WO2025219299A1

WO2025219299A1 - Hydroprocessing of renewable feeds for producing hydrocarbon products

Info

Publication number: WO2025219299A1
Application number: PCT/EP2025/060169
Authority: WO
Inventors: Shubhasis Chakraborty; Raktim ROY
Original assignee: Haldor Topsoe AS
Current assignee: Topsoe AS
Priority date: 2024-04-19
Filing date: 2025-04-14
Publication date: 2025-10-23
Anticipated expiration: 2026-10-19

Abstract

The invention relates to a process and plant for producing a hydrocarbon product from a renewable hydrocarbonaceous feedstock. The process includes hydroprocessing the renewable hydrocarbonaceous feedstock, which involves conducting the feed stream to a catalytic hydrodeoxygenation (HDO) unit to produce a hydrodeoxygenated effluent stream. This stream is then conducted to a hot separator and a cold separator, with portions of the overhead stream recycled back to the catalytic HDO unit. The bottom stream from the hot separator is conducted to a stripper, with the overhead stream combined with the bottom stream from said cold separator. Impurities are removed from the combined stream, and the resulting sour gas stream is conducted to a separator. The bottom stream from the stripper is conducted to a catalytic hydroisomerization (ISOM) unit to produce an isomerized effluent stream, which is then conducted to a cold separator. The hydrocarbon product, such as jet fuel for use as sustainable aviation fuel and/or hydrotreated vegetable oil (HVO), is then separated from the bottom stream of the cold separator.

Description

Title: Hydroprocessing of renewable feeds for producing hydrocarbon products

TECHNICAL FIELD

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).

BACKGROUND

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.

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 make-up gas from a make-up 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.

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 lower its freeze point while light diesel may be taken as a motor fuel. 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.

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.

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.

Despite the advancements in this field, there are still challenges that need to be addressed. For instance, the high-pressure operation of the stripper overhead section and its overhead drum can lead to operational difficulties and increased costs. Additionally, the high hydrogen requirement in the high-pressure stripper can also be a limiting factor in the overall efficiency and cost-effectiveness of the process. Therefore, there is a need for improved processes and plants (systems) for the hydroprocessing of renewable feedstocks that can address these challenges. There is also a need for process and a plant that enable future revamps and grass root designs for renewable hydroprocessing.

SUMMARY

In accordance with embodiments, a process is provided for producing a hydrocarbon product from a renewable hydrocarbonaceous feed. The process involves hydroprocessing the renewable hydrocarbonaceous feed in a catalytic hydrodeoxygenation (HDO) unit to produce a hydrodeoxygenated effluent stream. This stream is then conducted to a HDO hot separator, in particular a HDO high-pressure hot separator (HDO- HPHS), and a HDO cold separator, with portions of the HDO cold separator overhead stream being recycled back to the catalytic HDO unit as part of a first hydrogen-rich recycle gas stream. At least a portion of the HDO hot separator bottom stream is conducted to a HDO stripper, and the HDO stripper bottom stream is conducted to a catalytic hydroisomerization (ISOM) unit to produce an isomerized effluent stream. This ISOM effluent stream is then separated in a ISOM cold separator, with portions of the ISOM cold separator overhead vapor stream being recycled back to the catalytic ISOM unit. The hydrocarbon product is then separated from the ISOM cold separator bottom stream.

In accordance with other embodiments, the process may further involve recycling a portion of a second hydrogen-rich recycle gas stream, by diverting a portion of the ISOM cold separator overhead vapor stream, to the catalytic HDO unit or the HDO stripper. The process may also involve operating the HDO hot separator and the HDO stripper at specific pressures and temperatures, and may involve combining the HDO stripper overhead stream with the HDO cold separator bottom stream in a HDO stripper reflux drum. The process may also involve removing impurities from the sour gas stream withdrawn from the HDO stripper in a separator such as an amine absorber, and the process may further involve hydrocracking in a catalytic hydrocracking zone after the hydroisomerization to produce the isomerized and thereby also hydrocracked effluent stream, i.e. an isomerized and hydrocracked effluent stream. In yet other embodiments, the process may involve withdrawing a first recycle oil stream from the HDO hot separator bottom stream and supplying it to the catalytic HDO unit after preheating only in a feed/effluent heat exchanger of the HDO unit. The process may also involve combining the first recycle oil stream with the renewable feedstock after preheating. The process may also involve conducting the ISOM cold separator bottom stream to a product stripper and a fractionator to withdraw various product streams. The renewable hydrocarbonaceous feed may be obtained from a variety of raw materials of renewable origin.

DETAILED DESCRIPTION

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 hot separator and withdrawing therefrom a HDO hot separator bottom stream and a HDO hot separator overhead stream; conducting the HDO hot separator overhead stream to a HDO cold separator and withdrawing therefrom a HDO cold separator bottom stream and a HDO cold separator overhead stream; and recycling via a first recycle gas compressor at least a portion of the HDO cold separator overhead stream as a first hydrogen-rich recycle gas stream to the catalytic HDO unit; i-3) conducting said HDO hot separator bottom stream to a HDO stripper, and withdrawing from the HDO stripper a HDO stripper bottom stream and a HDO stripper overhead stream; combining the HDO stripper overhead stream with the HDO cold separator bottom stream; separating from the thus combined stream a sour gas stream comprising at least one of the impurities H2S, CO, CO2, H2O, NH3; and conducting the sour gas stream to a separator, such as an amine absorber, for removing the impurities and producing a treated fuel gas; i-4) conducting the HDO stripper bottom stream to a catalytic hydroisomerization (ISOM) unit for producing an isomerized effluent stream; i-5) conducting the isomerized effluent stream to a ISOM cold separator and withdrawing therefrom a ISOM cold separator bottom stream and a ISOM cold separator overhead vapor stream; recycling via a second recycle gas compressor, i.e. a make-up gas (MUG) compressor, at least a portion of the ISOM cold separator overhead stream as a second hydrogen-rich recycle gas stream, i.e. as a make-up gas (MUG) stream, to the catalytic ISOM unit.

Suitably, the ISOM cold separator bottom stream is withdrawn as said hydrocarbon product.

For the purposes of the present application:

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.

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

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

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

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

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.

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.

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

The term “a hydrocarbon product” means one or more hydrocarbon products. A hydrocarbon product is for instance the ISOM cold separator bottom 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 stabilized naphtha.

More generally, the use of the indefinite article “a” or “an” in connection with an item means one or more. For instance, also, a feed/effluent heat exchanger means one or more feed/effluent heat exchangers.

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.

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

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 dewaxing, and optional hydrocracking in a hydrocracking (HCR) unit. Two separate reactor effluent cold separators are used for the two stages keeping them separate. Further, a HDO hot separator is provided in connection with the HDO stripper, which i.a. enables that the size of the HDO stripper to be reduced. The cost of the HDO hot separator and a smaller HDO stripper is also lower than the cost of an original stand-alone HDO stripper, i.e. an original high-pressure (HP) stripper. The requirements for any stripping medium in the second separation unit are also reduced.

The invention enables also significant reduction of energy consumption compared to a layout (process or plant) without the HDO hot separator.

It would be understood that the overhead stream of the HDO hot separator being conducted to the HDO cold separator, or the isomerized effluent stream to the ISOM cold separator stream are first at least partly condensed in e.g. and air cooler. As used herein, HDO encompasses also decarboxylation.

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:

HDO pathway: C17H34COOH + 3.5 H2 «-> CisHss + 2 H2O

Decarboxylation pathway: C17H34COOH + 0.5 H2 C17H36 + CO2

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).

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.

As is well-known in the art, the term “stripper”, herein the “HDO stripper”, means a stripping column where gaseous components of the HDO hot separator hydrotreated 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. In an embodiment, the process further comprises: ii) separating from the ISOM cold separator bottom stream said hydrocarbon product. The ISOM cold separator bottom stream is thereby refined via i.a. fractionation for producing the hydrocarbon product.

In an embodiment, step i-5) further comprises recycling a portion of the second hydro- gen-rich recycle gas stream to at least one of:

- the catalytic HDO unit, suitably by combining with the first hydrogen-rich recycle gas stream upstream the first recycle gas compressor;

- the HDO stripper, as stripping gas.

High integration is thereby achieved for reducing the need of externally sourcing hydrogen to the process. The gases from the HP cold separator of each loop, i.e. the HDO and ISOM-loop,are advantageously combined in a knock-out (KO) drum upstream the first recycle gas compressor. The HDO-loop may be referred to as “sour loop” and ISOM-loop may be referred to as “sweet loop”. In the ISOM-loop the MUG compressor is used to compress the second hydrogen-rich recycle gas stream, herein also referred to as make-up gas (MUG) stream, going into the sweet loop comprising the ISOM unit in once-through mode. A portion of MUG from the ISOM cold separator, i.e. sweet HP cold separator, is advantageously used as stripping gas in the HDO stripper to separate the impurities (CO, CO2, H2O, H2S, NH3) from the hydrodeoxygenated effluent stream. Thereby, the requirements for any stripping medium in the HDO stripper, such as the provision of hydrogen from external sources, is also reduced.

In an embodiment:

- the HDO hot separator, in particular a 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;

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

- the HDO hot separator, in particular a 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 hot separator or the inlet temperature of the HDO hot separator bottom stream to the HDO stripper. The HDO stripper is suitably therefore a low pressure (LP) HDO stripper operating in the pressure range of 4 to 10 barg, suitably also with a portion of the second hydrogenrich gas as the stripping medium. Several benefits result from this: the size of the LP HDO stripper is much smaller and less expensive, due to lower pressure, than a conventional high pressure (HP) stripper. Significant reduction in capital expenditures (CAPEX) are thus also achieved. In addition, the use of the second hydrogen-rich recycle stream from the ISOM cold separator, thus sweet gas from sweet HP cold separator, results in lower hydrogen requirement for LP HDO stripper used for removal of impurities compared to a conventional HP stripper, i.e. the amount of hydrogen required for operation of a HP stripper is much higher. Thereby also, operating expenditures (OPEX) are reduced.

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

The HDO hot separator, in particular a 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 hot separator overhead stream.

The HDO stripper operates 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 hot separator 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 as a low pressure (LP) hot stripper, or simply a LP HDO stripper.

For instance, the HDO hot separator, in particular a HDO-HPHS, operates at 230- 250°C and 45-65 barg.

For instance, the HDO stripper operates at 230-250°C and 4-10 barg. The term “barg”, denotes as is well known, the pressure in bar above atmospheric pressure, the atmospheric pressure being about 1 bar.

The HDO hot separator 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.

Accordingly, in an embodiment, the process comprises conducting the hydrodeoxygenated effluent stream to a steam generator, such as a waste-heat boiler using boiler feed water (BFW) as heat exchanging medium, for providing said operating temperature of 150-300°C, such as 180-250°C or 200-230°C. The waste-heat boiler is suitably arranged downstream a feed/effluent heat exchanger of the HDO unit, for instance immediately upstream the HDO hot separator, in particular a HDO-HPHS. The temperature of the hydrodeoxygenated effluent stream is thus reduced from e.g. 270°C to 250°C or 230°C at inlet to the HDO hot separator. Medium pressure steam is thereby also generated which may be use for driving other units in the process or plant, for instance for driving a downstream product stripper associated to said step ii) of separating from the ISOM cold separator bottom stream said hydrocarbon product.

In an embodiment, step i-2) further comprises withdrawing a first recycle oil stream from said HDO hot separator bottom stream and supplying it to the catalytic hydrodeoxygenation (HDO) unit after preheating only in a feed/effluent heat exchanger of the catalytic hydrodeoxygenation (HDO) unit.

The term “preheating only” means that there is no heat exchange with another heating unit other than a feed/effluent heat exchanger. The “another heating unit” is in particular a fired heater arranged to heat feed streams to the HDO unit. The fired heater is a sizable unit requiring the combustion of typically a hydrocarbon gas such as natural gas, thus conveying high CAPEX and OPEX.

The invention is useful in processes and plants requiring recycle oil for diluting the hy- drocarbonaceous feed, thus for controlling the exothermicity of the HDO unit, and the subsequent stripping of impurities such as sour components, for instance H2S, as well as water and carbon oxides, from the hydrocarbon liquid being sent to the subsequent process steps or downstream process units, here the ISOM step (dewaxing step) and associated ISOM unit.

The first recycle stream is exclusively from the HDO hot separator. The size of the HDO reactor effluent air cooler, HDO cold separator and HDO stripper is thus further reduced the most where the recycle oil stream is exclusively from the hot separator, as less feed is introduced into the HDO stripper.

The first recycle oil stream is taken from the HDO hot separator bottoms, at e.g. 180- 250°C and is then further heated in HDO effluent/recycle oil exchanger to achieve the required HDO reactor inlet temperature. Due to this first recycle oil being at higher temperature than conventional recycle oils, a HDO reactor fired heater which is typically associated with the HDO unit to preheat feed streams, is not necessary for normal or continuous operation. The fired heater may only be required as a start-up heater. This further enables a lower energy consumption and environmental emissions, in particular reduction of CO2 and thereby the carbon intensity (Cl) of the plant, as the use of a hydrocarbon fuel gas such as natural gas, typically required for generating the heat of the fired heater, is avoided.

In an embodiment, the process further comprises, prior to the preheating, combining the first recycle oil stream with at least one of: the first hydrogen-rich recycle gas stream; a portion of the second hydrogen-rich recycle gas stream; and after the preheating, further combining the first recycle oil stream with the renewable feedstock.

This provides the best arrangement for heat integration of the feed streams to the HDO unit.

In an embodiment, in step i-3), the combining of the HDO stripper overhead stream with the HDO cold separator bottom stream is conducted in a HDO stripper reflux drum, and the process further comprises withdrawing a bottom stream from the HDO stripper reflux drum and supplying it as a full reflux to the HDO stripper. Hence, 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.

The HDO cold separator and/or the ISOM cold separator operate at high pressure, this pressure suitably being said of 20-80 barg, such as 30-70 barg for the HDO cold separator, suitably also for the ISOM cold separator. These units may thus also be referred to HDO high pressure (HP) cold separator and ISOM high pressure (HP) cold separator. In contrast thereto, the HDO stripper reflux drum operates at low pressure, this pressure suitably being said 2-15 barg, such as 4-10 barg.

In an embodiment, in step i-3) the separator for removing the impurities and producing the treated fuel gas is at least one of an amine absorption unit, a caustic scrubber, and a sulfur absorbent. In a particular embodiment, the amine absorption unit is a low pressure (LP) amine absorber to which a lean amine is supplied and a rich amine is withdrawn. The above-mentioned separators are well known in the art.

In an embodiment, step i-4) further comprises hydrocracking in a catalytic hydrocracking zone, such as in a catalytic hydrocracking (HCR) unit, for producing said isomerized effluent stream.

Accordingly, the ISOM step, herein used interchangeably with the term “dewaxing step”, comprises using the ISOM unit under the presence of a noble metal catalyst, and 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. The isomerized effluent stream may thus be regarded as a isomerized and hydrocracked effluent stream.

It will be understood that, where no HCR unit is provided downstream the ISOM unit, the ISOM unit outlet is in direct fluid communication with the ISOM cold separator. Hence, the isomerized effluent stream is directly conducted to the ISOM cold separator. The isomerized effluent stream is directly supplied to the ISOM cold separator. It will be understood that, where a HCR unit is provided downstream the ISOM unit, the ISOM outlet is in direct fluid communication with the HCR unit while the HCR unit outlet is in direct fluid communication with the ISOM cold separator. The outlet the ISOM unit outlet is thereby in indirect fluid communication with the ISOM cold separator.

The term “directly conducted” may be used interchangeably with the term “directly supplied” and 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.

The material catalytically active in ISOM i.e. hydrodewaxing (or simply "dewaxing”) 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).

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.

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.

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.

In an embodiment, step ii) comprises: ii-1) conducting the ISOM cold separator bottom stream to a product stripper and withdrawing therefrom a product stripper overhead gas stream and a product stripper bottom stream; ii-2) conducting the product stripper bottom stream to a fractionator and withdrawing therefrom: a fractionator overhead gas stream comprising stabilized naphtha, and suitably withdrawing thereof a stabilized naphtha stream; a fractionator bottom product comprising diesel or HVO, and withdrawing thereof: a second recycle oil stream and supplying it to the HDO stripper, and/or a diesel or HVO product stream; a fractionator middle product stream comprising jet fuel, and suitably withdrawing thereof a jet fuel stream product for use as sustainable aviation fuel (SAF).

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

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

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

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).

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).

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.

Accordingly, the plant comprises:

- a catalytic hydrodeoxygenation (HDO) unit comprising a catalyst which is arranged to receive a renewable hydrocarbonaceous feed stream and provide a hydrodeoxygenated effluent stream;

- a HDO hot separator arranged to receive the hydrodeoxygenated effluent stream and provide: a HDO hot separator bottom stream and a HDO hot separator overhead stream; a HDO cold separator arranged to receive the HDO hot separator overhead stream and provide: a HDO cold separator bottom stream and a HDO cold separator overhead stream; a conduit and a first recycle gas compressor arranged to recycle at least a portion of the HDO cold separator overhead stream as a first hydrogen-rich recycle gas stream to the catalytic HDO unit;

- a HDO stripper arranged to receive said HDO hot separator bottom stream and provide: a HDO stripper bottom stream and a HDO stripper overhead stream; a unit, preferably a HDO stripper reflux drum, arranged to combine the HDO stripper overhead stream with the HDO cold separator bottom stream, and to provide: a sour gas stream comprising at least one of the impurities H2S, CO, CO2, H2O, NH3; a separator, such as an amine absorber, arranged to receive the sour gas stream and provide a treated fuel gas;

- a catalytic hydroisomerization (ISOM) unit arranged to receive the HDO stripper bottom stream and provide an isomerized effluent stream; - a ISOM cold separator arranged to receive the isomerized effluent stream and provide: a ISOM cold separator bottom stream, and a ISOM cold separator overhead vapor stream as a second hydrogen-rich recycle gas stream; a conduit and a second recycle gas compressor arranged to recycle at least a portion of the second hydrogenrich recycle gas stream to the catalytic ISOM unit.

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

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

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.

Advantages (benefits) of the invention include:

- Significant reduction of energy consumption compared to layout without HDO hot separator. Energy reduction of about 15 MW for an approx. 6000 BPSD unit. OPEX is accordingly also reduced.

- Significant reduction in CAPEX by using the HDO stripper being operated at low pressure (LP HDO stripper)

- Significant reduction of hydrogen consumption for stripping in the LP HDO stripper compared to a conventional HP stripper e.g. 100 to 500 Nm³/hr compared to 2000 Nm³/hr.

- Total CAPEX reduction compared to operation without HDO hot separator is about 2- 3 Million Euro compared to standard sweet loop layout

- The size of LP HDO stripper is much smaller and less expensive, due to lower pressure, than a conventional HP stripper.

The sole accompanying figure shows a process and plant 100 according to an embodiment of the invention.

The process (plant) comprises a so-called “sour loop” where impurities produced by the HDO unit are being treated, and a “sweet loop” comprising a ISOM unit and where no impurities are carried in the process lines as these have been removed in the sour loop.

Sour-loop:

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 hot separator, in particular a HDO-HPHS 104 which provides a HDO hot separator bottom stream 105 from which a first recycle oil stream 105’ is divided, and a HDO hot separator overhead stream 107. The first recycle oil stream 105’ from the HDO hot separator bottom stream 105 is supplied to the hydrodeoxygenation (HDO) unit 102 after preheating only in a feed/effluent heat exchanger (not shown) of the HDO unit. Prior to the preheating, the first recycle oil stream 105’ is combined with first hydrogen-rich recycle gas stream 111”, and after the preheating, further combined with renewable feedstock 101 to provide inlet HDO stream 10T.

The HDO hot separator overhead stream 107 is then cooled in an air cooler (not shown) and conducted to HDO cold separator 104’. The HDO hot separator 104 and HDO cold separator 104’ operate at high pressure (20-80 barg). From the latter unit, a HDO cold separator bottom stream 109 and a HDO cold separator overhead stream 111 , as well as a sour water stream 113, are withdrawn. At least a portion of the HDO cold separator overhead stream 111 is recycled via a first recycle gas compressor 108 as first hydrogen-rich recycle gas stream 111’, 111” to the HDO unit 102. A makeup gas (MUG) stream 135^IV rich in hydrogen from downstream ISOM loop (sweet loop) may also be provided downstream the first recycle gas compressor 108, as shown in the figure.

The rest 105” of the HDO hot separator bottom stream 105 is conducted to a HDO stripper 110, from which a HDO stripper bottom stream 117 and a HDO stripper overhead stream 119 are withdrawn. The HDO stripper overhead stream 119 is combined with the HDO cold separator bottom stream 109 in a HDO stripper reflux drum 110’. The HDO stripper 110 and HDO stripper reflux drum 110’ operate at low pressure (2-15 barg). A bottom stream 121 from the HDO stripper reflux drum 110’ is supplied as a full reflux to the HDO stripper 110, while a sour water stream 123 is also withdrawn. A sour gas stream 125 comprising at least one of the impurities H2S, CO, CO2, H2O, NH3 is separated, optionally combined with off-gases 127 from other units of the process or plant, and then conducted to a separator 112 such as an amine absorber, for removing the impurities and producing a treated fuel gas 129.

Sweet-loop:

The HDO stripper bottom stream 117, 117’ is conducted to a hydroisomerization (ISOM) unit 114 comprising a ISOM (dewaxing) catalyst 114’ for producing an isomerized effluent stream 131 which is then optionally conducted to a hydrocracking (HCR) unit 116 comprising a HCR catalyst 116’. The thus isomerized effluent stream 131 , 13T, optionally also hydrocracked effluent stream 131”, is then cooled in a feed/efflu- ent heat exchanger (not shown) of the ISOM or HCR unit as well as in an air cooler (not shown) and conducted to ISOM cold separator 118. From this unit, a ISOM cold separator bottom stream 133 and a ISOM cold separator overhead stream 135 are withdrawn, as so is a sour water stream 137. The ISOM cold separator overhead stream 135 is withdrawn as a second hydrogen-rich recycle gas stream, of which at least a portion 135’ is provided via a second stage recycling to inlet of makeup gas (MUG) compressor 120 as MUG stream 135” to the ISOM unit 114 and/or HCR unit 116. Excess hydrogen 137 may also be provided, for instance from external sources. From the MUG compressor 120, optionally a portion 135’” is provided as quench-gas for reactor (reactor units) or other units, or another portion 135^IV is supplied downstream the first recycle gas compressor 108. A portion 135^v" of the second hydrogenrich recycle gas stream 135 is recycled to the HDO unit 102 by combining with the first hydrogen-rich recycle gas stream 111 upstream the first recycle gas compressor 108, suitably in an upstream knock-out (KO) drum (not shown). A portion 135^VI of the second hydrogen-rich recycle gas stream 135 is suitably also recycled to the HDO stripper 108, as stripping gas.

Separation of products:

From ISOM cold separator bottom stream 133 hydrocarbon products are separated. The ISOM cold separator bottom stream 133 is conducted to a product stripper 120, from which a product stripper overhead gas stream 145 and a product stripper bottom stream 137 are withdrawn. From the overhead gas 145 an off-gas stream and a stream comprising naphtha compounds (not shown) may be withdrawn. The product stripper bottom stream 137 is conducted to a fractionator 122, from which the following streams are withdrawn: a fractionator overhead gas stream 139 comprising stabilized naphtha, and suitably withdrawing thereof a stabilized naphtha stream; a fractionator middle product stream 143 comprising jet fuel, and suitably withdrawing thereof a jet fuel stream product for use as sustainable aviation fuel (SAF); a fractionator bottom product 141 comprising diesel or HVO. From the fractionator bottom product 141 a diesel or HVO product stream 14T is withdrawn. Suitably also, a second recycle oil stream 141” is divided and supplied to the HDO stripper 108.

Claims

1 . 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 hot separator and withdrawing therefrom a HDO hot separator bottom stream and a HDO hot separator overhead stream; conducting the HDO hot separator overhead stream to a HDO cold separator and withdrawing therefrom a HDO cold separator bottom stream and a HDO cold separator overhead stream; and recycling via a first recycle gas compressor at least a portion of the HDO cold separator overhead stream as a first hydrogen-rich recycle gas stream to the catalytic HDO unit; i-3) conducting said HDO hot separator bottom stream to a HDO stripper, and withdrawing from the HDO stripper a HDO stripper bottom stream and a HDO stripper overhead stream; combining the HDO stripper overhead stream with the HDO cold separator bottom stream; separating from the thus combined stream a sour gas stream comprising at least one of the impurities H2S, CO, CO2, H2O, NH3; and conducting the sour gas stream to a separator, such as an amine absorber, for removing the impurities and producing a treated fuel gas; i-4) conducting the HDO stripper bottom stream to a catalytic hydroisomerization (ISOM) unit for producing an isomerized effluent stream; i-5) conducting the isomerized effluent stream to a ISOM cold separator and withdrawing therefrom: a ISOM cold separator bottom stream, and a ISOM cold separator overhead vapor stream as a second hydrogen-rich recycle gas stream; recycling via a second recycle gas compressor at least a portion of the second hydrogen-rich recycle gas stream to the catalytic ISOM unit.

2. Process according to claim 1 , wherein the process further comprises: ii) separating from the ISOM cold separator bottom stream said hydrocarbon product.

3. Process according to any of claims 1-2, wherein step i-5) further comprises recycling a portion of the second hydrogen-rich recycle gas stream to at least one of:

- the HDO stripper, as stripping gas.

4. Process according to any of claims 1-3, wherein:

- the HDO hot separator operates at a pressure of 20-80 barg, such as 30-70 barg and at a temperature of 150-300°C, such as 180-250°C;

- the HDO stripper operates at 2-15 barg, such as 4-10 barg;

- the HDO hot separator 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 hot separator or the inlet temperature of the HDO hot separator bottom stream to the HDO stripper.

5. Process according to claim 4, wherein the process further comprises conducting the hydrodeoxygenated effluent stream to a steam generator, such as a waste-heat boiler using boiler feed water (BFW) as heat exchanging medium, for providing said operating temperature of 150-300°C, such as 180-250°C.

6. Process according to any of claims 1-5, wherein step i-2) further comprises withdrawing a first recycle oil stream from said HDO hot separator bottom stream and supplying it to the catalytic hydrodeoxygenation (HDO) unit after preheating only in a feed/effluent heat exchanger of the catalytic hydrodeoxygenation (HDO) unit.

7. Process according to claim 6, further comprising: prior to the preheating, combining the first recycle oil stream with at least one of: the first hydrogen-rich recycle gas stream; a portion of the second hydrogen-rich recycle gas stream; and after the preheating, further combining the first recycle oil stream with the renewable hydrocarbonaceous feedstock.

8. Process according to any of claims 1-7, wherein in step i-3), the combining of the HDO stripper overhead stream with the HDO cold separator bottom stream is conducted in a HDO stripper reflux drum, and the process further comprises withdrawing a bottom stream from the HDO stripper reflux drum and supplying it as a full reflux to the HDO stripper.

9. Process according to any of claims 1-8, wherein in step i-3) the separator for removing the impurities and producing the treated fuel gas is at least one of an amine absorption stage, a caustic scrubber, and a sulfur absorbent.

10. Process according to any of claims 1-9, wherein step i-4) further comprises hydrocracking in a catalytic hydrocracking zone, such as in a catalytic hydrocracking (HCR) unit, for producing said isomerized effluent stream.

11. Process according to any of claims 2-10, wherein step ii) comprises: ii-1) conducting the ISOM cold separator bottom stream to a product stripper and withdrawing therefrom a product stripper overhead gas stream and a product stripper bottom stream; ii-2) conducting the product stripper bottom stream to a fractionator and withdrawing therefrom: a fractionator overhead gas stream comprising stabilized naphtha, and suitably withdrawing thereof a stabilized naphtha stream; a fractionator bottom product comprising diesel or HVO, and withdrawing thereof: a second recycle oil stream and supplying it to the HDO stripper, and/or a diesel or HVO product stream; a fractionator middle product stream comprising jet fuel, and suitably withdrawing thereof a jet fuel stream product for use as sustainable aviation fuel (SAF).

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 catalytic hydroisomerization (ISOM) unit arranged to receive the HDO stripper bottom stream and provide an isomerized effluent stream;

- a ISOM cold separator arranged to receive the isomerized effluent stream and provide: a ISOM cold separator bottom stream, and a ISOM cold separator overhead vapor stream as a second hydrogen-rich recycle gas stream; a conduit and a second recycle gas compressor arranged to recycle at least a portion of the second hydrogenrich recycle gas stream to the catalytic ISOM unit.