WO2025214947A1

WO2025214947A1 - Fluorine removal from renewable feedstocks

Info

Publication number: WO2025214947A1
Application number: PCT/EP2025/059446
Authority: WO
Inventors: Jens Anders Hansen; Christian Frederik WEISE
Original assignee: Haldor Topsoe AS
Current assignee: Topsoe AS
Priority date: 2024-04-08
Filing date: 2025-04-07
Publication date: 2025-10-16
Anticipated expiration: 2026-10-08

Abstract

The present invention relates to the removal of organically bound fluorine in the processing of renewable feedstocks by hydrotreatment in the presence of low amounts of organically bound nitrogen.

Description

Title of Invention: Fluorine removal from renewable feedstocks

Technical Field

[0001] The present invention relates to the removal of organically bound fluorine in the processing of renewable feedstocks.

Background

[0002] Renewable feedstocks derived by thermochemical decomposition, such as pyrolysis and hydrothermal liquefaction (HTL) of solid waste (e.g. sewage sludge, plastic waste, municipal solid waste) can have a significant content of fluorine. Some fluorine compounds have very high chemical and thermal stability and may be hard to remove and are presently referred to as refractive fluorine compounds. Especially when the feedstock contains material of industrial origin, such refractive fluorine compounds may be present.

[0003] Upgrading of renewable feedstock to transportation fuel such as jet fuel and diesel fuel requires removal of sulfur, nitrogen, and oxygen to very low levels as well as reduction of other unwanted elements like fluorine to meet the relevant product specifications for use as transportation fuel. It has been found that it is hard to produce a jet fuel with a low halogen level e.g. below 1 wt ppm, due to an inability to remove fluorine. It has turned out that this can be difficult to achieve by hydroprocessing alone even at very severe conditions in the reactor.

[0004] Removal of heteroatoms from hydrocarbonaceous compounds in the presence of base metal catalysts is well known in fossil fuel-based refining processes. However, as the fluorine content of the feed in fossil fuels is typically significantly lower than limits, the removal of fluorine has not been a specific concern, but it has been expected that organic fluorine compounds would be hydrotreatable under conditions similar to other heteroatoms, including other halogens, such as chlorine, which is commonly found in plastic pyrolysis oil and algae.

[0005] US 5,773,549, EP 0 643 123 and US 5,354,931 describe the conversion of halogenated hydrocarbons, and mention the conversion of chlorofluorocarbons in this respect, without concern over conversion. US 5,773,549 discloses a process for reducing the level of nitrogen and oxygen compounds to below 20 ppm_wt in a process for hydrotreatment of 90 wt% dichloropropane with 99.9% conversion to minimize the risk of corrosion by hydrochloric acid and plugging by ammonium chloride salts. The product concentration of chloride is not mentioned, but from the conversion it may be calculated to be less than 900 ppm_wt.

[0006] Conversion of fluoride compounds are only mentioned, as a possibility and only for chlorofluorocarbons.

[0007] In practice organically bound fluorine in feedstocks originating from thermochemical decomposition has been observed to be surprisingly difficult to hydrotreat fully, i.e. to levels below 10 ppm_wt.

Summary of Invention

[0008] According to the present disclosure it has been identified that if organic and inorganic nitrogen is present in low amounts, then a hydrotreatment stage is surprisingly more effective in the hydrotreatment of organically bound fluorine.

[0009] This knowledge has been implemented in a chemical process for conversion of organically bound fluorine involving limits for the presence of organically bound nitrogen, as well as processes including steps for removal of organically bound nitrogen, involving steps such as efficient hydrotreatment of a hydrocarbonaceous mixture rich in oxygenates and other heteroatomic molecules in the presence of sulfided base metal catalyst, subsequent separation of sour gases and hydrocarbon comprising organically bound fluorine and final hydrotreatment of the hydrocarbon comprising organically bound fluorine in the presence of a hydrotreatment catalyst.

Definitions

[0010] The waste plastic particles may be understood as including a mixed or sorted waste comprising at least 50 wt%, 80 wt% or 90 wt% plastic and other synthetic polymers.

[0011] For the purpose of the present application, the unit pppm_wt shall designate weight/weight parts per million and the unit pppm_voi shall designate volume/volume parts per million. Similarly wt% designate weight/weight percentage.

[0012] In the following a hydrocarbonaceous feedstock shall be used to signify a feedstock rich in molecules comprising hydrogen and carbon, but possibly also heteroatoms, i.e. other elements, such as halogens, oxygen, sulfur and nitrogen.

[0013] In the following a hydrocarbon mixture shall also be used to signify a feedstock rich in molecules comprising hydrogen and carbon, but it shall not be construed exclusively, i.e. the term hydrocarbon mixture does not exclude mixture with a presence of heteroatoms, i.e. other elements, such as oxygen, sulfur and nitrogen.

[0014] A feedstock of biological origin may be defined by tracing the origin, but it may also be defined by the ¹⁴C content being above 0.5 parts per trillion of the total carbon content.

[0015] Where concentrations of oxygenates or functional groups of molecules are referred to this shall signify the concentration of all the molecules of such a group, and not to the functional group itself.

[0016] Where concentrations of atoms referred to they shall signify the concentration of all the atoms mentioned of such a group, and not to molecules comprising such atoms.

[0017] As used herein, the term “thermochemical 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 substoichiometric 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.

[0018] The term “fluorine” is used in the present invention to mean the element F contained in inorganic and organic compounds. A “low content” of fluorine means a content of less than 1 wt ppm fluorine unless stated explicitly otherwise. Fluorine and other halogen content is measured by ASTM D7359, and jet fuel specifications are commonly related to the sum of halogens. [0019] The term “section”, as in “separator section” shall be construed to cover a single piece of equipment, or multiple pieces of equipment, carrying out a function in an integrated manner. One example is a separator section, which may comprise one or more gas/liquid separators, which may include three-phase separators separating gas, polar liquid and non-polar liquid, possibly configured as a cascade of separators with intermediate cooling and pressure release. When polar compounds are removed, addition of a polar stream, such as water, an acidic aqueous solution or a basic aqueous solution may also be a part of a separator section. If the polar stream is an aqueous basic stream or significant amounts of ammonia is captured in the polar stream, the formation of fluoric acid and release of hydrogen fluoride in the gas phase is minimized. As a further example, separator section may also be a part of a fractionator section. Analogously, a process step may be implemented in multiple pieces of equipment.

[0020] For convenience the term pyrolysis oil shall in the following be construed as the product of any thermochemical decomposition method, unless otherwise specified.

Technical Problem

[0021] The present disclosure relates to the hydrotreatment of hydrocarbonaceous mixtures comprising fluorine. Flourine-containing hydrocarbonaceous mixtures may originate from multiple sources, but a common example is the product of thermochemical decomposition of a solid renewable feedstock, such as municipal waste and/or plastic waste, especially to the extent that the solid feedstock contains an amount of PFAS; per- and polyfluoroalkyl substances, and the derived pyrolysis oil also contains refractive fluorine compounds. Multiple different structures of refractive fluorine compounds are expected. As the refractive fluorine compounds will be derived from perfluorated compounds, the fluorine containing compounds in the hydrocarbonaceous stream will have an atomic F:C ratio above 1 , and accordingly the present invention is especially relevant for hydrocarbonaceous mixtures which comprise fluorine, and in which at least 50% of the fluorine is present in molecules where the average atomic F:C ratio is above 1 . [0022] The disclosure is especially relevant for hydrocarbonaceous mixtures comprising fluorine as impurity, e.g. in concentrations below 1 wt%, 500 ppm_wt or 100 ppm_wt.

[0023] In one aspect, the solid renewable feedstock may comprise lignocellulosic biomass including: wood products, forestry waste, and agricultural residue. In another aspect the solid renewable feedstock comprises municipal waste, in particular the organic portion thereof. For the purposes of the present application, the term “municipal waste” is interchangeable with the term “municipal solid waste” and means a feedstock containing materials of items discarded by the public, such as mixed municipal waste given the waste code 200301 in the European Waste Catalogue.

[0024] Solid feedstock shall also be understood to include dispersed solid materials, such as sewage sludge and manure, in which at least 5 weight% is solid.

[0025] In one aspect, the solid renewable feedstock comprises waste plastic.

[0026] In one aspect, the thermal decomposition is hydrothermal liquefaction. Hydrothermal liquefaction means the thermochemical conversion of biomass into liquid fuels by processing in a hot, pressurized water environment for sufficient time to break down the solid bio-polymeric structure to mainly liquid components. Typical hydrothermal processing conditions are temperatures in the range of 250- 390°C and operating pressures in the range of 40-350 bar. This technology offers the advantage of operation at a lower temperature, higher energy efficiency and lower tar yield compared to pyrolysis, e.g. fast pyrolysis.

[0027] In one aspect, the thermal decomposition further comprises passing said solid renewable feedstock through a solid renewable feedstock preparation section comprising for instance drying for removing water and/or comminution for reduction of particle size. Any water/moisture in the solid renewable feedstock which vaporizes in for instance the pyrolysis section condenses in the pyrolysis oil stream and is thereby carried out in the process, which may be undesirable. Furthermore, the heat used for the vaporization of water withdraws heat which otherwise is necessary for the pyrolysis. By removing water and providing a smaller particle size in the solid renewable feedstock, the thermal efficiency of the pyrolysis section is increased. [0028] Commonly hydrocarbonaceous feedstock derived from a thermochemical decomposition of a solid renewable material, comprises 50-85 wt% C and 3-50 wt% 0 and an atomic ratio between H and C of less than 1.8 or 1 .6.

[0029] The hydrocarbonaceous feedstock may be derived from a thermochemical decomposition of a stream comprising material of biological origin, including sewage sludge or municipal waste. If the solid feedstock contains protein or other nitrogen containing biological material or plastic waste comprising nitrogen containing polymers, such as polyamides, polyurethanes, and polyureas, the content of nitrogen in the thermochemical decomposition product may be high, commonly be above 500 ppm_wt, such as 1 wt% or even up to 10 wt%.

[0030] The product of thermal decomposition, for simplicity pyrolysis oil, must commonly be upgraded to remove heteroatoms. If the physical properties such as boiling point and freezing point of the pyrolysis oil are satisfactory, such that removal of impurities is the only requirement, which is carried out by hydrotreatment - the addition of hydrogen without intended breaking of carboncarbon bonds, such as removal of heteroatoms such as sulfur, oxygen, nitrogen, metals and halogens - notably fluorine - and saturation of olefins. Under some circumstances molecular structure is modified by hydrocracking and isomerization are carried out. In hydrocracking, carbon-carbon bonds are broken, with the addition of hydrogen, such that the size of molecules is reduced, or rings are opened. In hydroisomerization, carbon-carbon bonds are broken, but reestablished in other positions, such that molecules change their skeletal structure, which may change freezing point without changing boiling point significantly. These processes are collectively called hydroprocessing as there are several similarities between hydrocracking and isomerization process steps..

[0031] The material catalytically active in hydrotreatment, typically comprises an active metal (sulfided base metals such as nickel, cobalt, tungsten and/or molybdenum, but if the hydrocarbon is free of catalyst poisons such as sulfur compounds and ammonia possibly also elemental noble metals such as platinum and/or palladium and other metals of the platinum group) and a refractory support (such as alumina, silica or titania, or combinations thereof). Hydrotreating conditions typically involve a temperature in the interval 250-450°C, a pressure in the interval 3-20 MPa, and a liquid hourly space velocity (LHSV) in the interval 0.1-5 hr¹ and a GOR (gas to oil ratio) of 300-10000 Nm³/m³ optionally together with intermediate cooling by quenching with cold hydrogen, feed or product. The high gas to oil ratio reflects a need for excess hydrogen, which commonly is available by a safety factor of 6 as obtained by multiplication with the observed or the theoretical consumption of hydrogen, but a safety factor from 3 to 8 may be observed in practice. Due to this high excess of hydrogen, the gaseous product phase is commonly purified and recycled to reduce the cost of operation. However, for reactive compounds, such as olefins, hydrotreatment may take place at temperatures down to 100°C, and to avoid run-away reactions; either polymerization or thermal overheating, it may be necessary to conduct hydrotreatment at such very mild conditions, to slow down reactivity.

[0032] As mentioned above hydroprocessing catalysts may comprise noble metals or sulfided base metals. Noble metals (one or both of platinum and palladium - and possibly other metals of the platinum group - IIIPAC Groups 8, 9 and 10, periods 5 and 6) are active in the elemental form and active in low amounts, such as 0.05 wt% to 2 wt%. The noble metals are sensitive to the presence of especially sulfur and nitrogen, which may reduce the activity dramatically, and must therefore operate in the presence of less than 50 ppm_wt sulfur and nitrogen, which is called sweet mode. Contrary to this, base metals (commonly molybdenum and tungsten, which may be promoted by presence of nickel and cobalt) are active in their sulfided form, requires higher concentrations (2-20 wt% molybdenum and/or tungsten in combination with nickel and/or cobalt in an atomic ratio of 0.2-1.0), and thus very robust in the presence of such heteroatoms (called sour gases) and actually must operate in the presence of more than 50-200 ppm_wt sulfur and nitrogen, which is called sour mode. In addition, the acidity of the support of hydrocracking and isomerization catalyst may be reduced by ammonia, being a product of hydrotreatment of hydrocarbons comprising nitrogen.

[0033] Materials catalytically active in hydrocracking and materials catalytically active in isomerization have common features such as an active metal (either elemental noble metals such as platinum and/or palladium or sulfided base metals such as nickel, cobalt, tungsten and/or molybdenum) and a support typically comprising a refractory compound (such as alumina, silica or titania, or combinations thereof) and an acidic compound. The difference to material catalytically active isomerization is typically the nature of the acidic support (typically a molecular sieve showing high cracking activity, and having a topology such as MFI, BEA and FAU), which may be of a different structure (even amorphous silica-alumina) or have a different acidity e.g. due to silica:alumina ratio. Hydrocracking conditions using sulfided catalysts typically involve a temperature in the interval 315-450°C, a pressure in the interval from 3 MPa to15 MPa, 20 MPa or 30 MPa, a liquid hourly space velocity (LHSV) in the interval 0.5-8 hr¹ and a GOR of 300- 2500 Nm³/m³, optionally together with intermediate cooling by quenching with cold hydrogen, feed or product. Hydrocracking conditions using elemental noble metal catalysts typically involve a lower temperature in the interval 230-315°C, but otherwise similar conditions.

[0034] The material catalytically active in isomerization typically comprises an active metal (either elemental noble metals such as platinum and/or palladium or sulfided base metals such as nickel, cobalt, tungsten and/or molybdenum), an acidic support (typically a molecular sieve showing high shape selectivity, and having a topology such as MOR, FER, MRE, MWW, AEL, TON and MTT) and a refractory support (such as alumina, silica or titania, or combinations thereof). Isomerization conditions typically involves a temperature in the interval 250- 350°C for noble metals and 300-420°C for base metals, a pressure in the interval 2-10 MPa, a liquid hourly space velocity (LHSV) in the interval 0.5-8 hr¹ and a GOR of 300-1500 Nm³/m³, optionally together with intermediate cooling by quenching with cold hydrogen, feed or product.

[0035] In the commercial bulk hydrotreatment of renewable and fossil feedstocks the active catalysts almost always comprise sulfided base metals operating in sour mode, due to the cost and the general presence of sulfur and nitrogen. However, we discovered that normal hydrotreatment conditions were insufficient for removing organically bound fluorine from hydrocarbonaceous mixtures, such as pyrolysis oils, even if the severity of hydroprocessing is increased towards temperatures above 400°C where thermal cracking occurs.

[0036] However, we surprisingly found that the strongly bound fluorine could be released if hydrotreated in the presence of low amounts of especially organically bound nitrogen but also in limited amounts of ammonia are preferred. In an exemplary embodiment organic nitrogen is converted to ammonia by hydrotreatment, which is followed by removal of ammonia by water washing and subsequent three phase (gas/polar liquid/non-polar liquid) separation. The following hydroprocessing stage may be a fully sweet mode using noble metal catalysts, after removal of the sulfur, nitrogen and oxygen in sour mode, or it may be a nitrogen free stage using sulfided catalysts, and accordingly we propose a process configuration, in which a hydrocarbon comprising fluorine may be hydrodefluorinated in a second stage after removal of nitrogen. Even for a sweet mode hydrotreatment step severe conditions are required, such as temperatures in the range from 350C°, 360°C or 370°C, to 400°C, 410°C or 420°C and pressures from 8 MPa, 9 MPa, 10 MPa to 12 MPa, 15 MPa or 20MPa. Furthermore, we identified that such a hydrocarbon containing low amounts of nitrogen may be provided by a sour mode hydrotreatment, followed by a separation of ammonia.

[0037] Absence of organic and inorganic nitrogen may be provided by multiple alternative methods of treatment, and it may also be a characteristic of traded intermediate product, with an unknown history. In addition to hydrotreatment optionally followed by gas separation, washing with an aqueous phase having an affinity for organic nitrogen compounds, such as sulfuric acid, hydrochloric acid or phosphoric acid, absorption of organic nitrogen in various process positions on a fixed bed of appropriate materials with high absorption capacity, such as alumina, silica-alumina, zeolite, activated carbon, titania, zirconia.

[0038] As mentioned, the nature of the pyrolysis oil commonly involves a molecular structure, which does not require additional treatment to modify the boiling point range to achieve transportation fuels. However, for some feedstocks or thermochemical decomposition methods, the molecular structure may require one or both of hydrocracking and hydroisomerization, which may be carried out with higher selectivity, and thus higher yield, in sweet mode. In some cases, the severe conditions for hydrodefluorination may be used also for hydrocracking and hydroisomerization, but there is also a risk that severe conditions cause a too high cracking activity, which would result in a high yield loss. Therefore, the configuration of the sweet mode step may either be a combination of a step with severe conditions and non-acidic (or mildly acidic) catalytically active material with less severe hydrocracking and hydroisomerization in separate steps, with the severe step either upstream or downstream the hydrocracking and hydroisomerization steps, or a careful balancing of catalytic properties and process condition, with few active acidic sites and severe conditions.

[0039] To the extent that hydroprocessing of the feedstock is required, to optimize the boiling point by hydrocracking and/or to adjust the freezing point by isomerization, this may be accomplished in process steps before or after the sweet mode hydrotreatment, without requiring removal, purification or replenishing of the hydrogen rich gas phase. It may however be relevant to consider either some removal of hydrogen fluorine or use of corrosion resistant materials, depending on specific circumstances.

[0040] Due to the nature of the thermochemical decomposition and the solid feedstock, the pyrolysis oil will differ from fossil fuels as well as natural fats and oils used to produce so called first- and second-generation feedstocks, which are easy to hydrotreat as they contain high amounts of reactive oxygen and few other heteroatoms, while the amount of highly reactive di-olefins is low. The oils of firstand second-generation feedstocks will be dominated by C12, C14, C16 and C18 un-branched fatty acids. In contrast, pyrolysis oils will contain significant amounts of di-olefins and for many solid feedstocks the heteroatoms will have a higher share of nitrogen and sulfur and less oxygen. Finally, chlorine and fluorine from synthetic materials, such as PVC and PFAS, may be present, especially in waste products. The molecular structure will have far more variation, both in terms of molecular size - and thus boiling point - and the molecular structure will be more cyclic and branched, and thus cloud point and freezing point will be lower than for the linear hydrocarbons.

[0041 ] As the concentration of organically bound fluorine has been observed to vary with the boiling point, it is a relevant consideration to include a step of fractionation in the process, which may be configured to provide a single fraction which will contain a large portion or even the majority of the organically bound fluorine. By limiting the hydrocarbonaceous material directed to the fluorine removal step, to e.g. a light jet fraction boiling from 150°C to 200°C which may be the fraction containing the majority of fluorine, the reactor volume and other costs related to removal of fluorine may be limited, while maintaining a high extent of fluorine removal. [0042] An overall process for fluorine removal may therefore, in addition to a step of hydrotreatment in the presence of a low amount of nitrogen, contain one or more of the steps of directing a solid feedstock, such as sewage sludge or municipal waste to a process step of any thermochemical decomposition principle, as described above. Such a thermochemical decomposition step releases at least an oxygenate rich feedstock, which may be a stable oxygenate rich stream or may require an optional stabilization. This optional stabilization of the oxygenate rich feedstock may be carried out under conditions stabilizing very reactive compounds to provide a stable oxygenate rich stream, to avoid downstream polymerization or other undesired reactions. The stable oxygenate rich stream may be inherently free of solid heteroatoms or may optionally require removal of solid heteroatoms such as metals and phosphorous. This removal may be carried out in a guard step operating under hydrotreatment conditions; typically mild hydrotreatment conditions, and the catalytically active material will have a pore structure resulting a high capacity for capture of heteroatoms. The demetallized stream will commonly be directed to a hydrodeoxygenation reactor, in which hydrotreatment releasing organically bound oxygen as water is carried out. Commonly the amount of oxygen is high and the hydrodeoxygenation reaction is exothermic, so the reactor is configured for handling this by appropriate means, such as gradually increased activity of the catalytically active material, split injection of feed in the reactor, dilution with product or other less reactive fluids and quench with cold hydrogen. The hydrodeoxygenation reactor may also be split in two, with intermediate cooling. In the hydrodeoxygenation reactor, other hydrotreatment reactions will also occur, such as hydrodenitrification removing organically bound nitrogen, hydrodesulfurization removing organically bound sulfur and hydro-dechlorination removing organically bound chlorine, but conversion of the less reactive compounds, including some nitrogen compounds, may require more severe conditions, including a highly active catalytically active material.

[0043] Following hydrodeoxygenation, cooling and three phase separation in water, a purified non-polar phase stream and gas phase (not shown) may be carried out, optionally after addition of wash water especially in the cases where high amounts of ammonia and other undesired impurities are present in the hydrodeoxygenated stream.

[0044] If the purified non-polar stream contains amounts of organically bound nitrogen it may is together with added hydrogen in the example directed to a further step of hydrotreatment, to reduce the nitrogen content to levels required for hydrodefluorination. Optionally fractionation may be carried out upstream this step or upstream the hydrodefluorination step, to minimize the equipment volume for these steps, by removing the fractions not requiring hydrodefluorination and/or hydrodenitrification.

[0045] Depending on the specific nature of the feedstock treated the individual steps above may or may not be required.

Advantageous Effects of Invention

[0046] A broad aspect of the present disclosure relates to process for reducing the amount of organically bound fluorine in a hydrocarbonaceous stream containing at least 1 ppm_wt, 2 ppm_wt or 20 ppm_wt fluorine and comprising the step of hydrotreatment by contacting said hydrocarbonaceous stream and an amount of dihydrogen with a material catalytically active in hydrotreatment, under active hydrotreatment conditions to provide a hydrodefluorinated stream, characterized in said hydrocarbonaceous stream containing less than 50 ppm_wt, 20 ppm_wt, 8 ppm_wt, 4 ppm_wt , 3 ppm_wt or 1 ppm_wt nitrogen.

[0047] This has the associated benefit of enabling active hydrodefluorination of refractive fluorine containing hydrocarbonaceous streams, by either reducing the amount of organically bound fluorine by at least 50% or to a level below 4 ppm_wt, 2 ppm_wt or 1 ppm_wt. Such a reduction may be sufficient for the product to be used as an aviation fuel or to be used in high amounts as an aviation fuel component.

[0048] One additional aspect relating to the composition of said hydrocarbonaceous stream involves the fraction boiling above 110°C, such as the fraction boiling from 110°C to 300°C containing at least 1 ppm_wt, 2 ppm_wt or 20 ppm_wt fluorine. This limitiation has the effect of defining the fluorine compounds to be treated to be compounds boiling in the jet fuel range, for which strict fluoride limits exists. [0049] Another aspect relating to the composition of said hydrocarbonaceous stream is that the amount of organically bound fluorine in the hydrocarbonaceous stream is less than 5 wt%, 1000 ppm_wt , 200 ppm_wt or 100 ppm_wt fluorine. These limits have the effect of focusing the scope of the process on treating a hydrocarbonaceous stream which originates from a non-pure source such as treatment of mixed waste products.

[0050] An even further additional aspect relating to the composition of said hydrocarbonaceous stream involves the 50 wt%, 80 wt% or 90 wt% of the fluoride being present in perfluorated and polyfluorated compounds, commonly entering the municipal waste cycle.

[0051 ] A second aspect of the present disclosure relates to a process according to the first aspect, wherein said material catalytically active in hydrotreatment comprises one or more metals, being either taken from the group of base metals, such as molybdenum, tungsten, nickel and cobalt active in sulfided form or being taken from the group of elemental noble metals such as Pt and Pd, and a refractive support such as activated carbon and/or one or more oxides taken from the group of alumina, silica, amorphous silica-alumina and molecular sieves.

[0052] This has the associated benefit that such a support may have a high stability, surface area and porosity.

[0053] A third aspect of the present disclosure relates to a process according to the first or second aspect, wherein active hydrotreatment conditions involve a temperature in the range 250 to 450°C, a pressure from 3 MPa to 20 MPa, a gas to oil ratio from 300 Nm³/m³ to 5000 Nm³/m³ and a LHSV from 0.1 hr¹ to 5 hr¹.

[0054] This has the associated benefit of these conditions enabling the use of the most common catalytically active materials for hydrotreatment.

[0055] A fourth aspect of the present disclosure relates to a process according to any of the first three aspects, wherein said hydrocarbonaceous stream is provided from a nitrogen rich feedstock comprising from 100 ppm_wt, 0.1 wt% to 10 wt% organically bound nitrogen, by a process comprising the further steps of first step hydrotreatment contacting said nitrogen rich feedstock and an amount of dihydrogen with a material catalytically active in hydrotreatment comprising from 3 wt% to 30 wt% sulfided base metal, taken as one or more elements from the group comprising molybdenum, tungsten, nickel and cobalt on an refractive support comprising activated carbon and/or oxides taken from the group of alumina, silica, amorphous silica-alumina and molecular sieves, under active first step hydrotreatment conditions, to provide a hydrotreated stream, optionally cooling said hydrotreated stream, optionally adding an amount of wash water, separating said hydrocarbonaceous stream from said hydrotreated stream by gas/liquid separation or if liquid water is present in said hydrotreated stream by three phase separation.

[0056] This has the associated benefit of enabling active hydrodefluorination of refractive fluorine containing hydrocarbonaceous streams, even if nitrogen is present in the feedstock. The optional addition of wash water will enable even more efficient removal of e.g. ammonia from the hydrotreated stream.

[0057] A fifth aspect of the present disclosure relates to a process according to the fourth aspect, wherein first step active hydrotreatment conditions involve a temperature in the range 270 to 450°C, a pressure from 3 MPa to 20 MPa, a gas to oil ratio from 300 Nm³/m³ to 10000 Nm³/m³ and a LHSV from 0.1 hr¹ to 1 hr¹.

[0058] This has the associated benefit of these conditions enabling the use of the most common catalytically active materials for sour mode hydrotreatment.

[0059] A sixth aspect of the present disclosure relates to a process according to the fourth or fifth aspect, wherein said nitrogen rich feedstock originates from a thermochemical decomposition of a solid material, such as waste plastic, municipal waste or sewage sludge comprising fluorine compounds.

[0060] This has the associated benefit of these conditions enabling the conversion of pyrolysis oils originating from waste materials comprising fluorine compounds to commercial hydrocarbon products with strict limits for the fluorine content, such as jet fuel.

[0061 ] A seventh aspect of the present disclosure relates to a process according to the sixth aspect, wherein said thermochemical decomposition is pyrolysis, such as pyrolysis in the presence of added hydrogen and/or a catalytically active material or solvolysis, involving presence of pressurized liquids, such as water, methanol, ethanol or propanol. [0062] This has the associated benefit of these conditions enabling the cost effective preconversion of pyrolysis oils originating from waste materials comprising fluorine compounds to commercial hydrocarbon products with strict limits for the fluorine content, such as jet fuel.

[0063] An eighth aspect of the present disclosure relates to a process according to any aspect above, wherein at least 80 wt% of the intermediate feedstock boils in the range from 80°C to 370°C.

[0064] This has the associated benefit of such a process not requiring hydrocracking to provide a hydrocarbon boiling in the transportation fuel range.

[0065] A ninth aspect of the present disclosure relates to a process according to any aspect above, wherein the pour point of the intermediate feedstock is below - 10°C.

[0066] This has the associated benefit of such a process not requiring isomerization to provide a hydrocarbon having suitable cold flow properties for being used as a transportation fuel range.

[0067] A tenth aspect of the present disclosure relates to a process according to the any aspect above wherein either at least 20 wt% of the hydrodefluorinated stream boils above 370°C or the pour point of said hydrodefluorinated stream is above -10°C, which process further comprises, a step of hydroprocessing involving contacting said hydrocarbonaceous stream or said hydrodefluorinated stream in the presence of an amount of dihydrogen with a material catalytically active in hydrocracking or hydroisomerization.

[0068] This has the associated benefit of such a process enabling hydrocracking and/or isomerization to provide a hydrocarbon having suitable cold flow properties and boiling point for being used as a transportation fuel range.

[0069] An eleventh aspect of the present disclosure relates to a process according to the tenth aspect above further comprising a step of heating or cooling a process stream, such that the hydroprocessing step is carried out at an average temperature at least 20°C below the average temperature of the hydrotreatment step. [0070] This has the associated benefit of such a process reducing the yield loss during hydrocracking and/or hydroisomerization.

Brief Description of Drawings

[0071] Fig.1 shows a process step actively converting organically bound fluorine.

[0072] [Fig.2] shows an exemplary process for converting a solid feedstock comprising fluorine to a stream comprising low amounts of organically bound fluorine.

[0073] [Fig.1 ] shows an exemplary process for reducing the amount of organically bound fluorine in a hydrocarbonaceous stream (120). The essential step in this process is the supply of a hydrocarbonaceous stream (120) comprising a low amount of organically bound nitrogen, such as less than 50 ppm_wt, as well an amount of organically bound fluorine, such as more than 1 ppm_wt. This stream may be provided by any upstream process, including a process in other premises, where the stabilization and other reaction are carried out. By the hydrocarbonaceous stream (120) comprising such a low amount of organically bound nitrogen the process conditions in a hydrodefluorination reactor (HDF), including selection of catalytically active material, temperature, hydrogen pressure and space velocity, may be selected such that substantial conversion of organically bound fluorine is carried out by hydrotreatment and fluorine is transferred to the gas phase as hydrogenfluoride. The gas phase may then be separated from the liquid phase by ordinary means, optionally involving addition of wash water and separation in three phases; gas (not shown), non-polar liquid product (126), and polar liquid waste water (124). Optional further refining of the non-polar product may be carried out, e.g. fractionation and/or hydrocracking in steps not shown in Fig.2.

[0074] [Fig.2] shows an exemplary process for converting a solid feedstock comprising fluorine to a stream comprising low amounts of organically bound fluorine. While Fig.2 illustrates a process with multiple steps in the same location, each of these steps are optional, depending on feedstock and requirements, and it is also a possibility that steps upstream the process illustrated in Fig.1 are carried out in a different location. In the process illustrated in Fig.2 hydrogen and water addition is illustrated, but these are optional, since sufficient presence of water and hydrogen may be available in the streams without such addition. Further Fig.2 shows multiple reaction steps, in the following described as reactors, but several steps may be collected in a single reactor and individual steps may be distributed over several reactors.

[0075] A solid feedstock, such as sewage sludge or municipal waste (202) is directed to a pyrolysis unit (PY), which optionally may be operating according any thermochemical decomposition principle, as described above. The pyrolysis unit may require additional input, and may also release multiple streams, but at least an oxygenate rich feedstock (204) to downstream hydroprocessing is provided. The amount of oxygenates may be dependent on the nature of the solid feedstock and the nature of the thermochemical decomposition process. An optional stabilization may, after addition of hydrogen if required, be carried out in a selective hydrogenation unit (SHU) operating under conditions stabilizing very reactive compounds to provide a stable oxygenate rich stream (206), to avoid downstream polymerization or other undesired reactions. The stable oxygenate rich stream (206) may then be directed to a guard reactor (HDM) for releasing and capturing any organically bound heteroatoms, which are released as solids, such as metals, phosphorous etc. Out of the guard reactor (HDM) a demetallized stream (208) will be directed to a hydrodeoxygenation reactor (HDO), in which hydrotreatment releasing organically bound oxygen as water is carried out.

[0076] Following hydrodeoxygenation, addition of washing water to the hydrodeoxygenated stream (210) and three-way separation in spent water (212), a purified non-polar phase stream (214) and gas phase (not shown) is optionally carried out, especially in the cases where high amounts of ammonia and other undesired impurities are present in the hydrodeoxygenated stream (210).

[0077] The purified stream (214) is together with added hydrogen in the example directed to a step denoted hydrodenitrification (HDN). Other reactions may take place in this step, but especially some of the less reactive nitrogen species may react in this step, as the severity of conditions is higher. The catalyst may be the same as in the final part of hydrodeoxygenation step, or a more active catalyst, but due to the removed nitrogen, the severity will be higher. The product of the hydrodenitrification (216) may optionally undergo a further step of washing by addition of water and three phase separation, to yield spent water (218) and a hydrocarbonaceous stream (220) comprising a low amount of organically bound nitrogen. This stream will still contain a significant amount of organically bound fluorine, which requires severe hydrotreatment conditions in the hydrodefluorination reactor (HDF). These severe conditions may be provided by a combination of selecting the catalytically active material, temperature, hydrogen pressure and space velocity, and the very low amount of organically bound nitrogen also contribute to this increased severity, such that organically bound fluorine is converted to hydrogen fluoride in a hydrodefluorinated stream (222). According to Fig.2, hydrogen fluoride and other compounds having affinity for water are removed by washing with added water and three phase separation, providing spent washing water (224) and a hydrodefluorinated product stream (226).

[0078] As will be clear to the skilled person, optional steps may be omitted, and additional steps may be included. Specifically, heat exchange or control of the temperature of added streams may be used in combination with the exothermic nature of the process to control the temperature of each process step, such as cooling of streams to condensate water and product in the separators shown, as well as heating of process stream prior to reactors.

Examples

[0079] Conversion of organic fluorine was investigated by two series of tests. Both series simulated a two step process, with intermediate removal of gaseous product. The tests were carried out as a first conversion of a product from pyrolysis of municipal waste was hydrotreated at two different seventies, yielding intermediates A and B. The intermediates were collected and subsequently hydrotreated at three different temperatures.

[0080] Table 1 shows the composition of a pyrolysis oil after a stabilization and removal of metals by mild hydrotreatment used in this testing. Notable properties are the nitrogen content of 6.4 wt% and the fluorine content of 39 ppm_wt.

[0081] The fluorine compounds in the pyrolysis oil were not speciated, but considering the source of pyrolysis oil, the likely origin is waste containing fluorine-compounds, such as polyfluorated hydrocarbons and perfluorated hydrocarbons, from household waste, including food packaging, non-stick materials and clothing, and thus a dominant group of organic fluorine compounds is assumed to be PFAS and PFAS derivatives, which mainly will be present in the boiling point range from 110°C to 300°C. This also corresponds to the observation that significant amounts of fluoride was present in this freaction of the pyrolysis oil.

[0082] Table 2 shows key properties of the intermediate products A (high seventy hydrotreatment) and B (low seventy hydrotreatment). The conversion was made by hydrotreatment of the pyrolysis oil described in Table 1 under severe hydrotreatment conditions (p=12 MPag, LHSV=0.5 hr¹, T=380°C, H2:oil=1400 Nm³/m³) and under moderate severity conditions (decreased LHSV). From Table 2, as well as additional analysis, it is clear that the most significant difference between intermediate products A and B is the amount of organic nitrogen. The severe treatment also had a minor effect on aromaticity, end boiling point (T90) and the amount of organic fluorine (23 ppm_wt vs. 27 ppmwt).

[0083] Table 3 shows the results of hydrotreating the two intermediates at different temperatures, but otherwise similar conditions; (p=12 MPag, LHSV=1 hr¹, T=360/380/400°C, H₂:oil=1440 Nm³/m³). At 360°C the organic nitrogen of intermediate product B remained elevated (28 ppm_wt) while the other 5 experiments converted organic nitrogen to levels around 1 ppm_wt. Despite the conversion of organic nitrogen, significant amounts of organic fluorine remains in the product, and for the product samples where nitrogen was efficiently removed the conversion of organic fluorine was substantially higher under similar conditions. The effect of nitrogen on process seventy is also reflected in less conversion of aromatics and high boiling product.

[0084] The experiment shows that a key factor in conversion of organic fluorine is the presence of organic nitrogen, which reduces catalyst activity. In this experiment, organic nitrogen was removed by deep hydrotreatment, but alternative methods of removing organic nitrogen are also relevant, such as acid wash, if the feedstock has a nature where organic nitrogen is released easily to an acid phase.

[0085] A confirmation of the surprising effect is based on a comparison of hydrotreatment of a feedstock with 40 ppm_wt of perfluorooctanoic acid as a model compound dissolved in decane, in combination with 0 ppm_wt, 0.5 ppm_wt, 1 ppm_wt, 10 ppm_wt and 50 ppm_wt nitrogen from an appropriate nitrogen compound. At comparable conditions, this experiment shows substantially full conversion of organically bound fluorine in the absence of organic nitrogen and significant inhibition of the conversion of organically bound fluorine at elevated nitrogen levels.

Table 1

Pyrolysis oil

N wt% 6.4

0 wt% 3.5

F pprriwt 39

Aromatics wt% 29.77

BP

10% °C 140

50% °C 266

90% °C 451

Table 2

A B

N pprriwt 18 279

0 wt% ND ND

F pprriwt 23 26.6

Aromatics wt% 20.1 29.4

BP

10% °C 102 105

50% °C 216 221

90% °C 341 356

Table 3 A/360°C A/380°C A/400°C B/360°C B/380°C B/400°C

N pprriwt 0.5 0.4 0.4 28 0.6 0.8

0 wt% ND ND ND ND ND ND

F pprriwt 4.8 0.6 < 1 20 11 5.9

Aromatics wt% 0.55 0.88 1.41 25.06 17.89 12.08

BP

10% °C 102 101 90 112 106 106

50% °C 199 185 164 225 205 209

90% °C 304 283 255 355 330 318

Claims

[Claim 1 ] A process for reducing the amount of organically bound fluorine in a hydrocarbonaceous stream containing at least 1 ppm_wt fluorine and less than 5 wt% fluorine and comprising the step of hydrotreatment by contacting said hydrocarbonaceous stream and an amount of dihydrogen with a material catalytically active in hydrotreatment, under active hydrotreatment conditions to provide a hydrodefluorinated stream, characterized in said hydrocarbonaceous stream containing less than 50 ppm_wt nitrogen.

[Claim 2] A process according to claim 1 in which said hydrocarbonaceous stream contains at least 2 ppm_wt or 20 ppm_wt fluorine.

[Claim 3] A process according to any claim above in which said hydrocarbonaceous stream contains less than 8 ppm_wt, 5 ppm_wt, 3 ppm_wt or 1 ppm_wt nitrogen.

[Claim 4] A process according to any claim above, wherein the amount of organically bound fluorine in the fraction of the hydrocarbonaceous stream boiling above 110°C is at least 1 ppm_wt, 2 ppm_wt or 20 ppm_wt fluorine.

[Claim 5] A process according to any claim above, wherein the amount of organically bound fluorine in the hydrocarbonaceous stream is less than 1000 ppm_wt , 200 ppm_wt or 100 ppm_wt fluorine.

[Claim 6] A process according to any claim above, wherein said material catalytically active in hydrotreatment comprises one or more metals, being either from 3 wt% to 30 wt% taken from the group of base metals, such as molybdenum, tungsten, nickel and cobalt active in sulfided form or being from 0.05 wt% to 3 wt% taken from the group of elemental noble metals such as Pt and Pd, and a refractive support such as activated carbon and/or one or more oxides taken from the group of alumina, silica, amorphous silica-alumina and molecular sieves.

[Claim 7] A process according to any claim above, wherein active hydrotreatment conditions involve a temperature in the range 250 to 450°C, a pressure from 3 MPa to 20 MPa, a gas to oil ratio from 300 Nm³/m³ to 5000 Nm³/m³ and a LHSV from 0.1 hr¹ to 5 hr¹.

[Claim 8] A process according to any claim above, wherein said hydrocarbonaceous stream is provided from a nitrogen rich feedstock comprising from 100 ppm_wt, 0.1 wt% to 10 wt% organically bound nitrogen, by a process comprising the further steps of i. first step hydrotreatment contacting said nitrogen rich feedstock and an amount of dihydrogen with a material catalytically active in hydrotreatment comprising from 3 wt% to 30 wt% sulfided base metal, taken as one or more elements from the group comprising molybdenum, tungsten, nickel and cobalt on an refractive support comprising activated carbon and/or oxides taken from the group of alumina, silica, amorphous silica- alumina and molecular sieves, under active first step hydrotreatment conditions, to provide a hydrotreated stream, ii. optionally cooling said hydrotreated stream, iii. optionally adding an amount of wash water, iv. separating said hydrocarbonaceous stream from said hydrotreated stream by gas/liquid separation or if liquid water is present in said hydrotreated stream by three phase separation.

[Claim 9] A process according to claim 8, wherein first step active hydrotreatment conditions involve a temperature in the range 270 to 450°C, a pressure from 3 MPa to 20 MPa, a gas to oil ratio from 300 Nm³/m³ to 10000 Nm³/m³ and a LHSV from 0.1 hr¹ to 1 hr¹.

[Claim 10] A process according to claim 8 or 9, wherein said nitrogen rich feedstock originates from a thermochemical decomposition of a solid material, such as waste plastic, municipal waste or sewage sludge comprising fluorine compounds.

[Claim 11] A process according to claim 10, wherein said thermochemical decomposition is pyrolysis, such as pyrolysis in the presence of added hydrogen and/or a catalytically active material or solvolysis, involving presence of pressurized liquids, such as water, methanol, ethanol or propanol.

[Claim 12] A process according to any claim above, wherein at least 80 wt% of the hydrodefluorinated stream boils in the range from 80°C to 370°C.

[Claim 13] A process according to any claim above, wherein the pour point of the hydrodefluorinated stream is below -10°C.

[Claim 14] A process according to any claim above wherein either at least 20 wt% of the hydrodefluorinated stream boils above 370°C or the pour point of said oxygenate rich feedstock is above -10°C, which process further comprises, a step of hydroprocessing involving contacting said hydrocarbonaceous stream or said hydrodefluorinated stream in the presence of an amount of dihydrogen with a material catalytically active in hydrocracking or hydroisomerization.

[Claim 15] A process according to claim 14 further comprising a step of heating or cooling a process stream, such that the hydroprocessing step is carried out at an average temperature at least 20°C below the average temperature of the hydrotreatment step.