Removal of impurities in methods for the production of hydrocarbon products

Abstract

1. A method for producing a hydrocarbon product, comprising: i) a process for producing a hydrocarbon product; i) passing a feedstock derived from renewable and / or fossil resources through a hydroprocessing step to produce a main hydrotreated stream; said hydroprocessing step comprising: passing said feedstock through one or more catalytic hydrotreating units under a supply of hydrogen to produce a first hydrotreated stream; passing said first hydrotreated stream through a first separation step comprising the use of a separation unit to remove, inter alia, the impurities H2S, CO, CO2 and HO; taking an overhead stream from said first separation step and separating an overhead hydrocarbon liquid stream therefrom and passing it as a reflux stream to said first separation unit; taking a bottoms stream from said first separation step and passing at least a portion of said bottoms stream through a dewaxing step comprising the use of one or more catalytic hydrotreating units under a supply of hydrogen to produce said main hydrotreated stream; and ii) passing the main hydrotreated stream through a second separation step to produce said hydrocarbon products.

Description

Technical Field

[0001] The present invention relates to a method for producing hydrocarbons, particularly hydrocarbons boiling above 30 ° C, such as jet fuel, from feedstocks derived from renewable resources and / or fossil resources. Preferably, the fossil resources represent a small portion thereof and are at most 30 wt% or less, for example at most 10 wt% of the feedstock. The method includes A hydroprocessing step including the use of one or more catalytic hydrogenation units and a dewaxing step passing the feedstock, provided that in a separation step prior to the dewaxing step, the content of impurities such as H2S, H2O, CO and CO2 (which can be harmful to the catalyst used in the dewaxing step) is significantly reduced.

Background Art

[0002] There is growing interest in producing jet fuel or jet fuel and diesel oil from renewable feedstocks or by co-processing with conventional fossil fuel feedstocks. In particular, when processing renewable feedstocks, in hydrotreating, the oxygen in the feedstock is mainly removed as H2O, whereby a paraffinic fuel consisting of paraffins having the same number of carbon atoms as in the basic skeleton of triglycerides is obtained. This is called the hydrodeoxygenation (HDO) pathway. Oxygen can also be removed by the decarboxylation pathway, which produces CO2 instead of H2O:

[0003]

Chemical formula

[0004] When producing hydrocarbon products, particularly jet fuel, or jet and diesel oil, the feed material is passed through a hydroprocessing step in a hydroprocessing section. This step typically includes HDO to obtain a hydrogenated stream, which is then passed through a separation step, which usually involves the use of a separation unit, such as a high-pressure stripper (HP stripper), from which an overhead stream is extracted. This overhead stream is partially condensed, and the resulting hydrocarbon liquid fraction is sent directly to a downstream dewaxing step in a dewaxing section contained within the hydroprocessing step or hydroprocessing section, where side reactions of hydrogen isomerization and, optionally, hydrocracking occur. After the dewaxing step, the hydrogenated stream is usually passed through another separation step to produce hydrocarbon products.

[0005] In the dewaxing step, precious metal catalysts are used, which are easily contaminated and thereby damaged by impurities carried over into the hydrocarbon liquid, particularly H2S. Other impurities, such as H2O, NH3, CO, and CO2, may also be present. When operating with feedstock derived from fossil fuel sources, high sulfur content is present, and therefore hydrogenation in the form of hydrodesulfurization (HDS) or hydrodenitrification (HDN) is usually performed. When operating with feedstock derived from renewable resources, the sulfur content is very low, and therefore hydrogenation rather involves HDO and optionally HDN treatment. As a result, the hydrogenated stream contains not only H2S but also H2O, NH3, CO, and CO2 as impurities, which need to be removed before the downstream dewaxing step.

[0006] EP2362892A1 (WO2010 / 053468A1) (Patent Document 1) discloses the hydroprocessing of fuel feedstocks derived from biocomponent materials, as well as the hydroprocessing of blends of biocomponents and mineral oil fuel feedstocks. More specifically, the cited document discloses a method for producing diesel fuel from biocomponent feedstocks, comprising the hydrogenation of the feedstocks and subsequent catalytic dewaxing. The hydrogenated feedstocks may be cascaded directly to the dewaxing step, or the hydrogenated feedstocks may undergo intermediate separation in a separation unit, such as a fractionation column. There is no explicit or implicit disclosure of the use of reflux in the separation unit: the use of a fractionation column does not necessarily mean that it has reflux, which is clearly not the purpose of the cited document. A reboiling column that includes feed to the first stage and does not recycle could easily be considered a fractionation column.

[0007] US2002 / 112990A1 (Patent Document 2) discloses a method for hydroprocessing fossil fuels in two or more hydroprocessing steps, wherein liquid and vapor products from a first step are sent to a separation zone (S), where a liquid phase fraction is separated from a vapor phase fraction containing vaporized heavy hydrocarbon components. The vapor phase fraction is passed through an sorption zone (ST) in the presence of an sorbent (STA), where at least a portion of the heavy hydrocarbon components are removed. Both the liquid phase fraction and the sorbed heavy hydrocarbon components are sent to at least one additional hydroprocessing step. Optionally, partial condensation and reflux are present in the sorption zone (ST) to remove high-boiling point hydrocarbon components (heavy tail) from the vapor fraction. There is no stripping or reflux in the separation zone (S), and therefore impurities in the bottom stream, H2S, H2O, NH3, CO, and CO2, will go directly to the second hydroprocessing stage.

[0008] US2005 / 167334A1 (Patent Document 3) discloses a hydrotreatment of fossil fuels, where the hydrotreatment is hydrodesulfurization, hydrodenitrification, hydrodemetallation (for removing one or more metals such as vanadium, nickel, iron, sodium, titanium, silicon, and copper), and hydrodesaromatherapy. The hydroprocessing has an intermediate stripping of the effluent from a first step and comprises at least two reaction steps, each step being carried out using a hydrogen recycling loop limited to that step, thereby removing a portion of the H2S formed. The hydrotreatment in the first reaction step does not contain HDO, and therefore its effluent does not contain additional impurities in the form of CO, CO2, in addition to H2O. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] EP2362892A1(WO2010 / 053468A1) [Patent Document 2] US2002 / 112990A1 [Patent Document 3] US2005 / 167334A1 [Overview of the project] [Problems that the invention aims to solve]

[0010] The objective of the present invention is to significantly reduce the content of impurities H2S, H2O, NH3, CO, and CO2 that can come into contact with the noble metal catalyst used in the dewaxing step. [Means for solving the problem]

[0011] This and other objectives are addressed by the present invention.

[0012] Therefore, the present invention relates to a method for producing hydrocarbon products, as described below: i), ii): i) Passing a supply material derived from renewable and / or fossil resources through a hydroprocessing step to generate a main hydrogenated stream; the hydroprocessing step includes: - To produce a first hydrogenated stream, for example, a stream containing C1-C30+ hydrocarbons, the feed material is passed through one or more catalytic hydrogenation units under the supply of hydrogen, where the hydrogenated stream, i.e., the first hydrogenated stream, contains impurities H2S, NH3, CO, CO2 and H2O; - To remove impurities, the first hydrogenated stream is passed through a first separation step, which includes the use of a separation unit; - From the first separation step described above, for example, from the separation unit, the overhead stream is taken out, the overhead hydrocarbon liquid stream is separated therefrom, and at least a portion of it is passed through the first separation unit as a reflux stream; - From the first separation step described above, for example, from the separation unit described above, the bottom stream is removed; - To generate the aforementioned main hydrogenated stream, at least a portion of the bottom stream is passed through a dewaxing step, which includes the use of one or more catalytic hydrogenation units under a supply of hydrogen; ii) Passing the main hydrogenated stream through a second separation step in order to produce the hydrocarbon product; Includes, One or more catalytic hydrogenation units for generating the first hydrogenated stream include hydrogenated deoxygenation (HDO) and optionally hydrogenated denitrification (HDN); One or more catalytic hydrogenation units in the dewaxing step for generating the main hydrogenated stream include hydrodewaxing (HDW) in the presence of a precious metal catalyst, and optionally hydrocracking (HCR); and The entire overhead hydrocarbon liquid stream (i.e., at least a portion of the aforementioned overhead hydrocarbon liquid stream constitutes the entire overhead hydrocarbon liquid stream) is passed through the separation unit as a reflux stream. The above method is provided.

[0013] It will be understood that impurities are H2S, NH3, CO, CO2, and H2O, or combinations thereof. For example, impurities can be CO and CO2.

[0014] The first hydrogenated stream from the catalytic hydrogenation unit typically contains such impurities, which can be detrimental to the catalyst used in the subsequent dewaxing step. When operating in so-called sweet mode, as in the present invention, the catalyst used in the catalytic hydrogenation unit (hydrodenasking unit, HDW) in the dewaxing step is a precious metal catalyst that is sensitive to impurities, thereby requiring the use of a first separation step, such as the use of a separation unit in the form of a high-pressure separator or column, to reduce the impurity content.

[0015] The present invention uses the overhead hydrocarbon liquid stream (e.g., from a separation unit) as reflux to the separation unit instead of sending it to the dewaxing step as part of the feedstock. It has been found that impurities in the feedstock to the dewaxing step, particularly H2O and H2S, are significantly reduced (e.g., by an order of magnitude), as shown in the example below, thereby avoiding degradation of the precious metal catalyst used therein.

[0016] The present invention is particularly useful when producing jet fuel, or jet fuel and diesel oil. When producing only diesel oil, the overhead stream from a separation unit in the first separation step, for example, the overhead stream from an HP stripper, usually completely bypasses the catalytic hydrogenation unit in the dewaxing step, so there is no need to protect it. Finally, since it becomes a small part of the total diesel product stream, even if it does not pass through the catalytic hydrogenation unit in the dewaxing step, this would be acceptable because it would not affect the overall diesel characteristics.

[0017] However, the overhead stream from the separation unit in the first separation step contains some jet-boiling range components. Therefore, when producing jet fuel, these components need to go through the dewaxing step to isomerize them. Otherwise, there is a risk of not meeting the jet fuel product specifications, particularly those related to the pour point of jet fuel. Thus, according to the present invention, the overhead stream of the separation unit, for example, the HP stripper overhead stream, is withdrawn, partially condensed, for example, in an air cooler, and sent to a further (low-temperature) separator to withdraw the condensed hydrocarbon liquid stream, i.e., the overhead hydrocarbon liquid stream. This stream is usually sent directly as a feed to the dewaxing step, but the present invention instead uses it as reflux to the column, thereby surprisingly obtaining better overall impurity removal, and as a result, better protecting the catalytic hydrogenation unit(s) used in the dewaxing step.

[0018] In step ii), the main hydrogenated stream obtained from the dewaxing step is passed through a second separation step, which preferably includes the use of a separator, such as a cold separator, and a product stripper and fractionator, such as a stripping section including a distillation column, thereby producing hydrocarbon products, particularly jet fuel, diesel oil and naphtha.

[0019] In one embodiment, step ii) includes passing the main hydrogenated stream through a separator, preferably a cold separator, to produce an aqueous stream (sour water stream), a hydrogen-rich stream, and a hydrocarbon stream which is further separated into the hydrocarbon products in a subsequent stripping section; the hydrogen-rich stream is fed as a single recycle loop in the process by feeding it to one or more catalytic hydrogenation units for producing the first hydrogenated stream.

[0020] Thereby, a single (common) recycle loop for hydrogen recycling is provided, so that the hydrogen-rich gas from the cold separator can be fed not only to, for example, the HDO step before the first separation step, but also optionally to the dewaxing step after the first separation step. Instead of separate recycle compressors and additional piping for an independent supply of hydrogen to the HDO or dewaxing step, a single hydrogen recycle compressor is required.

[0021] In one embodiment, the method further includes feeding the hydrogen-rich stream to a dewaxing step including the use of one or more catalytic hydrogenation units for producing the main hydrogenated stream.

[0022] In another embodiment, the hydrogen-rich stream is not supplied to the dewaxing step. Instead, a makeup hydrogen gas (e.g., from an external source) is supplied to the dewaxing step. After passing through the dewaxing step, the makeup hydrogen gas is preferably mixed with the hydrogen-rich stream (recycled gas) and then returned to the HDO step as a single recycled gas loop. In other words, according to this embodiment, the method further comprises: not supplying a hydrogen-rich stream to the dewaxing step; supplying a makeup hydrogen gas (e.g., from an external source) to the dewaxing step; and, after passing through the dewaxing step, mixing it with the hydrogen-rich stream to produce a mixed hydrogen stream, which is then supplied as the single recycled loop. It is advantageous to use only a makeup hydrogen gas because, unlike the hydrogen-rich stream, the makeup hydrogen gas is essentially pure H2 and therefore free from contaminants.

[0023] In one embodiment, the method further comprises: separating an overhead gas stream containing impurities from the overhead stream from the overhead stream from the first separation step, passing the overhead gas stream through the separator in step ii), preferably after mixing it with the main hydrogenated stream, and preferably subsequently cooling it, for example, in an air cooler.

[0024] This ensures that impurities, such as H2S and NH3, are carried over and removed along with the sour water stream extracted from a separator, such as a low-temperature separator, while simultaneously providing the aforementioned single (common) recycling loop for hydrogen recycling. In this way, further process integration, simplicity, and flexibility are achieved.

[0025] In one embodiment, the hydrocarbon product boils above 30°C and comprises one or more of the following: jet fuel, diesel oil, naphtha, and optionally lube base stock. In a particular embodiment, the hydrocarbon is jet fuel, or jet fuel and diesel oil.

[0026] According to the present invention, the entire overhead hydrocarbon liquid stream of the first separation step (e.g., from the separation unit) is passed to the separation unit as a reflux stream.

[0027] Therefore, complete reflux is provided, i.e., the entire overhead hydrocarbon liquid stream is used. Where used herein, the term “entire” means 95% by weight or more, preferably 100% by weight, of the overhead hydrocarbon liquid stream. Thereafter, complete reflux of the overhead hydrocarbon liquid stream is present, and the only feedstock to the dewaxing step comes from the bottom of the first separation step (e.g., from the separation unit), thus further increasing the removal of impurities, for example, with respect to some impurities, more specifically with respect to H2O and H2S, by up to an order of magnitude or more.

[0028] If complete recirculation is present, it will be understood that the bottom stream from the first separation step, particularly the bottom stream from the separation unit, is the stream that proceeds to the dewaxing step.

[0029] In the absence of complete reflux but the presence of partial reflux, a purified first hydrogenated stream is optionally formed by combining the bottom stream from the first separation step, particularly the bottom stream from the separation unit, with the non-reflux portion of the overhead liquid stream. The purified first hydrogenated stream is then passed through a dewaxing step. At least a portion of the bottom stream from the first separation step, particularly the bottom stream from the separation unit, and a portion of the non-reflux overhead liquid stream may be passed through the dewaxing step individually, i.e., without combining these streams.

[0030] In one embodiment of the present invention, the hydrocarbon product boils above 30°C and comprises one or more of the following: jet fuel, diesel oil, naphtha, and optionally a lubricating oil base stock. Preferably, the hydrocarbon product is jet fuel, or jet fuel and diesel oil.

[0031] In one embodiment of the present invention, in the first separation step, the separation unit is a high-pressure stripper (HP stripper). The HP stripper is also called an HP stripping column.

[0032] HP strippers are well known in the art. HP strippers provide optimal removal of impurities. Stripping media for HP strippers may be makeup hydrogen gas, i.e., hydrogen-rich makeup gas, separator off gas, such as hot separator off-gas, or nitrogen. HP strippers may be operated, for example, in a pressure range of 40 to 70 barg and a temperature range of 150 to 250°C.

[0033] In one embodiment, the first separation step further includes using a high-temperature separator upstream of the separation unit.

[0034] The liquid from the high-temperature separator is sent to a downstream separation unit, such as an HP stripper, thereby increasing the flexibility and purification efficiency of the stripping step in the process.

[0035] As is well known in the art, high-temperature separators are two-phase or three-phase vertical or horizontal separators, most commonly two-phase, having a gas stream from the top and a liquid stream from the bottom, and are operated at temperatures above 100°C, thereby removing water as vapor in the gas stream. High-temperature separators can be operated at high, medium, or low pressures, for example, in the range of 1 to 70 barg.

[0036] The term "hot separator" refers to a case where water is removed as vapor. The term "cold separator" refers to a case where water is removed as liquid.

[0037] According to the present invention, at least a portion of the bottom stream is passed through a dewaxing step. In one embodiment, in step i), the recycled oil stream is separated from the bottom stream, for example, the bottom stream of the first separation step (from the high-pressure stripper), and passed upstream through one or more catalytic hydrogenation units, i.e., catalytic hydrogenation units for producing the first hydrogenated stream.

[0038] Recycled oil is used as a diluent to reduce the exothermic nature of hydrogenation processes, particularly those resulting from the use of renewable resource feedstocks. Renewable feedstocks are more reactive than typical hydrocarbon feedstocks based on fossil fuels. Renewable feedstocks contain more sulfur and especially more oxygen, and these reactions, forming H2O and H2S respectively, are more exothermic. This allows for greater integration, flexibility, efficiency, and especially safety in the process.

[0039] In one embodiment, one or more catalytic hydrogenation units for generating the first hydrogenated stream are deoxygenated hydrogenation (HDO) and denitrified hydrogenation (HDN).

[0040] As used herein, HDO also includes decarboxylation.

[0041] Catalytically active materials in hydrogenation typically include active metals (base metal sulfides such as nickel, cobalt, tungsten, and / or molybdenum, but in some cases also any elemental noble metal such as platinum and / or palladium) and refractory carriers (e.g., alumina, silica, or titania, or a combination thereof).

[0042] Hydrogenation conditions include a temperature in the range of 250–400°C, a pressure in the range of 30–150 bar, and a liquid space velocity (LHSV) in the range of 0.1–2, which optionally involves intermediate cooling by quenching with low-temperature hydrogen, feedstock, or product.

[0043] In one embodiment, the dewaxing step includes using hydrodeswaxing (HDW) in the presence of a noble metal catalyst, and optionally also using hydrocracking (HCR).

[0044] In the dewaxing step, the wax content is reduced by isomerization and, optionally, by decomposition under isomerization conditions in the presence of hydrogen. Therefore, as used herein, the term hydrogenated dewaxing (HDW) is interchangeable with the term hydrogenated isomerization (HDI).

[0045] Catalytically active materials in hydrogenation dewaxing are typically active metals (either elemental noble metals such as platinum and / or palladium), acidic supports (typically exhibiting high shape selectivity, such as MOR, FER, and MRE (more specifically MRE) *This includes molecular sieves having topologies such as MWW, AEL, TON, and MTT, and refractory carriers (e.g., alumina, silica, or titania, or a combination thereof).

[0046] Isomerization (HDI) conditions include a temperature in the range of 250–400°C, a pressure in the range of 20–100 bar, and a liquid-space velocity (LHSV) in the range of 0.5–8, which optionally involves intermediate cooling by quenching with low-temperature hydrogen, feedstock, or product.

[0047] The catalytically active materials in hydrocracking have properties similar to those in isomerization, and 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 exhibiting high decomposition activity and having topologies such as MFI, BEA, and FAU), and refractory supports (e.g., alumina, silica, or titania, or combinations thereof). The difference from the catalytically active materials in isomerization is typically the properties of the acidic support, which may have different structures (even amorphous silica-alumina) or different acidities (e.g., due to the silica:alumina ratio). In the context of the present invention, it will be understood that there may be differences in the properties of the metals; for example, metals for HDW may include noble metal catalysts such as platinum, while metals for hydrocracking may include base metals such as nickel and / or molybdenum.

[0048] Hydrocracking conditions include a temperature in the range of 250–400°C, a pressure in the range of 30–150 bar, and a liquid space velocity (LHSV) in the range of 0.5–8, which optionally involve intermediate cooling by quenching with low-temperature hydrogen, feedstock, or product.

[0049] In one embodiment, the supply material derived from renewable resources is obtained from raw materials of renewable resources, such as plants, algae, animals, fish, vegetable oil refining, household waste, plastic-rich waste, or industrial organic waste such as tall oil or black liquor, or is a supply material derived from one or more oxygen-containing substances selected from the group consisting of triglycerides, fatty acids, resin acids, ketones, aldehydes, or alcohols, where the oxygen-containing substance is derived from one or more of the following: biosources, gasification processes, pyrolysis processes, Fischer-Tropsch synthesis, or methanol-based synthesis.

[0050] In one embodiment, the supply material derived from fossil fuel sources is diesel fuel, kerosene, naphtha, and vacuum gas oil (VGO).

[0051] Optionally, the recycling of hydrocarbon products generated in the method, for example, the recycled oil stream in step i), is provided as part of the supply material.

[0052] The present invention provides the use of a supply material derived from renewable resources, or a supply material derived from fossil fuel sources, or a combination thereof, i.e., co-processing. In one embodiment, the supply material is derived from renewable resources and fossil resources, where the fossil resource constitutes a small portion thereof, making up to 30% by weight or less, for example, up to 10% by weight, of the supply material.

[0053] 100% renewable feedstock, i.e., feedstock derived from renewable resources and not accompanied by co-supply of feedstock from, for example, fossil fuel sources, or when the latter constitutes only a small portion as described above, contains significantly less sulfur than pure fossil fuel feedstock and requires hydrogenation treatment including HDO to remove oxygen from the renewable feedstock, thus resulting in not only H2S but also significantly higher concentrations of other impurities such as H2O, NH3, CO, and CO2. [Brief explanation of the drawing]

[0054] [Figure 1] Figure 1 shows a schematic process and plant layout for producing naphtha, jet, and diesel oil from a supply material using prior art. The figure includes an enlarged view of the separation unit used in the first separation step. [Figure 2] Figure 2 shows a schematic process and plant layout for producing naphtha, jet, and diesel oil from a feed material according to one embodiment of the present invention. The figure includes an enlarged view of the separation unit used in the first separation step.

[0055] Referring in detail to Figure 1, a block flow diagram of the overall process / plant 10 is shown. The feed material 12, for example, the feed material derived from renewable resources, is supplied to the hydroprocessing step or hydroprocessing section 110. This step or hydroprocessing section includes an optional feed step or feed section 112, and a reactor section including a catalytic hydrogenation treatment unit 114 such as HDO, a dewaxing step or dewaxing section 118, and a first separation step 116 (indicated here by the use of a separation unit 116 in the form of an HP stripper). From the hydroprocessing step 110, and especially from the dewaxing step 118, a main hydrogenated stream 14 is produced, which is then passed to a second separation step 120, which produces an aqueous (water) stream 16; an off-gas stream 20 including hydrocarbons, for example a light hydrocarbon stream, and also including NH3, CO, CO2 and H2S; and hydrocarbon products in the form of diesel oil 22, jet fuel 24 and naphtha 26.

[0056] After the feed material 12 optionally passes through an optional feed step 112, the feed material 12' passes through a catalytic hydrogenation unit 114 such as HDO, from which a first hydrogenation stream 12'' is extracted. This stream then passes through an HP stripper 116, generating a vapor stream 46, i.e., an overhead gas stream containing most of the impurities, and a bottom stream 44 (from which recycled oil streams 44' and 44'' are separated, with stream 44'' combining with the overhead liquid stream from the HP stripper 116 to form a purified first hydrogenated stream 12'''). The latter enters a dewaxing step 118, which includes the use of a catalytic hydrogenation unit, i.e., an HDW unit 118, to generate a main hydrogenated stream 14. Additional catalytic hydrogenation units, in the form of hydrocracking units (HCR units), may also be provided downstream or upstream of the HDO or HDW units, for example, to generate a first hydrogenated stream 12'' or a main hydrogenated stream 14, respectively.

[0057] The second separation step 120 includes the use of a separator 122, preferably a cryogenic separator, and a stripping section 124, which includes a product stripper and a fractionator, such as a distillation column (not shown). The overhead gas stream 46 generated in the previous HP stripper 116 may be used with the main hydrogenated stream 14 for the operation of the separator 122, or may be mixed, for example. A hydrogen-rich stream 18 is taken out of the separator 122, which may be used for hydrogen gas recycling by mixing it with streams 12' and 44' that enter the catalytic hydrogenation unit 114, for example, and the separator 122 also generates the water stream 16 described above. Impurities are therefore carried over into the water stream 16 (sour water stream). A hydrocarbon stream 14' is generated from the separator 122, which is then fed to the stripping section 124, under the production of an off-gas stream 20 containing hydrocarbons, and hydrocarbon products, diesel oil 22, jet fuel 24, and naphtha 26. For example, makeup hydrogen gas 40 from an external battery limit is supplied to the HP stripper 116, and optionally to the catalyst units 114 and 118 of the hydroprocessing step 110.

[0058] An enlarged schematic diagram of the HP stripper 116 is also provided in Figure 1. Stream 12'' is supplied, for example, to the first stage of the HP stripper 116. As shown in the figure, the HP stripper overhead stream is taken out and partially condensed, for example, in an air cooler 116', and then sent to a separator 116'' to take out a condensed hydrocarbon liquid stream, i.e., the overhead hydrocarbon liquid stream 28, as well as a sour water stream 30 and a vapor stream 46. The overhead hydrocarbon liquid stream 28 is optionally combined with the bottom stream 44'' taken out of the HP stripper 116 and then sent as feedstock to the dewaxing step 118. Makeup hydrogen gas 40 is used in stripping, and the recycled oil stream 44' is separated from the bottom stream 44 of the HP stripper 116 and passed upstream to one or more catalytic hydrogenation units 114.

[0059] Referring now to Figure 2, which shows an embodiment according to the present invention, the overall block flow diagram of the process / plant 10 is identical to that of Figure 1, except that stream 44'' separated from the bottom stream 44 from the HP stripper 116 is the sole hydrocarbon feedstock to the dewaxing step 118.

[0060] An enlarged schematic diagram of the HP stripper 116 shows, here, the use of the overhead liquid stream 28 as reflux to the HP stripper instead. As shown here, the entire overhead hydrocarbon liquid stream 28 is passed through as reflux, thereby surprisingly resulting in a significant improvement in overall impurity removal, and consequently better protecting the catalytic hydrogenation unit(s) in the dewaxing step 118.

[0061] From the separator 122, preferably a low-temperature separator, a hydrogen-rich stream 18 is taken out, which may be used as a hydrogen gas recycle, and which is preferably provided as a single recycle loop in the process, i.e., the hydrogen-rich stream 18 is supplied to one or more catalytic hydrogenation units 114 for generating a first hydrogenated stream 12. [Examples]

[0062] example Conventional technology: According to Figure 1, the level of impurities in the liquid phase before heating in the dewaxing step or dewaxing section 18 is as follows: H2O: 1589wppb, NH3: 14wppb, H2S: 1528wppb, CO+CO2: 3798wppb.

[0063] This invention: As shown in Figure 2, the entire overhead hydrocarbon liquid stream 28 is passed as reflux to the HP stripper 116, i.e., as complete reflux. The same operating conditions (pressure, temperature, stripping gas flow) in the HP stripper as in Figure 1 are used. The level of impurities in the liquid phase before the dewaxing step or dewaxing section 18 is as follows: H2O: 136wppb, NH3: 9wppb, H2S: 124wppb, CO+CO2: 1197wppb.

[0064] This results in a remarkably large reduction in the levels of impurities, particularly H2S, H2O, and / or CO+CO2. A reduction of approximately an order of magnitude is obtained with respect to H2S and H2O. While this application relates to the invention described in the claims, it may also encompass the following other embodiments. 1. A method for producing hydrocarbon products, the following i), ii): i) Passing a supply material derived from renewable and / or fossil resources through a hydroprocessing step to generate a main hydrogenated stream; wherein the hydroprocessing step includes: - To generate a first hydrogenated stream, the supply material is passed through one or more catalytic hydrogenation units under the supply of hydrogen, where the hydrogenated stream is free of impurities H 2 S, NH 3 CO, CO 2 and H 2 Includes O; - To remove impurities, the first hydrogenated stream is passed through a first separation step, which includes the use of a separation unit; - From the first separation step, the overhead stream is taken out, the overhead hydrocarbon liquid stream is separated from it, and at least a portion of it is passed through the first separation unit as a reflux stream; - From the first separation step described above, remove the bottom stream; - To generate the aforementioned main hydrogenated stream, at least a portion of the bottom stream is passed through a dewaxing step, which includes the use of one or more catalytic hydrogenation units under a supply of hydrogen; ii) Passing the main hydrogenated stream through a second separation step in order to produce the hydrocarbon product; Includes, One or more catalytic hydrogenation units for generating the first hydrogenated stream include hydrogenated deoxygenation (HDO) and optionally hydrogenated denitrification (HDN); One or more catalytic hydrogenation units in the dewaxing step for generating the aforementioned main hydrogenated stream include dewaxing by hydrogenation (HDW) in the presence of a noble metal catalyst, and optionally also hydrocracking (HCR); and the entire overhead hydrocarbon liquid stream is passed through the separation unit as a reflux stream. The aforementioned method. 2. The method according to 1, wherein step ii) comprises passing the main hydrogenated stream through a separator, preferably a cryogenic separator, to produce an aqueous stream (sour water stream), a hydrogen-rich stream, and a hydrocarbon stream which is further separated into the hydrocarbon products in a subsequent stripping section; the hydrogen-rich stream is supplied as a single recycle loop in the method by supplying it to one or more catalytic hydrogenation units for producing the first hydrogenated stream. 3. Furthermore, the following: Do not supply a hydrogen-rich stream to the defacing step; supply makeup hydrogen gas, for example, from an external source, to the defacing step, and after it has passed through the defacing step, mix it with the hydrogen-rich stream to create a mixed hydrogen stream, which is then supplied as the single recycling loop. The method described in item 2 above, including the method described in item 2 above. 4. Furthermore: From the overhead stream from the first separation step, the overhead gas stream containing impurities is separated, and the overhead gas stream is passed through the separator in step ii), preferably after being mixed with the main hydrogenated stream and preferably subsequently cooled, for example, in an air cooler. The method described in item 2 above, including the method described in item 2 above. 5. The method according to any one of 1 to 4 above, wherein the hydrocarbon product boils at over 30°C and comprises one or more of jet fuel, diesel oil, naphtha, and optionally one or more of a lubricating oil base stock. 6. The method according to any one of 1 to 5 above, wherein in the first separation step, the separation unit is a high-pressure stripper, preferably a high-pressure stripper in the form of a stripping column that uses makeup hydrogen gas as a stripping medium and is operated in a pressure range of 40 to 70 barg and a temperature range of 150 to 250°C. 7. The method according to any one of 1 to 6 above, wherein the first separation step further includes using a high-temperature separator upstream of the separation unit, preferably in the form of a two-phase or three-phase, preferably two-phase, vertical or horizontal separator, having a gas stream from the top and a liquid stream from the bottom, and being operated at a temperature above 100°C, thereby removing water as vapor in the gas stream. 8. The method according to any one of 1 to 7 above, wherein in step i), the recycled oil stream is separated from the bottom stream and passed upstream through one or more catalytic hydrogenation units. 9. A method according to any one of 1 to 8 above, wherein the supply material derived from renewable resources is obtained from raw materials of renewable resources, such as plants, algae, animals, fish, vegetable oil refining, household waste, plastic-rich waste, or industrial organic waste such as tall oil or black liquor, or is derived from one or more oxygen-containing substances selected from the group consisting of triglycerides, fatty acids, resin acids, ketones, aldehydes or alcohols, wherein the oxygen-containing substance is derived from one or more of the following: a biosource, a gasification process, a pyrolysis process, a Fischer-Tropsch synthesis or a methanol-based synthesis. 10. The method according to any one of items 1 to 9 above, wherein the supply material derived from a fossil fuel source is selected from diesel oil, kerosene, naphtha, and vacuum gas oil (VGO). 11. The method according to any one of 1 to 10 above, wherein the supply material is derived from renewable resources and fossil resources, where the fossil resources constitute a small portion thereof and amount to a maximum of 30% by weight or less, for example, a maximum of 10% by weight, of the supply material.

Claims

1. A method for producing hydrocarbon products, the following i), ii): i) Passing a feed material derived from renewable resources through a hydroprocessing step to generate a main hydrogenated stream; wherein the hydroprocessing step includes: - To generate a first hydrogenated stream, the supply material is passed through one or more contact hydrogenation units under the supply of hydrogen, where the hydrogenated stream is free of impurities H ２ S, NH ３ CO, CO ２ and H ２ Includes O; - To remove impurities, the first hydrogenated stream is passed through a first separation step, which includes the use of a separation unit; - From the first separation step, the overhead stream is taken out, the overhead hydrocarbon liquid stream is separated therefrom, and at least a portion of it is passed through the first separation unit as a reflux stream; - From the first separation step described above, extract the bottom stream; - To generate the main hydrogenated stream, at least a portion of the bottom stream is passed through a dewaxing step, which includes the use of one or more catalytic hydrogenation units under a supply of hydrogen; ii) Passing the main hydrogenated stream through a second separation step in order to produce the hydrocarbon product; Includes, One or more catalytic hydrogenation units for generating the first hydrogenated stream include hydrogenated deoxygenation (HDO) and optionally hydrogenated denitrification (HDN); One or more catalytic hydrogenation units in the dewaxing step for generating the aforementioned main hydrogenated stream include dewaxing by hydrogenation (HDW) in the presence of a noble metal catalyst, and optionally also hydrocracking (HCR); and the entire overhead hydrocarbon liquid stream is passed through the separation unit as a reflux stream. In the above method, Step ii) comprises passing the main hydrogenated stream through a separator to generate an aqueous stream (sour water stream), a hydrogen-rich stream, and a hydrocarbon stream which is further separated into the hydrocarbon products in a subsequent stripping section; the hydrogen-rich stream is supplied as a single recycling loop in the method by supplying it to one or more catalytic hydrogenation units for generating the first hydrogenated stream. The method further includes separating an overhead gas stream containing impurities from the overhead stream from the first separation step, and passing the overhead gas stream through the separator in step ii), The aforementioned method.

2. The method according to claim 1, wherein the separator in step ii) is a low-temperature separator.

3. Furthermore, see below: Not supplying a hydrogen-rich stream to the defacing step; supplying makeup hydrogen gas to the defacing step, which, after passing through the defacing step, mixes with the hydrogen-rich stream to create a mixed hydrogen stream, which is then supplied as the single recycling loop. The method according to claim 1 or 2, including the method according to claim 1 or 2.

4. The method of claim 1 or 2, wherein the overhead gas stream is passed through the separator in step ii) after being mixed with the main hydrogenated stream and subsequently cooled.

5. The method according to any one of claims 1 to 4, wherein the hydrocarbon product boils at over 30°C and comprises one or more of jet fuel, diesel oil, naphtha, and optionally one or more of a lubricating oil base stock.

6. The method according to any one of claims 1 to 5, wherein in the first separation step, the separation unit is a high-pressure stripper in the form of a stripping column that uses makeup hydrogen gas as a stripping medium and is operated in a pressure range of 40 to 70 barg and a temperature range of 150 to 250°C.

7. The method according to any one of claims 1 to 6, wherein the first separation step further includes using a high-temperature separator upstream of the separation unit.

8. The method according to claim 7, wherein the high-temperature separator is a two-phase or three-phase vertical or horizontal separator having a gas stream from the top and a liquid stream from the bottom, and is operated at a temperature above 100°C, thereby removing water as vapor in the gas stream.

9. The method according to any one of claims 1 to 8, wherein in step i), the recycled oil stream is separated from the bottom stream and passed upstream to one or more catalytic hydrogenation units.

10. The method according to any one of claims 1 to 9, wherein the supply material derived from renewable resources is obtained from raw materials of renewable resources or derived from one or more oxygen-containing substances selected from the group consisting of triglycerides, fatty acids, resin acids, ketones, aldehydes, or alcohols, wherein the oxygen-containing substance is derived from one or more of the following: a biosource, a gasification process, a pyrolysis process, a Fischer-Tropsch synthesis, or a methanol-based synthesis.

11. The method according to any one of claims 1 to 10, wherein the supply material is further derived from a fossil fuel source selected from diesel oil, kerosene, naphtha and vacuum gas oil (VGO).

12. The method according to any one of claims 1 to 11, wherein the supply material is derived from renewable resources and fossil resources, wherein the fossil resources constitute a small portion thereof and amount to a maximum of 30% by weight or less of the supply material.

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