Method for stabilizing unstable crude hydrocarbonaceous products

Abstract

A first aspect of the present invention is a method for producing a stabilized hydrocarbon product from a solid feedstock, the method comprising: providing a solid feedstock for pyrolysis; guiding the solid feedstock for pyrolysis into a pyrolysis process to provide a fluid product and a solid phase of pyrolysis; introducing, as a crude feedstock, at least an amount of the fluid product of pyrolysis and an amount of hydrogen, and contacting the crude feedstock with a catalytically active material in hydrogenation of conjugated diolefin carbon-carbon bonds under conditions active for hydrogenation of conjugated diolefin carbon-carbon bonds. In the production method, the ratio between hydrogen and the crude feedstock is 1 Nm 3 / m 3 ~100 Nm 3 / m 3 characterized in that it relates to the production method. This has the associated advantage that such a method requires only a small amount of hydrogen while providing a stabilized hydrocarbon product for transportation.

Description

Technical Field

[0001] The pyrolysis of solid feedstocks, such as mixed municipal waste, mixed or sorted plastic waste and forestry waste, can be upgraded to high-quality hydrocarbons and provides liquid products (for the sake of simplicity, pyrolysis oil or crude pyrolysis oil) that can be used as transport fuels or petrochemical feedstocks.

Background Art

[0002] Pyrolysis is a process of medium complexity and can be carried out in a plant that converts a medium amount of solid feedstock. Since the transport of solid feedstock is quite costly in this regard, pyrolysis in a medium-sized decentralized plant can be convenient, but the requirements for processing the product, i.e., pyrolysis oil, according to current trading standards require extensive processing that is not suitable for small-scale operation.

[0003] Crude pyrolysis oil - the direct liquid product of most pyrolysis processes - is very unstable and shows a high tendency to solidify (e.g., by polymerization), and thus upgrading is usually preferably carried out in the same plant as the pyrolysis. However, since the upgrading process requires the provision of process support including utilities such as hydrogen and steam, it is beneficially carried out in a large-scale hydroprocessing plant.

Summary of the Invention

[0004] To overcome these conflicting requirements, we propose an overall process that includes the decentralized stabilization of crude pyrolysis oil, the transport of the stabilized pyrolysis oil to a central upgrading hydroprocessing plant (including a cost-effective process for the decentralized production of such stabilized pyrolysis oil).

[0005] Definition It will be understood that the pressures cited are gauge pressures, i.e., pressures above ambient.

[0006] As is well known in the art, the term "continuous operation" means that during a given manufacturing cycle, feedstock is provided and the product is removed without interruption. This is in contrast to batch operation, also well known in the art, where the entire amount of liquid oil and catalyst is introduced at the start of the process and the resulting product is removed after a certain period of time, i.e., discontinuous operation.

[0007] Unit Nm 3 is understood to mean "normal" m 3 , i.e., the amount of gas taken up at this volume at 0 °C and 1 atmosphere.

[0008] As used herein, the term "hydrogen to liquid oil ratio" or "H2 / oil ratio" means the volume ratio of hydrogen to the flow rate of the liquid oil stream, reported as Nm 3 / m 3 where the gas phase is reported at standard conditions and the liquid phase is reported at standard state (25 °C and 1 atmosphere).

[0009] When concentrations are given in weight % (wt%), this is understood as weight / weight %.

[0010] As used herein, the term "thermal decomposition" is used broadly for any decomposition process where, for convenience, a solid material is partially decomposed at elevated temperatures (typically from 250 °C to 800 °C or even up to 1000 °C) in the presence of less than stoichiometric amounts of O2 (excluding added oxygen). The products are typically a combined liquid and gaseous stream, as well as some amount of solid char. The term should be interpreted to include processes known as pyrolysis and hydrothermal liquefaction, both in the presence and absence of a catalyst. For convenience, the products of such thermal decomposition processes may be referred to as pyrolysis oil, but it should be understood to cover any thermal decomposition process.

[0011] As used herein, the term "section" means a physical section that includes a unit or combination of units for performing one or more steps and / or sub-steps.

[0012] The term polymer source or feedstock for waste polymers can be understood to include sorted mixed waste containing at least 50 wt%, at least 80 wt% or at least 90 wt% of plastics and other artificial polymers.

[0013] Feedstocks of biological origin can be defined by tracing their origin, but 14 it can also be defined by the C content exceeding 0.5 parts per trillion of the total carbon content.

[0014] When referring to hydrogen and hydrogen concentration, this is generally understood as molecular elemental hydrogen, unless it is suggested that hydrogen is part of other molecules.

[0015] When referring to the oxygen content, this is generally understood as atomic oxygen as part of other molecules, unless O2 is referred to.

[0016] Technical problem For example, the cost-effective operation of a plant for the pyrolysis of plastic waste generally produces a crude pyrolysis oil product that is not suitable for transportation because the crude pyrolysis oil product is highly reactive, especially in the presence of moderately elevated temperatures and / or O2, and is likely to solidify during transportation. Processes for the conversion and stabilization of such reactive materials typically require large amounts of hydrogen consumption and a number of process steps and thus enjoy the advantages of large-scale operation, which does not match the fact that such process plants are generally preferably local plants in order to minimize the transportation of solid feedstock to the plant. Therefore, it is desirable to establish a process for decentralized stabilization and thus find a stabilization process suitable for such intermediate products on a small scale and to facilitate their production and storage.

[0017] Solution to the problem Typically, the composition of the oil derived from the pyrolysis of artificial polymers can contain 0.5 to 5 wt% conjugated diolefins and 30 to 90 wt%, for example 65 wt% of olefins. The atomic oxygen content can typically be less than 1 wt%, but when the solid feedstock contains a large amount of organic material, such as in household mixed waste, the atomic oxygen content can be as high as 50 wt%.

[0018] According to the present invention, crude products of thermochemical decomposition, such as pyrolysis oil, are stabilized at low pressure and moderate temperature with minimal hydrogen consumption, at least by the conversion of the most reactive compounds in the pyrolysis oil. For raw materials of polymer origin, such as waste plastics, the crude pyrolysis products often contain hydrocarbon molecules having a conjugated diolefin structure, i.e., hydrocarbon molecules in which two double bonds or aromatic bonds between carbon atoms are separated by single bonds, including vinyl-aromatic and styrene-type structures. These conjugated diolefins can polymerize while forming larger molecules, especially at temperatures above 50 °C and / or in the presence of O2, and they may not be liquid under the conditions used during storage, transportation or processing. In particular, low molecular weight diolefins are prone to such polymerization because the conjugated double bonds near the ends of the molecules are more reactive.

[0019] Similar problems exist for materials of biological origin, where carbonyl-containing oxygenated substances, such as furfural, furan, aldehydes, ketones and acids, are compounds that can polymerize, and generally, pyrolysis oil can contain both compounds having a diolefin structure and carbonyl oxygen.

[0020] To stabilize these reactive compounds at a reasonable cost, we have found that we can provide a limited amount of hydrogen that is only slightly in excess with respect to the hydrogenation of the most reactive groups. The amount of hydrogen provided may, in some cases, only consider the conjugated diolefins that can be present in an amount of 0.5 to 5 wt% for oils derived from the thermal decomposition of synthetic polymers, and we propose to limit the conditions (temperature and pressure) so that only the reactive groups are converted and accordingly the amount of hydrogen can also be limited. As an example, the hydrogen to liquid oil can 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 advantage that the reactor and process lines do not need to be designed for the contact of gas and liquid in a two-phase flow.

[0021] The conversion of plastic waste, biomass, and municipal waste into liquid products by thermochemical decomposition, such as pyrolysis and hydrothermal liquefaction, especially with subsequent hydrogenation treatment, is considered to be an environmentally friendly source for alternatives to petroleum products, particularly from the perspective of global warming. Due to the nature of these liquid products (for the sake of simplicity, pyrolysis oil regardless of the original process), they need to be upgraded by hydrogenation treatment to remove heteroatoms such as sulfur and oxygen and to hydrogenate olefin structures. The said properties of the formations mean that the products are not stabilized and, thus, unlike typical fossil raw materials, they are very reactive, require a large amount of hydrogen, release a considerable amount of heat during the reaction, and further have a high polymerization tendency. The release of heat can further increase polymerization, and at elevated temperatures, the catalyst can also be deactivated by coking.

[0022] The thermochemical decomposition process plant section for providing a hydrocarbonaceous feedstock according to the present disclosure may be in many forms, including rotary kilns, fluidized beds, transported beds or circulating fluidized beds, as well known in the art. This decomposition converts the pyrolysis feedstock into solids (char), high-boiling liquids (tar) and a gaseous fraction at elevated temperatures. The gaseous fraction includes a fraction condensable at standard temperature (pyrolysis oil or condensate, C5+ compounds) and a non-condensable fraction (pyrolysis gas including pyrolysis offgas). For example, the thermochemical decomposition process plant section (pyrolysis section) can include a pyrolyzer unit (pyrolysis reactor), cyclone(s) and / or filter to remove particulate solids, e.g., char, and a cooling unit to produce therefrom a pyrolysis offgas stream and said pyrolysis oil stream, i.e., condensed pyrolysis oil. The pyrolysis gas stream includes light hydrocarbons, e.g., C1-C4 hydrocarbons, and also typically H2O, CO and CO2. Typically, the term pyrolysis oil includes condensate and tar, and the pyrolysis oil stream from the pyrolysis of biomass can also be referred to as bio-oil or biocrude. Pyrolysis oil is generally a liquid material rich in a blend of molecules consisting of more than 200 different compounds, mainly oxygenated substances such as acids, sugars, alcohols, phenols, guaiacols, syringols, aldehydes, ketones, furans, and other mixed oxygenated substances resulting from the depolymerization of the solids treated in pyrolysis. The thermochemical decomposition of non-biological waste, including used tires, containing a suitable composition such as plastic parts or rubber generally provides only products with a low oxygen content, generally providing a hydrocarbonaceous feedstock having a structure reflecting the solid pyrolysis feedstock, unless O2 is added to the decomposition process.

[0023] For the purposes of the present invention, the pyrolysis section may be a rapid pyrolysis, also known as flash pyrolysis in the art. Rapid pyrolysis typically means the thermochemical decomposition of a solid feedstock at a temperature in the range of 350 to 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, typically in the absence of O2. Rapid pyrolysis can be carried out, for example, by autothermal operation, for example in a fluidized bed reactor. The latter is also called autothermal pyrolysis and is characterized by using air (optionally together with an inert gas or recycle gas) as the fluidizing gas. Thereby, the partial oxidation of the pyrolysis compounds generated in the pyrolysis reactor (autothermal reactor) provides energy for pyrolysis while simultaneously improving heat transfer. In so-called catalytic rapid pyrolysis, a catalyst can be used. To upgrade the pyrolysis vapor, an acid catalyst generally containing zeolite and not containing an active metal can be used, which can be operated in both in-situ mode (the catalyst is located in the pyrolysis reactor) and ex-situ mode (the catalyst is placed in a separate reactor). The use of the catalyst helps to stabilize the pyrolysis oil, thereby bringing the advantage of making hydroprocessing easier. In addition, it is possible to achieve an increased selectivity towards the desired pyrolysis oil compounds.

[0024] In some cases, hydrogen is added to the catalytic pyrolysis, which is then called reactive catalytic rapid pyrolysis in that case. When the catalytic pyrolysis is carried out at a high hydrogen pressure, for example above 0.5 MPa, it is often called catalytic hydro-pyrolysis. The catalyst for upgrading in the presence of hydrogen typically contains one or more metals active in hydrogenation, for example metals from Group 6 or Groups 8, 9 or 10.

[0025] The pyrolysis stage can be a rapid pyrolysis carried out without the presence of a catalyst and hydrogen, i.e., the rapid pyrolysis stage is not catalytic fast pyrolysis, hydro-pyrolysis or catalytic hydro-pyrolysis. This enables a much simpler and cheaper process.

[0026] In one embodiment, the thermal decomposition is hydrothermal liquefaction. Hydrothermal liquefaction means the thermochemical conversion of a solid feedstock, such as solid waste, biomass, municipal solid waste or sewage sludge, into a liquid fuel by treatment in a high-temperature pressurized water environment for a time sufficient to decompose the solid biopolymer structure mainly into liquid components. Typical hydrothermal treatment conditions are temperatures in the range of 200 - 500 °C, particularly 300 - 450 °C, and operating pressures in the range of 4 - 40 MPa, particularly 25 - 35 MPa. This technology offers the operating advantages of lower temperature, higher energy efficiency and lower tar yield compared to pyrolysis, such as rapid pyrolysis.

[0027] In one embodiment, the thermal decomposition further includes passing the solid feedstock through a solid feedstock preparation section including, for example, drying to remove water and / or grinding to reduce the particle size. Water / moisture in the solid feedstock that vaporizes (e.g., in the pyrolysis section) condenses in the pyrolysis oil stream and is thereby removed from the process, which may be undesirable. Further, the heat used for the vaporization of water takes away the heat required for pyrolysis in another situation. By removing water and providing a smaller particle size in the solid feedstock, the thermal efficiency of the pyrolysis section is increased.

[0028] Finally, other related thermochemical decomposition methods are intermediate or slow pyrolysis with lower temperatures and generally higher residence times, and these methods may also be known as carbonization or torrefaction. The main advantage of these thermochemical decomposition methods is lower investment, but they may also have specific advantages with respect to certain feedstocks or certain product requirements, such as the need for biochar as a related product.

[0029] When a large amount of solid product is produced, for example in the process of producing biochar, or when it is desirable to recover unconverted carbon black particles from the thermochemical conversion of used tires, it may be beneficial to filter the liquid product as part of the thermochemical conversion process, which also has the advantage of minimizing the deactivation of downstream catalysts.

[0030] The hydrotreating of reactive compounds is exothermic depending on the chemistry of the process. This causes a temperature rise as long as the temperature is sufficient for the ignition of the hydrogenation of the most reactive compounds, ensuring further reaction of other compounds, but by limiting the availability of hydrogen, the temperature rise means that the hydrocarbons do not proceed to the level where they are converted to solid carbon deposits and deactivate the catalyst.

[0031] As described above, the reactivity of larger molecules is generally lower than that of smaller molecules. Therefore, sufficient stabilization for transport while minimizing the local process volume and hydrogen consumption can only be achieved by leading to the lightest and least stable fractions of the pyrolysis products for stabilization. In practice, such fractionation can be carried out by fractionating products with a wide boiling range in a fractionator or by condensing the high-boiling fraction, for example at 250 °C, while the less stable lower-boiling fractions are either hydrotreated in the vapor state or condensed before being hydrotreated.

[0032] Accordingly, we propose a method for hydrotreating a liquid oil stream by reacting the liquid oil stream with hydrogen in the presence of a hydrotreating catalyst having moderate sulfur tolerance during continuous operation. This catalyst may typically be a sulfided catalyst containing one or more of nickel, cobalt, molybdenum and tungsten that operates at an inlet temperature of 130-200 °C, or alternatively may be a metal catalyst containing one or more of nickel, palladium and platinum that typically operates at an inlet temperature of 80-130 °C. In most cases, the pressure can be 0.5-2 MPa, but may be up to 35 MPa, and the liquid hourly space velocity (LHSV) can be 0.1-5 h -1 -1, and these conditions enable the formation of a stabilized liquid oil stream.

[0033] The process is moderately exothermic, and thus a temperature rise of 5-20 °C typically occurs.

[0034] According to the present invention, a continuous operation process is used because, in contrast to batch operation, the resulting product (the stabilized liquid oil) does not depend on always being a fluid. The method can be carried out, inter alia, in a fixed bed reactor, a slurry bed reactor, a trickle bed reactor and a fluidized bed reactor.

[0035] The supply of hydrogen for hydroprocessing is a significant cost, and the reduction of requirements for hydrogen can be a driver for cost reduction. In hydroprocessing, a certain amount of hydrogen is consumed per volume of oil, which is called the H2:oil consumption ratio. Depending on the properties of the crude product, for complete hydroprocessing, the H2:oil consumption ratio can be 50 Nm 3 / m 3 3 - 1000 Nm 3 / m 3 3. However, to minimize the risk of coke deposition on the catalyst, it is common to operate with a safety factor of 2, 4 or even 8, and as a result, an H2:oil consumption ratio of 200 Nm 3 / m 3 3 is used for an H2:oil consumption ratio of 1000 Nm 3 / m3 up to H2: operation with oil results in a gas:oil ratio of 500 Nm 3 / m 3 when the purity of the H2-rich gas during the process is only 80% by volume. Such an excess of gas will of course make the equipment size larger, and the excess H2 also increases the reactivity, so that the actual H2 consumption becomes higher just for availability.

[0036] When the hydrogen level rises in this way, it becomes economically appropriate to recycle the gas, and the related costs in terms of equipment (such as recycle gas compressors) and process size give rise to requirements for an increase in the processing volume.

[0037] The requirements for a large excess of H2 are mainly appropriate at elevated temperatures, similar to complete hydrogenation. Therefore, we propose to limit H2 to less than the amount required for complete hydrogenation. Because this will protect the process from thermal runaway, while at the same time limiting hydrogen consumption, resulting in the elimination of recycling and recycle compressors, leading to a reduction in operating costs, a reduction in process volume, and a reduction in capital investment.

[0038] In one embodiment, the catalyst is in a sulfided form, such as NiMoS or CoMoS. The catalyst may be pre-sulfided by exposure to a sulfur-containing stream, or may be sulfided in-situ, i.e., during operation, by sulfur present, for example, in pyrolysis oil, so that the sulfided catalyst is in a sulfided state and thus in an active state due to the presence of sulfur.

[0039] The method can further comprise passing the stabilized pyrolysis oil stream through yet another hydrotreating step 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 (optionally, after transportation to a central site where the stabilized pyrolysis oil can be further processed). Further processing can include hydrodewaxing, hydrocracking, or isomerization, as is well known in the art of petroleum refining.

[0040] Particularly, catalytically active materials in the initial hydrotreating, such as hydrogenation, typically include active metals (base metal sulfides such as nickel, cobalt, tungsten, and / or molybdenum, but also optionally both noble metals such as elemental nickel and platinum and / or palladium) and heat-resistant supports (such as alumina, silica, or titania, or combinations thereof). Initial hydrotreating conditions can include 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. Under certain conditions, elevated pressures up to 35 MPa may be required.

[0041] Final hydrogenation, such as hydrogenation conditions, generally include 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, which may optionally involve intermediate cooling by quenching with cold hydrogen, feedstock, or product.

[0042] Catalytically active materials in isomerization typically include active metals (either elemental noble metals such as platinum and / or palladium or base metal sulfides such as nickel, cobalt, tungsten, and / or molybdenum), acidic supports (typically molecular sieves having topologies such as MOR, FER, MRE, MWW, AEL, TON, and MTT, which exhibit high shape selectivity), and heat-resistant supports (such as alumina, silica, or titania, or combinations thereof).

[0043] The isomerization conditions include a temperature in the range of 250 to 400 °C, a pressure in the range of 2 to 10 MPa, and a liquid hourly space velocity (LHSV) in the range of 0.5 to 8.

[0044] The catalytically active material in hydrocracking has properties similar to those of the catalytically active material in isomerization, which typically includes an active metal (either a noble metal element such as platinum and / or palladium, or a base metal sulfide such as nickel, cobalt, tungsten and / or molybdenum), an acidic support (typically a molecular sieve having a topology such as MFI, BEA and FAU, showing high cracking activity), and a heat-resistant support (such as alumina, silica or titania, or a combination thereof). The difference from the catalytically active material in isomerization is typically the nature of the acidic support, which may have a different structure (even amorphous silica-alumina) or a different acidity (e.g., due to the silica:alumina ratio).

[0045] The hydrocracking conditions include a temperature in the range of 250 to 400 °C, a pressure in the range of 3 to 20 MPa, and a liquid hourly space velocity (LHSV) in the range of 0.5 to 8, which may optionally involve intermediate cooling by quenching with low-temperature hydrogen, feedstock or product.

[0046] Other types of hydrotreating, such as hydrodearomatization (HDA), are also conceivable. The catalytically active material in hydrodearomatization typically includes an active metal (typically a noble metal element such as platinum and / or palladium, but optionally also a base metal sulfide such as nickel, cobalt, tungsten and / or molybdenum), and a heat-resistant support (such as amorphous silica-alumina, alumina, silica or titania, or a combination thereof).

[0047] The conditions for hydrodearomatization include a temperature in the range of 200 to 350 °C, a pressure in the range of 2 to 10 MPa, and a liquid hourly space velocity (LHSV) in the range of 0.5 to 8.

[0048] Any embodiments and related benefits of the first aspect of the present invention can be used with the second aspect of the present invention, and vice versa.

[0049] Advantageous effects of the invention A first aspect of the present invention is a method for producing a stabilized hydrocarbonaceous product from a solid feedstock, the method comprising: providing a solid feedstock for pyrolysis; guiding the solid feedstock for pyrolysis into a pyrolysis process to provide a fluid product and a solid phase of pyrolysis; introducing at least an amount of the fluid product of pyrolysis and an amount of hydrogen as a crude liquid feedstock into a catalytic process, and contacting the fluid product with a catalytically active material under conditions active for hydrogenation of conjugated diolefin carbon-carbon bonds to provide the stabilized hydrocarbonaceous product, wherein the catalytic process may have several catalytically distinct steps, the crude liquid feedstock and hydrogen being added together or independently at one or more locations, and optionally removing the stabilized hydrocarbonaceous product after removal of an aqueous phase or other impurities and taking it out for transportation or storage. In the production method, the ratio of the total amount of hydrogen added to the amount of the crude liquid feedstock is from 1 Nm 3 / m 3 to 100 Nm 3 / m 3 and up to, characterized in that, related to the production method.

[0050] This has the related advantage that such a method requires only a small amount of hydrogen while providing a stabilized hydrocarbon product for transportation or storage.

[0051] A second aspect of the present invention is that 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 to 20 Nm 3 / m 3 or 50 Nm 3 / m 3Relates to a method according to the first aspect, characterized in that it is up to

[0052] This has the associated advantage that such an amount of hydrogen corresponds to the amount of reactive compounds in the fluid product of the pyrolysis.

[0053] The third aspect of the invention relates to a method according to the first or second aspect, characterized in that the solid feedstock comprises at least 50% waste polymer.

[0054] This has the associated advantage that such a method is very suitable for the treatment of waste polymer feedstocks for the use of stabilized products in steam crackers (optionally after further treatment).

[0055] The fourth aspect of the invention relates to a method according to the first or second aspect, further comprising separating the fluid product of the pyrolysis into at least a polar liquid phase and a non-polar liquid phase.

[0056] This has the associated advantage that it provides a method suitable for handling feedstocks with a high oxygen content that is converted to water, for example feedstocks containing a large amount of feedstocks of biological origin.

[0057] The fifth aspect of the invention relates to a method according to the first, second, third or fourth aspect, characterized in that the active hydrogenation conditions include a pressure that is ambient pressure or from 0.5 MPa to 10 MPa, 20 MPa or 35 MPa.

[0058] This has the associated advantage that since the pressure does not limit the hydrogen solubility, it reduces the cost of the apparatus without adversely affecting the performance.

[0059] The sixth aspect of the invention relates to a method according to the first, second, third, fourth or fifth aspect, characterized in that the active hydrogenation conditions include an inlet temperature of 80 to 210 °C.

[0060] This has the associated advantage of providing a sufficient temperature for ignition of the process while maintaining a low temperature such that only the most reactive compounds are converted.

[0061] A seventh aspect of the invention relates to a method according to the first, second, third, fourth, fifth or sixth aspect, in which the catalytically active material in the hydrogenation comprises at least one of Ni, Co, Mo, W and Pd.

[0062] An eighth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth or seventh aspect, in which the hydrogen is provided, at least in part, by a reaction of a quantity of the fluid product of the pyrolysis product stream, optionally using electrical heating.

[0063] This has the associated advantage of converting waste gas from the pyrolysis stream to process hydrogen with minimal CO2 emissions, particularly when the electricity is from excess process heat or from a renewable energy source such as solar energy, wind energy or wave energy.

[0064] A ninth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect, in which the hydrogen is produced, at least in part, by electrolysis, optionally using electricity generated from excess process heat or from a renewable energy source such as solar energy, wind energy or wave energy.

[0065] This has the associated advantage of converting waste gas from the pyrolysis stream to process hydrogen with minimal CO2 emissions.

[0066] A tenth aspect of the invention relates to a method according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect, in which the pyrolysis product is cooled to a temperature between 20 °C and 150 °C, 180 °C or 230 °C before being contacted with the catalytically active material in the hydrogenation treatment.

[0067] This has the associated advantage of avoiding solidification by polymerization.

[0068] 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 the solid feedstock is at least 10 tons / day or at least 50 tons / day and less than 2000 tons / day, less than 1000 tons / day or less than 500 tons / day.

[0069] This has the associated advantage that a process of such a size is well - suited for decentralized stabilization but is too small for optimal operation with full conversion.

[0070] 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 means of transportation, such as a tank or a pipeline, and transported to an upgrading facility for upgrading to a final hydrocarbon product.

[0071] This has the associated advantage that such a method is very suitable for the centralized finalization of processing for the purpose of generating hydrocarbon products for use in steam cracking or as part of transportation fuels.

[0072] A further aspect relates to a process plant comprising means for implementing any of the above aspects, wherein the means are correspondingly configured. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] FIG. 1 shows a thermochemical decomposition process in which all liquid hydrocarbon products are stabilized by hydrotreating.

[0074] FIG. 2 shows a thermochemical decomposition process in which only light hydrocarbon products are stabilized by hydrotreating.

[0075] Figure 1 In Figure 1, a solid feedstock (102) is introduced into a thermochemical decomposition reactor (PYR). The thermochemical decomposition produces three streams: a hot gas stream (104), solid char (106) and liquid pyrolysis oil (108). The thermochemical decomposition process may have internal recycle or additional inlets, such as gas, water and solvent, which are not shown in Figure 1.

[0076] The full range pyrolysis oil (108) is combined with a moderate amount of hydrogen (114) and is heated, optionally by heating a single stream or by heating the combined crude feedstock stream (116). The crude feedstock stream is introduced into a hydrotreating reactor (HYD) at a moderate temperature, such as 150 °C, and a moderate pressure, such as 2 MPa, to contact a catalytically active material in the hydrotreating. This hydrotreating reactor (HYD) is shown separately but may be integrated within the thermochemical decomposition reactor (PYR).

[0077] The product stream (118) is typically introduced into a gas-liquid product separator (SEP) to separate the light gas (120) from the stabilized hydrocarbon product (124). If the crude product contains oxygen, this product separator may be a ternary separator since the liquid contains a hydrocarbon phase and an aqueous phase. In the figure, the separator (SEP) is a reboiling stripper and has the advantage of driving off dissolved hydrogen and other gases from the product.

[0078] The stabilized hydrocarbon phase is stable enough for transport and storage but not of sufficient quality for use as a transport fuel or as a feedstock for chemical processes such as steam cracking.

[0079] If the process contains significantly excessive hydrogen, it is economically reasonable to recover this hydrogen by gas recycling (although such a recycling circuit involves capital costs and operating costs). If the excess of hydrogen is small, the gas may be led to thermochemical decomposition for use as a heat source.

[0080] Figure 2 In Figure 2, the solid feedstock (202) is led to the 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 recycling or additional inlets, such as gas, water, and solvents, although these are not shown in Figure 2.

[0081] In this figure, the pyrolysis oil (208) is separated into a light-region pyrolysis oil (210) and a heavy-region pyrolysis oil (212). Although it is shown that the separation is carried out in a separator, a process for the condensation of the pyrolysis oil can also be used for a similar separation.

[0082] The light-region pyrolysis oil (210) is combined with a moderate amount of hydrogen (214) and is heated, optionally, by heating a single stream or by heating the combined crude feedstock stream (216). The crude feedstock stream is led to a hydrotreating reactor (HYD) to contact a catalytically active material in the hydrotreating at a moderate temperature, such as 150 °C, and a moderate pressure, such as 2 MPa. This hydrotreating reactor (HYD) is shown separately but may be integrated into the thermochemical decomposition reactor (PYR).

[0083] The product stream (218) is typically directed to a vapor-liquid product separator (SEP) to separate the light gas (220) from the stabilized light product (222). If the crude product contains oxygen, since the liquid contains a hydrocarbon phase and an aqueous phase, this product separator may be a ternary separator. In the figure, the separator (SEP) is a reboiling stripper, which has the advantage of driving off dissolved hydrogen and other gases from the product.

[0084] The stabilized light product (222) is combined with the regional pyrolysis oil (212) to form a stabilized hydrocarbon product (224), which is sufficiently stable for transportation and storage but not of sufficient quality for use as a transportation fuel or as a feedstock for chemical processes such as steam cracking.

[0085] Figure 3 Figure 3 shows a very simplified layout for quantitative hydrogen addition according to the prior art. Although the layout is shown similarly to Figure 1, in reality, an increase in hydrogen flow rate, elevated temperature, and elevated pressure would cause a larger apparatus and the need for numerous modifications.

[0086] As in Figure 1, a 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 recycle or additional inlets, such as gas, water, and solvent, but these are not shown in Figure 3.

[0087] The full-range pyrolysis oil (308) is combined with an amount of hydrogen (314) and is heated, optionally, by heating a single stream or by heating the combined crude feed stream (316). Since the aim is the complete hydrogenation of the pyrolysis oil (308), the amount of hydrogen introduced into the process must match the total amount chemically required, and furthermore, as a safety measure, an excess amount must be provided to minimize the risk of coke formation on the catalyst. The crude feed stream (316) is introduced into a hydrotreating reactor (HYD) to contact a catalytically active material in the hydrotreating at a moderate temperature, for example 150 °C, and the temperature is further increased downstream, by heat release in the process and possibly also by external heating, to, for example, 350 °C. The pressure is preferably increased to, for example, 20 MPa. Here, a single hydrotreating reactor (HYD) is shown separately, but generally, several reactors are required and the first reactor may be integrated into the thermochemical decomposition reactor (PYR).

[0088] The product stream (318) is typically introduced into a gas-liquid product separator (SEP) to separate the light gas (320) from the stabilized hydrocarbon product (324), and if the crude product contains oxygen, this product separator may be a ternary separator since the liquid contains a hydrocarbon phase and an aqueous phase. In the figure, the separator (SEP) is a reboiling stripper and has the advantage of driving off dissolved hydrogen and other gases from the product.

[0089] The stabilized hydrocarbon phase is highly stable and useful as a transport fuel or as a feedstock for chemical processes such as steam cracking.

[0090] Since the process contains significantly excessive hydrogen, it is economically reasonable to recover this hydrogen by gas recycling (although such a recycling circuit involves capital costs and operating costs). Therefore, the light gas (320) is pressurized by a recycling compressor (CMP) and guided to be combined with hydrogen (314). Generally, this light gas stream is purified by appropriate means (not shown).

Example

[0091] Example To illustrate the present invention, three examples were compared. Tables 1, 2, and 3 show the boiling point curves and the contents of conjugated diolefins and olefins in a process for treating 1200 t / day (50 t / hour) of the products of hydrothermal liquefaction of plastic waste (treated by gentle hydrogenation according to one of FIGS. 1 or 2). Due to the presence of diolefins, the feedstock has a tendency to polymerize and solidify during transportation, especially when heated above 50°C.

[0092] In Example 1 according to FIG. 1 (reported in Table 1), the full-range pyrolysis oil is led to a gentle hydrogenation treatment at 150°C using an amount of hydrogen corresponding to twice the theoretical hydrogen consumption for diolefin saturation (this is an amount that can be dissolved 99% in the said oil), which ensures good contact and avoids the practical problem of a large gas flow rate. This corresponds to a hydrogen-to-oil ratio of 4 Nm 3 / m 3 . The amount of conjugated diolefin decreases from 1.9 wt% to 0.095 wt%, which results in a stable product for transportation.

[0093] In Example 2 according to FIG. 2 (reported in Table 2), only the naphtha-range pyrolysis oil is led to a gentle hydrogenation treatment at 150°C using an amount of hydrogen corresponding to twice the theoretical hydrogen consumption for diolefin saturation (this is also substantially dissolved in the said oil in this example). This is 4 Nm in the stream for hydrogenation treatment 3 / m 3corresponds to the hydrogen-to-oil ratio. The amount of conjugated diolefin only decreases from 1.9 wt% to 1.35 wt%, but the most reactive small conjugated diolefin decreases by 95%. Therefore, the product is sufficiently stable for transportation.

[0094] In Example 3 according to Figure 3 (reported in Table 3), the total range pyrolysis oil corresponds to about 7 times the theoretical hydrogen consumption of 5200 Nm 3 / h, i.e., 35200 Nm 3 / h of hydrogen is used (corresponding to a hydrogen-to-oil ratio of 560 Nm 3 / m 3 ), and it is led to hydrotreating at 180 °C to 350 °C. In a simplified manner, this process corresponds to Figure 1 and Example 1. However, in reality, since a significant amount of gas does not dissolve in the oil, in order to optimize the thermal efficiency and ensure good contact between hydrogen and oil, additional equipment is required, such as a gas recycle circuit including a recycle line and a compressor, and a number of reactors enabling various temperatures and pressures to optimize the hydrogen consumption. Although excess hydrogen is recycled, a certain amount of hydrogen is taken out by purge, so makeup hydrogen of 5850 Nm 3 / hr is required.

[0095] Comparing the three examples, it is shown that the required addition of makeup hydrogen varies from 77.5 Nm 3 / hr in Example 2 to 5850 Nm 3 / hr in Example 3. The relative amount of hydrogen taken out as offgas is lower in Example 3 because recycling reduces it, but the higher absolute level also makes the amount of hydrogen taken out as offgas larger.

[0096] In all three examples, a certain amount of offgas is taken out. This offgas is preferably led to a hydrogen plant to produce hydrogen while minimizing the need for resources.

[0097]

Table 1

[0098]

Table 2

[0099]

Table 3

Claims

1. A method for producing a stabilized hydrocarbonaceous product from a solid feedstock, comprising the following steps: (a) providing a solid feedstock for pyrolysis; (b) introducing the solid feedstock for pyrolysis into a pyrolysis process to provide a fluid product and a solid phase of pyrolysis; (c) introducing at least an amount of the fluid product of the pyrolysis and an amount of hydrogen as a crude liquid feedstock into a catalytic process and contacting with a catalytically active material under conditions active for hydrogenation of conjugated diolefin carbon-carbon bonds to provide the stabilized hydrocarbonaceous product, wherein the catalytic process may have several catalytically distinct steps and the crude liquid feedstock and hydrogen are added together or independently at one or more positions; (d) and optionally removing the aqueous phase or other impurities, taking out the stabilized hydrocarbonaceous product for transportation or storage. In the manufacturing method comprising, The ratio of the total amount of hydrogen added to the amount of the crude liquid feedstock is from 1 Nm ３ / m ３ to 100 Nm ３ / m ３ up to, characterized in that, Said manufacturing method.

2. 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 to 20 Nm ３ / m ３ or 50 Nm ３ / m ３ up to, the method according to claim 1.

3. The method 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 pyrolysis into at least a polar liquid phase and a non-polar liquid phase.

5. The method according to claim 1, 2, 3 or 4, wherein the active hydrogenation conditions include a pressure of 0.5 MPa to 35 MPa.

6. The method according to claim 1, 2, 3, 4 or 5, wherein the active hydrogenation conditions include an inlet temperature of 80 to 210 °C.

7. The method according to claim 1, 2, 3, 4, 5 or 6, wherein the catalytically active material in the hydrogenation comprises at least one of Ni, Co, Mo, W and Pd.

8. The method according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the hydrogen is provided at least in part by a reaction using an amount of the fluid product of the pyrolysis, optionally with electrical heating.

9. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that the hydrogen is at least partially generated by electrolysis optionally using electricity generated from excess process heat or from a renewable energy source such as solar energy, wind energy or wave energy.

10. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8 or 9, characterized in that the pyrolysis product is cooled to a temperature between 20 °C and 150 °C, 180 °C or 230 °C before being contacted with a catalytically active material in the hydrogenation treatment.

11. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, characterized in that the amount of solid feedstock is at least 10 tons / day or at least 50 tons / day and less than 2000 tons / day, less than 1000 tons / day or less than 500 tons / day.

12. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, characterized in that the stabilized hydrocarbon product is transferred to a means of transport such as a tank or pipeline and transported to an upgrading facility for upgrading the hydrocarbon product.

13. A process plant for carrying out the method according to any one of claims 1 to 12.

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