 70 wt %, 80 wt % or 85 wt % C and from 2 wt % 3 wt % 5 wt % or 10 wt % to 50 wt % 0, which an exemplary elemental composition range of a liquid, non-aqueous thermochemical decomposition product such as a pyrolysis oil stream or a hydrothermal liquefaction oil (HTL oil) stream. Possibly the 14C / 12C isotope ratio is 0.5 to 2 parts per trillion, which is the isotope composition defining samples of biological origin.

[0022] In one aspect, the catalyst is Ni-based, Mo-based, CoMo-based, NiMo-based, W-based, NiW-based or Ru-based, optionally in sulfided or reduced form.

[0023] When a catalyst is “based” on a particular metal (e.g. Ni-based), this means that that the listed metal Ni, Mo, . . . is at least 90 wt %, 99% or 100% of the Group 1-12 materials in the catalyst. The following ranges for each category is provided: Ni-based (2-30 wt % Ni sulfided or reduced), Mo-based (2-30 wt % Mo preferably sulfided), CoMo-based (1-10 wt % Co, 2-30 wt % Mo preferably sulfided), NiMo-based (1-10 wt % Ni, 2-30 wt % Mo preferably sulfided), W-based (2-30 wt % W preferably sulfided), NiW-based (1-10 wt % Ni, 2-30 wt % W preferably sulfided) or Ru-based (0.1-10 wt % preferably reduced), optionally in sulfided or reduced form.

[0024] In one aspect of the process, the catalyst is a supported catalyst having a Mo content of 2-30 wt %, and optionally also a P content of 0-3 wt %, based on the total weight of the catalyst. The support may be selected from alumina, silica, titania and combinations thereof; optionally in combination with a solid acid such as silica-alumina or a molecular sieve having topology MFI, BEA or FAU. As used herein, the term “topology MFI, BEA or FAU”, means a structure as assigned and maintained by the International Zeolite Association Structure Commission in the Atlas of Zeolite Framework Types, which is at http: / / www.iza-structure.org / databases / or for instance also as defined in “Atlas of Zeolite Framework Types”, by Ch. Baerlocher, L. B. McCusker and D. H. Olson, Sixth Revised Edition 2007.

[0025] The process may further comprise a prior step of thermal decomposition of a solid renewable feedstock, for producing said liquid oil stream. As used herein, the term “thermal decomposition” shall for convenience be used broadly for any decomposition process, in which a material is partially decomposed at elevated temperature (typically 250° C. to 800° C. or even 1000° C.), in the presence of sub-stoichiometric amount of oxygen (including no oxygen). The product will typically be a combined liquid and gaseous stream, as well as an amount of solid char. The term shall be construed to include processes known as pyrolysis and hydrothermal liquefaction, both in the presence and absence of a catalyst.

[0026] Accordingly, in a particular embodiment, the thermal decomposition is pyrolysis, such as fast pyrolysis, thereby producing said pyrolysis oil stream. It should be understood that the thermal decomposition is conducted in a thermal decomposition section, Hence, the pyrolysis is conducted in a pyrolysis section, and the hydrothermal liquefaction is conducted in a hydrothermal liquefaction section. As used herein, the term “section” means a physical section comprising a unit or combination of units for conducting one or more steps and / or sub-steps.

[0027] One kind of pyrolysis is fast pyrolysis, also referred in the art as flash pyrolysis. Fast pyrolysis means the thermal decomposition of a solid renewable feedstock in the absence of oxygen, at temperatures in the range 350-650° C. e.g. about 500° C. and reaction times of 10 seconds or less, such as 5 seconds or less, e.g. about 2 sec. Fast pyrolysis may for instance be conducted by autothermal operation e.g. in a fluidized bed reactor. The latter is also referred as autothermal pyrolysis and is characterized by employing air, optionally with an inert gas or recycle gas, as the fluidizing gas, or by using a mixture of air and inert gas or recycle gas. Thereby, the partial oxidation of pyrolysis compounds being produced in the pyrolysis reactor (autothermal reactor) provides the energy for pyrolysis while at the same time improving heat transfer. For details about autothermal pyrolysis, reference is given to e.g “Heterodoxy in Fast Pyrolysis of Biomass” by Robert Brown: https: / / dx.doi.Org / 10.1021 / acs.energyfuels.0c03512. In an embodiment, the pyrolysis is fast pyrolysis, wherein said fast pyrolysis is suitably conducted in the absence of a catalyst and hydrogen.

[0028] “Intermediate” or “slow” pyrolysis are also suitable for high N feedstocks, and may be even more suitable than fast pyrolysis. One reason is that high N containing feedstocks tend to comprise more alkaline metals, which increases the risk of agglomeration and defluidization.

[0029] In another embodiment, therefore, the pyrolysis step is intermediate pyrolysis, in which the vapor residence time is in the range of 10 seconds-5 minutes, such as 11 seconds-3 minutes. As for fast pyrolysis, the temperature is also in the range 350-650° C. e.g. about 500° C. Often this pyrolysis is conducted in pyrolysis reactors handling different types of waste, where the vapor is burned after the pyrolysis reactor. Typical reactors are: Herreshoff furnace, rotary drums, amaron, CHOREN paddle pyrolysis kiln, auger reactor, and vacuum pyrolysis reactor.

[0030] In another embodiment, the pyrolysis step is slow pyrolysis, in which the solid residence time is in the range of 5 minutes-2 hours, such as 10 min-1 hour. The temperature is suitably about 300° C. This pyrolysis gives a high char yield and the char can be used as a fertilizer or as char coal; the pyrolysis still produces some gas and renewable crude and if the carbon is used a fertilizer the final bio-oil can have a GHG above 100%, thus being carbon negative. Typical reactors are auger reactor (yet with a different residence time than for intermediate pyrolysis), fixed bed reactor, kiln, lambiotte SIFIC / CISR retort, Lurgi process, wagon reactor, and carbo twin resort.

[0031] Hydrothermal liquefaction (HTL) involves the reaction of biomass or organic material in the presence of water or other solvents at hydrothermal conditions, effectively in the range of temperatures from 250° C. to 450° C., and pressures from approximately 100-350 bar. At these conditions, water remains in a liquid or relatively dense supercritical state. Due to the requirement of a wet reaction environment, HTL is especially suited to wet feedstocks as the need for drying is alleviated. During HTL processing, organic material undergoes a number of depolymerization reactions including hydrolysis, dehydration and decarboxylation to form water-soluble intermediates, and repolymerization reactions including various condensation mechanisms to form water insoluble products including renewable crude and char. Other products are gases, typically dominated by CO2 but, depending on biomass and reaction conditions, with varying contents of H2, CH4 and CO, as well as an aqueous phase with soluble organics, mostly in the form of alcohols, acids and phenols (for lignocellulosics).

[0032] Suitably, therefore, the thermal decomposition step may be:

[0033] pyrolysis, such as fast, intermediate or slow pyrolysis, thereby producing a pyrolysis oil stream; or

[0034] hydrothermal liquefaction (HTL), thereby producing a HTL oil stream.

[0035] In one aspect of the process according to the invention, the solid renewable feedstock is:

[0036] a lignocellulosic biomass including: wood products, forestry waste, and agricultural residue; and / or

[0037] municipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public, such as mixed municipal waste given in EU Directive 2018 / 2001 (RED II), Annex IX, part A.

[0038] The term “renewable” shall be construed to exclude fossil crudes, but to include recycled waste of fossil origin, such as plastic waste.

[0039] Any combination of the above is also envisaged.

[0040] As used herein, the term “lignocellulosic biomass” means a biomass containing, cellulose, hemicellulose and optionally also lignin. The lignin or a significant portion thereof may have been removed, for instance by a prior bleaching step. The lignocellulosic biomass is suitably forestry waste and / or agricultural residue and comprises biomass originating from plants including grass such as nature grass (grass originating from natural landscape), wheat e.g. wheat straw, oats, rye, reed grass, bamboo, sugar cane or sugar cane derivatives such as bagasse, maize and other cereals.

[0041] In an embodiment, the process further comprises passing the stabilized liquid oil stream through a hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), or hydrodesulfurisation (HDS) step, suitably wherein the HDO is conducted at a higher temperature than the prior step for forming said stabilized liquid oil stream.

[0042] Thereby, any organic nitrogen present in the stabilized pyrolysis oil stream is removed and a hydrotreated stream is produced, which can be further treated for producing hydrocarbon products boiling in the transportation fuel range, such as diesel, jet fuel and naphtha. During the hydrotreating of renewable feedstock or liquid oil, oxygen is mainly removed as H2O, which gives a paraffinic fuel consisting of paraffins with the same number for carbon atoms as in the backbone of the triglycerides. This is called the hydrodeoxygenation (HDO) pathway. Oxygen can also be removed by dicarboxylic (DCO) pathway, which generates CO2 instead of H2O: HDO pathway: C17H34COOH+3.5H2<->C18H38+2H2O Decarboxylation pathway: C17H34COOH+0.5H2<->C17H36+CO2.

[0043] The material catalytically active in hydrotreating, e.g. HDO, typically comprises an active metal (sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum, but possibly also either elemental noble metals such as platinum and / or palladium) and a refractory support (such as alumina, silica or titania, or combinations thereof).

[0044] In one embodiment, the process further comprises passing the stabilized liquid oil stream through one or more metal guards active in hydrometallation (HDM) and / or hydrodeoxygenation (HDO), prior to said HDO step. A suitably guard bed for at least removing P and Fe is a porous material comprising alumina, the alumina comprising alpha-alumina, with the porous material comprising one or more metals selected from Co, Mo, Ni, W and combinations thereof, and said porous material having a BET-surface area of 1-110 m2 / g, suitably also having a total pore volume of 0.50-0.80 ml / g, as measured by mercury intrusion porosimetry, and a pore size distribution (PSD) with at least 30 vol % of the total pore volume being in pores with a radius >400 A, suitably pores with a radius >500 A, such as pores with a radius up to 5000 A; as for instance disclosed in co-pending patent application PCT / EP2021 / 068656. Another suitable guard bed is a catalyst comprising molybdenum supported on alumina, i.e. a Mo / Al2O3 catalyst. Yet another suitably catalyst is a catalyst having demetallization activity and moderate hydrodesulfurization activity, such as a NiMo catalyst, e.g. in which the metal content is Mo: 6.0 wt %, Ni: 1.8 wt %.

[0045] Hydrodemetallation (HDM), as is well known in the art, means a pretreatment, by which organically bound metals are deposited as sulfides or oxides. It would be understood, that while the reaction is similar for hydrodesulfurization (HDS) the heteroatom (S) is removed as H2S in gas form.ExampleSummary

[0046] Oils derived from sewage sludge and other nitrogen rich feedstocks have a high nitrogen content (>1 wt %). These oils are more thermally stable than fast pyrolysis oil, but a stabilization step is still necessary before it can be heated to 300° C. In this research, an oil with 9 wt % nitrogen has been stabilized using a NiMoS / Al2O3(Mo: 6.0 wt %, Ni: 1.8 wt %) catalyst operating at LHSV: 0.25-0.5 h-1, 20-120 barg and 190-220° C. The oil was successfully stabilized and further hydrotreated, which decreased the nitrogen content to 0.17 wt %.Catalyst, Feedstock and Test Conditions

[0047] The oil composition is shown in Table 1. The oil was produced from sewage sludge, which is the reason for its high nitrogen content (9.0 wt %).TABLE 1Oil compositionAnalysisMethodH (wt %)D 71718.64S (wt %)D 70391.15N (wt %)D 5373 Mod9.0O (wt %)D 5373 Mod5.6Water (wt %)1033, Karl Fischer3.04SG 60 / 60° F.D 40520.9886MCR (wt %)D 45309.81Carbonyl concentrationE 31460.8

[0048] Three tests were carried out in a two once-through trickle-bed reactors system (reactor operating in series, R1 and R2) using 100% hydrogen as treat gas. The catalysts were diluted with carborundum and loaded in an isothermal stainless steel tubular reactor. A total volume of 230 ml was used in each test. Before testing, the catalyst was activated. At each condition, samples of the gas and liquid products were taken out and analyzed after reaching line-out.

[0049] An overview of the test conditions is shown in Table 2.TABLE 2Overview of catalysts and test conditions(Total LHSV: 0.25 h−1, H2 / oil: 4000 NI / I)Test #Cat R1Cat R2T R2 (° C.)T R2 (° C.)P (barg)1AC3003401202BB190-220190-220203BC220100-360120Catalyst A is a guard catalyst with medium HDS / HDO / HDN activity. Mo: 6.2 wt %, Ni: 1.6 wt %, P: 1.2 wt %

[0051] Catalyst B is a guard catalyst with medium HDS / HDO / HDN activity. Mo: 6.0 wt %, Ni: 1.8 wt

[0052] Catalyst C is a high activity HDO / HDN / HDS catalyst. Mo: 19.7 wt %, Ni: 3.6 wt %, P: 2.0 wt %.Catalyst, Feedstock and Test Conditions

[0053] In the first test the first test it was assumed that the oil was thermally stable and the first reactor was therefore loaded with HDM catalyst, but the inlet to R1 plugged after 167 hours. The liquid product from the first test contained 2.6 wt % nitrogen as shown in Table 3. The purpose of the second test was to investigate if the oil could be stabilized at 20 bar at 190 and 220° C. The test ran for 431 hours without any observed pressure drop over the reactors and as shown in Table 3 the MCR was decreased to between 3.80 and 3.96 wt % compared to 9.81 wt for the feed, hence indicating that the product is more thermally stable than the feed. The nitrogen, sulfur and oxygen content was also decreased to between 8.3 and 8.8 wt %, 0.49 and 0.60 wt %, and 4.4 and 4.9 wt %, respectively, while the hydrogen content was increased to between 8.85 and 9.00 wt % hence indicating that an additional feature of the stabilization reactor is that it removes some heteroatoms while hydrogenating the oil.

[0054] In the third pilot plant test the pressure was increased to 120 bar and in the first condition the temperature in the first reactor 220° C. while the temperature in the second reactor was 100° C., hence the catalyst in the second reactor was considered to be inactive at this temperature. At this condition the product had a Micro Carbon Residue (MCR) according to ASTM D4530 of 2.36 wt % while the nitrogen was reduced to 7.6 wt %. Increasing the temperature in condition 2 to 340° C. and in 3 to 360° C. decreased nitrogen content to 1.3 and 0.17 wt %, respectively, while the MCR decreased to below <0.05 wt % and the oxygen content decreased to below 1 wt %.TABLE 3Process conditions and product composition.Test #122333Condition #112123Max. RH at cond.16724743195151201Temp. R1 (° C.)300190220220220220Temp. R2 (° C.)340190220100340360Pressure (barg)1202020120120120LHSV R1 (h−1)0.50.50.50.50.50.5LHSV R2 (h−1)0.50.50.50.50.50.5H2 / Oil (Nl / l)400040004000400040004000ProductcompositionSG @60 / 60° F.0.88640.99720.99270.97060.84790.8345S (wt %)0.01930.60110.48560.580.02520.0255N (wt %)2.68.88.37.61.30.17H (wt %)11.638.859.009.4912.3912.77O (wt %)—4.44.94.30.60.3MCR (wt %)—3.803.962.36<0.05<0.05

[0055] Although the invention has been described with reference to a number of embodiments and examples, the skilled person may freely combine embodiments and aspects as required. The full scope of the invention is defined in the appended patent claims. All references cited herein are incorporated by reference.

Examples

example

Summary

[0046]Oils derived from sewage sludge and other nitrogen rich feedstocks have a high nitrogen content (>1 wt %). These oils are more thermally stable than fast pyrolysis oil, but a stabilization step is still necessary before it can be heated to 300° C. In this research, an oil with 9 wt % nitrogen has been stabilized using a NiMoS / Al2O3(Mo: 6.0 wt %, Ni: 1.8 wt %) catalyst operating at LHSV: 0.25-0.5 h-1, 20-120 barg and 190-220° C. The oil was successfully stabilized and further hydrotreated, which decreased the nitrogen content to 0.17 wt %.

Catalyst, Feedstock and Test Conditions

[0047]The oil composition is shown in Table 1. The oil was produced from sewage sludge, which is the reason for its high nitrogen content (9.0 wt %).

TABLE 1Oil compositionAnalysisMethodH (wt %)D 71718.64S (wt %)D 70391.15N (wt %)D 5373 Mod9.0O (wt %)D 5373 Mod5.6Water (wt %)1033, Karl Fischer3.04SG 60 / 60° F.D 40520.9886MCR (wt %)D 45309.81Carbonyl concentrationE 31460.8

[0048]Three tests were carrie...

TECHNICAL FIELD

[0001] The present invention relates to a process for hydrotreating a nitrogen rich liquid oil stream by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.BACKGROUND

[0002] The field of renewable feedstocks has been attracting a great deal of attention, not only in Europe, but also US and China. Using renewable feedstocks enables a sustainable approach to the production of hydrocarbon products for use as transportation fuel, in particular any of marine fuel, diesel, jet fuel and naphtha as well as for use as petrochemical raw materials, such as steam cracker feeds.

[0003] Oils derived from nitrogen rich feedstocks such as sewage sludge, algae or other nitrogen-rich renewable sources have a higher propensity for polymerization than oils derived from wood or straw.

[0004] If the oils derived from nitrogen rich feedstocks are not stabilized they may quickly coke and plug catalyst bed. If they are stabilized using the same method as used for pyrolysis oil derived from woody biomass, then an unnecessary high pressure, low LHSV and very expensive catalyst is used, leading to a very high CAPEX.

[0005] WO 2022 / 152900 describes a method for low temperature stabilization of liquid oils.

[0006] Zacher et al “Technology advancements in hydroprocessing of bio-oils”, Biomass and Bioenergy, 125 (2019) 151-168 teaches that oils with a carbonyl content of 1.3 mmol / g should be sufficiently stable for hydrotreatment to take place at 400° C. Since a step of low temperature stabilization is adding cost and complexity to a process, this teaching implies avoiding such a step.

[0007] However, it has been found that this is not the case if the feed oil has a high N content. A feed with high N content, and with a carbonyl content between <0.5-1.13 mmol / g, may cause plugging in a reactor at an operating temperature of 300° C.

[0008] The present technology provides the discovery of a new problem—that for feeds with low carbonyl numbers, such as above the detection limit, but below 1.13 mmol / g, but high concentrations of nitrogen, plugging of the reactor is a risk. It is an object to provide a stable renewable crude, and a process for the formation thereof, that can be further hydroprocessed using more traditional hydroprocessing conditions.SUMMARY

[0009] It has been found by the present inventor(s) that plugging of a hydroprocessing reactor by a feed with high N content, yet low carbonyl content, can be reduced, and even avoided, if the feed is first stabilised.

[0010] So, in a first aspect the present invention relates to a process for hydrotreating a nitrogen rich liquid oil stream by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.DETAILED DISCLOSURE

[0011] The unit “barg” denotes pressure above atmospheric (atmospheric pressure: about 1 bar).

[0012] A process is provided for hydrotreating a nitrogen rich liquid oil stream, comprising at least 0.5 wt % nitrogen and a carbonyl content from 0.5 mmol / g to 1.13 mmol / g by, in a continuous operation in a fixed bed reactor, reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream. The combination of features recited above, enables stabilization of the liquid oil.

[0013] In preferred embodiments, the temperature is in the range 180-220° C., e.g. 190-200° C. In another embodiment, the pressure is 80-175 barg, e.g. 150 barg. In another embodiment LHSV is 0.2-4.0 h−1, such as 0.2-0.2 h−1, or 0.8-1.0 h−1, e.g. 0.9 h−1.

[0014] In a further embodiment, the temperature is in the range 180-220° C., e.g. 190-200° C. In another embodiment, the pressure is 15-80 barg, e.g. 50 barg. In another embodiment, LHSV is 0.2-4.0 h−1, such as 0.2-0.2 h−1, or 0.8-1.0 h−1, e.g. 0.9 h−1.

[0015] The temperature range 80-250° C. encompasses the inlet temperature of the liquid oil stream and the outlet temperature of stabilized liquid oil stream. Preferred temperature ranges include 100-250° C., 120-250° C., and 150-250° C. The process is exothermic thus a raise in temperature of about 100° C. or more may occur. The higher the inlet temperature e.g. 80° C., the easier the ignition of the process to initiate the exotherm. The outlet temperature can for instance be 150 or 200 or 240° C. More generally, the temperature in a given step or reactor (unit) thereof, means the inlet temperature in an adiabatic step, or the reaction temperature in an isothermal step.

[0016] By the present invention, a continuous operation process is used, since contrary to a batch operation, there is no dependency on the outcoming product (stabilized liquid oil) being fluid at all times. The term continuous operation, as is well known in the art, means that the incoming stream of liquid oil during a given production cycle is continuous, as also is the stabilized liquid oil stream being withdrawn as the outcoming product. This is in contrast to a batch operation i.e. discontinuous operation, as is also well known in the art, in which the total amount of liquid oil and catalyst is introduced at the beginning of the process, and the outcoming product is withdrawn after a certain period of time.

[0017] The process suitably has a hydrogen to liquid oil ratio, defined as the volume ratio of hydrogen to the flow of the liquid oil stream, of 100-8000 NL / L, such as 2000-5000 NL / L. By the invention, the process is also conducted at a hydrogen to liquid oil ratio of 1000-6000 NL / L, such as 2000-5000 NL / L, for instance 2500, 3000, 3500, 4000 or 4500 NL / L. As used herein, the term “hydrogen to liquid oil ratio” or “H2 / Oil ratio” means the volume ratio of hydrogen to the flow of the liquid oil stream. It should be understood that the unit NL means “normal” liter, i.e. the amount of gas taken up this volume at 0° C. and 1 atmosphere. The volume of liquid oil is in line with the practice in the field determined at 15° C. and 1 atmosphere.

[0018] In an embodiment, the liquid oil stream contains at least 2 wt % N, or at least 5 wt % N. The liquid oil stream may contain 10 wt % nitrogen (N), such as at least 2 wt % N, or at least 5 wt % N. The nitrogen content is suitably determined by standard elemental analysis.

[0019] In an embodiment, the liquid oil stream contains at least 0.5 wt % oxygen (O), such as at least 2 wt % 0, or at least 4 wt % 0. The oxygen content is suitably determined by standard elemental analysis.

[0020] In one aspect the micro carbon residue (MCR) of the liquid oil stream, before hydrotreating, as determined by ASTM D 4530, is between 5-20 wt %, such as between 5-15 wt %, as such elevated MCR values indicate an inclination for coke depositing. After hydrotreating, the micro carbon residue (MCR) of the stabilized liquid oil stream, as determined by ASTM D 4530, is suitably below 5 wt %, such as below 4.5 wt %, which indicates lower inclination for coke depositing.

[0021] In an embodiment, the liquid oil stream is a pyrolysis oil stream or a hydrothermal liquefaction oil (HTL oil) stream. In an embodiment, the liquid oil stream is a stream of oil originating from a thermochemical decomposition process, such as pyrolysis or hydrothermal liquefaction, being part of the same process plant or a separate process plant. In an embodiment the liquid oil stream is a pyrolysis oil stream which comprises at least 0.5 mol / kg of one or more of: aldehyde compounds, ketones, alcohols, furfural, as determined by ASTM E3146-20. In an embodiment the liquid oil stream may be characterized by it's elemental composition being from 50 wt % to 70 wt %, 80 wt % or 85 wt % C and from 2 wt % 3 wt % 5 wt % or 10 wt % to 50 wt % 0, which an exemplary elemental composition range of a liquid, non-aqueous thermochemical decomposition product such as a pyrolysis oil stream or a hydrothermal liquefaction oil (HTL oil) stream. Possibly the 14C / 12C isotope ratio is 0.5 to 2 parts per trillion, which is the isotope composition defining samples of biological origin.

[0022] In one aspect, the catalyst is Ni-based, Mo-based, CoMo-based, NiMo-based, W-based, NiW-based or Ru-based, optionally in sulfided or reduced form.

[0023] When a catalyst is “based” on a particular metal (e.g. Ni-based), this means that that the listed metal Ni, Mo, . . . is at least 90 wt %, 99% or 100% of the Group 1-12 materials in the catalyst. The following ranges for each category is provided: Ni-based (2-30 wt % Ni sulfided or reduced), Mo-based (2-30 wt % Mo preferably sulfided), CoMo-based (1-10 wt % Co, 2-30 wt % Mo preferably sulfided), NiMo-based (1-10 wt % Ni, 2-30 wt % Mo preferably sulfided), W-based (2-30 wt % W preferably sulfided), NiW-based (1-10 wt % Ni, 2-30 wt % W preferably sulfided) or Ru-based (0.1-10 wt % preferably reduced), optionally in sulfided or reduced form.

[0024] In one aspect of the process, the catalyst is a supported catalyst having a Mo content of 2-30 wt %, and optionally also a P content of 0-3 wt %, based on the total weight of the catalyst. The support may be selected from alumina, silica, titania and combinations thereof; optionally in combination with a solid acid such as silica-alumina or a molecular sieve having topology MFI, BEA or FAU. As used herein, the term “topology MFI, BEA or FAU”, means a structure as assigned and maintained by the International Zeolite Association Structure Commission in the Atlas of Zeolite Framework Types, which is at http: / / www.iza-structure.org / databases / or for instance also as defined in “Atlas of Zeolite Framework Types”, by Ch. Baerlocher, L. B. McCusker and D. H. Olson, Sixth Revised Edition 2007.

[0025] The process may further comprise a prior step of thermal decomposition of a solid renewable feedstock, for producing said liquid oil stream. As used herein, the term “thermal decomposition” shall for convenience be used broadly for any decomposition process, in which a material is partially decomposed at elevated temperature (typically 250° C. to 800° C. or even 1000° C.), in the presence of sub-stoichiometric amount of oxygen (including no oxygen). The product will typically be a combined liquid and gaseous stream, as well as an amount of solid char. The term shall be construed to include processes known as pyrolysis and hydrothermal liquefaction, both in the presence and absence of a catalyst.

[0026] Accordingly, in a particular embodiment, the thermal decomposition is pyrolysis, such as fast pyrolysis, thereby producing said pyrolysis oil stream. It should be understood that the thermal decomposition is conducted in a thermal decomposition section, Hence, the pyrolysis is conducted in a pyrolysis section, and the hydrothermal liquefaction is conducted in a hydrothermal liquefaction section. As used herein, the term “section” means a physical section comprising a unit or combination of units for conducting one or more steps and / or sub-steps.

[0027] One kind of pyrolysis is fast pyrolysis, also referred in the art as flash pyrolysis. Fast pyrolysis means the thermal decomposition of a solid renewable feedstock in the absence of oxygen, at temperatures in the range 350-650° C. e.g. about 500° C. and reaction times of 10 seconds or less, such as 5 seconds or less, e.g. about 2 sec. Fast pyrolysis may for instance be conducted by autothermal operation e.g. in a fluidized bed reactor. The latter is also referred as autothermal pyrolysis and is characterized by employing air, optionally with an inert gas or recycle gas, as the fluidizing gas, or by using a mixture of air and inert gas or recycle gas. Thereby, the partial oxidation of pyrolysis compounds being produced in the pyrolysis reactor (autothermal reactor) provides the energy for pyrolysis while at the same time improving heat transfer. For details about autothermal pyrolysis, reference is given to e.g “Heterodoxy in Fast Pyrolysis of Biomass” by Robert Brown: https: / / dx.doi.Org / 10.1021 / acs.energyfuels.0c03512. In an embodiment, the pyrolysis is fast pyrolysis, wherein said fast pyrolysis is suitably conducted in the absence of a catalyst and hydrogen.

[0028] “Intermediate” or “slow” pyrolysis are also suitable for high N feedstocks, and may be even more suitable than fast pyrolysis. One reason is that high N containing feedstocks tend to comprise more alkaline metals, which increases the risk of agglomeration and defluidization.

[0029] In another embodiment, therefore, the pyrolysis step is intermediate pyrolysis, in which the vapor residence time is in the range of 10 seconds-5 minutes, such as 11 seconds-3 minutes. As for fast pyrolysis, the temperature is also in the range 350-650° C. e.g. about 500° C. Often this pyrolysis is conducted in pyrolysis reactors handling different types of waste, where the vapor is burned after the pyrolysis reactor. Typical reactors are: Herreshoff furnace, rotary drums, amaron, CHOREN paddle pyrolysis kiln, auger reactor, and vacuum pyrolysis reactor.

[0030] In another embodiment, the pyrolysis step is slow pyrolysis, in which the solid residence time is in the range of 5 minutes-2 hours, such as 10 min-1 hour. The temperature is suitably about 300° C. This pyrolysis gives a high char yield and the char can be used as a fertilizer or as char coal; the pyrolysis still produces some gas and renewable crude and if the carbon is used a fertilizer the final bio-oil can have a GHG above 100%, thus being carbon negative. Typical reactors are auger reactor (yet with a different residence time than for intermediate pyrolysis), fixed bed reactor, kiln, lambiotte SIFIC / CISR retort, Lurgi process, wagon reactor, and carbo twin resort.

[0031] Hydrothermal liquefaction (HTL) involves the reaction of biomass or organic material in the presence of water or other solvents at hydrothermal conditions, effectively in the range of temperatures from 250° C. to 450° C., and pressures from approximately 100-350 bar. At these conditions, water remains in a liquid or relatively dense supercritical state. Due to the requirement of a wet reaction environment, HTL is especially suited to wet feedstocks as the need for drying is alleviated. During HTL processing, organic material undergoes a number of depolymerization reactions including hydrolysis, dehydration and decarboxylation to form water-soluble intermediates, and repolymerization reactions including various condensation mechanisms to form water insoluble products including renewable crude and char. Other products are gases, typically dominated by CO2 but, depending on biomass and reaction conditions, with varying contents of H2, CH4 and CO, as well as an aqueous phase with soluble organics, mostly in the form of alcohols, acids and phenols (for lignocellulosics).

[0032] Suitably, therefore, the thermal decomposition step may be:

[0033] pyrolysis, such as fast, intermediate or slow pyrolysis, thereby producing a pyrolysis oil stream; or

[0034] hydrothermal liquefaction (HTL), thereby producing a HTL oil stream.

[0035] In one aspect of the process according to the invention, the solid renewable feedstock is:

[0036] a lignocellulosic biomass including: wood products, forestry waste, and agricultural residue; and / or

[0037] municipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public, such as mixed municipal waste given in EU Directive 2018 / 2001 (RED II), Annex IX, part A.

[0038] The term “renewable” shall be construed to exclude fossil crudes, but to include recycled waste of fossil origin, such as plastic waste.

[0039] Any combination of the above is also envisaged.

[0040] As used herein, the term “lignocellulosic biomass” means a biomass containing, cellulose, hemicellulose and optionally also lignin. The lignin or a significant portion thereof may have been removed, for instance by a prior bleaching step. The lignocellulosic biomass is suitably forestry waste and / or agricultural residue and comprises biomass originating from plants including grass such as nature grass (grass originating from natural landscape), wheat e.g. wheat straw, oats, rye, reed grass, bamboo, sugar cane or sugar cane derivatives such as bagasse, maize and other cereals.

[0041] In an embodiment, the process further comprises passing the stabilized liquid oil stream through a hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), or hydrodesulfurisation (HDS) step, suitably wherein the HDO is conducted at a higher temperature than the prior step for forming said stabilized liquid oil stream.

[0042] Thereby, any organic nitrogen present in the stabilized pyrolysis oil stream is removed and a hydrotreated stream is produced, which can be further treated for producing hydrocarbon products boiling in the transportation fuel range, such as diesel, jet fuel and naphtha. During the hydrotreating of renewable feedstock or liquid oil, oxygen is mainly removed as H2O, which gives a paraffinic fuel consisting of paraffins with the same number for carbon atoms as in the backbone of the triglycerides. This is called the hydrodeoxygenation (HDO) pathway. Oxygen can also be removed by dicarboxylic (DCO) pathway, which generates CO2 instead of H2O: HDO pathway: C17H34COOH+3.5H2<->C18H38+2H2O Decarboxylation pathway: C17H34COOH+0.5H2<->C17H36+CO2.

[0043] The material catalytically active in hydrotreating, e.g. HDO, typically comprises an active metal (sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum, but possibly also either elemental noble metals such as platinum and / or palladium) and a refractory support (such as alumina, silica or titania, or combinations thereof).

[0044] In one embodiment, the process further comprises passing the stabilized liquid oil stream through one or more metal guards active in hydrometallation (HDM) and / or hydrodeoxygenation (HDO), prior to said HDO step. A suitably guard bed for at least removing P and Fe is a porous material comprising alumina, the alumina comprising alpha-alumina, with the porous material comprising one or more metals selected from Co, Mo, Ni, W and combinations thereof, and said porous material having a BET-surface area of 1-110 m2 / g, suitably also having a total pore volume of 0.50-0.80 ml / g, as measured by mercury intrusion porosimetry, and a pore size distribution (PSD) with at least 30 vol % of the total pore volume being in pores with a radius >400 A, suitably pores with a radius >500 A, such as pores with a radius up to 5000 A; as for instance disclosed in co-pending patent application PCT / EP2021 / 068656. Another suitable guard bed is a catalyst comprising molybdenum supported on alumina, i.e. a Mo / Al2O3 catalyst. Yet another suitably catalyst is a catalyst having demetallization activity and moderate hydrodesulfurization activity, such as a NiMo catalyst, e.g. in which the metal content is Mo: 6.0 wt %, Ni: 1.8 wt %.

[0045] Hydrodemetallation (HDM), as is well known in the art, means a pretreatment, by which organically bound metals are deposited as sulfides or oxides. It would be understood, that while the reaction is similar for hydrodesulfurization (HDS) the heteroatom (S) is removed as H2S in gas form.ExampleSummary

[0046] Oils derived from sewage sludge and other nitrogen rich feedstocks have a high nitrogen content (>1 wt %). These oils are more thermally stable than fast pyrolysis oil, but a stabilization step is still necessary before it can be heated to 300° C. In this research, an oil with 9 wt % nitrogen has been stabilized using a NiMoS / Al2O3(Mo: 6.0 wt %, Ni: 1.8 wt %) catalyst operating at LHSV: 0.25-0.5 h-1, 20-120 barg and 190-220° C. The oil was successfully stabilized and further hydrotreated, which decreased the nitrogen content to 0.17 wt %.Catalyst, Feedstock and Test Conditions

[0047] The oil composition is shown in Table 1. The oil was produced from sewage sludge, which is the reason for its high nitrogen content (9.0 wt %).TABLE 1Oil compositionAnalysisMethodH (wt %)D 71718.64S (wt %)D 70391.15N (wt %)D 5373 Mod9.0O (wt %)D 5373 Mod5.6Water (wt %)1033, Karl Fischer3.04SG 60 / 60° F.D 40520.9886MCR (wt %)D 45309.81Carbonyl concentrationE 31460.8

[0048] Three tests were carried out in a two once-through trickle-bed reactors system (reactor operating in series, R1 and R2) using 100% hydrogen as treat gas. The catalysts were diluted with carborundum and loaded in an isothermal stainless steel tubular reactor. A total volume of 230 ml was used in each test. Before testing, the catalyst was activated. At each condition, samples of the gas and liquid products were taken out and analyzed after reaching line-out.

[0049] An overview of the test conditions is shown in Table 2.TABLE 2Overview of catalysts and test conditions(Total LHSV: 0.25 h−1, H2 / oil: 4000 NI / I)Test #Cat R1Cat R2T R2 (° C.)T R2 (° C.)P (barg)1AC3003401202BB190-220190-220203BC220100-360120Catalyst A is a guard catalyst with medium HDS / HDO / HDN activity. Mo: 6.2 wt %, Ni: 1.6 wt %, P: 1.2 wt %

[0051] Catalyst B is a guard catalyst with medium HDS / HDO / HDN activity. Mo: 6.0 wt %, Ni: 1.8 wt

[0052] Catalyst C is a high activity HDO / HDN / HDS catalyst. Mo: 19.7 wt %, Ni: 3.6 wt %, P: 2.0 wt %.Catalyst, Feedstock and Test Conditions

[0053] In the first test the first test it was assumed that the oil was thermally stable and the first reactor was therefore loaded with HDM catalyst, but the inlet to R1 plugged after 167 hours. The liquid product from the first test contained 2.6 wt % nitrogen as shown in Table 3. The purpose of the second test was to investigate if the oil could be stabilized at 20 bar at 190 and 220° C. The test ran for 431 hours without any observed pressure drop over the reactors and as shown in Table 3 the MCR was decreased to between 3.80 and 3.96 wt % compared to 9.81 wt for the feed, hence indicating that the product is more thermally stable than the feed. The nitrogen, sulfur and oxygen content was also decreased to between 8.3 and 8.8 wt %, 0.49 and 0.60 wt %, and 4.4 and 4.9 wt %, respectively, while the hydrogen content was increased to between 8.85 and 9.00 wt % hence indicating that an additional feature of the stabilization reactor is that it removes some heteroatoms while hydrogenating the oil.

[0054] In the third pilot plant test the pressure was increased to 120 bar and in the first condition the temperature in the first reactor 220° C. while the temperature in the second reactor was 100° C., hence the catalyst in the second reactor was considered to be inactive at this temperature. At this condition the product had a Micro Carbon Residue (MCR) according to ASTM D4530 of 2.36 wt % while the nitrogen was reduced to 7.6 wt %. Increasing the temperature in condition 2 to 340° C. and in 3 to 360° C. decreased nitrogen content to 1.3 and 0.17 wt %, respectively, while the MCR decreased to below <0.05 wt % and the oxygen content decreased to below 1 wt %.TABLE 3Process conditions and product composition.Test #122333Condition #112123Max. RH at cond.16724743195151201Temp. R1 (° C.)300190220220220220Temp. R2 (° C.)340190220100340360Pressure (barg)1202020120120120LHSV R1 (h−1)0.50.50.50.50.50.5LHSV R2 (h−1)0.50.50.50.50.50.5H2 / Oil (Nl / l)400040004000400040004000ProductcompositionSG @60 / 60° F.0.88640.99720.99270.97060.84790.8345S (wt %)0.01930.60110.48560.580.02520.0255N (wt %)2.68.88.37.61.30.17H (wt %)11.638.859.009.4912.3912.77O (wt %)—4.44.94.30.60.3MCR (wt %)—3.803.962.36<0.05<0.05

[0055] Although the invention has been described with reference to a number of embodiments and examples, the skilled person may freely combine embodiments and aspects as required. The full scope of the invention is defined in the appended patent claims. All references cited herein are incorporated by reference.

Examples

example

Summary

[0046]Oils derived from sewage sludge and other nitrogen rich feedstocks have a high nitrogen content (>1 wt %). These oils are more thermally stable than fast pyrolysis oil, but a stabilization step is still necessary before it can be heated to 300° C. In this research, an oil with 9 wt % nitrogen has been stabilized using a NiMoS / Al2O3(Mo: 6.0 wt %, Ni: 1.8 wt %) catalyst operating at LHSV: 0.25-0.5 h-1, 20-120 barg and 190-220° C. The oil was successfully stabilized and further hydrotreated, which decreased the nitrogen content to 0.17 wt %.

Catalyst, Feedstock and Test Conditions

[0047]The oil composition is shown in Table 1. The oil was produced from sewage sludge, which is the reason for its high nitrogen content (9.0 wt %).

TABLE 1Oil compositionAnalysisMethodH (wt %)D 71718.64S (wt %)D 70391.15N (wt %)D 5373 Mod9.0O (wt %)D 5373 Mod5.6Water (wt %)1033, Karl Fischer3.04SG 60 / 60° F.D 40520.9886MCR (wt %)D 45309.81Carbonyl concentrationE 31460.8

[0048]Three tests were carrie...

Claims

1. A process for hydrotreating a nitrogen rich liquid oil stream, comprising at least 0.5 wt % nitrogen and a carbonyl content from 0.5 mmol / g to 1.13 mmol / g by, in a continuous operation in a fixed bed reactor, the process comprising reacting the nitrogen rich liquid oil stream with hydrogen in the presence of catalyst at a temperature of 80-250° C., a total pressure of 10-200 barg, a liquid hourly space velocity (LHSV) of 0.1-6 h−1, thereby forming a stabilized liquid oil stream.

2. The process according to claim 1, wherein said process has a hydrogen to liquid oil ratio, defined as the volume ratio of hydrogen to the flow of the liquid oil stream, of 100-8000 NL / L.

3. The process according to claim 1, wherein the liquid oil stream contains at least 2 wt % nitrogen (N).

4. The process according to claim 1, wherein the liquid oil stream contains at least 0.5 wt % oxygen (O).

5. The process according to claim 1, wherein the micro carbon residue (MCR) of the liquid oil stream, as determined by ASTM D 4530, is between 5-20 wt %.

6. The process according to claim 1, wherein the micro carbon residue (MCR) of the stabilized liquid oil stream, as determined by ASTM D 4530, is below 5 wt %.

7. The process according to claim 1, wherein the liquid oil stream is a stream of oil originating from a thermochemical decomposition process.

8. The process according to claim 1, wherein the temperature is in the range 180-220° C.; the pressure is 80-175 barg; and LHSV is 0.2-4.0 h−1.

9. The process according to claim 1, wherein the temperature is in the range 180-220° C.; the pressure is 15-80 barg; and LHSV is 0.2-4.0 h−1.

10. The process according to claim 1, wherein the catalyst is a supported catalyst having a Mo content of 2-30 wt %, and optionally also a P content of 0-3 wt %, based on the total weight of the catalyst.

11. The process according to claim 10, wherein the support is selected from alumina, silica, titania and combinations thereof; optionally in combination with a molecular sieve having topology MFI, BEA or FAU.

12. The process according to claim 1, wherein the catalyst is Ni-based, Mo-based, CoMo-based, NiMo-based, W-based, NiW-based or Ru-based, optionally in sulfided or reduced form.

13. The process according to claim 1, further comprising a prior step of thermal decomposition of a solid renewable feedstock, for producing said liquid oil stream.

14. The process according to claim 13, wherein the thermal decomposition step is:pyrolysis, such as intermediate or slow pyrolysis, thereby producing a pyrolysis oil stream; orhydrothermal liquefaction (HTL), thereby producing an HTL oil stream.

15. The process according to claim 13, wherein the solid renewable feedstock is:a lignocellulosic biomass including: wood products, forestry waste, and agricultural residue; and / ormunicipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public.

16. The process according to claim 1, further comprising passing the stabilized liquid oil stream through a hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), or hydrodesulfurisation (HDS) step.

17. The process according to claim 1, further comprising passing the stabilized liquid oil stream through one or more metal guards active in hydrometallation (HDM) and / or hydrodeoxygenation (HDO), prior to passing the stabilized liquid oil stream through a hydrodeoxygenation (HDO) step.