Hydroprocessing of renewable feeds for producing hydrocarbon products

Abstract

The invention relates to a process and plant for producing a hydrocarbon product from a renewable hydrocarbonaceous feedstock. The process comprising the steps of: hydroprocessing the renewable hydrocarbon feed in a hydrodeoxygenation (HDO) unit for producing a HDO effluent stream; removing impurities therefrom via a HDO stripper into a sour gas stream comprising the impurities, e.g. any of H2S, CO, CO2, H2O, NH3, as a first hydrogen-rich recycle gas stream; conducting the first hydrogen-rich recycle gas stream to a contact unit under the addition of: a second hydrogen-rich recycle gas stream and a second isomerized effluent stream from downstream separation in a hydroisomerization (ISOM) cold separator, in which the second hydrogen-rich recycle gas stream is a portion of the ISOM cold separator overhead vapor stream and the second isomerized effluent stream is at least a portion of the ISOM cold separator bottom stream; recycling another a portion of the ISOM cold separator overhead vapor stream to the HDO stripper; recycling via a recycle gas compressor at least a portion of the contact unit effluent gas stream; and separating, from the contact unit bottom effluent stream, said hydrocarbon product.

Description

[0001] Title: Hydroprocessing of renewable feeds for producing hydrocarbon products

[0002] TECHNICAL FIELD

[0003] The present invention relates to a process and plant for hydroprocessing renewable hy- drocarbonaceous feedstocks such as used cooking oil or tall oil fatty acids, for thereby producing hydrocarbon products such as jet fuel for use as sustainable aviation fuel as well as diesel or hydrotreated vegetable oil (HVO).

[0004] BACKGROUND

[0005] The field of hydroprocessing of renewable hydrocarbonaceous feedstocks to produce hydrocarbon products such as jet fuel for use as sustainable aviation fuel (SAF) and hydrotreated vegetable oil (HVO) has seen significant advancements in recent years. These renewable hydrocarbonaceous feedstocks can include used cooking oil and tall oil fatty acids, among others. The hydroprocessing of these renewable hydrocarbonaceous feedstocks is a critical step in the production of these hydrocarbon products as transportation fuels, and the efficiency and effectiveness of this process can greatly impact the overall production process.

[0006] Traditionally, a two-stage process or plant with or without a hot separator and high- pressure stripper and no separate cold separator has been used. In this setup, the high-pressure stripper overhead section and its overhead drum operate at a higher pressure, and makeup gas (hydrogen gas) from a makeup gas compressor is used as the stripping medium in the high-pressure stripper. This process requires a significant amount of hydrogen, which can be a limiting factor in the overall efficiency and cost-effectiveness of the process.

[0007] Patent application WO2022087618A1 discloses a process for producing diesel stream from a biorenewable feedstock by hydrotreating to remove heteroatoms and hydroisomerization to improve cold flow properties. Heavy diesel can be hydrocracked to jet fuel range material or further hydroisomerized to increase its value by lowering its freeze point while light diesel may be taken as a motor fuel.

[0008] Patent application US2005167334A1 discloses the hydrotreament of fossil fuels, in which the hydrotreament is hydrodesulphurization, hydrodenitrogenation, hydrodemetallization (to eliminate one or more metals such as vanadium, nickel, iron, sodium, titanium, silicon, copper), and hydrodearomatization. The hydrotreatment comprises at least two reaction steps with intermediate stripping of the effluent from the first step and including a reflux, each step being carried out with a hydrogen recycle loop that is exclusive to that step, thereby eliminating part of the H2S formed. The hydrotreatment in the first reaction step does not include HDO, thus the effluent thereof does not contain additional impurities in the form of CO, CO2 in addition to H2O.

[0009] Patent application LIS2013305593 discloses a hydroprocessing process comprising a separation process with a modified enhanced hot separator system. The process eliminates undesirable entrainment while allowing for enhanced stripping of the net liquid only. The modified enhanced hot separator system combines a hot separator with a hot high pressure stripping column. A hydrogen-rich recycle is provided as a single recycle loop in the process by withdrawing a hydrogen-rich stream from a separator downstream the hot high pressure stripping column and further removing impurities such as H2S from the hydrogen-rich stream.

[0010] Applicant's patent application WO202253260A1 discloses a process for producing a hydrocarbon product which comprises a catalytic hydrotreating unit for producing a first hydrotreated stream comprising impurities such as H2S, carbon oxides and H2O, and which is then conducted to a high-pressure (HP) stripper operating in full reflux mode for removing the impurities. A hot separator may be provided upstream the HP stripper. The purified hydrotreated stream is conducted to a dewaxing (isomerization) and then to a cold separator for producing a hydrogen-rich stream which is provided as a single recycle loop in the process.

[0011] Despite the advancements in this field, there are still challenges that need to be addressed. For instance, in currently available processes, the capital expenses (CAPEX) and operating expenses (OPEX) are still high, and it is therefore desirable to be able to provide improved process and plant layouts with lower CAPEX and OPEX while at the same time reducing the carbon footprint.

[0012] For instance, in currently available process and plant layouts, as shown in appended figures 1 and 2, the required hydrogen to oil ratio (H2 / 0H ratio) for the hydroisomerization step (ISOM step) i.e. dewaxing step of hydredeoxygenated renewable feed conveys at least the following: a) The provision of makeup gas (hydrogen gas) once through the dewaxing step. In this scheme, excessive purge gas is required from a high-pressure stripper (HP stripper) associated with the hydrodeoxyenation (HDO) step to achieve the required make-up gas flow to meet the H2 / oi I ratio for the dewaxing. In this approach, a purge gas is diverted from the overhead stream of the cold separator of the HDO stripper comprising hydrogen and impurities for ISOM catalysts such as H2S and CO2 which is sent to the ISOM cold separator. Makeup gas (MUG) i.e. a hydrogen gas is provided via a MUG compressor, in which a portion of the MUG is used as a stripping gas in the HP stripper, and the other portion is sent to the dewaxing step for providing the required H2 / oi I ratio. High CAPEX results due to the need of a sizable MUG compressor, as well as sizable membrane separation unit or pressure swing adsorption (PSA) unit for the purge gas being released, thereby recovering hydrogen in the purge gas. High OPEX results due to higher power consumption in the MUG compressor and loss of hydrogen to fuel gas in connection with the purge gas; b) The provision of a dedicated recycle gas compressor and liquid recycle pump. To have a dedicated recycle gas compressor in the dewaxing step is needed to meet the required H2 / oi I ratio and the liquid recycle pump to pump the dewaxing step liquid to re-contact with HDO section recycle gas to improve the purity. A HDO hot separator, in particular a HDO high-pressure hot separator (HDO-HPHS) is provided upstream the HP stripper as well as a dewaxing feed pump to feed the HP stripper bottom stream to the dewaxing step. Very high CAPEX and OPEX due to at least additional compressor and dewaxing feed pump results.

[0013] It would therefore also be desirable to reduce or eliminate the need for purging gas from the overhead stream of the cold separator of the HDO stripper, while at the same time being able to provide the required H2 / 0H ratio for the ISOM step (dewaxing step) and optional hydrocracking (HCR) step with lower CAPEX and OPEX than current or traditional process layouts, as well as being able to increase the hydrogen purity of hydrogen-rich gas being recycled to the HDO step, and not least reducing or eliminating the lining requirements of HDO unit and associated heat exchangers. SUMMARY

[0014] In a first aspect, the invention relates to a process for producing a hydrocarbon product from a renewable hydrocarbonaceous feed, said process comprising the steps of: i) hydroprocessing the renewable hydrocarbonaceous feed, comprising: i-1) conducting the renewable hydrocarbonaceous feed stream to a catalytic hydrodeoxygenation (HDO) unit comprising a catalyst for producing a hydrodeoxygenated effluent stream; i-2) conducting the hydrodeoxygenated effluent stream to a HDO stripper and withdrawing therefrom a HDO stripper bottom stream and a HDO stripper overhead stream; i-3) separating from the HDO stripper overhead stream a sour gas stream comprising at least one of the impurities: H2S, CO, CO2, H2O, NH3, as a first hydrogen-rich recycle gas stream; i-4) conducting the first hydrogen-rich recycle gas stream to a contact unit, such as any of a sponge column or a re-contact drum, under the addition of: a second isomerized effluent stream from downstream separation in a hydroisomerization (ISOM) cold separator receiving: a first isomerized effluent stream, or an isomerized and hydrocracked effluent stream; withdrawing from the contact unit: a contact unit bottom effluent stream, and a contact unit effluent gas stream comprising at least one of the impurities, in particular H2S; and recycling via a recycle gas compressor at least a portion of the contact unit effluent gas stream as a combined hydrogen-rich recycle gas stream to the catalytic HDO unit; i-5) conducting the HDO stripper bottom stream to a catalytic hydroisomerization (ISOM) unit and producing said first isomerized effluent stream; i-6) conducting said first isomerized effluent stream, or an isomerized and hydrocracked effluent stream associated with an optional downstream hydrocracking (HCR) unit, to said ISOM cold separator and withdrawing therefrom: a ISOM cold separator overhead vapor stream and a ISOM cold separator bottom stream; and wherein said second isomerized effluent stream is at least a portion of the ISOM cold separator bottom stream; i-7) recycling at least a portion or another portion of the ISOM cold separator overhead vapor stream of step i-6) to the HDO stripper.

[0015] Suitably, the contact unit bottom effluent stream is withdrawn as said hydrocarbon product.

[0016] For the purposes of the present application:

[0017] The term “first aspect” or “first aspect of the invention” means the process of the invention. The term “second aspect” or “second aspect of the invention” means the plant, i.e. process plant, of the invention.

[0018] The term “invention” or “present invention” may be used interchangeably with, respectively, the term “application” or “present application”.

[0019] The term “comprises” or “comprising” includes “comprises only” or “comprising only", respectively, i.e. “consists of’ or “consisting of”.

[0020] The term “suitably” means “optionally”, i.e. an optional embodiment.

[0021] The term “conducting” may be used interchangeably with the term “supplying”.

[0022] The term “at least a portion” of a certain item, such as a stream (process stream), means the entire item or a portion thereof. For instance, for the item being a stream i.e. a process stream, the term “at least a portion” of a stream means the entire stream or a portion thereof.

[0023] The term “hydrocarbonaceous feed” may be used interchangeably with the term “hy- drocarbonaceous feedstock” and means a feedstock rich in molecules comprising hydrogen and carbon, but possibly also heteroatoms, i.e. other elements, such as oxygen, sulfur and nitrogen. In connection thereto, the term “renewable hydrocarbonaceous feed” means a hydrocarbonaceous feed obtained from a raw material of renewable origin.

[0024] The term “impurities” means a compound which damages the ISOM catalyst. An impurity is at least one of: H2S, CO, CO2, H2O, NH3.

[0025] The term “catalytic HDO unit” is used interchangeably with the term “HDO unit”. The term “catalytic ISOM unit” is used interchangeably with the term “ISOM unit”. The term “catalytic HCR unit” is used interchangeably with the term “HCR unit”.

[0026] The term “an isomerized and hydrocracked effluent stream associated with an optional downstream hydrocracking (HCR) unit” in step i-6) means that downstream the ISOM unit, a HCR unit may be provided which produces a hydrocracked effluent stream. The effluent stream from the HCR unit may be regarded as the isomerized and hydrocracked effluent stream where the first isomerized effluent stream from the ISOM unit is directly conducted to inlet of the HCR unit (see e.g. stream 441 in appended Fig. 4). The effluent stream from the HCR unit combined with the liquid fraction of the first isomerized effluent stream from the ISOM unit may be regarded as the isomerized and hydrocracked effluent stream, where the first isomerized effluent stream from the ISOM unit is indirectly conducted to inlet of the HCR unit (see e.g. stream 341 in appended Fig.3).

[0027] The term “directly conducted” or “directly conducting” means that there are no intermediate units or process steps in between the corresponding process steps and associated process units. More generally, the term “directly” means that there is no intermediate unit or step changing the composition of a process stream.

[0028] The term “a hydrocarbon product” means one or more hydrocarbon products. A hydrocarbon product is for instance the contact unit bottom effluent stream. A hydrocarbon product is for instance jet fuel or sustainable aviation fuel, or hydrotreated vegetable oil (HVO), or diesel. A hydrocarbon product is for instance also naphtha, such as stabilized naphtha.

[0029] More generally, the use of the indefinite article “a” or “an” in connection with an item means one or more.

[0030] The term “and / or” means in connection with a given embodiment any of three options. The term “and / or” may be used interchangeably with the term “at least one of” the three options.

[0031] Other definitions are provided in connection with one or more of above or below embodiments.

[0032] In an embodiment, the process further comprises: ii) separating, from the contact unit bottom effluent stream, said hydrocarbon product. The contact unit bottom effluent stream is thereby refined via i.a. fractionation for producing the hydrocarbon product.

[0033] In an embodiment, the process further comprises said step i-4) being under the addition to the contact unit of a second hydrogen-rich recycle gas stream upstream and / or downstream the contact unit; wherein the second hydrogen-rich recycle gas stream is a portion of the ISOM cold separator overhead vapor stream; and wherein the addition of the second hydrogen-rich recycle gas stream is immediately upstream the contact unit by directly conducting the second hydrogen-rich recycle gas to the contact unit, and / or the addition of the second hydrogen-rich recycle gas stream is immediately downstream the contact unit by directly conducting the second hydrogen-rich recycle gas to the contact unit effluent gas stream upstream the recycle gas compressor.

[0034] It is understood that in connection with this specific embodiment,

[0035] - said step i-7) may be interpreted as: recycling another portion of the ISOM cold separator overhead vapor stream of step i-6) to the HDO stripper; or

[0036] - since the term “at least a portion” means the entire portion or a portion, said step i-7) may be interpreted as: recycling a portion of the ISOM cold separator overhead vapor stream of step i-6) to the HDO stripper.

[0037] It is understood, that where this specific embodiment is not provided, said step i-7) may be interpreted as recycling at least a portion, for instance the entire portion or a portion of the ISOM cold separator overhead vapor stream of step i-6) to the HDO stripper.

[0038] For instance, in appended Fig. 3 and 4, this specific embodiment is provided. The second hydrogen-rich recycle gas stream (347”, 447”) is a portion of the ISOM cold separator overhead vapor stream (347, 447). A portion, also understood in this specific embodiment as another portion (347’, 347’) of the ISOM cold separator overhead vapor stream (326, 426) is recycled to the HDO stripper (308, 408).

[0039] By the invention, a process is provided with two steps (stages) of hydroprocessing, in a first stage of sour HDO unit loop and a second stage of sweet (noble metal catalyst) hydroisomerization (ISOM) unit, herein also referred to as isomerization or interchangeably dewaxing, and optional hydrocracking in a hydrocracking reactor. Two separate reactor effluent cold separators are used for the two stages keeping them separate.

[0040] The present invention enables that the required H2 / 0H ratio for the ISOM (dewaxing) step and optional HCR step is provided in a superior manner with respect to the prior art, by achieving said H2 / 0H ratio without adding an additional dewaxing recycle gas compressor and liquid recycle pump, or by doing excessive purge i.e. withdrawing excessive purge gas in the sour gas from the cold separator of the HDO stripper, i.e.

[0041] HDO cold separator, thereby increasing the hydrogen flow to the HDO unit. The invention ensures the provision of enough stripping gas (hydrogen) availability for the HDO stripper, e.g. HP stripper, without requiring the sourcing of makeup gas (MUG) and associated MUG compressor for providing the required hydrogen in the HP stripper. By recycling at least a portion or another portion, e.g. a portion, of the ISOM cold separator overhead vapor stream to the HDO stripper, a smaller MUG compressor is required, as hydrogen for use as stripping gas in the HP stripper is provided internally, thus enabling high integration in the process. The MUG compressor does not need to provide hydrogen to the HP stripper. The invention enables also avoiding the purging of gas during start-of-run (SOR) and middle-of-run (MOR) operation, as well as 80-90% less purge during end-of-run (EOR) operation. Furthermore, there is no requirement of additional compressor and liquid recycle oil pump, and optionally, no need of a hot separator (HDO-HPHS) upstream the HP stripper and a dewaxing feed pump. Smaller plot space is then needed due to less equipment and not least, overall, there is a lower carbon footprint due to less need for steel in connection with equipment, less power and hydrogen requirements.

[0042] The ISOM cold separator, which may be used interchangeably with the term “dewax- ing / HCR HP separator” is operated at approximately 1-5 bar, such as 1.5-2.5 bar higher than that of a HDO cold separator suitably used in step i-3) for separating said sour gas stream. This enables using the vapor from the downstream ISOM cold separator, i.e. the ISOM cold separator overhead stream, as a stripping gas in the HP stripper instead of using makeup gas, thereby enabling that the entire makeup gas available be sent via a smaller MUG compressor to the ISOM unit and optional HCR unit. This also results in a H2 / 0H ratio in the ISOM and optional HCR unit higher than that required without a requirement of purge in start-of-run (SOR) operation. Even where a small purge is required in end-of-run (EOR) operation to meet the H2 partial pressure at the HDO unit outlet, as mentioned above there is still 80-90% less purge gas.

[0043] There is enough stripping gas available to strip the H2S, NH3, CO, CO2 and H2O from the HDO stripper bottom stream, i.e. the feed to the ISOM unit. This also enables that instead of providing hydrogen to the ISOM optionally HCR by recycling a portion of the second hydrogen-rich recycle gas stream of step i-6) to any of the catalytic ISOM unit and HCR unit, and / or feeding a MUG gas via a MUG compressor to the HDO stripper bottom stream in step i-5), the MUG compressor is now dedicated to provide the required hydrogen to the ISOM optionally HCR unit, for instance by adding the hydrogen to the HP stripper bottom stream which is sent to the ISOM, while the stripping gas for the HP stripper is provided internally as said portion of the ISOM cold separator overhead vapor stream. Hence, in an embodiment, the process further comprises: providing a makeup gas (MUG), said MUG being a hydrogen gas, and supplying the entire portion thereof, via a MUG compressor, to said ISOM unit, preferably to the HDO stripper bottom stream in step i-5).

[0044] It is understood that the term “makeup gas (MUG)” means a hydrogen gas, for instance sourced from outside the battery limits of the process or plant.

[0045] In step i-3), the HDO stripper overhead stream is conducted to a HDO cold separator, and the HDO stripper overhead stream is suitably first at least partly condensed in e.g. an air cooler. In step i-6), the isomerized, optionally hydrocracked, effluent stream effluent stream to the ISOM cold separator stream is suitably first at least partly condensed in e.g. and air cooler.

[0046] As used herein, HDO encompasses also decarboxylation.

[0047] Particularly when treating renewable feedstocks, in the hydrotreating the oxygen in the feedstock is mainly removed as H2O, which gives a paraffinic fuel consisting of paraffins with the same number for carbon atoms as in the backbone of the triglycerides. This is called the hydrodeoxygenation (HDO) pathway. Oxygen can also be removed by decarboxylation pathway, which generates CO2 instead of H2O:

[0048] HDO pathway: C17H34COOH + 3.5 H2 «-> CisHss + 2 H2O Decarboxylation pathway: C17H34COOH + 0.5 H2 C17H36 + CO2

[0049] The material catalytically active in HDO, typically comprises an active metal (sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum, but possibly also either elemental noble metals such as platinum and / or palladium) and a refractory support (such as alumina, silica or titania, or combinations thereof).

[0050] Hydrotreating (here HDO) conditions involve a temperature in the interval 250-400°C, a pressure in the interval 30-150 bar, and a liquid hourly space velocity (LHSV) in the interval 0.1-2, optionally together with intermediate cooling by quenching with cold hydrogen, feed or product. As is well-known in the art, the term “hot separator” means a separation unit, such as a vapor-liquid separation vessel, where there is no dedicated outlet for withdrawing a liquid water stream, e.g. as a bottom water stream. In contrast to a hot separator, as also well-known in the art, the term “cold separator” means a separation unit arranged to operate at conditions for producing liquid water; hence, there is a dedicated outlet for withdrawing a bottom water stream. Typically also, wash water is injected to the feed to the cold separator, e.g. a high pressure separator, and the bottom water stream is withdrawn as a sour liquid water stream.

[0051] As is well-known in the art, the term “HDO stripper” means a stripping column where gaseous components of the hydrodeoxygenated effluent stream are stripped from the liquid components. The HDO stripper conducts the separation by means of a stripping medium, such as a hydrogen-rich stream.

[0052] In an embodiment, in step i-2) the hydrodeoxygenated effluent stream is directly conducted to the HDO stripper and the HDO stripper is a high-pressure stripper (HP stripper).

[0053] As defined above, the term “directly conducted” or “directly conducting” means that there are no intermediate units or process steps in between the corresponding process steps and associated process units. More generally, the term “directly” means that there is no intermediate unit or step changing the composition of a process stream.

[0054] Hence, the feature of step i-2) “the hydrodeoxygenated effluent stream is directly conducted to the HDO stripper” means for instance, that no HDO hot separator, such as a HDO high-pressure hot separator (HDO-HPHS), is provided upstream the HDO stripper, here a HP stripper. Thereby, the HDO-HPHS is eliminated, while its associated recycle oil pump is instead provided for supplying the HP stripper bottom stream to said ISOM unit. An additional pump, namely a dewaxing feed pump, otherwise required for pumping the HP stripper bottom stream where a HDO-HPHS is provided upstream, is also eliminated. Hence, preferably, no HDO-HPHS is provided in connection with the HDO stripper, i.e. a stand-alone HDO stripper is provided. As recited above, the HDO stripper is preferably a HP stripper, which operates at high pressure, i.e. 20-80 barg, such as 30-70 barg, for instance at 40, 50 or 60 barg, as measured by the pressure of the HP stripper overhead stream.

[0055] In another embodiment, in step i-2) the hydrodeoxygenated effluent stream is indirectly conducted to the HDO stripper, by providing a HDO hot separator, such as a HDO- HPHS, upstream the HDO stripper.

[0056] For instance:

[0057] - the HDO-HPHS operates at a pressure of 20-80 barg, such as 30-70 barg, thus at high pressure, and at a temperature of 150-300°C such as 180-250°C;

[0058] - the HDO stripper operates at 2-15 barg, such as 4-10 barg, thus at low pressure;

[0059] - the HDO-HPHS and the HDO stripper operate at the same temperature of 150-300°C such as 180-250°C, said temperature being defined as the inlet temperature of the hydrodeoxygenated effluent stream to the HDO-HPHS or the inlet temperature of the HDO-HPHS bottom stream to the HDO stripper.

[0060] Thus, the HDO stripper is, in an embodiment where a HDO-HPHS is provided upstream, a low pressure (LP) HDO stripper operating in the pressure range of 4 to 10 barg, suitably also with a portion of the second hydrogen-rich gas as the stripping medium.

[0061] For the purposes of the present application, the term “same temperature” or “same pressure” means within 10% of a given temperature in °C. For instance, the inlet temperature to the HDO-HPHS is 230°C and the inlet temperature to the HDO stripper is within 10% thereof, such as up to about 250°C.

[0062] The HDO-HPHS operates at high pressure, i.e. 20-80 barg, such as 30-70 barg, for instance at 40, 50 or 60 barg, as measured by the pressure of the HDO-HPHS overhead stream.

[0063] The HDO stripper operates, in connection with this embodiment where the HDO-HPHS is provided upstream, at low pressure, i.e. at 2-15 barg, such as 4-10 barg, for instance at as 5, 6, 7, 8, 9, 10 barg or 11 , 12, 13, 14 barg, as measured by the pressure at the HDO-HPHS bottom stream being conducted to the HDO stripper or by the pressure of the HDO stripper overhead stream. The HDO stripper may thus be understood in this embodiment as a low pressure (LP) hot stripper, or simply a LP stripper.

[0064] For instance, the HDO-HPHS operates at 230-250°C and 45-65 barg.

[0065] For instance, the HDO stripper operates at 230-250°C and 4-10 barg.

[0066] In another embodiment, where a HDO-HPHS is provided upstream, a HP stripper operating at the same pressure of the HDO hot separator, is provided, suitably also with a portion of the second hydrogen-rich gas as the stripping medium.

[0067] Again, for the purposes of the present application, the term “same temperature” or “same pressure” means within 10%, e.g. within 10% of a given temperature in °C.

[0068] As is well-known in the art, a HP stripper is a distillation column comprising a number of trays arranged to receive a hydrocarbon gas and liquid feed comprising impurities, such as any of H2S, CO, CO2, H2O, NH3, and under the addition of a stripping gas, typically hydrogen, separates the impurities in an overhead gas stream and the impurities- depleted hydrocarbon in the bottom stream. Suitably, the HDO stripper operates at full reflux mode and not withdrawing any product which ensures the stripped straight chain paraffins going out from HDO stripper overhead, again being sent back to the HDO stripper. Furthermore, this also enables improved removal of the impurities, particularly H2S and H2O being generated as a result of the HDO reactions in the HDO unit.

[0069] The term “barg”, denotes as is well known, the pressure in bar above atmospheric pressure, the atmospheric pressure being about 1 bar.

[0070] The HDO-HPHS temperature is maintained at 150-300°C, such as 180-250°C, for instance 200-230°C, through steam pressure. The steam is generated by heat recovery from HDO effluent.

[0071] In an embodiment, step i-5) comprises:

[0072] - providing a hydrocracking (HCR) unit downstream the ISOM unit; and wherein step i-5) further comprises:

[0073] - directly conducting the first isomerized effluent stream to inlet of the hydrocracking (HCR) unit, for producing said isomerized and hydrocracked effluent stream; or

[0074] - upstream the HCR unit, conducting the first isomerized effluent stream to a ISOM high-pressure hot separator (ISOM-HPHS); withdrawing from the ISOM-HPHS a ISOM-HPHS overhead stream and a ISOM-HPHS bottom stream; conducting the ISOM-HPHS overhead stream to inlet of the HCR unit; and conducting the ISOM- HPHS bottom stream to outlet of the HCR unit for producing said isomerized and hydrocracked effluent stream.

[0075] It is understood that where the HCR unit is provided, said second isomerized effluent stream, this being at least a portion of the ISOM cold separator bottom stream, may also be regarded as a second isomerized and hydrocracked effluent stream. Hence, suitably, the term “second isomerized effluent stream” may be used interchangeably with the term “second isomerized and optionally hydrocracked effluent stream”.

[0076] The ISOM-HPHS overhead stream being flashed from the ISOM-HPHS, contains light hydrocarbons and hydrogen, and is suitably mixed with a fractionator bottom stream e.g. a heavy diesel stream, being withdrawn in connection with downstream separation step ii), as it will become apparent from a below embodiment.

[0077] Suitably, the conditions of the optional HDO-HPHS, are applicable to the ISOM-HPHS of the ISOM and HCR step.

[0078] The ISOM step, herein used interchangeably with the term “dewaxing step”, comprises the provision of the ISOM unit under the presence of a noble metal catalyst, and optionally also hydrocracking (HCR). In the dewaxing step, the wax content is reduced by isomerization under isomerization conditions and optionally also cracking, under the presence of hydrogen.

[0079] The material catalytically active in ISOM i.e. hydrodewaxing typically comprises an active metal (either elemental noble metals such as platinum and / or palladium), an acidic support (typically a molecular sieve showing high shape selectivity, and having a topology such as MOR, FER, MRE (more specifically MRE*), MWW, AEL, TON and MTT) and a refractory support (such as alumina, silica or titania, or combinations thereof).

[0080] ISOM conditions involve a temperature in the interval 250-400°C, a pressure in the interval 20-100 bar, and a liquid hourly space velocity (LHSV) in the interval 0.5-8, optionally together with intermediate cooling by quenching with cold hydrogen, feed or product.

[0081] The material catalytically active in hydrocracking (HCR) is of similar nature to the material catalytically active in isomerization, and it typically comprises an active metal (either elemental noble metals such as platinum and / or palladium or sulfided base metals such as nickel, cobalt, tungsten and / or molybdenum), an acidic support (typically a molecular sieve showing high cracking activity, and having a topology such as MFI, BEA and FAU) and a refractory support (such as alumina, silica or titania, or combinations thereof). The difference to material catalytically active isomerization is typically the nature of the acidic support, which may be of a different structure (even amorphous silica- alumina) or have a different acidity e.g. due to silica:alumina ratio. It would be understood, that in the context of the present invention, there may also be a difference in the nature of the metals, e.g. the metals for HDW comprise a noble metal catalyst such as platinum, while the metals for hydrocracking may comprise a base metal such as nickel and / or molybdenum.

[0082] Hydrocracking (HCR) conditions involve a temperature in the interval 250-400°C, a pressure in the interval 30-150 bar, and a liquid hourly space velocity (LHSV) in the interval 0.5-8, optionally together with intermediate cooling by quenching with cold hydrogen, feed or product.

[0083] In an embodiment, in step i-4) the contact unit is a re-contact drum and the addition of said second isomerized effluent stream is carried out by mixing at least a portion thereof with the first hydrogen-rich recycle gas stream, upstream the re-contact drum.

[0084] As a portion of the vapor from the ISOM cold separator, i.e. the dewaxing / HCR HP separator, is used as stripping gas, the first hydrogen-rich recycle gas stream from the HP stripper of the HDO section cannot be routed to ISOM cold separator for re-contact, as this reduces the purity of the hydrogen-rich recycle gas to the catalytic HDO unit. The term “purity” means here the hydrogen concentration. So, to improve the purity of the hydrogen-rich recycle gas to the HDO, the ISOM cold separator bottom stream is re-contacted with the first hydrogen-rich recycle gas stream, in a re-contact drum to improve the purity of the combined hydrogen-rich recycle gas sent to the catalytic HDO unit. The re-contact drum is suitably a flash drum.

[0085] In an embodiment, in step i-4) the contact unit is a sponge column and the addition of said second isomerized effluent stream is conducted by directly feeding it to the sponge column. Thus, there is no prior mixing with the first hydrogen-rich recycle gas stream upstream the sponge column.

[0086] The re-contact drum provides a flash separation, while the sponge column suitably comprises a plurality of trays or a solid adsorbent material which enhances mass transfer compared to the re-contact drum and thereby enables better removal of lighter hydrocarbons such as C1-C3 hydrocarbons from the gas. A higher purity of the combined hydrogen-rich recycle gas stream to the catalytic HDO unit results, while the lighter hydrocarbons are carried over in the sponge column bottom effluent stream.

[0087] As is well-known in the art, a sponge column may be provided as an elongated cylindrical vessel typically packed with a solid adsorbent material, such as activated carbon or molecular sieves. Its primary purpose is to remove impurities, such as sulfur compounds, nitrogen compounds, and others, from hydrocarbon streams.

[0088] In an embodiment, a portion of the HDO stripper bottom stream of step i-5) is mixed with said combined hydrogen-rich recycle gas stream to the catalytic HDO unit.

[0089] The portion of the HDO stripper bottom stream of step i-5) serves as recycle liquid oil which is advantageously mixed with the combined hydrogen-rich recycle gas stream to the catalytic HDO unit, which thereby provides for the presence of H2S necessary for maintaining the HDO catalyst in its active, sulfided form, as well as keeping steel parts corrosion-free thus avoiding the need of expensive lining in HDO associated equipment, without resorting to external sulfur sources. The recycle oil serves also the purpose of diluting the hydrocarbonaceous feed, thus for controlling the exothermicity of the HDO unit. Said portion of the HDO stripper bottom of step i-5) is for instance diverted from the HDO stripper bottom at a point upstream the feeding point of said makeup gas (MUG) thereto.

[0090] In an embodiment, step i-6) further comprises withdrawing from said ISOM cold separator a bottom aqueous stream, e.g. a water stream, and providing at least a portion thereof as wash water for said HDO stripper overhead stream prior to separating said sour gas stream.

[0091] In connection with step i-3), the HDO stripper overhead stream being providing with the wash water is then suitably cooled in an air cooler prior to the separation of the sour gas stream in the HDO cold separator. A sour water stream is then withdrawn as the bottom stream in this separation, suitably in a cold separator, i.e. HDO stripper cold separator. The invention enables that the ISOM cold separator be operated at slightly higher pressure than the cold separator of the HDO stripper e.g. the HP stripper, hence the sour water from the ISOM cold separator can be used as wash water for the HDO stripper overhead stream without requiring an additional pump.

[0092] In an embodiment, step ii) comprises conducting the contact unit bottom effluent stream to a separation section comprising a product stripper and a fractionator; withdrawing from the separation section any of naphtha, jet, diesel or hydrotreated vegetable oil (HVO), as the hydrocarbon product; and wherein the process further comprises:

[0093] - withdrawing a fractionator bottom stream, such as a heavy diesel fraction, and mixing a portion thereof with said ISOM-HPHS overhead stream to said inlet to the HCR unit; or

[0094] - withdrawing a fractionator bottom stream, such as a heavy diesel fraction, and mixing a portion thereof with said HDO stripper bottom stream, suitably at a mixing point upstream the feeding point of said makeup gas (MUG) thereto.

[0095] By e.g. mixing a heavy diesel fraction with the ISOM-HPHS overhead stream to said inlet to the HCR unit, a more selective hydrocracking is possible. Suitably, a portion of the fractionator bottom stream is mixed with said ISOM-HPHS overhead stream to said inlet to the HCR unit and another portion of the fractionator bottom stream is mixed with the HDO stripper bottom stream.

[0096] In an embodiment, the renewable hydrocarbonaceous feed is obtained from a raw material of renewable origin selected from at least one of: plants, algae, animals, fish, vegetable oil refining, domestic waste, waste rich in plastic, industrial organic waste like tall oil or black liquor, or a feedstock derived from one or more oxygenates taken from the group consisting of: triglycerides, fatty acids, resin acids, ketones, aldehydes and alcohols, where said oxygenates originate from one or more of a biological source, a gasification process, a pyrolysis process, Fischer-Trop- sch synthesis, or methanol based synthesis; such as the raw feed stream originating from: a mixture rich in plastic, lignin, straw, lignocellulosic biomass, halide contaminated waste oils or aquatic biological material.

[0097] For instance, the renewable hydrocarbonaceous feed is used cooking oil.

[0098] For instance, the renewable feed is tall oil fatty acids.

[0099] For instance, the renewable hydrocarbonaceous feed is any of soy, canola, corn oil etc.)

[0100] For instance, the renewable hydrocarbonaceous feed is a free fatty acid feed such as a palm oil derived feed, e.g. palm oil mill effluent (POME).

[0101] In an embodiment, the renewable hydrocarbonaceous feed is co-processed with a hydrocarbonaceous feed of fossil origin, such as any of diesel, kerosene, naphtha, and vacuum gas oil (VGO).

[0102] In a second aspect of the invention, there is also provided a plant for carrying out the process according to any of the above embodiments of the first aspect of the invention.

[0103] Accordingly, there is provided a plant for carrying out the process according to any of the above process embodiments; the plant comprising:

[0104] - a hydroprocessing section comprising: -a catalytic hydrodeoxygenation (HDO) unit arranged to receive a renewable hydrocarbonaceous feed and provide a hydrodeoxygenated effluent stream;

[0105] - a HDO stripper arranged to receive the hydrodeoxygenated effluent stream and provide: a HDO stripper bottom stream and a HDO stripper overhead stream; wherein the HDO stripper comprises a HDO cold separator arranged to receive the HDO stripper overhead stream and provide a sour gas stream comprising at least one of the impurities: H2S, CO, CO2, H2O, NH3, as a first hydro- gen-rich recycle gas stream;

[0106] - a contact unit, such as any of a sponge column or a re-contact drum, arranged to receive: a second isomerized effluent stream from downstream hydroisomerization (ISOM) cold separator, and in which said ISOM cold separator is arranged to receive: a first isomerized effluent stream, or an isomerized and hydrocracked effluent stream; and wherein said contact unit is arranged to provide: a contact unit bottom effluent stream, and a contact unit effluent gas stream comprising at least one of the impurities, in particular H2S;

[0107] - a recycle gas compressor arranged to receive at least a portion of the contact unit effluent gas stream as a combined hydrogen-rich recycle gas stream and supply the combined hydrogen-rich recycle gas stream to the catalytic HDO unit;

[0108] - a catalytic hydroisomerization (ISOM) unit arranged to receive the HDO stripper bottom stream and provide said first isomerized effluent stream;

[0109] - wherein said ISOM cold separator is arranged to receive: said first isomerized effluent stream, or an isomerized and hydrocracked effluent stream associated with an optional downstream hydrocracking (HCR) unit; and said ISOM cold separator is arranged provide: a ISOM cold separator overhead vapor stream and a ISOM cold separator bottom stream; and in which said second isomerized effluent stream is at least a portion of the ISOM cold separator bottom stream;

[0110] - a conduit arranged to recycle at least a portion or another portion of the ISOM cold separator overhead vapor stream to the HDO stripper;

[0111] - optionally, a separation section, preferably comprising a product stripper and a fractionator, wherein said separation section is arranged to receive the contact unit bottom effluent stream and separating therefrom a hydrocarbon product, preferably said hydrocarbon product being any of naphtha, jet, diesel or hydrotreated vegetable oil (HVO).

[0112] The term “conduit” means a process line, such as a pipe, carrying a given process stream.

[0113] The term “arranged to” may be used interchangeably with the term “configured to”.

[0114] Any of the embodiments and associated benefits in connection with the first aspect of the invention (process) may be used in connection with the second aspect of the invention (plant), or vice versa.

[0115] Advantages (benefits) of the invention include:

[0116] - Achieving the H2 / 0H ratio to the dewaxing / HCR section in more optimized way and also ensures enough stripping gas availability in HP stripper.

[0117] - No purge in SOR & MOR and 80-90% lower in EOR

[0118] - Lower CAPEX: smaller MUG compressor, no membrane separation unit or additional PSA unit associated with purge gas, as the purge gas is substantially reduced or eliminated.

[0119] - No HDO hot separator, in particular a HDO-HPHS and associated dewaxing feed pumps are required, resulting approximately in at least 2 MM EUR CAPEX savings for a 10,000 BPSD (barrels per stream day) unit.

[0120] - Lower OPEX: no dewaxing feed pump and smaller MUG compressor resulting in lower power, lower hydrogen losses and also no OPEX associated with membrane separation systems - as mentioned above.

[0121] - Smaller plot space is needed due to less equipment.

[0122] - No lining required for corrosion protection of the shell metallurgy of HDO associated equipment, such as pipes and feed / effluent heat exchangers.

[0123] - Overall, lower carbon footprint due to less steel, power and hydrogen requirements.

[0124] BRIEF DESCRIPTION OF DRAWINGS

[0125] Fig. 1 shows a current process and plant layout, thus according to the prior art, of a hydroprocessing process for HVO and SAF production. Fig. 2 shows another current process and plant layout, thus according to the prior art, of a hydroprocessing process for HVO and SAF production.

[0126] Fig. 3 shows a process and plant layout of a hydroprocessing process for HVO and SAF production, in accordance with an embodiment of the invention.

[0127] Fig. 4 shows a process and plant layout of a hydroprocessing process for HVO and SAF production, in accordance with another embodiment of the invention.

[0128] DETAILED DESCRIPTION

[0129] Fig. 1 shows a process and plant 100 according to a current two-stage hydroprocessing layout for HVO and SAF production. The process begins with the introduction of a feedstock of renewable origin 101 , i.e. a renewable hydrocarbonaceous feed, such as used cooking oil or tall oil fatty acids. This is then processed in a HDO unit 102 comprising a catalyst 102’ which produces hydrodeoxygenated effluent 103. This stream is conducted to HDO-HPHS 104 which provides a HDO-HPHS bottom stream 105 of which a stream is diverted as a first recycle oil stream 105’ and sent to the HDO unit 102 via recycle oil pump 106. From the HDO-HPHS 104, a HDO-HPHS overhead stream 107 is also withdrawn. The first recycle oil stream 105’ is supplied to the HDO unit 102 after preheating in a feed / effluent heat exchanger and a fired heater, as shown. Prior to the preheating, the first recycle oil stream 105’ is mixed with a hydro- gen-rich recycle gas stream 147”, and after the preheating, further combined with renewable feedstock 101 to provide inlet HDO stream 10T.

[0130] The rest 105” of the HDO-HPHS bottom stream 105 is conducted to HDO stripper 108, from which a HDO stripper bottom stream 109 and a HDO stripper overhead stream 111 are withdrawn. The HDO stripper overhead stream 111 is combined with the HDO- HPHS overheat stream 107 into overhead stream 113, mixed with wash water 115 (also denoted as “A”), cooled in air cooler 114 into overhead stream 117 and then sent to a HDO cold separator 116. From the HDO cold separator 116, suitably provided as a stripper reflux drum, a bottom stream 121 is supplied as a full reflux to the HDO stripper 108, while a sour water stream 119 is also withdrawn. A sour gas stream 125 comprising at least one of the impurities H2S, CO, CO2, H2O, NH3 is separated, and a significant excess purge gas 125’ is diverted therefrom. The other portion 125” of the sour gas stream 125 is sent to the ISOM cold separator 126, by first mixing with isomerized and hydrocracked effluent stream 141 , under the prior addition of wash water 143 and cooling in air cooler 124.

[0131] A makeup gas (MUG) compressor 112 is associated with the HP stripper 108 for providing MUG i.e. hydrogen gas 123. A portion 123’ of the compressed MUG is used as stripping medium in the HP stripper 108, and another portion 123” is supplied to the HDO stripper bottom stream 109’ being fed via dewaxing feed pump 110 to the ISOM unit 118 comprising a catalyst 118’, thereby providing the required H2 / 0H ratio. A hydrocracking (HCR) unit 122 comprising a catalyst 122’ is provided downstream the ISOM unit 118. From the ISOM unit 118 a first isomerized effluent stream 131 is supplied to a ISOM high-pressure hot separator (ISOM-HPHS) 120; whereby a ISOM- HPHS overhead stream 135 and a ISOM-HPHS bottom stream 133 are withdrawn. The ISOM-HPHS overhead stream 135 is conducted to inlet of the HCR unit upon mixing with fractionator bottom stream 159” into inlet feed stream 137. The ISOM-HPHS bottom stream 133 is conducted to outlet 139 of the HCR unit for producing isomerized and hydrocracked effluent stream 141.

[0132] From the ISOM cold separator 126, wash water 115 (“A”) is sent via pump 128 as the wash water for the HDO stripper overhead stream 113, as mentioned above. A ISOM cold separator bottom stream 145, 145’, 145” is also withdrawn and sent to downstream separation section comprising: a product stripper 134 under the addition of steam 161 , and a fractionator 136. From the product stripper 136 light hydrocarbons products are withdrawn, e.g. off-gas 149 and light naphtha 151. A product stripper bottom stream 153 is withdrawn, from which a diesel product 153” is diverted, while another portion 153’ is supplied to the fractionator 136 under the production of heavy naphtha 155, and light diesel, or jet fuel for use as SAF 157. A fractionator bottom stream 159 is withdrawn from which a heavy diesel product or HVO 159” may be diverted. The other portion 159’ is then sent via hydrocarbon feed pump 138 as stream 159” to inlet of HCR unit, by combining with the ISOM-HPHS overhead stream 135, as explained above. From the ISOM cold separator 126 a ISOM cold separator overhead vapor stream 147 is withdrawn, sent to knock-out drum 130 to remove excess water, thereby providing a hydrogen-rich recycle gas stream 147’. A recycle gas compressor 132 supplies then the compressed hydrogen-rich recycle gas 147” to the HDO unit 102.

[0133] Fig. 2 shows a process and plant 200 according to a current two-stage hydroprocessing layout for HVO and SAF production. The layout is as in Fig. 1 with numerals starting from 200 instead. The only difference with respect to Fig. 1 is that other portion 259’ of the fractionator bottom stream 259 is sent via hydrocarbon feed pump 238 to a mixing point with said HDO stripper bottom stream 209, 209’. From the ISOM unit 218 a first isomerized effluent stream 231 is supplied directly to HCR unit 222, for producing isomerized and hydrocracked effluent stream 241.

[0134] Fig. 3 shows a process and plant 300 in accordance with an embodiment of the invention in which the contact unit as a sponge column. The process begins with the introduction of a feedstock of renewable origin 301 , i.e. a renewable hydrocarbonaceous feed, such as used cooking oil or tall oil fatty acids. This is then processed in a HDO unit 302 comprising a catalyst 302’ which produces hydrodeoxygenated effluent 303. This effluent stream 303 is conducted to a HDO stripper 308, from which a HDO stripper bottom stream 309 and a HDO stripper overhead stream 311 are withdrawn. The HDO stripper overhead stream 311 is mixed with wash water 315 (also denoted as “A”), cooled in air cooler 314 into overhead stream 317 and then sent to a HDO cold separator 316, thereby separating from the HDO stripper overhead stream a sour gas stream comprising at least one of the impurities: H2S, CO, CO2, H2O, NH3, as a first hydrogen-rich recycle gas stream 325. From the HDO cold separator 316, suitably provided as a stripper reflux drum, a bottom stream 321 is supplied as a full reflux to the HDO stripper 308, while a sour water stream 319 is also withdrawn. The first hydrogenrich recycle gas stream 325 comprising at least one of the impurities H2S, CO, CO2, H2O, NH3 is separated, and now a minor, if any, purge gas 325’ is diverted therefrom. The other portion 325” is sent to contact unit, here a sponge column 330. The sponge column 330 operates under the addition of: a second hydrogen-rich recycle gas stream 347” and a second isomerized effluent stream 345 from downstream separation in a hydroisomerization (ISOM) cold separator 326 of a first isomerized effluent stream 331 . From the contact unit (sponge column) 330 the following streams are withdrawn: a contact unit bottom effluent stream 365 comprising the hydrocarbon product, and a contact unit effluent gas stream 363 comprising at least one of the impurities, in particular H2S. This stream 363, also referred to as “treat gas”, and having now a higher purity in terms of hydrogen concentration, is recycled via a recycle gas compressor 332 as a combined hydrogen-rich recycle gas stream 363, 363’ to the HDO unit 302.

[0135] The HDO stripper bottom stream 309, 309’ is conducted via recycle oil pump 310 to catalytic hydroisomerization (ISOM) unit 318 comprising a catalyst 318’ for producing said first isomerized effluent stream 331. The recycle oil pump 310 is now sufficient also for the provision of the feed to the ISOM unit 318, instead of requiring a dedicated recycle oil pump in connection with a HDO-HPHS and a separate dedicated dewaxing feed pump in connection with the HDO stripper, e.g. HP stripper. A portion 309” of the HDO stripper bottom stream 309’ being recycled is mixed with said combined hydro- gen-rich recycle gas stream 363’ to the HDO unit 302. A makeup gas (MUG) i.e. a hydrogen gas 323 is provided, compressed into stream 323’ via makeup gas compressor 312 and supplied entirely to the HDO stripper bottom stream 309’” thereby providing the required H2 / 0H ratio for the dewaxing and optional hydrocracking. A hydrocracking (HCR) unit 322 comprising a catalyst 322 is thus provided downstream the ISOM unit 318. From the ISOM unit 318 the first isomerized effluent stream 331 is supplied to a ISOM high-pressure hot separator (ISOM-HPHS) 320, whereby a ISOM-HPHS overhead stream 335 and a ISOM-HPHS bottom stream 333 are withdrawn. The ISOM- HPHS overhead stream 335 is conducted to inlet of the HCR unit 322 by mixing with fractionator bottom stream 359” into inlet feed stream 337. The ISOM-HPHS bottom stream 333 is conducted to outlet 339 of the HCR unit for producing isomerized and hydrocracked effluent stream 341 . The isomerized and hydrocracked effluent stream 341 is mixed with wash water 343, cooled in air cooler 324 and conducted to ISOM cold separator 326. A ISOM cold separator overhead vapor stream 347 and a ISOM cold separator bottom stream 345 are withdrawn, in which: said second hydrogen-rich recycle gas stream 347” is a portion of the ISOM cold separator overhead vapor stream 347 and said second isomerized effluent stream 345 is at least a portion of the ISOM cold separator bottom stream. At least a portion 347’, more specifically here a portion 347’, also understood as another portion 347’ of the ISOM cold separator overhead vapor stream 347, is recycled to the HDO stripper 308. The bottom effluent stream 365 of the sponge column 330 comprises hydrocarbon products. These are separated in a separation section comprising a product stripper 334 under the addition of steam 361, and a fractionator 336. From the product stripper 334 light hydrocarbons products are withdrawn, e.g. off-gas 349 and light naphtha 351. A product stripper bottom stream 353 is withdrawn, from which a diesel product 353” is diverted, while another portion 353’ is supplied to the fractionator 336 under the production of heavy naphtha 355, and light diesel, or jet fuel for use as SAF 357. A fractionator bottom stream 359 is withdrawn from which a heavy diesel product or HVO 359” may be diverted. The other portion 359’ is then sent via hydrocarbon feed pump 338 as stream 359” to inlet of HCR unit, by combining with the ISOM-HPHS overhead stream 335, as explained above.

[0136] Fig. 4 shows a process and plant 400 in accordance with another embodiment of the invention in which the contact unit as a sponge column. The layout is as in Fig. 3 with numerals starting from 400 instead. The only difference with respect to Fig. 3 is that the other portion 459’ of the fractionator bottom stream 459 is sent via hydrocarbon feed pump 438 as stream 459” to a mixing point with said HDO stripper bottom stream 409”. From the ISOM unit 418 a first isomerized effluent stream 431 is supplied directly to HCR unit 422, for producing isomerized and hydrocracked effluent stream 441.

[0137] EXAMPLES

[0138] The following table provides a comparison of the layouts:

[0139] Current Scheme 1 corresponds to Fig. 1 (prior art)

[0140] Current Scheme 2 corresponds to Fig. 2 (prior art)

[0141] Invention Scheme 1A corresponds to Fig. 3.

[0142] Invention Scheme 2A corresponds to Fig. 4.

[0143] Invention Scheme 1 (no figure) but corresponds to Fig. 3 with the exception that the contact unit is a re-contact unit instead of a sponge column and the addition of said second isomerized effluent stream is carried out by mixing at least a portion thereof with the first hydrogen-rich recycle gas stream, upstream the re-contact drum.

[0144] Invention Scheme 2 (no figure) but corresponds to Fig. 4 with the exception that the contact unit is a re-contact unit instead of a sponge column and the addition of said second isomerized effluent stream is carried out by mixing at least a portion thereof with the first hydrogen-rich recycle gas stream, upstream the re-contact drum.

[0145]

[0146] HDO CS: HDO cold separator; DW CS: ISOM (Dewaxing) cold separator; Stripping gas: makeup gas (MUG); DW feed pump: dewaxing feed pump; REAC: reactor effluent cooler duty; Hot separator: HDO- HPHS. “Base - 2” means savings of 2 MM EUR for a 10,000 BPSD (barrels per stream day) unit.

Claims

CLAIMS1 . A process for producing a hydrocarbon product from a renewable hydrocarbona- ceous feed, said process comprising the steps of: i) hydroprocessing the renewable hydrocarbonaceous feed, comprising: i-1) conducting the renewable hydrocarbonaceous feed stream to a catalytic hydrodeoxygenation (HDO) unit comprising a catalyst for producing a hydrodeoxygenated effluent stream; i-2) conducting the hydrodeoxygenated effluent stream to a HDO stripper and withdrawing therefrom a HDO stripper bottom stream and a HDO stripper overhead stream; i-3) separating from the HDO stripper overhead stream a sour gas stream comprising at least one of the impurities: H2S, CO, CO2, H2O, NH3, as a first hydrogen-rich recycle gas stream; i-4) conducting the first hydrogen-rich recycle gas stream to a contact unit, such as any of a sponge column or a re-contact drum, under the addition of: a second isomerized effluent stream from downstream separation in a hydroisomerization (ISOM) cold separator receiving: a first isomerized effluent stream, or an isomerized and hydrocracked effluent stream; withdrawing from the contact unit: a contact unit bottom effluent stream, and a contact unit effluent gas stream comprising at least one of the impurities, in particular H2S; and recycling via a recycle gas compressor at least a portion of the contact unit effluent gas stream as a combined hydrogen-rich recycle gas stream to the catalytic HDO unit; i-5) conducting the HDO stripper bottom stream to a catalytic hydroisomerization (ISOM) unit and producing said first isomerized effluent stream; i-6) conducting said first isomerized effluent stream, or an isomerized and hydrocracked effluent stream associated with an optional downstream hydrocracking (HCR) unit, to said ISOM cold separator and withdrawing therefrom: a ISOM cold separator overhead vapor stream and a ISOM cold separator bottom stream; and wherein said second isomerized effluent stream is at least a portion of the ISOM cold separator bottom stream; i-7) recycling at least a portion or another a portion of the ISOM cold separator overhead vapor stream of step i-6) to the HDO stripper.

2. Process according to claim 1 , wherein the process further comprises:ii) separating, from the contact unit bottom effluent stream, said hydrocarbon product.

3. Process according to any of claims 1-2, wherein said step i-4) is under the addition to the contact unit of a second hydrogen-rich recycle gas stream upstream and / or downstream the contact unit; wherein the second hydrogen-rich recycle gas stream is a portion of the ISOM cold separator overhead vapor stream; and wherein the addition of the second hydrogen-rich recycle gas stream is immediately upstream the contact unit by directly conducting the second hydrogen-rich recycle gas to the contact unit, and / or the addition of the second hydrogen-rich recycle gas stream is immediately downstream the contact unit by directly conducting the second hydrogen-rich recycle gas to the contact unit effluent gas stream upstream the recycle gas compressor.

4. Process according to any of claims 1-3, wherein the process further comprises: providing a makeup gas (MUG), said MUG being a hydrogen gas, and supplying the entire portion thereof, via a MUG compressor, to said ISOM unit, preferably to the HDO stripper bottom stream in step i-5).

5. Process according to any of claims 1-4, wherein: in step i-2), the hydrodeoxygenated effluent stream is directly conducted to the HDO stripper and the HDO stripper is a high-pressure stripper (HP stripper).

6. Process according to any of claims 1-5, wherein step i-5) comprises:- providing a hydrocracking (HCR) unit downstream the ISOM unit; and wherein step i-5) further comprises:- directly conducting the first isomerized effluent stream to inlet of the hydrocracking (HCR) unit, for producing said isomerized and hydrocracked effluent stream; or- upstream the HCR unit, conducting the first isomerized effluent stream to a ISOM high-pressure hot separator (ISOM-HPHS); withdrawing from the ISOM-HPHS a ISOM-HPHS overhead stream and a ISOM-HPHS bottom stream; conducting the ISOM-HPHS overhead stream to inlet of the HCR unit; and conducting the ISOM- HPHS bottom stream to outlet of the HCR unit for producing said isomerized and hydrocracked effluent stream.

7. Process according to any of claims 1-6, wherein in step i-4) the contact unit is a recontact drum and the addition of said second isomerized effluent stream is carried out by mixing at least a portion thereof with the first hydrogen-rich recycle gas stream, upstream the re-contact drum.

8. Process according to any of claims 1-6, wherein in step i-4) the contact unit is a sponge column and the addition of said second isomerized effluent stream is conducted by directly feeding it to the sponge column.

9. Process according to any of claims 1-8, wherein a portion of the HDO stripper bottom stream of step i-5) is mixed with said combined hydrogen-rich recycle gas stream to the catalytic HDO unit.

10. Process according to any of claims 1-9, wherein step i-6) further comprises withdrawing from said ISOM cold separator a bottom aqueous stream, e.g. a water stream, and providing at least a portion thereof as wash water for said HDO stripper overhead stream prior to separating said sour gas stream.

11. Process according to any of claims 1-10, wherein: step ii) comprises conducting the contact unit bottom effluent stream to a separation section comprising a product stripper and a fractionator; withdrawing from the separation section any of naphtha, jet, diesel or hydrotreated vegetable oil (HVO), as the hydrocarbon product; and wherein the process further comprises:- withdrawing a fractionator bottom stream, such as a heavy diesel fraction, and mixing at least a portion thereof with said ISOM-HPHS overhead stream to said inlet to the HCR unit; or- withdrawing a fractionator bottom stream, such as a heavy diesel fraction, and mixing at least a portion thereof with said HDO stripper bottom stream, suitably at a mixing point upstream the feeding point of said makeup gas (MUG) thereto.

12. Process according to any of claims 1-11 , wherein the renewable hydrocarbona- ceous feed is obtained from a raw material of renewable origin selected from at least one of: plants, algae, animals, fish, vegetable oil refining, domestic waste, waste rich in plastic, industrial organic waste like tall oil or black liquor, or a feedstock derived from one or more oxygenates taken from the group consisting of: triglycerides, fatty acids, resin acids, ketones, aldehydes and alcohols, where said oxygenates originate from one or more of a biological source, a gasification process, a pyrolysis process, Fischer-Trop- sch synthesis, or methanol based synthesis; such as the raw feed stream originating from: a mixture rich in plastic, lignin, straw, lignocellulosic biomass, halide contaminated waste oils or aquatic biological material.

13. Process according to any of claims 1-12, wherein the renewable hydrocarbona- ceous feed is co-processed with a hydrocarbonaceous feed of fossil origin, such as any of diesel, kerosene, naphtha, and vacuum gas oil (VGO).

14. Plant for carrying out the process according to any of claims 1-13; the plant comprising:- a hydroprocessing section comprising:-acatalytic hydrodeoxygenation (HDO) unit arranged to receive a renewable hydrocarbonaceous feed and provide a hydrodeoxygenated effluent stream;- a HDO stripper arranged to receive the hydrodeoxygenated effluent stream and provide: a HDO stripper bottom stream and a HDO stripper overhead stream; wherein the HDO stripper comprises a HDO cold separator arranged to receive the HDO stripper overhead stream and provide a sour gas stream comprising at least one of the impurities: H2S, CO, CO2, H2O, NH3, as a first hydro- gen-rich recycle gas stream;- a contact unit, such as any of a sponge column or a re-contact drum, arranged to receive: a second isomerized effluent stream from downstream hydroisomerization (ISOM) cold separator, and in which said ISOM cold separator is arranged to receive: a first isomerized effluent stream, or an isomerized and hydrocracked effluent stream;and wherein said contact unit is arranged to provide: a contact unit bottom effluent stream, and a contact unit effluent gas stream comprising at least one of the impurities, in particular H2S;- a recycle gas compressor arranged to receive at least a portion of the contact unit effluent gas stream as a combined hydrogen-rich recycle gas stream and supply the combined hydrogen-rich recycle gas stream to the catalytic HDO unit;- a catalytic hydroisomerization (ISOM) unit arranged to receive the HDO stripper bottom stream and provide said first isomerized effluent stream;- wherein said ISOM cold separator is arranged to receive: said first isomerized effluent stream, or an isomerized and hydrocracked effluent stream associated with an optional downstream hydrocracking (HCR) unit; and said ISOM cold separator is arranged provide: a ISOM cold separator overhead vapor stream and a ISOM cold separator bottom stream; and in which said second isomerized effluent stream is at least a portion of the ISOM cold separator bottom stream;- a conduit arranged to recycle at least a portion or another portion of the ISOM cold separator overhead vapor stream to the HDO stripper;- optionally, a separation section, preferably comprising a product stripper and a fractionator, wherein said separation section is arranged to receive the contact unit bottom effluent stream and separating therefrom a hydrocarbon product, preferably said hydrocarbon product being any of naphtha, jet, diesel or hydrotreated vegetable oil (HVO).

Images