Process for stabilizing unstable crude hydrocarbonaceous products

Abstract

A first aspect of the invention relates to a process for producing a stabilized hydrocarbonaceous product from a solid feedstock, the process comprising the steps of: providing a solid feedstock for thermal decomposition; directing the solid feedstock for thermal decomposition to a thermal decomposition process to provide a thermally decomposed fluid product and a solid phase; and guiding at least an amount of the thermally decomposed fluid product and an amount of hydrogen as a crude feedstock to contact a material having catalytic activity in conjugated diene carbon-carbon bond hydrogenation under active conditions of conjugated diene carbon-carbon bond hydrogenation, characterized in that the ratio between hydrogen and crude feedstock is 1 Nm3 / m3 to 100 Nm3 / m3. This has the related benefit that the process requires only a small amount of hydrogen while still being able to provide a stabilized hydrocarbonaceous product that is easy to transport.

Description

Technical Field

[0001] Thermal decomposition of solid feedstocks (such as mixed municipal waste, mixed or sorted plastic waste and forestry waste) provides a liquid product (referred to as pyrolysis oil or crude pyrolysis oil) that can be upgraded to high-quality hydrocarbons and used as transportation fuels or petrochemical feedstocks.

[0002] Pyrolysis is a moderately complex process that can be carried out in plants converting moderate amounts of solid feedstock. Since the transportation cost of the solid feedstock is an important factor in this regard, it may be convenient to carry out pyrolysis in medium-scale decentralized plants, but processing the product pyrolysis oil to current commercial standards requires extensive processing that is not suitable for small-scale operations.

[0003] Crude pyrolysis oil (the direct liquid product of most thermal decomposition processes) is very unstable and has a high tendency to solidify, for example by polymerization, so upgrading is usually preferably carried out in the same equipment as the thermal decomposition. However, it is advantageous to carry out the upgrading process in a large hydroprocessing plant because of the need to provide process support, including facilities such as hydrogen and steam.

[0004] To bridge these conflicting demands, we propose a holistic approach involving decentralized stabilization of crude pyrolysis oil, transportation of the stabilized pyrolysis oil to a central upgrading hydroprocessing facility, and a cost-effective method for decentralized production of such stabilized pyrolysis oil.

[0005] definition

[0006] It should be understood that the pressures listed are gauge pressures, ie, pressures above ambient.

[0007] The term continuous operation, as is well known in the art, refers to the uninterrupted supply of feedstock and withdrawal of product during a given production cycle. This is in contrast to batch operation (i.e., discontinuous operation), which is also well known in the art, in which the entire amount of liquid oil and catalyst is introduced at the beginning of the process and the product is withdrawn after a certain period of time.

[0008] It is understandable that the unit Nm 3 Indicates "standard" m 3 , which is the amount of gas occupying that volume at 0°C and 1 atmosphere pressure.

[0009] As used herein, the term "hydrogen to liquid oil ratio" or "H2 / oil ratio" refers to the volume ratio of the flow rate of hydrogen to the liquid oil flow, expressed in Nm 3 / m 3 The units are reported, with the gas phase being reported at normal conditions and the liquid phase being reported at standard conditions (at 25°C and 1 atmosphere).

[0010] When concentration is expressed in wt %, it is to be understood as weight / weight %.

[0011] As used herein, for convenience, the term "thermal decomposition" should be used broadly for any decomposition process in which a solid material is partially decomposed at high temperatures (typically 250°C to 800°C or even 1000°C) in the presence of substoichiometric amounts of O2 (including without added oxygen). The product is typically a mixed stream of liquid and gas, as well as a certain amount of solid char. The term should be interpreted as including processes referred to as pyrolysis and hydrothermal liquefaction in the presence and absence of a catalyst. For convenience, the product of such a thermal decomposition process may be referred to as pyrolysis oil, but it should be understood to cover any thermal decomposition process.

[0012] As used herein, the term "stage" refers to a physical stage comprising a unit or combination of units for performing one or more steps and / or sub-steps.

[0013] The term "polymer-derived feedstock" or "waste polymers" may be understood to include mixed sorted waste containing at least 50 wt%, 80 wt% or 90 wt% of plastics and other man-made polymers.

[0014] Raw materials of biological origin can be defined by their origin, but can also be defined by 14 The carbon content is defined as being greater than 0.5 parts per trillion of the total carbon content.

[0015] When referring to hydrogen and hydrogen concentrations, this should generally be understood to refer to molecular elemental hydrogen unless it is implied that the hydrogen is part of another molecule.

[0016] When referring to oxygen content, this should generally be understood to refer to atomic oxygen as part of other molecules, unless referred to as O2.

[0017] Technical issues

[0018] Cost-effective operation of plants for thermal decomposition of, for example, plastic waste generally produces a crude pyrolysis oil product that is not suitable for transportation because the crude pyrolysis oil is highly reactive and tends to solidify during transportation, especially at moderately elevated temperatures and / or in the presence of O2. Contrary to the fact that processes for the conversion and stabilization of such reactive materials generally require high hydrogen consumption and multiple process steps and therefore benefit from large-scale operations, there is a general tendency to locate such processing plants locally to minimize transportation of solid feedstock to the plants. It is therefore desirable to establish a decentralized stabilization process to identify a stabilization process suitable for small-scale intermediates to facilitate their production and storage.

[0019] Solution to the problem

[0020] Typically, the composition of oils derived from the thermal decomposition of artificial polymers may include 0.5-5 wt% conjugated dienes and up to 30-90 wt% olefins, for example 65 wt% olefins. The atomic oxygen content may typically be less than 1 wt%, but if the solid feedstock contains a large amount of organic material (e.g. mixed household waste), the atomic oxygen content may be as high as 50 wt%.

[0021] According to the present invention, the crude product of thermochemical decomposition, such as pyrolysis oil, is stabilized at a minimum hydrogen consumption, low pressure and medium temperature by converting at least the most active compounds in the pyrolysis oil. For raw materials from polymer sources, such as waste plastics, the crude pyrolysis product may generally contain hydrocarbon molecules with conjugated diene structures, including structures of vinyl aromatics and styrene types, i.e., there are two double bonds or aromatic bonds separated by single bonds between carbon atoms. These conjugated dienes can be polymerized to form larger molecules, especially at temperatures above 50° C. and / or in the presence of O2, which may not be liquid under the conditions used during storage, transportation or processing. Especially low molecular weight dienes are prone to such polymerization because the conjugated double bonds near the ends of the molecules are more reactive.

[0022] Similar problems exist with biogenic materials, but in this case carbonyl oxygenates such as furfural, furan, aldehydes, ketones and acids are compounds that may polymerize, and typically pyrolysis oils may contain molecules with both diene structures and molecules including carbonyl oxygens.

[0023] In order to stabilize these active compounds at a moderate cost, we have identified the possibility of providing limited amounts of hydrogen, which are only slightly in excess relative to the hydrogenation of the most reactive groups. The amount of hydrogen provided may only take into account the conjugated dienes, which for oils originating from the thermal decomposition of artificial polymers may be present in an amount of 0.5-5 wt %, and we suggest limiting the conditions (temperature and pressure) so that only the reactive groups are converted and, accordingly, the amount of hydrogen may also be limited. For example, the ratio of hydrogen gas / liquid oil may be 4 Nm 3 / m 3 , which is low enough that the hydrogen can be almost completely dissolved in the oil. This also has the benefit that the reactor and process pipelines do not need to be designed for contact in the gas-liquid two-phase flow.

[0024] The conversion of plastic waste, biomass and municipal waste into liquid products by thermochemical decomposition (e.g. pyrolysis and hydrothermal liquefaction), in particular by subsequent hydrotreating, is considered an environmentally friendly source of alternatives to petroleum products, especially from a global warming perspective. Due to the nature of these liquid products (for simplicity, referred to as pyrolysis oils, regardless of the source process), they require upgrading, for example by hydrotreating to remove heteroatoms (e.g. sulphur and oxygen) and to hydrogenate the olefinic structure. The nature of the formation process means that the products are unstable and therefore can be very reactive compared to typical fossil crude feedstocks, requiring large amounts of hydrogen, releasing large amounts of heat during the reaction and also having a high tendency to polymerize. The release of heat can further increase the polymerization and at high temperatures the catalyst can also be deactivated by coking.

[0025] According to the present disclosure, the thermochemical decomposition process equipment section providing hydrocarbon feedstock can be in various forms, including rotary furnaces, fluidized beds, conveyor beds or circulating fluidized beds known in the art. The decomposition converts the pyrolysis feedstock into solids (charcoal), high boiling point liquids (tar) and gaseous fractions at high temperatures. The gaseous fraction includes condensable fractions (pyrolysis oil or condensate, C5+ compounds) and non-condensable fractions (pyrolysis gas, including pyrolysis waste gas) at standard temperature. For example, the thermochemical decomposition process equipment section (pyrolysis section) may include a pyrolyzer unit (pyrolysis reactor), a cyclone separator and / or a filter to remove particulate solids such as charcoal, and a cooling unit to produce a pyrolysis waste gas stream and the pyrolysis oil stream, i.e., condensed pyrolysis oil. The pyrolysis gas stream contains light hydrocarbons, such as C1-C4 hydrocarbons, and typically also contains H2O, CO and CO2. Typically, the term pyrolysis oil includes condensate and tar, and the pyrolysis oil stream produced by biomass pyrolysis can also be referred to as bio-oil or bio-crude oil. Pyrolysis oil is a liquid material rich in a mixture of molecules, typically composed of more than two hundred different compounds, mainly oxygenates such as acids, sugars, alcohols, phenols, guaiacol, eugenol, aldehydes, ketones, furans and other mixed oxygenates, which result from the depolymerization of solids during the pyrolysis process. Thermochemical decomposition of non-biowastes of suitable composition (e.g. plastic scraps or rubber, including scrap tires) generally provides only products with low oxygen content unless O2 is added during the decomposition process, and usually provides hydrocarbonaceous feedstocks with a structure reflecting the solid pyrolysis feedstock.

[0026] For the purposes of the present invention, the pyrolysis stage may be a fast pyrolysis, also known in the art as flash pyrolysis. Fast pyrolysis refers to the thermochemical decomposition of solid feedstocks, usually carried out in the absence of O2, at temperatures usually in the range of 350-650°C, for example about 500°C, with a reaction time of 10 seconds or less, for example 5 seconds or less, for example about 2 seconds. Fast pyrolysis can be carried out, for example, by autothermal operation, for example in a fluidized bed reactor. The latter, also known as autothermal pyrolysis, is characterized in that air, optionally together with an inert gas or a recycle gas, is used as a fluidizing gas. Thus, partial oxidation of the pyrolysis compounds produced in the pyrolysis reactor (autothermal reactor) provides energy for pyrolysis and improves heat transfer. In so-called catalytic fast pyrolysis, a catalyst may be used. Acidic catalysts, usually consisting of zeolites, free of active metals, can be used to upgrade the pyrolysis steam and can be operated in both in-situ mode (the catalyst is located in the pyrolysis reactor) and in ex-situ mode (the catalyst is placed in a separate reactor). The use of a catalyst has the advantage of helping to stabilize the pyrolysis oil, making it easier to carry out hydrogenation processing. Furthermore, higher selectivity towards desired pyrolysis oil compounds can be achieved.

[0027] In some cases, hydrogen is added to the catalytic pyrolysis, a process known as reactive catalytic fast pyrolysis. If the catalytic pyrolysis is carried out at high hydrogen pressure, e.g., above 0.5 MPa, it is often referred to as catalytic hydropyrolysis. The catalysts upgraded in the presence of hydrogen typically contain one or more metals active in hydrogenation, e.g., metals from Group 6 or Groups 8, 9, or 10.

[0028] The pyrolysis stage may be a fast pyrolysis, which is carried out in the absence of a catalyst and hydrogen, ie the fast pyrolysis stage is not a catalytic fast pyrolysis, a hydropyrolysis or a catalytic hydropyrolysis. This makes the process simpler and cheaper.

[0029] In one embodiment, the thermal decomposition is hydrothermal liquefaction. Hydrothermal liquefaction refers to the thermochemical conversion of solid raw materials (such as plastic waste, biomass, municipal solid waste or sewage sludge) into liquid fuels by treating them in a hot pressurized water environment for a sufficient period of time to decompose the solid biopolymer structure into a major liquid component. Typical hydrothermal treatment conditions are temperatures in the range of 200-500°C, particularly in the range of 300-450°C, and operating pressures in the range of 4-40MPa, particularly in the range of 25-35MPa. Compared with pyrolysis (such as fast pyrolysis), this technology has the advantages of lower operating temperatures, higher energy efficiency and lower tar production.

[0030] In one embodiment, the pyrolysis further comprises passing the solid feedstock through a solid feedstock preparation section, which includes, for example, drying to remove water and / or comminution to reduce particle size. Any water / moisture in the solid feedstock, after evaporation in, for example, the pyrolysis section, will condense in the pyrolysis oil stream (and thus proceed in the process), which may be undesirable. In addition, the heat used for water vaporization will take away the heat required for pyrolysis. By removing water while providing a smaller particle size of the solid feedstock, the thermal efficiency of the pyrolysis section will be improved.

[0031] Finally, other related thermochemical decomposition methods are moderate or slow pyrolysis, where conditions involve lower temperatures and generally longer residence times - these methods may also be referred to as carbonization or torrefaction. The main advantage of these thermochemical decomposition methods is lower investment costs, but they may also have specific advantages for specific feedstocks or specific product requirements (e.g. the need for biochar as a by-product).

[0032] When large amounts of solid products are produced, such as in processes for producing biochar or when unconverted carbon black particles need to be recovered from thermochemical conversion of scrap tires, it may be beneficial to filter the liquid products as part of the thermochemical conversion process, which also has the advantage of minimizing deactivation of downstream catalysts.

[0033] The hydrotreatment of reactive compounds is exothermic due to its chemical nature. This means that, as long as the temperature is sufficient to initiate the hydrogenation of the most reactive compounds, the temperature is increased, thus ensuring further reactions of other compounds, but by limiting the availability of hydrogen, the temperature increase does not reach a level that would lead to the conversion of hydrocarbons into solid carbon deposits, which would deactivate the catalyst.

[0034] As mentioned above, large molecules are generally less reactive than small molecules. Therefore, by directing only the lightest and most unstable fraction of the pyrolysis products to stabilization, sufficient transport stability can be obtained while minimizing local process volumes and hydrogen consumption. In practice, this fractionation can be carried out by fractionating products with a wide boiling point range in a fractionator, or by condensing the high-boiling fraction (e.g. 250°C), while the less stable low-boiling fraction is either hydrotreated in the vapor state or condensed before hydrotreatment.

[0035] We therefore propose a method for hydrotreating a liquid oil stream by reacting the liquid oil stream with hydrogen in a continuous operation in the presence of a hydrotreating catalyst having a moderate sulfur resistance. The catalyst may be a sulfided catalyst comprising one or more of nickel, cobalt, molybdenum and tungsten, typically operated at an inlet temperature of 130-200°C, or may be a metallic catalyst comprising one or more of nickel, palladium and platinum, typically operated at an inlet temperature of 80-130°C. In most cases, the pressure may be 0.5-2 MPa, but may be as high as 35 MPa, with a liquid hourly space velocity (LHSV) of 0.1-5 h -1 , these conditions can form a stable liquid oil flow.

[0036] The process is moderately exothermic so the temperature typically rises by 5-20°C.

[0037] The present invention adopts a continuous operation process because it does not rely on the output product (stable liquid oil) to be always fluid compared to batch operation. The process can be carried out in a fixed bed reactor, a slurry bed reactor, a trickle bed reactor and a fluidized bed reactor.

[0038] Providing hydrogen for hydroprocessing is a significant cost and reducing the need for hydrogen could potentially reduce costs. In hydroprocessing, a certain amount of hydrogen is consumed per volume of oil, which is known as the hydrogen:oil consumption ratio. Depending on the nature of the crude product, for a complete hydroprocessing, the H2:oil consumption ratio might be 50 Nm 3 / m 3 Up to 1000Nm 3 / m 3 However, in order to minimize the risk of carbon deposits on the catalyst, it is common to operate with a safety factor of 2, 4 or even 8, so that the H2: fuel consumption ratio is 200Nm 3 / m 3 When the fuel consumption of H2 is as high as 1000Nm 3 / m 3 - If the purity of the H2-rich gas in the process is only 80 vol%, the resulting gas-to-oil ratio will be 500 Nm 3 / m 3 This excess of gas will naturally lead to an increase in the size of the equipment, and the excess of H2 may also lead to increased reactivity, so that the actual H2 consumption is increased simply because of the presence of H2.

[0039] At such high hydrogen levels, it makes economic sense to recycle the gas, the associated equipment costs (eg, gas recycle compressors) and the scale of the process result in the need for increased throughput.

[0040] The need for high excess H2 is primarily related to the high temperatures approaching full hydrotreating. Therefore, we recommend limiting H2 to amounts below that required for full hydrotreating as this will protect the process from thermal runaway while limiting hydrogen consumption, thereby reducing operating costs, process volume, and capital investment as recycle and recycle compressors are not required.

[0041] In one embodiment, the catalyst is in a sulfided form, such as NiMoS or CoMoS. The catalyst may be presulfided by exposure to a sulfur-containing stream, or may be sulfided in situ (i.e., during operation), such as by sulfur present in the pyrolysis oil, so that the sulfided catalyst remains sulfided and therefore remains active due to the presence of sulfur.

[0042] The method may also include subjecting the stabilized pyrolysis oil stream to a further hydroprocessing step, possibly after transport to a central site, where the stabilized pyrolysis oil may be further processed to produce hydrocarbons suitable for conversion in a steam cracker or to produce products boiling in the transportation fuel range, such as diesel, jet fuel, and naphtha. Further processing may include hydrodewaxing, hydrocracking, or isomerization, which are well known in the fossil petroleum refining art.

[0043] Materials that are catalytically active in the initial hydrotreating, especially the hydrotreating of conjugated double bonds, typically include an active metal (sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum, but may also include elemental metals (including nickel) and noble metals (such as platinum and / or palladium) and a refractory support (such as alumina, silica or titania, or a combination thereof). Initial hydrotreating conditions may involve moderate temperatures in the range of 120-200° C., moderate pressures in the range of 0.5-5 MPa, and liquid hourly space velocities (LHSV) in the range of 0.1-5. For certain conditions, high pressures up to 35 MPa may be required.

[0044] Final hydrotreating, e.g., hydrogenation conditions, typically involve higher temperatures in the range of 250-400°C, higher pressures in the range of 3-15 MPa, and liquid hourly space velocities (LHSV) in the range of 0.1-4, optionally combined with intermediate cooling by quenching with cold hydrogen, feed or product.

[0045] Materials having catalytic activity in isomerization generally include an active metal (elemental noble metals such as platinum and / or palladium, or sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum), an acidic support (generally a molecular sieve having high shape selectivity and having topologies such as MOR, FER, MRE, MWW, AEL, TON and MTT) and a refractory support (e.g. alumina, silica or titania, or a combination thereof).

[0046] The isomerization conditions involve a temperature in the range of 250-400°C, a pressure in the range of 2-10 MPa, and a liquid hourly space velocity (LHSV) in the range of 0.5-8.

[0047] The materials catalytically active in hydrocracking have similar properties to those catalytically active in isomerization and generally comprise active metals (elemental noble metals such as platinum and / or palladium or sulphided base metals such as nickel, cobalt, tungsten and / or molybdenum), an acidic support (generally a molecular sieve having a high cracking activity and having a topology such as MFI, BEA and FAU) and a refractory support (for example alumina, silica or titania, or a combination thereof). The difference with the materials catalytically active in isomerization generally lies in the nature of the acidic support, which may have a different structure (even amorphous silica-alumina) or have a different acidity, for example due to the ratio of silica to alumina.

[0048] Hydrocracking conditions may involve temperatures in the range of 250-400°C, pressures in the range of 3-20 MPa and liquid hourly space velocities (LHSV) in the range of 0.5-8, optionally combined with intermediate cooling by quenching with cold hydrogen, feed or product.

[0049] Other types of hydroprocessing are also contemplated, such as hydrodearomatization (HDA). The catalytically active materials in hydrodearomatization generally comprise an active metal (generally an elemental noble metal such as platinum and / or palladium, but may also comprise sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum) and a refractory support (e.g., amorphous silica-alumina, alumina, silica or titania, or combinations thereof).

[0050] The hydrodearomatization conditions involve a temperature in the range of 200-350°C, a pressure in the range of 2-10 MPa, and a liquid hourly space velocity (LHSV) in the range of 0.5-8.

[0051] Any embodiments and associated benefits of the first aspect of the invention may be used with the second aspect of the invention, and vice versa.

[0052] Beneficial effects of the present invention

[0053] A first aspect of the present invention relates to a method for producing a stabilized hydrocarbonaceous product from a solid feedstock, the method comprising the following steps: providing a solid feedstock for thermal decomposition; directing the solid feedstock for thermal decomposition to a thermal decomposition process to provide a thermally decomposed fluid product and a solid phase; directing at least a certain amount of the thermally decomposed fluid product as a crude liquid feedstock and a certain amount of hydrogen to a catalytic process to contact a material having catalytic activity in hydrogenating the carbon-carbon bonds of conjugated dienes under active conditions for hydrogenating the carbon-carbon bonds of conjugated dienes, thereby providing the stabilized hydrocarbonaceous product, wherein the catalytic process may have several catalytically different steps, and wherein the crude liquid feedstock and hydrogen are added together or independently at one or more locations; and, optionally after removing an aqueous phase or other impurities, extracting the stabilized hydrocarbonaceous product for transportation or storage; characterized in that the ratio of the total amount of hydrogen added to the amount of the crude liquid feedstock is 1Nm 3 / m 3 Up to 100Nm 3 / m 3 .

[0054] The process has the benefit of requiring only small amounts of hydrogen while still providing a hydrocarbonaceous product that is stabilized for transport or storage.

[0055] A second aspect of the present invention relates to a method according to the first aspect, wherein the ratio of the total amount of hydrogen added to the amount of the crude liquid feedstock is 1, 2, 5 or 10 Nm 3 / m 3 Up to 20Nm 3 / m 3 or 50Nm 3 / m 3 .

[0056] This has the benefit that the amount of hydrogen corresponds to the amount of reactive compounds in the thermal decomposition fluid product.

[0057] A third aspect of the present invention relates to a method according to the first or second aspect, wherein the solid feedstock comprises at least 50% waste polymer.

[0058] This has the benefit that the process is well suited for processing waste polymer feedstocks in order to use the stabilized product in a steam cracker (optionally after further processing).

[0059] A fourth aspect of the present invention relates to a method according to the first or second aspect, further comprising separating the thermally decomposed fluid product into at least a polar liquid phase and a non-polar liquid phase.

[0060] This has the associated benefit of providing a method suitable for processing feedstocks that have a high oxygen content and can be converted to water, such as feedstocks that include a large amount of biogenic material.

[0061] A fifth aspect of the invention relates to a process according to the first, second, third or fourth aspect, wherein the active conditions for hydrogenation involve a pressure of ambient pressure or 0.5 MPa to 10 MPa, 20 MPa or 35 MPa.

[0062] This has the associated benefit of reducing equipment costs without negatively affecting performance since pressure does not limit the solubility of hydrogen.

[0063] A sixth aspect of the present invention relates to a process according to the first, second, third, fourth or fifth aspect, wherein the active conditions for hydrogenation involve an inlet temperature of 80 to 210°C.

[0064] This has the associated benefit of providing sufficient temperature for process initiation while keeping the temperature low so that only the most reactive compounds are converted.

[0065] A seventh aspect of the present invention relates to a method according to the first, second, third, fourth, fifth or sixth aspect, wherein the material having catalytic activity in hydrogenation comprises at least one of Ni, Co, Mo, W and Pd.

[0066] An eighth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth or seventh aspect, wherein the hydrogen is at least partially provided by reaction of a certain amount of fluid products of the thermal decomposition product stream, optionally using electrical heating.

[0067] This has the associated benefit of converting waste gases from the pyrolysis stream into process hydrogen while minimizing CO2 emissions, particularly if electricity is generated from excess process heat or from renewable energy sources such as solar, wind or wave power.

[0068] A ninth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect, wherein the hydrogen is at least partially produced by electrolysis, which optionally uses electricity generated from excess process heat or renewable energy (such as solar, wind or wave energy).

[0069] This has the associated benefit of converting waste gases from the pyrolysis stream into process hydrogen while minimizing CO2 emissions.

[0070] A tenth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect, wherein the thermal decomposition product is cooled to a temperature of 20°C to 150°C, 180°C or 230°C prior to contacting with a material having catalytic activity in a hydrotreatment.

[0071] This has the associated benefit of avoiding curing by polymerization.

[0072] The eleventh aspect of the present invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth aspect, wherein the amount of solid raw material is at least 10 tons / day or 50 tons / day and less than 2000 tons / day, less than 1000 tons / day or less than 500 tons / day.

[0073] This has the associated benefit that processes at this scale are well suited to decentralized stabilization, but are too small for optimal operation of full conversion.

[0074] The twelfth aspect of the present invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth or eleventh aspect, wherein the stabilized hydrocarbon product is transferred to a transportation vehicle (such as a tank truck or a pipeline) and transported to an upgrading facility for upgrading to a final hydrocarbon product.

[0075] This has the associated benefit that the process is well suited for centralized finalization of processes to produce hydrocarbon products for steam cracking or as part of transportation fuels.

[0076] Further aspects relate to process equipment comprising means for performing any of the above aspects, wherein the means are configured accordingly.

[0077] BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 A thermochemical decomposition process is shown, in which all liquid hydrocarbon products are stabilized by hydrotreating.

[0079] Figure 2 Thermochemical decomposition processes are shown, where only light hydrocarbons are stabilized by hydrotreating.

[0080] Figure 1

[0081] exist Figure 1 In the present invention, solid feedstock (102) is directed to a thermochemical decomposition reactor (PYR). The thermochemical decomposition produces three streams: a high temperature gas stream (104), solid char (106), and liquid pyrolysis oil (108). The thermochemical decomposition process may have internal recirculation or additional inlets, such as gas, water, and solvent, but these are not described in detail. Figure 1 Shown in.

[0082] The full range pyrolysis oil (108) is combined with an appropriate amount of hydrogen (114) and optionally heated by heating a single stream or heating a combined raw feed stream (116). The raw feed stream is directed to a hydroprocessing reactor (HYD) where it is contacted with a material that is catalytically active in the hydroprocessing at a moderate temperature (e.g., 150°C) and a moderate pressure (e.g., 2 MPa). The hydroprocessing reactor (HYD) is shown as a separate unit, but it can also be integrated in a thermochemical decomposition reactor (PYR).

[0083] The product stream (118) is typically directed to a gas-liquid product separator (SEP) to separate the light gases (120) from the stabilized hydrocarbonaceous product (124). If the crude product contains oxygen, the product separator may be a three-way separator because the liquid will contain a hydrocarbon phase and an aqueous phase. In the illustration, the separator (SEP) is a reboiler stripper, which has the advantage that dissolved hydrogen and other gases can be removed from the product.

[0084] Stabilized hydrocarbons are stable enough for transportation and storage, but are not of sufficient quality to be used as transportation fuels or as feedstock for chemical processes such as steam cracking.

[0085] If a large excess of hydrogen is involved in the process, it makes economic sense to recover this hydrogen by gas recycle, although such a recycle loop involves capital and operating costs. If the hydrogen excess is smaller, the gas can be directed to thermochemical decomposition for use as a heat source.

[0086] Figure 2

[0087] exist Figure 2 In the present invention, solid feedstock (202) is directed to a thermochemical decomposition reactor (PYR). The thermochemical decomposition produces three streams: a high temperature gas stream (204), solid char (206), and liquid pyrolysis oil (208). The thermochemical decomposition process may have internal recirculation or additional inlets, such as gas, water, and solvent, but these are not described in detail. Figure 2 Shown in.

[0088] In the figure, pyrolysis oil (208) is fractionated into light pyrolysis oil (210) and heavy pyrolysis oil (212). The fractionation shown in the figure is carried out in a fractionator, but the condensation process of pyrolysis oil can also be used for similar fractionation.

[0089] The light pyrolysis oil (210) is combined with an appropriate amount of hydrogen (214) and optionally heated by heating a single stream or heating a combined raw feed stream (216). The raw feed stream is directed to a hydroprocessing reactor (HYD) at a moderate temperature (e.g., 150°C) and a moderate pressure (e.g., 2 MPa) to contact with a material that is catalytically active in the hydroprocessing. The hydroprocessing reactor (HYD) is shown as a separate one, but it can also be integrated in the thermochemical decomposition reactor (PYR).

[0090] The product stream (218) is typically directed to a gas-liquid product separator (SEP) to separate the light gases (220) from the stabilized light products (222). If the crude product contains oxygen, the product separator may be a three-way separator because the liquid will contain a hydrocarbon phase and an aqueous phase. In the illustration, the separator (SEP) is a reboiler stripper, which has the advantage that dissolved hydrogen and other gases can be removed from the product.

[0091] The stabilized light products (222) are combined with the full range pyrolysis oil (212) to form a stabilized hydrocarbonaceous product (224) that is stable enough for transport and storage, but not of sufficient quality to be used as a transportation fuel or feedstock for chemical processes such as steam cracking.

[0092] Figure 3

[0093] Figure 3 According to the prior art, a highly simplified layout for quantitative hydrogenation is shown. Figure 1 Similar, but in practice, the increased hydrogen flow, higher temperatures and higher pressures result in the need for larger equipment and multiple modifications.

[0094] like Figure 1 As shown, the solid feedstock (302) is directed to a thermochemical decomposition reactor (PYR). The thermochemical decomposition produces three streams: a high temperature gas stream (304), solid char (306), and liquid pyrolysis oil (308). The thermochemical decomposition process may have internal recirculation or additional inlets, such as gas, water, and solvent, but these are not described in detail. Figure 3 Shown in.

[0095] The full range pyrolysis oil (308) is combined with a certain amount of hydrogen (314) and optionally heated by heating a single stream or by heating a combined raw feed stream (316). Since the goal is to fully hydrogenate the pyrolysis oil (308), the amount of hydrogen introduced into the process must match the total amount required chemically, and in addition, as a safety measure, an excess of hydrogen must be provided to minimize the risk of coke formation on the catalyst. The raw feed stream (316) is introduced into a hydroprocessing reactor (HYD) at a moderate temperature (e.g. 150°C) in contact with materials that are catalytically active in the hydroprocessing, which temperature is raised to, for example, 350°C in the downstream process by the heat released and possible external heating. The pressure is preferably increased, for example 20 MPa. A single hydroprocessing reactor (HYD) is shown here, but several reactors are generally required, and the first reactor may be integrated with the thermochemical decomposition reactor (PYR).

[0096] The product stream (318) is typically directed to a gas-liquid product separator (SEP) to separate the light gases (320) from the stabilized hydrocarbonaceous product (324). If the crude product contains oxygen, the product separator may be a three-way separator because the liquid will contain a hydrocarbon phase and an aqueous phase. In the illustration, the separator (SEP) is a reboiler stripper, which has the advantage that dissolved hydrogen and other gases can be removed from the product.

[0097] The stabilized hydrocarbon phase will be highly stable and can be used as a transportation fuel or as a feedstock for chemical processes such as steam cracking.

[0098] Since the process involves large amounts of excess hydrogen, it makes economic sense to recover this hydrogen by gas recycling, despite the capital and operating costs involved in such a recycling loop. Therefore, the light gas (320) is directed to a recycle compressor (CMP) where it is pressurized and combined with the hydrogen (314). Typically, this light gas stream is purified by appropriate means (not shown). Example

[0099] To illustrate the present invention, three examples are compared. Tables 1, 2 and 3 show the boiling point curves and the contents of conjugated dienes and olefins in the hydrothermal liquefaction product of 1200 t / d (50 t / h) of plastic waste. Figure 1 Or one of the two mild hydrogenation treatments. Due to the presence of dienes, the raw materials have a tendency to polymerize and solidify during transportation, especially when heated above 50°C.

[0100] The basis reported in Table 1 Figure 1In Example 1, the full range pyrolysis oil was directed to a mild hydrotreatment at 150°C with an amount of hydrogen equivalent to twice the theoretical hydrogen consumption for diene saturation, which could be 99% dissolved in the oil, ensuring good contact and avoiding the practical challenges of large gas flow rates. This corresponds to 4 Nm 3 / m 3 The amount of conjugated diene is reduced from 1.9 wt% to 0.095 wt%, which will produce a product that is stable for transportation.

[0101] The basis reported in Table 2 Figure 2 In Example 2 of , only naphtha-range pyrolysis oil was directed to a mild hydrotreatment at 150°C with an amount of hydrogen corresponding to twice the theoretical hydrogen consumption for diene saturation, which in this example was also substantially dissolved in the oil. This corresponds to a hydrogen / oil ratio of 4 Nm in the hydrotreated stream. 3 / m 3 The amount of conjugated dienes is reduced only from 1.9 wt% to 1.35 wt%, but the most reactive small conjugated dienes are reduced by 95%, so the product will be stable enough for shipping.

[0102] The basis reported in Table 3 Figure 3 In Example 3, the full range pyrolysis oil was directed to hydrotreating at 180°C to 350°C, with 35200Nm 3 / h of hydrogen is equivalent to the theoretical hydrogen consumption of 5200Nm for complete hydrogenation 3 / h is about 7 times, and the hydrogen / oil ratio is 560Nm 3 / m 3 In a simplified manner, this process corresponds to Figure 1 and Example 1, but in practice additional equipment is required to optimize thermal efficiency, ensure good contact between hydrogen and oil, as a large amount of gas is not dissolved in the oil, and optimize hydrogen consumption by providing a gas recirculation loop, which includes a recirculation line and compressor and multiple reactors to allow for different temperatures and pressures. Since a certain amount of hydrogen is extracted during the purge, even if the excess hydrogen is recovered, 5850Nm 3 / hour of supplemental hydrogen.

[0103] Comparing these three examples, it can be seen that the additional hydrogen required is increased from 77.5 Nm in Example 2 to 3 / h to 5850Nm in Example 3 3 The relative amount of hydrogen extracted as exhaust gas in Example 3 is lower because recirculation reduces this amount, but the higher absolute level also results in a higher amount of hydrogen extracted as exhaust gas.

[0104] In all three embodiments, a certain amount of waste gas is extracted, which can advantageously be directed to a hydrogen production plant in order to produce hydrogen with minimal resource requirements.

[0105] Table 1

[0106]

[0107] Table 2

[0108]

[0109] Table 3

[0110]

Claims

1. A method for producing a stabilized hydrocarbonaceous product from a solid feedstock, the method comprising the following steps: (a) providing a solid raw material for thermal decomposition, (b) directing the solid feedstock for thermal decomposition to a thermal decomposition process to provide a thermally decomposed fluid product and a solid phase, (c) directing at least an amount of said fluid product of thermal decomposition as a crude liquid feedstock and an amount of hydrogen to a catalytic process to contact a material having catalytic activity in hydrogenation of carbon-carbon bonds of conjugated dienes under active conditions for hydrogenation of carbon-carbon bonds of conjugated dienes, thereby providing said stabilized hydrocarbonaceous product, wherein said catalytic process may have several catalytically distinct steps and wherein the crude liquid feedstock and hydrogen are added together or independently at one or more locations, (d) and, optionally after removing the aqueous phase or other impurities, withdrawing the stabilized hydrocarbonaceous product for transportation or storage, The invention is characterized in that the ratio of the total amount of hydrogen added to the amount of the crude liquid raw material is 1Nm 3 / m 3 Up to 100Nm 3 / m 3 .

2. The method according to claim 1, wherein the ratio of the total amount of hydrogen added to the amount of the crude liquid feedstock is 1, 2, 5 or 10 Nm 3 / m 3 Up to 20Nm 3 / m 3 or 50Nm 3 / m 3 .

3. A process according to claim 1 or 2, wherein the solid feedstock comprises at least 50% waste polymer.

4. The method according to claim 1, 2 or 3, further comprising separating the fluid product of the thermal decomposition into at least a polar liquid phase and a non-polar liquid phase.

5. The method according to claim 1, 2, 3 or 4, characterized in that: Active conditions for hydrogenation involve pressures ranging from 0.5 MPa to 35 MPa.

6. The method according to claim 1, 2, 3, 4 or 5, characterized in that: Active conditions for the hydrogenation involve inlet temperatures of 80 to 210°C.

7. The method according to claim 1, 2, 3, 4, 5 or 6, characterized in that: The material having catalytic activity in hydrogenation includes at least one of Ni, Co, Mo, W and Pd.

8. The method according to claim 1, 2, 3, 4, 5, 6 or 7, characterized in that The hydrogen is provided at least in part by reaction of a quantity of the fluid product of the thermal decomposition, optionally using electrical heating.

9. The method according to claim 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that The hydrogen is produced at least in part by electrolysis, optionally using electricity generated from excess process heat or renewable energy sources such as solar, wind or wave power.

10. The process of claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the thermal decomposition product is cooled to a temperature of 20°C to 150°C, 180°C or 230°C prior to contact with the material having catalytic activity in the hydrotreatment.

11. The process of claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, wherein the amount of solid feedstock is at least 10 tons / day or 50 tons / day and less than 2000 tons / day, less than 1000 tons / day or less than 500 tons / day.

12. The process of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the stabilized hydrocarbonaceous product is transferred to a transport vehicle such as a tank truck or a pipeline and transported to an upgrading facility for upgrading to hydrocarbon products.

13. A process plant for carrying out the method according to any one of the preceding claims.

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