Jet fuel plant and process

Abstract

A process for producing a jet fuel fraction (41), said process comprising steps of feeding at least one of a biogas stream (1), a carbon dioxide stream (2), or a methane stream (3), and at least a fraction of a tail gas recycle stream (32), to a reformer section (10) to provide a synthesis gas stream (11); feeding said synthesis gas stream (11, 22) to a synthesis section (30) to provide a stabilized condensate stream (31), a liquid wax stream (38), the tail gas recycle stream (32) and a concentrated oxygenate recycle stream (36); refining at said stabilized condensate stream (31) and liquid wax stream (38) in a refinery section (40) to provide a jet fuel fraction stream (41); and recycling said concentrated oxygenate recycle stream (36) to a biogas plant, and a plant for carrying out the process.

Description

[0001] JET FUEL PLANT AND PROCESS

[0002] Field of the Invention

[0003] The present invention relates to a plant producing a jet fuel fraction with effective use and recycling of various by-product streams in particular aqueous streams comprising oxygenates and aqueous and / or gaseous streams comprising hydrocarbons. A process for producing a jet fuel fraction is also provided. The plant and process of the present invention may also provide a jet fuel product. The present invention provides a process and a plant with a high overall carbon utilization for the exclusive production of a jet and / or jet fuel product. of the Invention

[0004] Jet fuels obtained from renewable sources reduces the CO2 emission associated with aviation compared to conventional fossil jet fuels. There is therefore a high demand for renewable jet fuels also called Sustainable Aviation Fuel (SAF).

[0005] The Fischer-Tropsch (FT) synthesis has for a long time been utilised for producing synthetic fuels from non-petroleum sources. The FT synthesis converts a synthesis gas into a syncrude of liquid hydrocarbons of different chain lengths and by-products such as tail gas and oxygenates. Presently, the liquid hydrocarbons are upgraded to a diesel fraction, a gasoline fraction and a jet fuel fraction, the tail-gas may be recycled or upgraded, and the oxygenates are removed as waste products needing further processing.

[0006] Due to the large demand for hydrocarbons in the jet fuel range obtained from renewable sources, and the fact that carbon from renewable sources is a limiting factor in the production of hydrocarbons, there is a need for a plant and a process for producing jet fuel that ensures that most of the carbon feedstock is turned into jet fuel with a high carbon efficiency.

[0007] The jet fuel derived from a FT synthesis cannot be directly substituted with the conventional petroleum-derived jet fuel, due to their low aromatic content. Jet fuel products derived from FT synthesis, therefore need to be blended with an aromatic component to comply with the specifications of industry jet fuel such as density, seal swell propensity and lubricity.

[0008] There is, therefore, a further need in the industry for a plant and a process that produces a jet fuel product, which can be directly substitutable with conventional petroleum- derived jet fuel.

[0009] Biogas is a gaseous renewable energy source that can be utilized for heating, electricity, and various other applications. Biogas is produced by decomposition of organic matter such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste under anaerobic conditions in a biogas reactor. The microorganisms present in the biogas reactor are further capable of digesting most hydrocarbon feedstocks.

[0010] It would therefore be desirable to provide a plant and a process for effective use of biogas and exploit the natural conversion of carbohydrates in a biogas reactor to improve the carbon utilization of jet fuel production.

[0011] A chemical plant for effective use of biogas for synthesis gas production is described in WO2023242356 Al.

[0012] A methanol plant for improved carbon utilization comprising a biomass digester, wherein hydrocarbon-containing off-gas streams are recycled to the biomass digester is described in WO2023242360 Al and WO2023242358 Al.

[0013] Object of the Invention

[0014] An object of the present invention is to provide a plant and a process for producing a jet fuel fraction and / or a jet fuel product with a high carbon efficiency.

[0015] A further object of the present invention is to provide a plant and a process for exclusively producing a jet fuel fraction and / or a jet fuel product, with all other byproduct streams recycled. A further object of the present invention is to provide a plant and a process for producing a jet fuel fraction from a biogas feed provided by a biogas plant.

[0016] A further objective of the present invention is to provide a plant and a process for producing a jet fuel fraction and / or a jet fuel product with a reduced greenhouse gas (GHG) footprint.

[0017] A further object of the present invention is to provide a plant and a process for producing a jet fuel fraction and / or a jet fuel product directly substitutable with conventional petroleum-derived jet fuel.

[0018] Description of the Invention

[0019] It has been found by the present inventor(s) that by recycling all by-product streams from a plant or process for producing a jet-fuel faction or jet-fuel product and only recovering the jet-fuel fraction or jet-fuel product, a high overall carbon utilisation of more than 90% or between 97-98% or more than 97% or more than 98% or more than 98.5% or more than 98.75% or about 99% or above 99% can be achieved for the production of the jet- fuel fraction or jet-fuel product.

[0020] One objective of the present invention is achieved by providing a plant for producing a jet fuel fraction, said plant comprising:

[0021] - a reformer section arranged to convert at least one of a biogas stream, a carbon dioxide stream, or a methane stream, and at least a fraction of a tail gas recycle stream into a synthesis gas stream;

[0022] - a synthesis section arranged to receive said synthesis gas stream and provide a stabilized condensate stream, a liquid wax stream, the tail gas recycle stream and a concentrated oxygenate recycle stream;

[0023] - a refinery section arranged to receive the stabilized condensate stream and the liquid wax stream and provide a jet fuel fraction stream; wherein said concentrated oxygenate recycle stream is recycled to a biogas plant.

[0024] Another objective of the present invention is achieved by providing a process for producing a jet fuel fraction, said process comprising steps of - feeding at least one of a biogas stream, a carbon dioxide stream, or a methane stream, and at least a fraction of a tail gas recycle stream, to a reformer section to provide a synthesis gas stream;

[0025] - feeding said synthesis gas stream to a synthesis section to provide a stabilized condensate stream, a liquid wax stream, the tail gas recycle stream and a concentrated oxygenate recycle stream;

[0026] - refining at said stabilized condensate stream and liquid wax stream in a refinery section to provide a jet fuel fraction stream; and

[0027] - recycling said concentrated oxygenate recycle stream to a biogas plant.

[0028] The inventors of the present invention have, surprisingly, discovered that by recycling the often disregarded oxygenates back to a biogas plant, the carbon efficiency of the plant can be increased considerably.

[0029] By recycling the oxygenates to a biogas plant, the present invention provides a process and a plant capable of producing a jet fuel fraction or a jet fuel product with an overall high carbon efficiency of more than 98% or more than 99%, because all carbon containing by-product streams are recycled for the exclusive production of the jet fuel fraction.

[0030] The concentrated oxygenates recycle stream comprises over 1% of the overall carbon and it is therefore impossible to reach a carbon efficiency of over 99% without the recycling of the oxygenates within the plant.

[0031] One embodiment of the present invention provides a plant for producing a jet fuel fraction, said plant comprising:

[0032] - a reformer section arranged to convert at least one of a biogas stream, a carbon dioxide stream, or a methane stream, and at least a fraction of a tail gas recycle stream into a synthesis gas stream;

[0033] - a synthesis section arranged to receive said synthesis gas stream and provide a stabilized condensate stream, a liquid wax stream, the tail gas recycle stream and a concentrated oxygenate recycle stream;

[0034] - a refinery section arranged to receive the stabilized condensate stream and the liquid wax stream and provide a jet fuel fraction stream; wherein said concentrated oxygenate recycle stream is recycled to a biogas plant and wherein at least a fraction of the tail gas recycle stream from the synthesis section is recycled back to the synthesis section as an internal tail gas recycle stream.

[0035] By recycling at least a part of the tail gas stream provided by the synthesis section a plant with higher utilization of the hydrocarbons is achieved.

[0036] In one embodiment the present invention provides a plant producing a jet fuel fraction, said plant comprising:

[0037] - a reformer section arranged to receive: o a biogas stream from a biogas plant; o a carbon dioxide stream; o at least a fraction of a tail gas recycle stream from the synthesis section; o a second gas hydrocarbon recycle stream from the synthesis section; o a first fraction of the second liquid hydrocarbon recycle stream from the synthesis section; o a first hydrocarbon recycle stream from the synthesis section; o an off-gas stream from distillation unit(s) of the refinery section, and o a liquid hydrocarbon recycle stream from distillation unit(s) of the refinery section; and and convert into a synthesis gas stream;

[0038] - a synthesis section arranged to receive: o said synthesis gas stream from the reformer section, wherein said synthesis gas stream is either

[0039] ■ the synthesis gas stream provided directly to the synthesis section; and / or

[0040] ■ a stream comprising the synthesis gas mixed with a fraction of the tail gas recycle stream and / or hydrogen stream; and / or

[0041] ■ a carbon dioxide lean synthesis gas stream provided by a carbon dioxide removal section after treating the synthesis gas stream from the reformer section; and / or

[0042] ■ a stream comprising the carbon dioxide lean synthesis gas stream provided by a carbon dioxide removal section after treating the synthesis gas stream from the reformer section mixed with a fraction of the tail gas recycle stream and / or hydrogen stream; and to provide a hydrogen stream, a liquid hydrocarbon stream and provide a stabilized condensate stream, a liquid wax stream, the tail gas recycle stream, a first hydrocarbon recycle stream, a concentrated oxygenate recycle stream, and a aqueous / water stream; wherein said concentrated oxygenate recycle stream is recycled to a biogas plant;

[0043] - a refinery section arranged to receive the stabilized condensate stream, a liquid wax stream, and a hydrogen stream and provide a jet fuel fraction stream, an off-gas stream from distillation unit(s) in refinery, and a liquid hydrocarbon recycle stream from distillation unit(s) in refinery; and

[0044] - a purge section arranged to receive a tail gas purge stream and provide a nitrogen-rich purge stream, and a liquid hydrocarbon stream.

[0045] Definitions

[0046] Biogas plant

[0047] In the following, the term “biogas plant” denotes a plant for producing biogas. The biogas plant may comprise one or more biogas reactors arranged to receive a biomass feed and to provide a biogas stream by conversion of the biomass into biogas by microorganism in one or more anaerobic biogas reactors. The biogas plant may be arranged to receive any biomass feed, such as agricultural waste as well as industrial waste and / or recycling streams from the plant provided by the present invention, and / or at least a fraction of one or more recycling streams comprising oxygenates.

[0048] The term “biogas reactor” is meant any anaerobic biogas producing facility. The term “biogas reactor” is therefore interchangeable with the terms “biomass digester”, “biogas digester”, “biomass reactor”, “anaerobic digester”, and “anaerobic reactor”.

[0049] Biogas stream

[0050] In the following, the term “biogas stream” denotes a gas stream from the combustion or decomposition of organic material comprising 50-75% Methane, 25-50% Carbon dioxide, 0-10% Nitrogen, 0-1% Hydrogen, and 0-1% Oxygen. The biogas stream may further comprise traces of hydrogen sulphide and argon.

[0051] Carbon dioxide stream

[0052] In the following, the term “carbon dioxide stream” denotes a stream comprising 90- 100% carbon dioxide. The carbon dioxide may be biogenic carbon dioxide, carbon dioxide obtained by carbon capture, or carbon dioxide obtained from any other source.

[0053] By the term “biogenic carbon dioxide” is meant carbon dioxide released as a result of combustion or decomposition of organic material, such as biomass and its derivatives.

[0054] In a preferred embodiment of the present invention, the carbon dioxide stream is a biogenic carbon dioxide stream, in which the vast majority is carbon dioxide with small amounts of inert gas. The biogenic carbon dioxide stream may comprise 90-100% Carbon dioxide, 0-10% Nitrogen, 0-2% Oxygen, 0-1% Argon.

[0055] Methane stream

[0056] In the following, the term “methane stream” denotes a stream comprising 90-100% methane. The methane may be a natural gas or methane obtained from any other source.

[0057] Steam

[0058] In the following, the term “steam” denotes water steam. stream

[0059] In the following, the term “hydrogen stream” denotes a stream comprising over 99% hydrogen, such as around 99.9% hydrogen. The hydrogen stream may be produced outside of the plant of the present invention, or the hydrogen stream may be a recycling stream of hydrogen produced and collected by the process and / or the plant provided by the present invention. The hydrogen may be produced by electrolysis, such as low temperature water electrolysis (LT-WE) or high temperature water electrolysis (HT- WE), or the hydrogen may be obtained from any other source.

[0060] The water electrolysis may be powered by renewable energy such as solar power, wind power and / or hydropower. Reformer section / s

[0061] By the term “reforming sections” or “reformer section” is understood one or more reformer unit(s) arranged to receive at least one of a biogas stream, a carbon dioxide stream, and a methane stream, and optionally one or more gas and / or liquid hydrocarbon recycle stream from a synthesis section, said gas and / or liquid recycle streams comprising hydrocarbons from a stabilizer column or any other unit suitable for removing volatile components and stabilizing, dividing and separating hydrocarbons according to chain length from hydrocarbon condensate in a synthesis section of the plant; and / or external tail gas recycle stream from a synthesis section of the plant; and / or a carbon dioxide rich recycle stream provided by a carbon dioxide removal section; and / or at least a fraction of a combined hydrocarbon recycle stream from a refinery section of the plant; and / or a liquid and / or gas hydrocarbon stream from a purge section; and / or one or more hydrogen streams; and / or a hydrogen recycle stream comprising sulphur from a refinery section of the plant and provide a synthesis gas stream.

[0062] As both the biogas and any recycle stream from a refinery section may comprise sulphur, the reformer section comprises one or more hydrogen desulphurization sections (HDS) upstream to the reformer and pre-reformer unit / s. The hydrogen recycle stream from the refinery section of the plant and optionally one or more second hydrogen streams are introduced to the biogas stream upstream to the one or more HDS units.

[0063] The one or more gas and / or liquid hydrocarbon recycle streams and / or external tail gas recycle stream from a synthesis section of the plant; and / or a carbon dioxide rich offgas recycle stream and / or one or more second hydrogen streams can be recycled either upstream and / or downstream from the one or more HDS units.

[0064] The reforming section may comprise one or more pre -reformers upstream to the one or more reformer units. The one or more pre-reformers break down higher hydrocarbons such as but not limited to propane, butane, and naphtha into methane, which allows for a more efficient reforming process downstream in the one or more reforming units.

[0065] The choice of whether to recycle at least a fraction of the tail gas as an external tail gas recycle stream and / or at least a fraction of one or more gas and / or liquid recycle streams comprising hydrocarbons from the synthesis section of the plant; and / or a carbon dioxide rich recycle stream; and / or at least a fraction of a combined hydrocarbon recycle stream from the refinery section; and / or a liquid hydrocarbon stream from a purge section and / or a hydrogen recycle stream from a refinery section back to the reformer section, typically depends on the technology (e.g., the type of reactor / s) utilised for the synthesis section and / or the refinery section. Thus, a skilled person in the art would know the relevant streams to recycle to the reformer section and if to recycle the streams upstream or downstream to the one or more hydrogen desulphurization sections depending on the technology utilised in the plant.

[0066] The one or more reformer units may be one or more autothermal reforming (ATR) units, one or more steam methane reforming (SMR) units, one or more electrically heated steam methane reforming (e-SMR) units, or one or more carbon dioxide reforming (also called dry reforming) units.

[0067] The one or more pre -reformers may be one or more adiabatic pre-reformers.

[0068] In an aspect of the invention, the reformer section comprises one or more autothermal reforming (ATR) units.

[0069] An additional feed of steam and oxygen to the reformer section is required for the embodiment with one or more ATR units.

[0070] In an embodiment, the reformer section comprises one or more electrified steam methane re-forming (e-SMR) units.

[0071] An additional feed of steam to the reformer section is required for the embodiment with one or more e-SMR units.

[0072] The e-SMR unit are advantageous, as they are more energy efficient than the ATR units. Thus, the e-SMR units require less energy and are therefore associated with a reduced production cost. However, due to the low maturity of the e-SMR technology, it may be advantageous to utilize one or more ATR units instead of e-SMR units, since faster scaling of the plant and the production output is possible with the more mature ATR technology.

[0073] In a preferred embodiment, the reformer section comprises one or more adiabatic prereformers and one or more electrified steam methane reforming (e-SMR) units and one or more waste heat boilers (WHB) downstream the one or more electrified steam methane reforming units.

[0074] An additional feed of steam to the reformer section is required due to both the one or more adiabatic pre-reformer and the one or more e-SMR units consuming steam.

[0075] The one or more adiabatic pre -reformers may be arranged upstream to the one or more e-SMR units, thereby reducing the load on the one or more e-SMR units. All recycled streams or all infeed streams provided to the reformer section may be provided upstream to the adiabatic pre-reformer.

[0076] Downstream the one or more e-SMR units, one or more WHBs are needed for heat recovery and cooling of the synthesis gas.

[0077] Additional feedstocks such as steam, a hydrogen stream, and / or an oxygen-rich stream may be supplied to the reformer section, as required, depending on the type of reforming and pre-reforming process to be carried out. For example, SMR and e-SMR require a steam feed, ATR requires a steam feed and an oxygen feed, and adiabatic pre -reformers require a steam feed.

[0078] In a preferred embodiment, the reformer section comprises one or more adiabatic prereformers and the one or more reformer units are one or more e-SMR units, which preferably is powered by renewable power sources. Compared to conventional SMR reactors, the required high temperatures of an e-SMR unit (1000°C) are achieved by directly heating the catalyst surface using electricity, instead of combusting part of the feed gas or natural gas. An e-SMR reactor is up to lOOx times smaller than conventional SMR reactor and has faster dynamics, due to the electric heating. In another preferred embodiment, the reformer section comprises one or more adiabatic pre-reformers and the one or more reformer unit are one or more ATR units. The ATR unit obtains the required heat / energy for the reforming process from internal combustion processes, such as combustion of hydrogen. The reformer section may preferably be connected to an electrolyser powered by a renewable energy source, wherein the electrolyser produces a hydrogen stream and an oxygen stream. The oxygen stream may then be fed to a combustion chamber in the one or more ATR units for the partial oxidation reaction between oxygen and methane or the oxidation reaction between oxygen and hydrogen. Overall, oxygen will react with hydrogen to form H2O and heat for the reforming reactions. The hydrogen stream may be fed to the one or more ATR units at an optimal location. A skilled person in the art would know, where it is optimal to add the hydrogen feedstock to the one or more ATR-units.

[0079] A reformer section comprising one or more ATR units and, therefore, requires additional electrolysis capacity compared to a reformer section comprising one or more e-SMR units, where the additional electrolysis capacity corresponds to the amount of oxygen needed in the ATR units. The H2O which is split into hydrogen and oxygen in the additional electrolysis capacity will react in the ATR units and form H2O and heat. The e-SMR units are therefore more energy efficient than the ATR units, since the e- SMR units have 100% efficiency on the power supplied, whereas the electrolyser is not 100% efficient. However, due to the low maturity of the e-SMR technology, it may be advantageous to utilize one or more ATR units instead of e-SMR units, since faster scaling of the plant and the production output is possible with the more mature ATR technology.

[0080] The amount of oxygen needed for the ATR unit depends on the composition of the streams provided to the reformer rection.

[0081] The amount of steam needed in the reformer section depends on the composition of the streams provided to the reformer section, and the desired H2 / CO ratio of the provided synthesis gas. For SMR and e-SMR a high excess of steam is required, this is expressed by the (molar) steam-to-carbon (S / C) ratio, to prevent carbonization in the reformer unit. Typically, the S / C ratio is around 1.0-2.0 for SMR or e-SMR and can be as low as 0.6 for ATR. A hydrogen stream may be provided upstream or downstream to the reformer section. A skilled person in the art knows where in the plant and process hydrogen is required. It may be advantageous to provide a small amount of hydrogen upstream to the reformer section, as it prevents carbonization in the one or more pre-reformers. Otherwise, it is preferred to provide the hydrogen stream downstream to the reformer section to avoid heating the hydrogen in the reformer section, which requires additional energy, and therefore is associated with increased production costs.

[0082] The reforming process only produces a portion of the hydrogen needed in the production of the jet fuel fraction, the remaining hydrogen needs to be imported either upstream or downstream to the reformer section. The more carbon dioxide contained in the feedstock to the reformer section, the more hydrogen needs to be imported.

[0083] The reformer section may further provide a condensate stream comprising condensates of gaseous components including water in the reformer section may be steam- stripped for hydrocarbon recovery thereby creating a hydrocarbon recycle stream that can be recycled to the one or more hydrogen desulphurization sections (HDS) and / or the one or more pre -reformer unit and / or the one or more reformer unit.

[0084] It is understood that all streams fed to the reforming unit(s) are pressurized, either separately or jointly, upstream of the reforming section. Depending on the type of reactor in the synthesis unit, the pressure(s) of the feed stream(s) is / are chosen so that the pressure within the reformer section is between 15 to 30 bar, or preferably between 20 and 25 bar.

[0085] Synthesis gas stream

[0086] In the following, the term “synthesis gas” (abbreviated to “syngas”) denotes a synthesis gas obtained from a reformer section comprising 40-70% hydrogen, 10-30% carbon monoxide, 2-20% carbon dioxide, 0.5-5% methane, and small amounts of other gasses such as argon, nitrogen, and hydrogen sulphide.

[0087] Carbon dioxide removal section In the following, the term “carbon dioxide removal section” denotes one or more units arranged to receive the synthesis gas stream from the reformer section and provide a carbon dioxide lean synthesis gas stream and a carbon dioxide rich off-gas stream and optionally a water condensate stream.

[0088] Depending on the type of carbon dioxide removal section, the carbon dioxide removal section may optionally be arranged to provide a water condensate stream, when cooling is applied before carbon dioxide removal, said water condensate stream may be steamstripped for hydrocarbon recovery thereby creating a hydrocarbon recycle stream that can be recycled to the reformer section of the plant, such as upstream to the one or more hydrogen desulphurization sections and / or the one or more pre -reformer unit and / or the one or more reformer unit and / or the carbon dioxide removal section. The carbon dioxide removal section may provide the water condensate stream prior to the removal of carbon dioxide from the synthesis gas.

[0089] In one embodiment the present invention provides a plant comprising a carbon dioxide removal section, wherein the carbon dioxide removal section may comprise one or more carbon dioxide Pressure-Swing adsorption (PSA) units and / or one or more cryogenic carbon dioxide separation units and / or one or more membrane carbon dioxide separation units.

[0090] Carbon dioxide lean synthesis gas stream

[0091] In the following, the term “carbon dioxide lean synthesis gas” denotes a synthesis gas obtained from a carbon dioxide removal section, where carbon dioxide is removed from the synthesis gas.

[0092] Total synthesis gas stream

[0093] In the following, the term “total synthesis gas” denotes a carbon dioxide lean synthesis gas stream from a carbon dioxide removal section or a synthesis gas stream from a reformer section after being mixed with one or more recycle streams and / or one or more hydrogen stream.

[0094] In one embodiment of the present invention the total synthesis gas is obtained by mixing a carbon dioxide lean synthesis gas stream from a carbon dioxide removal section with hydrogen stream and / or a fraction of the tail gas recycle stream from the synthesis section as an internal tail gas recycle stream upstream to a synthesis section whereinafter the total synthesis gas is provided to the synthesis section.

[0095] In another embodiment of the present invention, the total synthesis gas is obtained by mixing a synthesis gas stream from a reformer section with a hydrogen stream and / or a fraction of the tail gas recycle stream from the synthesis section as an internal tail gas recycle stream upstream to a synthesis section whereinafter the total synthesis gas is provided to the synthesis section.

[0096] Cabon dioxide rich off-gas stream

[0097] In the following, the term “carbon dioxide rich off-gas” denotes a carbon dioxide rich off-gas obtained from a carbon dioxide removal section, where the carbon dioxide is removed from a synthesis gas.

[0098] Stabilized condensate

[0099] In the following, the term “stabilized condensate” denotes a stream provided by a second separation unit of the synthesis section to the reformer section / s, comprising naphtha hydrocarbons (C5-C10) and distillate hydrocarbons (C11-C22) in the range of from 30-60mol% naphtha hydrocarbons and around 40-70mol% distillate hydrocarbons.

[0100] In one embodiment of the present invention the stabilized condensate provided by the second separation unit of the synthesis section of the plant provided by the invention comprises naphtha hydrocarbons (C5-C10) in the range from around 30mol% to 60mol%, such as between 35-55 mol%, preferably between 40-50 mol%, such as around 45% mol%, such as between 42-48 mol%; and distillate hydrocarbons (C11-C22) in the range from around 40 mol% to around 70 mol%, such as between 45-65 mol%, such as between 50-60 mol%, such as around 55 mol% or such as between 52-58 mol%.

[0101] The sum of wax streams and the stabilized condensate streams are considered the syncrude.

[0102] Tail gas recycle stream In the following the term “tail gas recycle” denotes an off-gas stream obtained from the one or more synthesis units such as one or more FT reactors of the synthesis section / s, preferably a Fischer-Tropsch tail-gas. The tail gas recycle stream comprises unconverted synthesis gas (CO and H2), light gas (e.g. CO2, N2, Ar), and light gaseous hydrocarbons (C1-C2). The tail gas recycle stream may also comprise lighter liquid hydrocarbons (C3-C4) not meeting the jet fuel specifications.

[0103] The tail gas recycle stream may be divided into separate recycle streams and / or purge streams. In one embodiment of the present invention a fraction of the tail gas recycle stream is recycled upstream to the synthesis section as an internal tail gas recycle stream. In another embodiment of the present invention a fraction of the tail gas recycle stream is recycled upstream to the reformer section as an external tail gas recycle stream. In yet another embodiment of the present invention a fraction of the tail gas recycle stream is removed from the plant as a tail gas purge, optionally after a further processing for hydrocarbon recovery before purging.

[0104] In one embodiment of the present invention the tail gas recycle stream is divided into three different streams:

[0105] - An external tail gas recycle stream that is recycled upstream to the reformer section / s and / or recycled to the reformer section / s;

[0106] - An internal tail gas recycle stream that is recycled upstream to the synthesis section / s and / or recycled to the synthesis section / s; and

[0107] - A tail gas purge stream that is purged from the plant, optionally after further processing for recovering hydrocarbons.

[0108] FT reactor gas stream

[0109] In the following, the term “FT reactor gas stream” denotes a gaseous stream collected from one or more synthesis unit / FT reactor in the synthesis section and provided to one or more first separation units in the synthesis section. The FT reactor gas stream comprises smaller hydrocarbons, unconverted synthesis gas, inert compounds and higher chain length hydrocarbons.

[0110] Second combined liquid and / or gas hydrocarbon recycle streams In the following, the terms “second combined liquid and / or gas hydrocarbon recycle streams” denotes one or more gas and / or liquid streams comprising hydrocarbons collected from one or more second separation unit of the synthesis section, such as from a condensate stabilizer column.

[0111] The second combined liquid and / or gas hydrocarbon recycle streams may be separated into one or more second gas hydrocarbon recycle streams and / or one or more second liquid hydrocarbon recycle streams.

[0112] The one or more second gas hydrocarbon recycle streams comprise light gasses (e.g. H2, CO, CO2, N2, Ar) and light hydrocarbons and may be recycled upstream to a reformer section of the plant.

[0113] The one or more second liquid hydrocarbon recycle streams comprise liquid hydrocarbons with a carbon range (C2-C8) not meeting the jet fuel specifications, wherein the one or more second liquid hydrocarbon recycle streams may be sent to an aromatization unit of a refinery section and / or recycled upstream to a reformer section of the plant and / or divided into two liquid hydrocarbons streams that are recycled upstream to a reformer section and sent to said aromatization unit, respectively

[0114] A person skilled in the art will know whether the one or more second liquid hydrocarbon recycle streams should be recycled upstream to a reformer section in their totality and / or provided to an aromatization unit of the reformer in their totality and / or divided, and correspondingly the amount or ratio of the one or more second liquid hydrocarbon recycle streams should be recycled to the aromatization unit and / or upstream to the reformer section, depending on the plant process parameters and desired products.

[0115] An aqueous oxygenates and hydrocarbon recycle stream

[0116] In the following, the term “an aqueous oxygenates and hydrocarbon recycle stream” denotes an aqueous stream collected from one or more first separation units of the synthesis section, such as from a three-phase separator, comprising a mixture of liquid hydrocarbons with a carbon range (C2-C8) not meeting the jet fuel specifications, oxygenates and water. The aqueous oxygenates and hydrocarbons recycle stream is sent to one or more third separation units, where the last traces of hydrocarbons and the remaining oxygenates (e.g. organic acids, alcohols) are separated from the aqueous stream.

[0117] First hydrocarbon recycle stream

[0118] In the following, the term “first hydrocarbon recycle stream” denotes a liquid stream comprising liquid hydrocarbons with a carbon range (C2-C8) not meeting the jet fuel specifications, collected from one or more third separation units of the synthesis section and recycled upstream to the reformer section and / or to the reformer section.

[0119] The one or more third separation units of the synthesis section are arranged for receiving an aqueous oxygenates and hydrocarbon recycle stream from the one or more first separation units of the synthesis section / s and to recover and separate any traces of hydrocarbons and oxygenates from the water, thereby providing three different streams, one comprising the recovered hydrocarbons, one comprising the oxygenates and one comprising predominantly water.

[0120] Any technology suitable for separating the hydrocarbons from the aqueous stream may be applied, such as macro porous polymer extraction.

[0121] Concentrated oxygenate recycle stream

[0122] In the following, the term “concentrated oxygenates recycle stream” denotes a concentrated aqueous stream comprising oxygenates such as alcohols, aldehydes, ketones, and organic acids, collected from the one or more third separation units of the synthesis section.

[0123] The one or more third separation units of the synthesis section are arranged for receiving an aqueous oxygenates and hydrocarbon recycle stream from the one or more first separation units of the synthesis section / s to recover and separate any traces of hydrocarbons and oxygenates from the water, thereby providing three different streams, one comprising the recovered hydrocarbons, one comprising the concentrated oxygenates and one comprising predominantly water.

[0124] Any technology suitable for concentrating and separating oxygenate from the aqueous oxygenates and hydrocarbon recycle stream may be applied, such as distillation. The concentrated oxygenates recycle stream is preferably recycled to a biogas plant for enhanced carbon utilization.

[0125] By recycling the oxygenates to a biogas plant, the present invention provides a process and a plant capable of producing a jet fuel fraction or a jet fuel product with an overall high carbon efficiency of more than 98% or more than 99%, because all carbon containing by-product streams are recycled for the exclusive production of the jet fuel fraction.

[0126] The concentrated oxygenates recycle stream comprises over 1% of the overall carbon, and it is therefore impossible to reach a carbon efficiency of over 99% without the recycling of the oxygenates within the plant. stream

[0127] In the following, the term “aqueous / water stream” denotes a stream comprised predominantly of water provided by the one or more third separation units of the synthesis section.

[0128] The one or more third separation units of the synthesis section are arranged for receiving an aqueous oxygenates and hydrocarbon recycle stream from the one or more first separation units of the synthesis section / s and to recover and separate any traces of hydrocarbons and oxygenates from the water, thereby providing three different streams, one comprising the recovered hydrocarbons, one comprising the oxygenates and one comprising predominantly water.

[0129] Any technology suitable for concentrating and separating oxygenate from the aqueous oxygenates and hydrocarbon recycle stream may be applied, such as distillation.

[0130] The aqueous stream may comprise traces of oxygenates such as alcohols, aldehydes, ketones, and organic acids and / or traces of hydrocarbons and may be recycled to a wastewater treatment plant and / or discharged as wastewater.

[0131] Liquid wax stream In the following, the term “liquid wax stream” denotes a liquid stream collected from one or more synthesis units / FT reactors of the synthesis section comprising a liquid wax hydrocarbons (C22+).

[0132] The liquid wax stream is sent to the refinery section of the plant for further processing.

[0133] Organic condensate stream

[0134] In the following, the term “organic condensate stream” denotes a liquid stream collected from one or more first separation units of the synthesis section and provided to one or more second separation unit of the synthesis section. The organic condensate stream comprises a mixture of hydrocarbons, mainly distillate hydrocarbons (C11-C22) and hydrocarbons in the naphtha range (C5-C10) and smaller contents of lighter hydrocarbons (C3-C4) and volatile components (C1-C2).

[0135] The organic condensate stream is provided to one or more second separation unit of the synthesis section for further processing.

[0136] Synthesis section

[0137] By the term “synthesis section” or “synthesis sections” is understood a section of the plant comprising one or more synthesis units, preferably one or more Fischer-Tropsch (abbreviated to FT) reactors, one or more first product separation units and one or more second product separation units, and optionally one or more third separation units and / or one or hydrogen desulphurization sections (HDS) and any other units required for a combination suitable for converting gas into stabilized condensate stream, a wax hydrocarbon stream, one or more liquid and / or gas and / or aqueous recycle streams and optionally one or more purge gas streams and / or one or more waste water streams.

[0138] The H2 / CO ratio of the synthesis gas and / or the total synthesis gas sent to the synthesis section plays a role in determining the chain growth probability for the FT product and this ratio can be directly managed by the amount of hydrogen sent to the synthesis section or mixed with the synthesis gas upstream the synthesis section. The synthesis gas composition fed to the low temperature FT reactor(s) may have a H2 / CO ratio between 1.5 and 2.5, preferably between 1.6 and 2.4, such as between 1.8 and 2.2, preferably between 1.9 and 2.1, such as slightly above 2. However, the optimal H2 / CO ratio depends on the type of FT catalyst utilized. For Co-based FT catalyst, a H2 / CO ratio around 2.05 is preferred.

[0139] The H2 / CO ratio may be adjusted by adding additional hydrogen upstream or downstream to the reformer section. Preferably a hydrogen stream is provided downstream to the reformer section, thereby adding additional hydrogen to the synthesis gas upstream to the synthesis section. The H2 / CO ratio may also be adjusted by adding additional methane to the reformer section.

[0140] Additional feeds such as a hydrogen stream and / or an internal tail gas recycle stream and / or a liquid hydrocarbon stream from a purge section of the plant may be supplied either upstream to the one or more FT reactors and / or upstream to the one or more first product separation units and / or upstream to the one or more second product separation units. The hydrogen stream may be supplied to adjust the H2 / CO ratio of the synthesis gas provided to the synthesis section and the internal tail gas recycle stream may be supplied to improve the composition of the stabilized condensate stream and the liquid was stream provided by the one or more second separation units of the synthesis section by increasing the content of higher hydrocarbons due to re-adsorption and reincorporation into the growing chains from the C3-C8 fraction of the tail gas recycle stream from the synthesis section recycled as an internal tail gas recycle stream. Recycling part of the tail gas recycle stream as an internal tail gas recycle stream to the one or more FT reactors of the synthesis section may further act as a temperature control for the Fischer-Tropsch reaction and, thus, help dampen the reaction.

[0141] It is understood that the plant may comprise equipment for heat exchange throughout the plant’s layout, such that throughout the plant any excess heat provided in different section / s and / or unit / s and / or during different processes of the plant can be recycled or reused in other sections / s and / or unit / s and / or processes.

[0142] Downstream to the synthesis section the layout of the plant may be simpler than prior art plants, as less emphasis is put on producing side products, as the plant layout of the present invention only exports a jet fuel fraction. Finer separation of the wax hydrocarbons (C22+) and higher hydrocarbons comprised in the stabilized condensate stream is therefore not important for the present invention, as all by-products are recycled.

[0143] Synthesis unit / FT reactor

[0144] By the term “synthesis unit” or “FT reactor” is understood one or more synthesis units, preferably one or more Fischer-Tropsch (abbreviated to FT) reactors.

[0145] Different types of synthesis units or reactors can be employed such as high temperature FT reactors or preferably low temperature FT reactors. In low temperature FT reactors, mainly two types of catalysts are employed, namely an iron (Fe) based or a cobalt (Co) based catalyst. Depending on the choice of catalysts, small differences in the temperature range of the reactor(s) must be employed. In a preferred embodiment, a cobalt (Co) based FT catalyst is used, as low temperature FT with a Co-based FT catalyst has a high product affinity for saturated hydrocarbons.

[0146] The synthesis units / FT reactor / s are arranged to receive any mixture of a synthesis gas stream from the reformer section / s and / or a carbon dioxide lean synthesis gas stream from a carbon dioxide removal section and / or optionally a total synthesis gas stream provided by mixing a synthesis gas stream from a reformer section and / or a carbon dioxide lean synthesis gas stream from a carbon dioxide removal section with a hydrogen stream and / or an internal tail gas recycle stream and / or optionally a liquid hydrocarbon stream from a purge section of the plant for providing liquid stream comprising hydrocarbon wax (C22+ hydrocarbons) and a gaseous stream comprising smaller hydrocarbons, unconverted synthesis gas, inert compounds and higher chain length hydrocarbons.

[0147] A person skilled in the art would know what temperatures to employ for the different types of catalysts for a successful FT synthesis.

[0148] The synthesis unit / FT reactor / s receive a syngas comprising CO and Fh and convert into a mixture of gaseous and liquid hydrocarbons and water, wherein the FT reactor receives a syngas stream and provides: - a liquid stream comprising hydrocarbon wax (C22+ hydrocarbons), said hydrocarbon wax stream provided to a refinery section / s in the plant for further processing, and

[0149] - a gaseous stream comprising smaller hydrocarbons, unconverted synthesis gas, inert compounds and higher chain length hydrocarbons to one or more first separation unit.

[0150] First separation unit / s

[0151] By the term “first separation unit / s” is understood one or more units arranged for receiving and processing FT reactor gas stream from the one or more synthesis units / FT reactors.

[0152] Different types of a first separation units can be employed, such as three-phase separators or any other separating unit suitable for removing volatile components and stabilizing, dividing and separating hydrocarbons according to chain length from hydrocarbon condensate.

[0153] In a preferred embodiment of the present invention, each first separation unit is arranged for receiving the gaseous stream from an FT reactor and provide three different streams:

[0154] - a tail gas recycle stream comprising unconverted synthesis gas (CO and H2), light gas (e.g. CO2, N2, Ar), and light gaseous hydrocarbons (C1-C2) and possibly lighter liquid hydrocarbons (C3-C4) not meeting the jet fuel specifications;

[0155] - a stream comprising organic condensates; and

[0156] - an aqueous oxygenates and hydrocarbon recycle stream.

[0157] In a preferred embodiment of the present invention, the tail gas stream is divided into at least two separate tail gas recycle streams, an internal tail gas recycle stream that is recycled to the syngas stream upstream of the FT reactor / s and an external tail gas recycle stream that is recycled to a reformer section / s of the plant and optionally a third tail gas stream as a purge tail gas, wherein the purge gas can be processed further for recovering hydrocarbons before it is purged. A person skilled in the art will know that the amount or ratio of the tail gas stream should be recycled to the FT reactor / s and / or recycled to the reformer section / s and / or purged.

[0158] The one or more first separation unit / s are arranged for providing an aqueous oxygenates and hydrocarbon recycle stream comprising oxygenates such as alcohols, aldehydes, ketones, and organic acids and hydrocarbons. In a preferred embodiment of the present invention, the aqueous stream comprising oxygenates provided by the first separation unit / s of the synthesis section of the plant is processed further in one or more third separation unit.

[0159] The one or more first separation unit / s are arranged for providing organic condensate stream to one or more second separation unit / s of the synthesis section / s of the plant, said organic condensate stream comprising organic condensates comprising a mixture of hydrocarbon condensates, mainly distillate hydrocarbons (C11-C22) and hydrocarbons in the naphtha range (C5-C10) and smaller contents of lighter hydrocarbons (C3-C4) and volatile components (C1-C2).

[0160] Second separation unit / s

[0161] By the term “second separation unit / s” is understood one or more units arranged for receiving and processing an organic condensate stream from one or more first separation unit / s.

[0162] Different types of a second separation units can be employed, such as a condensate stabilizer column or any other unit suitable for removing volatile components and optionally other hydrocarbons not meeting the jet fuel specifications from the organic condensate stream from the one or more first separation unit / s.

[0163] In one embodiment of the present invention, the one or more second separation units are stabilizer columns, arranged for receiving organic condensate stream from the one or more first separation unit / s and provide:

[0164] - combined second liquid and / or gas hydrocarbon recycle streams, wherein the combined second liquid and / or gas hydrocarbon recycle streams may be separated into one or more second gas hydrocarbon recycle stream and / or one or more second liquid hydrocarbon recycle streams, and

[0165] - stabilized condensate stream comprising naphtha hydrocarbons (C5-C10) and distillate hydrocarbons (C11-C22), to the refinery section / s of the plant.

[0166] The one or more second gas hydrocarbon recycle streams comprise light gasses (e.g. H2, CO, CO2, N2, Ar) and light hydrocarbons and may be recycled upstream to a reformer section of the plant.

[0167] The one or more second liquid hydrocarbon recycle streams comprise liquid hydrocarbons with a carbon range (C2-C8) not meeting the jet fuel specifications, wherein the one or more second liquid hydrocarbon recycle streams may be sent to an aromatic section and / or recycled upstream to a reformer section of the plant.

[0168] Third separation unit / s

[0169] By the term “third separation unit / s” is understood one or more units arranged for receiving and processing one or more aqueous oxygenates and hydrocarbon recycle streams from one or more first separation unit / s.

[0170] The one or more third separation units of the synthesis section are arranged for receiving one or more aqueous oxygenates and hydrocarbon recycle streams from the one or more first separation units of the synthesis section / s and to recover and separate any traces of hydrocarbons and oxygenates from the stream / water, thereby providing three different streams:

[0171] - one or more first hydrocarbons recycle stream comprising liquid hydrocarbons with a carbon range (C2-C8), that is recycled to the reformer section / s of the plant and / or recycled upstream to the reformer section of the plant;

[0172] - one or more concentrated oxygenates recycle stream comprising oxygenates such as alcohols, aldehydes, ketones, and organic acids, that is preferably recycled to a bioplant; and

[0173] - one or more aqueous / water stream comprising predominantly water, that is discharged as wastewater.

[0174] Refinery section / s By the term “refinery section” or “refinery sections” is understood a refinery section / s configured for refining the stabilized condensate stream and / or the liquid wax stream from the synthesis section to at least a jet fuel fraction. The refinery section / s may further provide a combined hydrocarbon recycle stream and / or a diesel product stream and / or a hydrogen recycle stream. The refinery section is arranged to receive the stabilized condensate stream from one or more second separation units of the synthesis section / s and / or a liquid wax hydrocarbons (C22+) stream from the one or more synthesis units / FT reactors of the synthesis section / s and provide one or more of the following streams: A combined hydrocarbon recycle stream and / or a jet fuel fraction stream and / or a diesel product stream and / or a jet fuel product stream.

[0175] The combined hydrocarbon recycle stream comprises different recycle streams from the refinery, including off-gas from one or more distillation unit / s and / or liquid hydrocarbon recycle stream from one or more distillation unit / s and / or off-gas recycle stream from one or more aromatization unit / s, wherein the combined hydrocarbon recycle stream may be recycled to the reformer section while the jet fuel fraction and / or the diesel product stream and / or jet fuel product stream are exported.

[0176] In one embodiment of the present invention the refinery section provides a hydrogen recycle stream comprising traces of sulphur, said hydrogen recycle stream may be recycled upstream to a desulphurization unit of the reformer section of the plant.

[0177] In one embodiment of the present invention, the refinery section comprises a hydrocracker unit is arranged to receive a stabilized condensate stream and a liquid wax hydrocarbons (C22+) stream from the synthesis section of the plant. The hydrocracker unit may be arranged to receive an additional hydrogen stream, as a hydrogen import is required for the hydrocracking process. Most of the hydrocarbon products obtained from the hydrocracker unit meets the jet fuel specifications and is exported as a jet fuel faction.

[0178] In the following the term hydrocracker unit is taken to include a section of the plant comprising one or more hydrocracker units and / or one or more hydroisomerization units and / or any other combination of treatment units suitable for receiving the stabilized condensate stream and a liquid wax hydrocarbons (C22+) and cracking / breaking down the long-chain hydrocarbon and to rearranging the carbon-carbon bonds for branched hydrocarbons for higher octane rating.

[0179] In one embodiment of the present invention the refinery section comprises one or more distillation units, such as one or more distillation columns and / or one or more fractionators and / or one or more extraction columns and / or one or more steam stripped columns.

[0180] In the following the term distillation unit is taken to mean any kind of unit that is suitable for separating and / or purifying the hydrocarbon stream for providing recyclable off-gas and / or recyclable liquid hydrocarbon stream and / or one or more condensed product streams.

[0181] In one embodiment of the present invention, the refinery section comprises an aromatization unit arranged to receive a second liquid hydrocarbon recycle stream from the synthesis section comprising C3-C8 hydrocarbons and / or a C3-C8 fraction stream from one or more hydrocracker units of the refinery section / s for providing an aromatic stream.

[0182] The aromatic stream provided by one or more aromatization unit of the refinery section / s, thereby provides the aromatics fraction of a jet fuel product. With the aromatization unit, the present invention provides a plant capable of producing the necessary aromatics for meeting the jet fuel specifications and thus a process for producing a jet fuel product.

[0183] The aromatization unit may further provide a small stream of C2 and methane which is recycled to the reformer section.

[0184] In an embodiment, the refinery section may further comprise an alkylation unit downstream to the aromatization unit, the alkylation unit is arranged to receive the aromatic stream and provide an alkylated aromatics stream. Not all the aromatics produced in the aromatization unit can be directly applied in a jet fuel product, as it could provide the jet fuel product with a too low flash point. This can be overcome by 1 an alkylation of the aromatics, thereby increasing the average molecular mass of the aromatics.

[0185] Jet fuel fraction stream

[0186] In the following, the term “jet fuel fraction” denotes a hydrocarbon fraction meeting the jet fuel specification. More specifically, a hydrocarbon fraction boiling in the range 150- 300°C, preferably in the range 175-285°C. This is typically saturated hydrocarbons such as alkanes and isoalkanes having a carbon range of predominantly C9-C16. A jet fuel fraction stream can either be provided by a refinery section and / or a blending section.

[0187] The jet fuel fraction may be blended with aromatics to provide a jet fuel product that can be directly substitutable with conventional petroleum-derived jet fuel.

[0188] Thereby, the plant produces a jet fuel fraction or a jet fuel product with an overall high carbon utilization of the carbon provided to the plant of more than 90%, because the first external recycle stream, is recycled for the exclusive production of the jet fuel fraction with no other by-products, such as gasoline and naphtha, exported from the plant.

[0189] A combined hydrocarbon recycle stream

[0190] By the term “combined hydrocarbon recycle stream” is understood a combination of different recycle streams from the refinery, including off-gas from one or more distillation unit / s and / or liquid hydrocarbon recycle stream from one or more distillation unit / s and / or off-gas recycle stream from one or more aromatization unit / s.

[0191] The distillation units and / or fractionators of the refinery section provide one or more off-gas recycle streams and one or more liquid hydrocarbon recycle streams that are recycled to the reformer section and / or upstream to the reformer section.

[0192] In one embodiment of the present invention the refinery section may comprise one or more aromatization units, wherein the one or more aromatization units may provide an off-gases recycle stream that is recycled to the reformer section and / or upstream to the reformer section. Jet fuel product stream

[0193] In the following, the term “jet fuel product” denotes a stream comprising a blend of a jet fuel fraction and aromatics meeting the jet fuel specifications, which can be directly substitutable with conventional petroleum-derived jet fuel. The jet fuel product stream may comprise 85-95% jet fuel fraction and 5-15% aromatics.

[0194] A jet fuel product stream can either be provided by a refinery section and / or a blending section.

[0195] Aromatic stream

[0196] By the term “aromatic stream” is understood a stream comprising aromatics provided by one or more aromatization unit / s of the refinery section / s.

[0197] In one embodiment of the present invention the aromatic stream is provided by the one or more aromatization unit / s of the refinery section / s to the one or more hydrocracker units of the refinery section / s, thereby enabling the refinery section to produce a jet fuel product.

[0198] Purge section

[0199] In the following, the term “purge section” denotes a section comprising one or more nitrogen removal units, arranged for receiving and removing nitrogen from at least a fraction of the tail gas stream from the synthesis section / s for providing a nitrogen-rich purge stream for purging and one or more cooling units, arranged for cooling down the gas stream for providing a liquid hydrocarbon stream comprising recovered hydrocarbon, that is recycled to the synthesis section / s.

[0200] The fraction of the tail gas stream entering the one or more cooling units of the purge section is cooled in order to separate as many hydrocarbons as possible, thereby providing a liquid hydrocarbon stream that is recycled to the synthesis section, preferably to the first separation unit of the synthesis section, and a purge gas, which is purged from the plant. The composition of the liquid hydrocarbon stream provided by the one or more cooling units depends on the final cooling temperature applied, which can be between 15 °C and -30 °C. In one embodiment of the present invention, the cooling units may comprise one or more re-compressors, for providing a liquid hydrocarbon stream comprising recovered hydrocarbon, that is recycled to the synthesis section / s.

[0201] In one embodiment of the present invention, the purge section may comprise one or more nitrogen removal units, such as nitrogen Pressure-Swing adsorption (PSA) units and / or one or more hydrogen membrane separation units.

[0202] In one embodiment, the purge section comprises a nitrogen PSA unit downstream to a hydrogen membrane separation unit. The hydrogen membrane separation unit is efficient for bulk separation, and the nitrogen PSA is suitable for producing a higher purity of the nitrogen-rich purge stream. A higher degree of separation can therefore be obtained than by either of the two processes alone.

[0203] The purge section may give rise to a small carbon loss. Thus, the nitrogen-rich purge stream may be the only place in the plant, where carbon is lost in the production process.

[0204] By exporting the nitrogen-rich purge stream and recycling the liquid hydrocarbon stream comprising recovered hydrocarbon to the synthesis section / s, the present invention provides a process and a plant capable of producing a jet fuel fraction or a jet fuel product with an overall high carbon efficiency of more than 98% or more than 99%, because all carbon containing by-product streams are recycled for the exclusive production of the jet fuel fraction. Thus, the nitrogen purge and the recycle of the liquid hydrocarbon stream comprising recovered hydrocarbon improves the overall carbon utilisation of the plant.

[0205] A possible build-up of argon as an inert gas in the process and / or the plant provided by the present invention, could also be a challenge, however, the purge section also removes argon from the from the liquid hydrocarbon stream comprising recovered hydrocarbon.

[0206] -rich stream

[0207] In the following, the term “nitrogen-rich purge” denotes a stream provided by a purge section comprised predominantly of nitrogen, though the stream can comprise traces of other gasses, such as argon. In one embodiment of the present invention the purge section receives at least a fraction of the tail gas stream from the synthesis section / s and removes nitrogen from the tail gas stream and provides a nitrogen-rich purge gas stream for purging, and a liquid hydrocarbon stream comprising recovered hydrocarbon, that nthesis section / s. stream

[0208] In the following, the term “liquid hydrocarbon stream” denotes a liquid stream comprising range of hydrocarbons not meeting the jet fuel specifications, predominantly in the range between C4 and Ce, often around C4-C5 depending on the temperature applied in cooling process in the purge section, preferably a temperature between -30 °C to 5 °C. provided by the purge section and recycled to the synthesis section / s.

[0209] In a preferred embodiment of the present invention, the purge section receives at least a fraction of the tail gas stream from the one or more first separation unit of the synthesis section / s and removes nitrogen from the tail gas stream providing a nitrogen-rich purge gas stream for purging and a liquid hydrocarbon stream comprising recovered hydrocarbon, that is recycled to the synthesis section / s.

[0210] Plant

[0211] An object of the invention is achieved by providing a plant for producing a jet fuel fraction, said plant comprising:

[0212] - a reformer section arranged to convert at least one of a biogas stream, a carbon dioxide stream, and a methane stream, into a synthesis gas stream;

[0213] - a synthesis section arranged to receive said synthesis gas stream and provide a stabilized condensate stream, a liquid was stream and a concentrated oxygenate recycle stream; and

[0214] - a refinery section arranged to receive said stabilized condensate stream and the liquid wax stream and provide a jet fuel fraction stream, wherein said concentrated oxygenate recycle stream is recycled to a biogas plant.

[0215] In one embodiment, the present invention provides a plant for producing a jet fuel fraction, said plant comprising: - a reformer section arranged to receive at least one of a biogas stream, a carbon dioxide stream, and a methane stream, said reformer section further arranged for receiving an external tail gas recycle stream and / or at least a fraction of a second combined liquid and / or gas hydrocarbon recycle streams and / or first hydrocarbon recycle stream and / or at least a fraction of a combined hydrocarbon refinery recycle stream and convert into a synthesis gas stream;

[0216] - a synthesis section arranged to receive said synthesis gas stream and provide a stabilized condensate stream, a liquid wax stream and a concentrated oxygenate recycle stream; and

[0217] - a refinery section arranged to receive said stabilized condensate stream and the liquid wax stream and provide a jet fuel fraction stream; wherein said concentrated oxygenate recycle stream is recycled to a biogas plant.

[0218] Oxygenates are difficult to reform due to the high exothermic process and risk of carbon formation on the reformer reactor’s catalytic bed and are therefore not easy to recycle to the reforming section. Furthermore, the oxygenates may comprise acids that can have a dampening effect on the catalytic effect of the reformer reactor’s catalytic bed. Oxygenates can therefore only be recycled to the reformer section in limited amounts or concentrations. However, by recycling the concentrated oxygenate recycle stream comprising oxygenates to a biogas plant as additional feed, the problems with recycling to the reformer section are overcome and the need for further treatment of the concentrated oxygenate recycle stream and any comprised oxygenates is avoided, as the microorganisms present in the biogas plant are capable of digesting and thereby breaking down the oxygenates to produce a methane-rich biogas, thereby reducing the complexity and cost of the plant and process for producing a jet fuel fraction.

[0219] It may be advantageous to recycle at least a fraction of the tail gas recycle stream as external tail gas recycle stream to the reformer section of the plant and / or as an internal tail gas recycle stream to the synthesis section of the plant, for reducing the amount of material sent to the refinery section, thereby, reducing the size of piping and other equipment in the refinery section, and reducing the amount material to be processed in the refinery section. In an embodiment, the plant may comprise fully electric equipment, and the plant may be entirely powered by renewable energy resources such as solar power, wind power and / or hydropower. Thereby, the plant becomes a green refinery plant.

[0220] It is understood that the plant can also comprise a supply of power.

[0221] All feedstocks provided to the plant may be non-petroleum feedstocks, thereby reducing the CO2 emission from the jet fuel fraction and or jet fuel product. The plant consequently produces renewable jet fuel (also called SAF).

[0222] In a preferred embodiment, the feedstocks to the plant are a biogas stream and / or a biogenic carbon dioxide stream, and a hydrogen stream produced by electrolysis powered by renewable energy sources. By providing feedstock from sustainable sources and running the plant on power from renewable energy sources, the greenhouse gas (abbreviated to GHG) footprint of the plant is minimized.

[0223] The plant may further be coupled to a water electrolyser for providing a hydrogen stream

[0224] In an embodiment, the plant comprises a biogas plant and an electrolyser, and optionally an energy park for producing renewable energy, thereby the plant comprises the entire value chain, which may provide a more economically favourable production of jet fuel

[0225] In an embodiment, the plant may comprise means for heating the biogas plant with excess heat from the process plant especially from the refinery section. The excess heat may be recovered from heat exchangers or condensers. The streams leaving the refinery section may have an elevated temperature, which is useful for heating the one or more biogas reactors in the biogas plant, which operates most efficiently at a temperature of about 50°C. The one or more biogas reactors are usually heated by burning biogas from the plant to heat the biogas plant. However, by utilizing the excess heat from the process plant to heat the biogas plant the overall energy consumption of the plant is reduced and the excess heat is reused. Another way of providing heat to the biogas plant is to use the heat energy from the one or more heat exchangers that may be located within the plant for cooling of the different streams.

[0226] Another way of providing heat to the biogas plant may be to use the excess heat from a low temperature water electrolysis.

[0227] In an aspect of the invention, the reformer section comprises one or more autothermal reforming (ATR) units.

[0228] An additional feed of steam and oxygen to the reformer section is required for the embodiment with one or more ATR units.

[0229] In an embodiment, the reformer section comprises one or more electrified steam methane re-forming (e-SMR) units.

[0230] An additional feed of steam to the reformer section is required for the embodiment with one or more e-SMR units.

[0231] The e-SMR unit are advantageous, as they are more energy efficient than the ATR units. Thus, the e-SMR units require less energy and are therefore associated with a reduced production cost. However, due to the low maturity of the e-SMR technology, it may be advantageous to utilize one or more ATR units instead of e-SMR units, since faster scaling of the plant and the production output is possible with the more mature ATR technology.

[0232] In a preferred embodiment, the reformer section comprises one or more adiabatic prereformers and one or more electrified steam methane reforming (e-SMR) units and one or more waste heat boilers (WHB) downstream the one or more electrified steam methane reforming units.

[0233] An additional feed of steam to the reformer section is required due to both the one or more adiabatic pre-reformer and the one or more e-SMR units consuming steam. The one or more adiabatic pre -reformers may be arranged upstream to the one or more e-SMR units, thereby reducing the load on the one or more e-SMR units. All recycled streams or all infeed streams provided to the reformer section may be provided upstream to the adiabatic pre-reformer.

[0234] Downstream the one or more e-SMR units, one or more WHBs are needed for heat recovery and cooling of the synthesis gas.

[0235] In one embodiment the present invention provides a reforming section comprising one or more desulphurization units to protect the Fischer-Tropsch catalyst, the pre-reformer catalyst, and / or the reformer catalyst from traces of sulphur, thereby preventing the FT- catalyst, the pre-reformer catalyst, and / or reformer catalyst from sulphur poisoning. This is especially important in embodiments, where a biogas stream and / or the first external recycle stream from a refinery section is provided to the reformer section, as biogas often contains traces of hydrogen sulphide and the first external recycle stream from the refinery section also contains sulphur. The first external recycle stream from the refinery section and hydrogen gas are introduced upstream of the desulphurization step.

[0236] Following desulphurization, the gas is mixed with recycled streams from the synthesis section and processed in a pre-reformer, which breaks down longer hydrocarbons into methane (CFU) and CO2 via steam reforming reactions without intermediate products. This process step is necessary to produce syngas from the recycled higher hydrocarbons coming from the FT and refinery section. The pre-reformer also acts as a sulphur guard and reduces the risk of carbon formation in the eSMR reactor. Additionally, its temperature profile is used to monitor the sulphur slip and therefore enables preventative catalyst replacement in desulphurization reactors, ensuring that there is no sulphur entering the eSMR reactor.

[0237] Both the adiabatic pre-reformer and the e-SMR are equilibrium-based reactors, and as a consequence the synthesis gas stream provided by the reforming section comprise an amount of carbon dioxide. The carbon dioxide acts as an inert in the Fischer-Tropsch reaction and, consequently, merely takes up space in the Fischer-Tropsch reactor(s). The build-up in the level of carbon dioxide in the synthesis section can be reduced by removing the carbon dioxide from the synthesis gas upstream to the synthesis section, thereby, reducing the size of piping and other equipment required in the synthesis section and the rest of the plant due to the carbon dioxide flow throughout the plant. This is further advantageous, as less purge downstream to the synthesis section is needed, as less inert carbon dioxide is coming from the synthesis section.

[0238] In another embodiment, the reformer section comprises two or more parallel lines of reformer units for reforming, thereby ensuring production in case of unplanned downtime of one of the reforming units. This is especially advantageous in embodiments of the present invention using e-SMR, due to the low maturity of the e- SMR technology.

[0239] Depending on the type of carbon dioxide removal section, the carbon dioxide removal section may further be arranged to provide a water condensate stream, when cooling is applied before carbon dioxide removal, which may be exported or recycled to a biogas plant. The carbon dioxide removal section may provide the water condensate stream prior to the removal of carbon dioxide from the synthesis gas.

[0240] In one embodiment the present invention provides a plant comprising a carbon dioxide removal section, wherein the carbon dioxide removal section may comprise one or more carbon dioxide Pressure-Swing adsorption (PSA) units and / or one or more cryogenic carbon dioxide separation units and / or one or more membrane carbon dioxide separation units.

[0241] In an embodiment, the plant may further comprise a blending section, wherein the jet fuel fraction stream is blended with the aromatic stream to provide a jet fuel product.

[0242] Thereby, providing a jet fuel product meeting the jet fuel specifications that can be directly substitutable with conventional petroleum-derived jet fuel.

[0243] In an aspect of the invention, the plant produces the jet fuel fraction or a jet fuel product with an overall carbon utilization of more than 90% or between 97-98% or more than 97% or more than 98% or more than 98.5% or more than 98.75% or about 99% or above 99%. In embodiments of the plant comprising a purge section, the plant produces the jet fuel fraction or a jet fuel product with an overall carbon utilization between 97-98% or more than 97% or more than 98% or more than 98.5% or more than 98.75% or about 99% or above 99%.

[0244] In embodiments of the plant not comprising a purge section, the plant produces the jet fuel fraction or a jet fuel product with an overall carbon utilization of more than 90%.

[0245] The recycling of the external tail gas recycle stream and / or at least a fraction of the second combined liquid and / or gas hydrocarbon recycle stream and / or the first hydrocarbon recycle stream from the synthesis section, either to the reformer section and / or upstream to the reformer section, resulting in more lighter hydrocarbons being present in the reformer section compared to prior art plant layouts due to less extraction of by-product downstream the synthesis section. This ensures that most of the carbon from the infeed to the plant will be turned into a jet fuel fraction or a jet fuel product and no other by-products such as gasoline and naphtha.

[0246] In one embodiment, the present invention provides a plant wherein the reformer section is arranged to receive an external tail gas recycle stream and / or at least a fraction of the second combined liquid and / or gas hydrocarbon recycle stream and / or the first hydrocarbon recycle stream from the synthesis section for providing a synthesis gas stream, thereby, providing a plant for producing a jet fuel fraction with an overall high carbon efficiency of more than 90%.

[0247] In one embodiment, the present invention provides a plant comprising a biogas plant arranged to receive the concentrated oxygenate recycle stream and provide a biogas stream, wherein the reformer section is arranged for receiving said biogas stream.

[0248] Thereby, the oxygenates comprised in concentrated oxygenate recycle stream resulting from the jet fuel synthesis can be decomposed by the microorganism in the one or more biogas reactors of the biogas plant and returned as carbon feedstocks in the form of biogas that can be utilised in the plant for jet fuel synthesis. 31

[0249] In one embodiment, the present invention provides a plant comprising a biogas plant wherein the biogas plant is further arranged for receiving a biomass feed. The concentrated oxygenate recycle stream may be supplied to and mixed with the biomass feed prior to supplying it to the biogas reactor(s) or the concentrated oxygenate recycle stream may be supplied directly to the biogas reactor(s).

[0250] Components of biogas reactor(s) and optimal operational parameters of the biogas plant are known to a person skilled in the art.

[0251] In one embodiment, the present invention provides a plant comprising a synthesis section that is further arranged for receiving at least a fraction of the tail gas recycle stream.

[0252] In one embodiment, the present invention provides a plant comprising a synthesis section that is further arranged for receiving at least a fraction of the tail gas recycle stream as an internal tail gas recycle stream.

[0253] In one embodiment, the present invention provides a plant comprising a synthesis section that is further arranged to receive a fraction of the tail gas recycle, hereby named the internal tail gas recycle, from the synthesis section. The internal tail gas recycle stream is recycled upstream the synthesis section and may also act as a temperature control for the Fischer-Tropsch reaction.

[0254] Additional feeds can be provided to the reforming section such as one or more of external tail gas recycle stream and / or at least a fraction of the second combined liquid and / or gas hydrocarbon recycle stream and / or the first hydrocarbon recycle stream from the synthesis section; and / or at least a fraction of the combined hydrocarbon refinery recycle stream from the refinery section; and / or hydrogen stream provided upstream to the reforming section from the refinery section, and / or other hydrogen stream and / or steam. The amount of steam needed depends on the composition of the recycle streams as well as the desiredkh / CO ratio in the synthesis gas stream provided by the reformer section. In one embodiment, the present invention provides a plant wherein the plant further comprises:

[0255] - a carbon dioxide removal section arranged to receive the synthesis gas stream from the reformer section and provide a carbon dioxide lean synthesis gas stream and a carbon dioxide rich off-gas stream; and wherein the synthesis section is arranged to receive said carbon dioxide lean synthesis gas stream and wherein said carbon dioxide rich off-gas stream is optionally recycled to the reformer section.

[0256] In one embodiment of the present invention the carbon dioxide lean synthesis gas stream from a carbon dioxide removal section is mixed with hydrogen stream and / or a fraction of the tail gas recycle stream from the synthesis section as an internal tail gas recycle stream upstream to a synthesis section for providing a total synthesis gas to the synthesis section.

[0257] The total synthesis gas stream may have a H2 / CO ratio between 1.5-2.5, such as between 1.6-2.4, preferably between 1.8-2.2 such as between 1.9-2.1 or about 2.05.

[0258] The carbon dioxide rich off-gas stream may be recycled to the reformer section or to a biogas plant, where methanogens can reduce carbon dioxide into methane in the presence of hydrogen.

[0259] The biogas stream and / or carbon dioxide stream and / or methane stream provided to the reformer section may comprise a small fraction of nitrogen, in particular the biogas stream which may comprise between 0-10% nitrogen. Nitrogen acts as an inert in the Fischer-Tropsch reaction and all other sections of the plant and, consequently, merely takes up space in the plant. The build-up in the level of nitrogen in the plant can be reduced by removing the nitrogen from the streams within the plant downstream to the refinery section or synthesis section, respectively, to provide a nitrogen-rich purge stream. The nitrogen-rich purge stream exported from the plant ensures that inert nitrogen gas is not accumulated in the plant, thereby, reducing the size of piping and other equipment required in the plant. In one embodiment, the present invention provides a plant wherein the refinery section comprises a hydrotreater unit arranged to receive at least a fraction of the stabilized condensate and the liquid wax stream from the synthesis section for providing the jet fuel fraction stream and a C3-C8 fraction stream.

[0260] The hydrocracker unit may further be arranged to receive a hydrogen stream.

[0261] The jet fuel fraction may be exported from the plant as a blend or may be blended with aromatics to provide a jet fuel product that may be exported from the plant as jet fuel product, that can be directly substitutable with conventional petroleum-derived jet fuel.

[0262] The C3-C8 fraction stream may be recycled to the reformer section, thereby increasing the overall carbon utilisation of the plant, as all carbon containing by-product streams are recycled for the exclusive production of the jet fuel fraction.

[0263] - All carbon-containing stream produced in the plant that does not meet the jet fuel specifications can be recycled in the plant for reuse in the jet fuel synthesis to increase the overall carbon utilization of the jet fuel fraction or jet fuel product production. The carbon-containing streams that may be produced in the plant and may be recycled include: A carbon dioxide rich off-gas stream provided by the carbon dioxide removal unit and recycled to the reformer section;

[0264] - An external tail gas recycle stream provided by the synthesis section and recycled to the reformer section;

[0265] - An internal tail gas recycle stream provided by the synthesis section and recycled upstream to the synthesis section and / or to the synthesis section;

[0266] - A concentrated oxygenate recycle stream comprising oxygenates provided by the synthesis section and recycled to the biogas plant;

[0267] - A combined hydrocarbon refinery recycle provided by the refinery section, wherein at least a fraction is recycled to the reformer section;

[0268] - A hydrocarbon recovery stream provided by the hydrocarbon recovery unit of the synthesis section, recycled back to the synthesis section;

[0269] - A second combined liquid and / or gas hydrocarbon recycle streams provided by the synthesis section, wherein at least a fraction is recycled to the reformer section; - A second gas hydrocarbon recycle stream provided by the synthesis section and recycled to the reformer section;

[0270] - A first fraction of the second liquid hydrocarbon recycle stream provided by the synthesis section and recycled to the reformer section;

[0271] A second fraction of the second liquid hydrocarbon recycle stream provided by the synthesis section and recycled to the aromatization unit in the refinery section; and

[0272] - A carbon-rich off-gas stream provided by the purge section and recycled to the synthesis section;

[0273] By creating all of these recycle streams, the plant and process ensures the high carbon efficiency of the jet fuel fraction or jet fuel product production.

[0274] Process:

[0275] All details described above for a plant for producing a jet fuel fraction according to the present invention are equally relevant and applicable for a process for producing a jet fuel fraction according to the present invention.

[0276] An object of the invention is achieved by providing a process for producing a jet fuel fraction, said process comprising the steps of:

[0277] - feeding at least one of a biogas stream, a carbon dioxide stream, and a methane stream to a reformer section arranged for providing a synthesis gas stream;

[0278] - feeding said synthesis gas stream to a synthesis section arranged for providing a stabilized condensate stream, a liquid wax stream and a concentrated oxygenate recycle stream;

[0279] - feeding said stabilized condensate and the liquid wax stream to a refinery section arranged for providing a jet fuel fraction stream; and recycling said concentrated oxygenate recycle stream to a biogas plant.

[0280] In one embodiment, the present invention provides a process for producing a jet fuel fraction, said process comprising the steps of:

[0281] - feeding at least one of a biogas stream, a carbon dioxide stream, and a methane stream to a reformer section arranged for providing a synthesis gas stream; - further feeding an external tail gas recycle stream and / or at least a fraction of a second combined liquid and / or gas hydrocarbon recycle streams and / or first hydrocarbon recycle stream and / or at least a fraction of a combined hydrocarbon refinery recycle stream to said reformer section;

[0282] - feeding said synthesis gas stream to a synthesis section arranged for providing a stabilized condensate stream, a liquid wax stream and a concentrated oxygenate recycle stream;

[0283] - feeding said stabilized condensate and the wax stream to a refinery section arranged for providing a jet fuel fraction stream; and recycling said concentrated oxygenate recycle stream to a biogas plant.

[0284] Examples

[0285] In the following, four different examples of plant layouts according to the present invention are presented, and the layouts are based on the following parameters:

[0286] The carbon dioxide stream 2 is estimated to contain the same amount of nitrogen as the biogas stream 1.

[0287] The composition of the biogas stream used in the calculations is an exemplary composition comprising 61.7% methane (CH4), 37.9% carbon dioxide (CO2), -0.01% nitrogen (N2), and 0.4% oxygen (O2). The carbon dioxide stream is assumed to contain the same concentration of nitrogen as the biogas stream.

[0288] Example Cl NEW (based on figure 2):

[0289] The plant 100 of example Cl comprises:

[0290] - a reformer section (10) arranged to convert a biogas stream (1), a carbon dioxide stream (2), a fraction of a tail gas recycle stream (32), a second gas hydrocarbon recycle stream (34A), a first fraction of the second liquid hydrocarbon recycle stream (34B), a first hydrocarbon recycle stream (35), an off-gas stream (42A) from distillation unit(s) in refinery, and a liquid HC recycle stream (42B) from distillation unit(s) in refinery, into a synthesis gas stream (11);

[0291] - a synthesis section (30) arranged to receive said synthesis gas stream (11), an internal tail gas recycle (32A), a hydrogen stream (6), a liquid hydrocarbon stream (52) and provide a stabilized condensate stream (31), a liquid wax stream (38), the tail gas recycle stream (32), a first hydrocarbon recycle stream (35), a concentrated oxygenate recycle stream (36), and a aqueous / water stream (37); wherein said concentrated oxygenate recycle stream (36) is recycled to a biogas plant.

[0292] - a refinery section (40) arranged to receive the stabilized condensate stream (31) a liquid wax stream (38) and the hydrogen stream (7) and provide a jet fuel fraction stream (41), an off-gas stream (42A) from distillation unit(s) in refinery, and ajiquid HC recycle stream (42B) from distillation unit(s) in refinery;

[0293] - a purge section (50) arranged to receive a tail gas purge stream (32C) and provide a nitrogen-rich purge stream (51), and a liquid hydrocarbon stream (52).

[0294] The biogas feed is provided from a biogas plant with a nitrogen content of 0.01 mole% is used as feedstock to the plant. The chiller in the purge section cools the tail gas purge stream (32C) to 5 degrees Celsius.

[0295] A biogas feed of 11774 kg / h, a carbon dioxide feed of 4846 kg / h, and a hydrogen feed of 1222 kg / h are provided to the plant, resulting in a jet fuel fraction stream of 7650 kg / h and an overall carbon utilization of 99.40%.

[0296] Example C2:

[0297] The plant layout of example C2 is similar to the plant layout of example Cl .

[0298] The biogas feed is provided from a biogas plant with a nitrogen content 0.1 mol% and used as feedstock to the plant. The chiller in the purge section cools the tail gas purge stream (32C) to 5 degrees Celsius.

[0299] A biogas feed of 11774 kg / h, a carbon dioxide feed of 4846 kg / h, and a hydrogen feed of 1222 kg / h are provided to the plant, resulting in a jet fuel fraction stream of 7580 kg / h and an overall carbon utilization of 99.15%.

[0300] It can be seen, that if the biogas has a higher nitrogen content, then the carbon utilization of the plant becomes lower due to higher purge needs.

[0301] The plant layout of example C3 is similar to the plant layout of example Cl and C2. The biogas feed is provided from a biogas plant with a nitrogen content 0.1 mol% and used as feedstock to the plant. The chiller in the purge section cools the tail gas purge stream (32C) to -30 degrees Celsius.

[0302] A biogas feed of 11774 kg / h, a carbon dioxide feed of 4846 kg / h, and a hydrogen feed of 1222 kg / h are provided to the plant, resulting in a jet fuel fraction stream of 7654 kg / h and an overall carbon utilization of 99.45%.

[0303] It can be seen that a higher nitrogen content in the biogas feed can be mitigated by cooling to a lower temperature in the purge section.

[0304] Cases summarized:

[0305] We consider a feed of 80 mol% biogas and 20 mol% CO2. Three cases are presented:

[0306] Cl is base N2 amount and chiller to 5 degrees Celsius.

[0307] C2 is 10 times higher N2 amount and chiller to 5 degrees Celsius.

[0308] C3 is 10 times higher N2 amount and chiller to -30 degrees Celsius.

[0309] Table 2 - Feed parameter and results from the conceivable layouts

[0310] Description of the Drawing

[0311] The present invention has been described in the following with reference to a number of embodiments and figures. However, a skilled person is able to select and combine various embodiments within the scope of the invention, which is defined by the appended claims.

[0312] Various examples are described hereinafter with reference to the figures. Like reference numerals refer to like elements throughout. Like elements will thus not be described in detail with respect to the description of each figure. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. In addition, an illustrated example will not necessarily have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

[0313] Embodiments of the invention wills be described in the figures, wherein:

[0314] Fig. 1 illustrates a plant according to an embodiment of the present invention for producing a jet fuel fraction stream, the plant comprising a carbon dioxide removal section

[0315] Fig. 2 illustrates a plant according to an embodiment of the present invention for producing a jet fuel fraction stream

[0316] Fig. 3 illustrates a plant according to an embodiment of the present invention for producing a jet fuel fraction stream and a diesel product stream

[0317] Fig. 4 illustrates a plant according to an embodiment of the present invention for producing a jet fuel product stream, the plant comprising an aromatization unit and a blending section

[0318] Fig. 5 illustrates a refinery section according to an embodiment of the invention for producing a jet fuel product stream

[0319] Fig. 6 illustrates a plant according to an embodiment of the present invention for producing a jet fuel product stream

[0320] Fig. 7 illustrates a refinery section according to an embodiment of the invention for producing a jet fuel product stream

[0321] Fig. 8 illustrates a reformer section according to an embodiment of the invention Fig. 9 illustrates a synthesis section according to an embodiment of the invention

[0322] Detailed Description of the Invention

[0323] Figure 1 illustrates a plant 100 for producing a jet fuel fraction stream 41 according to an embodiment of the invention. The plant 100 comprises a reformer section 10, a carbon dioxide removal section 20, a synthesis section 30, a refinery section 40 and a purge section 50.

[0324] In the embodiment of Fig. 1, the reformer section 10 is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11.

[0325] In the embodiment of Fig. 1, the carbon dioxide removal section 20 is arranged for receiving the synthesis gas stream 11 from the reformer section 10 and to provide a carbon dioxide rich off-gas stream 23 and a carbon dioxide lean synthesis gas stream 21.

[0326] In the embodiment of Fig. 1, the synthesis section 30 is arranged for receiving the synthesis gas stream 11, either directly and / or as a total synthesis gas stream 22, where the total synthesis gas stream 22 is a mix of the carbon dioxide lean synthesis gas stream 21 and / or a fraction of the tail gas recycle stream 32 as an internal tail gas recycle stream 32A and / or hydrogen stream 6,

[0327] , wherein the synthesis section is arranged for providing a stabilized condensate stream 31, liquid wax stream 38, tail gas recycle stream 32 and concentrated oxygenate recycle stream 36.

[0328] In the embodiment of Fig. 1 the reformer section 40 is arranged for receiving the stabilized condensate stream 31 and liquid wax stream 38 from the synthesis section 30 and to provide a jet fuel fraction stream 41.

[0329] As demonstrated in Fig. 1, the reformer section 10 is further arranged for receiving at least a fraction of the tail gas recycle stream 32 from the synthesis section 30, as an externa tail gas recycle stream 32B and / or the carbon dioxide rich off-gas stream 23 from the carbon dioxide removal section 20 and / or a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or a first hydrocarbon recycle stream 35 from the synthesis section 30 and / or a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B, from the refinery section 40. The reformer section 10 of the embodiment demonstrated in figure 1 may be arranged for optionally receiving a steam stream 4 and / or hydrogen stream 5.

[0330] As demonstrated in Fig. 1, the synthesis section 30 of the embodiment of figure 1 is further arranged for providing a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or first hydrocarbon recycle stream 35 to the reformer section, and to provide a waste-water stream 37 that is discharged from the plant. In the embodiment of Fig. 1 the tail gas recycle stream 32 from the synthesis section is divided into three streams, an external tail gas recycle stream 32A that is recycled back to the synthesis section 30, a tail gas purge stream 32C that is provided to the purge section 50 and external tail gas recycle stream 32B that is provided to the reformer section 10. The hydrocarbons recovered from the tail gas purge stream 32C in the purge section are recycled back to the synthesis section 30 as liquid hydrocarbon stream 52.

[0331] As demonstrated in Fig. 1, the refinery section 40 of the embodiment is further arranged for providing a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B, to the reformer section 30 and optionally to receive a hydrogen stream 7.

[0332] The purge section 50 demonstrated in figure 1 is arranged for receiving a fraction of the tail gas recycle stream 32 as a purge tail gas stream 32C from the synthesis section 30 and provide a nitrogen-rich purge gas stream 51 that is purged and a liquid hydrocarbon stream 52 that is recycled back to the synthesis section 30.

[0333] Figure 2 illustrates a plant 100 for producing a jet fuel fraction stream 41 according to an embodiment of the invention.

[0334] The plant 100 comprises a reformer section 10, a synthesis section 30, a refinery section 40 and a purge section 50.

[0335] In the embodiment of Fig. 2, the reformer section 10 is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11. The reformer section 10 of figure 2 is further arranged for receiving at least a fraction of the tail gas recycle stream 32 as an external tail gas recycle stream 32B and / or a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or a first hydrocarbon recycle stream 35 from the synthesis section 30 and / or a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B, from the refinery section 40. The reformer section 10 of the embodiment demonstrated in figure 2 may be further be arranged for optionally receiving a steam stream 4 and / or hydrogen stream 5.

[0336] In the embodiment of Fig. 2, the synthesis section 30 is arranged for receiving the synthesis gas stream 11, either directly and / or as a total synthesis gas stream 22, where the synthesis gas stream 11 has been mixed with the a fraction of the tail gas recycle stream 32 provided by the synthesis section 30 as an internal tail gas recycle stream 32A and / or hydrogen stream 6, thereby providing the total synthesis gas stream 22. The synthesis section demonstrated in figure 2 is arranged for providing a stabilized condensate stream 31, liquid wax stream 38, tail gas recycle stream 32 and concentrated oxygenate recycle stream 36. As demonstrated in Fig. 2, the synthesis section 30 of the embodiment of figure 2 is further arranged for providing a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or first hydrocarbon recycle stream 35 to the reformer section, and to provide a waste-water stream 37 that is discharged from the plant.

[0337] In the embodiment of Fig. 2 the tail gas recycle stream 32 from the synthesis section is divided into three streams, an external tail gas recycle stream 32A that is recycled back to the synthesis section 30, a tail gas purge stream 32C that is provided to the purge section 50 and external tail gas recycle stream 32B that is provided to the reformer section 10. The hydrocarbons recovered from the tail gas purge stream 32C in the purge section are recycled back to the synthesis section 30 as liquid hydrocarbon stream 52, while the nitrogen-rich purge stream 51 provided by the purge section 50 is purged from the plant.

[0338] In the embodiment of Fig. 2 the refinery section 40 is arranged for receiving the stabilized condensate stream 31 and liquid wax stream 38 from the synthesis section 30 and to provide a jet fuel fraction stream 41. As demonstrated in Fig. 2, the refinery section 40 of the embodiment is further arranged for providing a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B to the reformer section 30 and optionally to receive a hydrogen stream 7.

[0339] Figure 3 illustrates a plant 100 for producing a jet fuel fraction stream 41 and a diesel product stream 49 according to an embodiment of the invention. The plant 100 comprises a reformer section 10, a synthesis section 30, a refinery section 40 and a purge section 50.

[0340] In the embodiment of Fig. 3, the reformer section 10 is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11. The reformer section 10 of figure 3 is further arranged for receiving at least a fraction of the tail gas recycle stream 32 as an external tail gas recycle stream 32B and / or a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or a first hydrocarbon recycle stream 35 from the synthesis section 30 and / or a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B from the refinery section 40. The reformer section 10 of the embodiment demonstrated in figure 3 may further be arranged for optionally receiving a steam stream 4 and / or hydrogen stream 5.

[0341] In the embodiment of Fig. 3, the synthesis section 30 is arranged for receiving the synthesis gas stream 11, either directly and / or as a total synthesis gas stream 22, where the synthesis gas stream 11 has been mixed with a fraction of the tail gas recycle stream 32 provided by the synthesis section 30 as an internal tail gas recycle stream 32A and / or hydrogen stream 6, thereby providing the total synthesis bas stream 22. The synthesis section demonstrated in figure 3 is arranged for providing a stabilized condensate stream 31, liquid wax stream 38, tail gas recycle stream 32 and concentrated oxygenate recycle stream 36. As demonstrated in Fig. 3, the synthesis section 30 of the embodiment of figure 3 is further arranged for providing a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or first hydrocarbon recycle stream 35 to the reformer section, and to provide a waste-water stream 37 that is discharged from the plant. In the embodiment of Fig. 3 the tail gas recycle stream 32 from the synthesis section is divided into three streams, an external tail gas recycle stream 32A that is recycled back to the synthesis section 30, a tail gas purge stream 32C that is provided to the purge section 50 and external tail gas recycle stream 32B that is provided to the reformer section 10. The hydrocarbons recovered from the tail gas purge stream 32C in the purge section 50 are recycled back to the synthesis section 30 as liquid hydrocarbon stream 52, while the nitrogen-rich purge stream 51 provided by the purge section 50 is purged from the plant.

[0342] In the embodiment of Fig. 3 the refinery section 40 is arranged for receiving the stabilized condensate stream 31 and liquid wax stream 38 from the synthesis section 30 and to provide a jet fuel fraction stream 41 and a diesel product stream 49. As demonstrated in Fig. 3, the refinery section 40 of the embodiment is further arranged for providing a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B, to the reformer section 30 and optionally to receive a hydrogen stream 7.

[0343] Figure 4 illustrates a plant 100 for producing a jet fuel product stream 61 and jet fuel fraction stream 62, according to an embodiment of the invention. The plant 100 comprises a reformer section 10, a synthesis section 30, a refinery section 40, a purge section 50 and a blending section 60.

[0344] In the embodiment of Fig. 4, the layout of the plant upstream to the refinery section 40 is similar to the layout of figure 2 and 3. The plant demonstrated in figure 4 comprises a reformer section 10 that is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11. The reformer section 10 of figure 4 is further arranged for receiving at least a fraction of the tail gas recycle stream 32 as an external tail gas recycle stream 32B and / or a second combined liquid and / or gas hydrocarbon recycle stream 34A, 34B and / or a first hydrocarbon recycle stream 35 from the synthesis section 30.

[0345] Though not shown in figure 4, the refinery section 40 of figure 4 comprises one or more aromatization units 40B and the refinery section 40 of the embodiment of figure 4 therefore provides a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A, the distillation units liquid hydrocarbon recycle stream 42B and the aromatization unit / s off-gas stream 42C.

[0346] The one or more aromatization units 40B of the refinery section 40 further provides a hydrogen recycle stream comprising sulphur 8 that is recycled to the reformer section 10, preferably upstream any hydrogen desulphurization section (HDS) of the reformer section 10.

[0347] In the embodiment of Fig. 4, the synthesis section 30 is arranged similar to the setup demonstrated in figures 2 and 3 , for receiving the synthesis gas stream 11 , either directly and / or as a total synthesis gas stream 22, where the synthesis gas stream 11 has been mixed with the a fraction of the tail gas recycle stream 32 provided by the synthesis section 30 as an internal tail gas recycle stream 32A and / or hydrogen stream 6, thereby providing the total synthesis bas stream 22, and synthesis section demonstrated in figure 2 is arranged for providing a stabilized condensate stream 31, liquid wax stream 38, tail gas recycle stream 32, concentrated oxygenate recycle stream 36, and second combined liquid and / or gas hydrocarbon recycle stream 34.

[0348] In figure 4, just as in figures 2 and 3 any gas stream comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 provided by the synthesis section 30, is recycled to the reformer section 10 as one or more second gas hydrocarbon recycle stream 34A, however in the embodiment demonstrated in figure 4, any liquid hydrocarbon recycle stream comprised in the one or more second liquid hydrocarbon recycle stream 34 may optionally be split into two fractions, the first fraction of the second liquid hydrocarbon recycle stream 34B that is recycled to the reformer section and / or the second fraction of the second liquid hydrocarbon recycle stream 34C that is recycled to the one or more aromatization units 40B of the refinery section 40.

[0349] How the liquid hydrocarbon part of the second combined liquid and / or gas hydrocarbon recycle streams 34 recycle stream is divided into the first fraction of the second liquid hydrocarbon recycle stream 34B and / or the second fraction of the second liquid hydrocarbon recycle stream 34C depends on the setup of the plant and the process parameters, such as between 0-100% of liquid hydrocarbons comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 are recycled as first fraction of the second liquid hydrocarbon recycle stream 34B to the reformer 10 and between 100-0% of liquid hydrocarbons comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 are recycled as the second fraction of the second liquid hydrocarbon recycle stream 34C to the one or more aromatization units 40B or refinery section 40.

[0350] In the embodiment of Fig. 4 the refinery section 40 is arranged for receiving the stabilized condensate stream 31 and liquid wax stream 38 from the synthesis section 30 and to provide a jet fuel fraction stream 41 and an aromatic stream 48 to a blending section 60. The blending section 60 is arranged for receiving the jet fuel fraction stream 41 and the aromatic stream 48 from the refinery section for blending the aromatic comprised in the aromatic stream 48 with the jet fuel fraction stream 41 for providing a jet fuel product stream 61 that may be exported from the plant as jet fuel product, that can be directly substitutable with conventional petroleum-derived jet fuel.

[0351] In the embodiment demonstrated in figure 4, the blending section optionally further provides a jet fuel fraction stream 62.

[0352] Figure 5 illustrates a refinery section 40 and blending section 60 of a plant provided by the same embodiment as figure 4.

[0353] The refinery section 40 of the embodiment demonstrated in figure 5 comprises a hydrocracker unit 40A and an aromatization unit 40B.

[0354] The hydrocracker unit 40A is arranged for receiving the stabilized condensate stream 31 and the liquid wax stream 38 from the synthesis section 30 and for providing a C3- Cs fraction stream 47 to the aromatization unit 40B and a jet fuel fractions stream 41 to the blending section 60. The hydrocracker unit 40A is further arranged for providing two recycling streams to the reformer section 10 (not shown in fig. 5), the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle the liquid hydrocarbon recycle stream 42B.

[0355] The aromatization unit 40B is arranged for receiving the C3-C8 fraction stream from the hydrocracker unit 40A and the second fraction of the second liquid hydrocarbon recycle stream 34C and for providing the blending section 60 with an aromatic stream 48. The aromatization unit 40B is further arranged for providing the reformer section 10 (not shown in fig. 5) with two recycling streams, the aromatization unit / s off-gas stream 42C and a hydrogen stream comprising sulphur 8, that is preferably recycled upstream to the one or more hydrogen desulphurization section 10A of the reformer section 10.

[0356] The blending section 60 is arranged for receiving the jet fuel fraction stream 41 from the hydrocracker unit 40A of the refinery section 40 and the aromatic stream 48 from the aromatization unit 40B of refinery section and for blending the aromatic comprised in the aromatic stream 48 with the jet fuel fraction stream 41 for providing a jet fuel product stream 61 that may be exported from the plant as jet fuel product, that is on specification with conventional petroleum-derived jet fuel.

[0357] In the embodiment demonstrated in figure 5, the blending section optionally further provides a jet fuel fraction stream 62.

[0358] Figure 6 illustrates a plant 100 for producing a jet fuel product stream 43, according to an embodiment of the invention. The plant 100 comprises a reformer section 10, a synthesis section 30, a refinery section 40 and a purge section 50.

[0359] In the embodiment of Fig. 6, the layout of the plant upstream to the refinery section 40 is similar to the layout of figure 2 and 3. The plant demonstrated in figure 6 comprises a reformer section 10 that is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11. The reformer section 10 of figure 6 is further arranged for receiving at least a fraction of the tail gas recycle stream 32 as an external tail gas recycle stream 32B and / or a second combined liquid and / or gas hydrocarbon recycle stream 34, comprising the second gas hydrocarbon recycle stream 34A and the first fraction of the second liquid hydrocarbon recycle stream 34B and / or a first hydrocarbon recycle stream 35 from the synthesis section 30.

[0360] Though not shown in figure 6, the refinery section 40 of figure 6 comprises one or more aromatization units 40B and the refinery section 40 of the embodiment of figure 6 therefore provides a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A, the distillation units liquid hydrocarbon recycle stream 42B and the aromatization unit / s off-gas stream 42C.

[0361] The one or more aromatization units 40B of the refinery section 40 further provides a hydrogen recycle stream comprising sulphur 8 that is recycled to the reformer section 10, preferably upstream any hydrogen desulphurization sections (HDS) 10A of the reformer section 10.

[0362] In the embodiment of Fig. 6, the synthesis section 30 is arranged similar to the setup demonstrated in figures 2 and 3 , for receiving the synthesis gas stream 11 , either directly and / or as a total synthesis gas stream 22, where the synthesis gas stream 11 has been mixed with the a fraction of the tail gas recycle stream 32 provided by the synthesis section 30 as an internal tail gas recycle stream 32A and / or hydrogen stream 6, thereby providing the total synthesis gas stream 22. The synthesis section demonstrated in figure 6 is arranged for providing the stabilized condensate stream 31 and the liquid wax stream 38 to the refinery section 40 and provide the tail gas recycle stream 32 and / or concentrated oxygenate recycle stream 36 and / or second combined liquid and / or gas hydrocarbon recycle stream 34.

[0363] In figure 6, just as in figures 2 and 3 any gas stream comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 provided by the synthesis section 30, is recycled to the reformer section 10 as one or more second gas hydrocarbon recycle stream 34A, however in the embodiment demonstrated in figure 6, any liquid hydrocarbon recycle stream comprised in the one or more second liquid hydrocarbon recycle stream 34 may optionally be split into two fractions, the first fraction of the second liquid hydrocarbon recycle stream 34B that is recycled to the reformer section 10 and / or the second fraction of the second liquid hydrocarbon recycle stream 34C that is recycled to the one or more aromatization units 40B of the refinery section 40.

[0364] How the liquid hydrocarbon part of the second combined liquid and / or gas hydrocarbon recycle streams 34 recycle stream is divided into the first fraction of the second liquid hydrocarbon recycle stream 34B and / or the second fraction of the second liquid hydrocarbon recycle stream 34C depends on the setup of the plant and the process parameters, such as anywhere between 0-100% of liquid hydrocarbons comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 are recycled as first fraction of the second liquid hydrocarbon recycle stream 34B to the reformer 10 and anywhere between 100-0% of liquid hydrocarbons comprised in the second combined liquid and / or gas hydrocarbon recycle streams 34 are recycled as the second fraction of the second liquid hydrocarbon recycle stream 34C to the one or more aromatization units 40B of the refinery section 40.

[0365] In the embodiment of Fig. 6 the refinery section 40 is arranged for receiving the stabilized condensate stream 31 and liquid wax stream 38 from the synthesis section 30, the reformer section 40 comprises one or more aromatization units 40B and is arranged for utilizing the aromatic stream provided by the one or more aromatization units 40B for providing a jet fuel product stream 43.

[0366] Figure 7 illustrates a refinery section 40 of a plant provided by the same embodiment as figure 6.

[0367] The refinery section 40 of the embodiment demonstrated in figure 7 comprises a hydrocracker unit 40A and an aromatization unit 40B.

[0368] The hydrocracker unit 40A is arranged for receiving the stabilized condensate stream 31 and the liquid wax stream 38 from the synthesis section 30 and an aromatic stream from the aromatization unit 40B and for providing a Ca-Cs fraction stream to the aromatization unit 40B and a jet fuel product stream 43.

[0369] The hydrocracker unit 40A is further arranged for providing two recycling streams to the reformer section 10 (not shown in fig. 7), the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle the liquid hydrocarbon recycle stream 42B.

[0370] The aromatization unit 40B is arranged for receiving the Ca-Cs fraction stream from the hydrocracker unit 40A and the second fraction of the second liquid hydrocarbon recycle stream 34C from the synthesis section 30 and for providing the hydrocracker unit 40A with an aromatic stream 48. The aromatization unit 40B is further arranged for providing the reformer section 10 (not shown in fig. 7) with two recycling streams, the aromatization unit / s off-gas stream 42C and a hydrogen stream comprising sulphur 8, that is preferably recycled upstream to the one or more hydrogen desulphurization section 10A of the reformer section 10.

[0371] In the embodiment demonstrated in figure 7, the hydrocracker unit 40A is arranged for utilising the aromatic stream provided by the aromatization unit 40B for providing a jet fuel product stream 43 that may be exported from the plant as jet fuel product, that can be directly substitutable with conventional petroleum-derived jet fuel.

[0372] Figure 8 illustrates a reformer section 10 of a plant 100 provided by one embodiment of the present invention.

[0373] The reformer section 10 demonstrated in the embodiment of figure 8 comprises one or more hydrogen desulphurization sections (HDS) 10A, one or more pre-reformers 10B, one or more reforming units 10C and one or more waste heat boilers 10D. The reformer section 10 is arranged for receiving at least one of a biogas stream 1 and / or carbon dioxide stream 2 and / or methane stream 3 and provide a synthesis gas stream 11.

[0374] The reformer section 10 demonstrated in figure 8 is further arranged for receiving the following recycle streams from the synthesis section 30: at least a fraction of the tail gas recycle stream 32 as an external tail gas recycle stream 32B and optionally any of the second combined liquid and / or gas hydrocarbon recycle stream 34 comprising a second gas hydrocarbon recycle stream 34A and / or a first fraction of the second liquid hydrocarbon recycle stream 34B and / or a first hydrocarbon recycle stream 35.

[0375] The reformer section 10 demonstrated in figure 8 is further arranged for receiving the following recycle streams from the refinery section: a combined hydrocarbon refinery recycle stream 42 comprising the distillation unit / s off-gas stream 42A and the distillation units liquid hydrocarbon recycle stream 42B and optionally an aromatization unit / s off-gas stream 42C and / or a hydrogen stream comprising sulphur 8. As demonstrated in figure 8, the recycle streams from the refinery section 40 are recycled upstream to the hydrogen desulphurization section. Figure 9 illustrates a synthesis section 30 and a purge section 50 of a plant 100 provided by one embodiment of the present invention.

[0376] The synthesis section 30 demonstrated in figure 9 comprises one or more synthesis units / FT reactors 30A, one or more first separation units 30B, one or more second separation units 30C and one or more third separation units 30D.

[0377] The one or more synthesis units / FT reactors 30A are arranged for receiving a synthesis gas stream 11 from the reformer section 10, either directly as the synthesis gas stream 11 from the reformer section 10 and / or as a total synthesis gas stream 22, where the synthesis gas stream 11 has been mixed with the a fraction of the tail gas recycle stream 32 provided by the synthesis section 30 as an internal tail gas recycle stream 32A and / or hydrogen stream 6, thereby providing the total synthesis gas stream 22, and to provide a FT reactor gas stream to the first separation unit 30B and a liquid wax stream to a refinery section 40.

[0378] The one or more first separation units 30B are arranged for receiving the FT reactor gas stream from the FT reactor gas stream and to provide an organic concentrate stream 39 to the second separation unit 30C, an aqueous oxygenates and hydrocarbon recycle stream 300 to the third separation unit 30D and tail gas recycle stream 32, wherein the tail gas recycle stream is separated into three fractions, an internal tail gas recycle stream 32A that is recycled back to the synthesis section 30, an external tail gas recycle stream 32B that is recycled to the reformer section 10 and a tail gas purge stream that is provided to the purge section 50.

[0379] The purge section 50 receives the tail gas purge stream 32C from the first separation unit 30B and provides a nitrogen-rich purge stream 51 that is purged from the plant and a liquid hydrocarbon stream 52 that is recycled back to the first separation unit 30B.

[0380] The second separation unit 30C is arranged for receiving the organic condensate stream from the first separation unit 30B and to provide a stabilized condensate stream 31 to the reformer section. The second separation unit 30C further provides a second combined liquid and / or gas hydrocarbon recycle stream 34 comprising a second gas hydrocarbon recycle stream 34A and / or a first fraction of the second liquid hydrocarbon recycle stream 34B that are recycled back to the reformer section 10, and as explained above, the liquid streams of the second combined liquid and / or gas hydrocarbon recycle streams can optionally be separated into two fractions, where the second fraction of the second liquid hydrocarbon recycle stream 34C is recycled to the aromatization unit 40B of the refinery section 40.

[0381] The third separation unit 30D is arranged for receiving the aqueous oxygenates and hydrocarbon recycle stream 300 from the first separation unit 30B and to provide an aqueous / waste-water stream 37 that may be recycled to a waste-water plant, a concentrated oxygenate recycle stream 36 that is recycled to a biogas plant, and a first hydrocarbon recycle stream 35 that is recycled back to the reformer section 10.

[0382] ITEMS

[0383]

Claims

CLAIMS1. A plant (100) for producing a jet fuel fraction (41), said plant (100) comprising:- a reformer section (10) arranged to convert at least one of a biogas stream (1), a carbon dioxide stream (2), or a methane stream (3), and at least a fraction of a tail gas recycle stream (32) into a synthesis gas stream (11);- a synthesis section (30) arranged to receive said synthesis gas stream (11,22) and provide a stabilized condensate stream (31), a liquid wax stream (38), the tail gas recycle stream (32) and a concentrated oxygenate recycle stream (36); and- a refinery section (40) arranged to receive the stabilized condensate stream (31) and the liquid wax stream (38) and provide a jet fuel fraction stream (41); wherein said concentrated oxygenate recycle stream (36) is recycled to a biogas plant.

2. A plant (100) according to claim 1, wherein at least a fraction of the tail gas recycle stream (32) from the synthesis section (30) is recycled back to the synthesis section (30).

3. A plant (100) according to claim 1 or 2, wherein the plant (100) comprises a purge section (50) arranged for receiving at least a fraction of the tail gas recycle stream (32) from the synthesis section (30) and provide a nitrogen-rich purge stream (51) and a liquid hydrocarbon stream (52), wherein said liquid hydrocarbon stream (52) is recycled back to the synthesis section (30).

4. A plant (100) according to claim 1, wherein the plant comprises a biogas plant arranged to receive concentrated oxygenate recycle stream (36) and provide a biogas stream (1) to the reformer section (10).

5. A plant (100) according to any one of the preceding claims, wherein the plant (100) comprises:- a carbon dioxide removal section (20) arranged to receive the synthesis gas stream (11) from the reformer section (10) and provide a carbon dioxide lean synthesis gas stream (21) and a carbon dioxide rich off-gas stream (23);wherein the synthesis section (30) is arranged to receive said carbon dioxide lean synthesis gas stream (21) and wherein said carbon dioxide rich off-gas stream (32) is recycled to the reformer section (10).

6. A plant (100) according to any one of the preceding claims, wherein the synthesis section (30) is further arranged for providing a second combined liquid and / or gas hydrocarbon recycle stream (34), said second combined liquid and / or gas hydrocarbon recycle stream (34) comprising a second gas hydrocarbon recycle stream (34A) and a second liquid hydrocarbon recycle stream (34B, 34C), wherein said second gas hydrocarbon recycle stream (34A) and optionally a fraction of said second liquid hydrocarbon recycle stream (34B, 34C) is recycled to the reformer section (10).

7. A plant (100) according to any one of the preceding claims, wherein the reformer section (10) comprises:- one or more hydrogen desulphurization sections (10A);- one or more adiabatic pre -reformers (10B);- one or more electrified steam methane reforming (e-SMR) units (10C); and- one or more waste heat boilers (WHBs); wherein the one or more hydrogen desulphurization sections (10A) are upstream to the one or more pre-reformers (10B) and the one or more reformer units (10C).

8. A plant (100) according to any one of the preceding claims, wherein the refinery section (40) is further arranged for providing a combined hydrocarbon refinery recycle stream (42), wherein said combined hydrocarbon refinery recycle stream (42) is recycled upstream to the reformer section (10).

9. A plant (100) according to any one of the preceding claims, wherein the refinery section (40) comprises a hydrocracker unit (40A) arranged to receive at least a fraction of the raw product stream (31) and provide the jet fuel fraction stream (41) and a Ca-Cs fraction (47).

10. A plant (100) according to any one of the preceding claims, wherein the refinery section (40) comprises an aromatization unit (40B) arranged to receive a second fraction of the second liquid hydrocarbon recycle stream (34C) and / or a Ca-Cs fraction streamfrom distillation unit(s) of the refinery (47) from a hydrocracker unit (40A) to provide an aromatic stream (48).

11. A plant (100) according to claim 10, wherein the plant (100) comprises a blending section (60), wherein the jet fuel fraction stream (41) is blended with the aromatic stream (48) to provide a jet fuel product (61).

12. A plant (100) according to any one of the preceding claims, wherein the plant (100) produces the jet fuel fraction (41) with an overall carbon utilization of more than 90% or between 97-98% or more than 97% or more than 98% or more than 98.5% or more than 98.75% or about 99% or above 99%.

13. A process for producing a jet fuel fraction (41), said process comprising steps of:- feeding at least one of a biogas stream (1), a carbon dioxide stream (2), or a methane stream (3), and at least a fraction of a tail gas recycle stream (32), to a reformer section (10) to provide a synthesis gas stream (11);- feeding said synthesis gas stream (11, 22) to a synthesis section (30) to provide a stabilized condensate stream (31), a liquid wax stream (38), the tail gas recycle stream (32) and a concentrated oxygenate recycle stream (36);- refining at said stabilized condensate stream (31) and liquid wax stream (38) in a refinery section (40) to provide a jet fuel fraction stream (41); and- recycling said concentrated oxygenate recycle stream (36) to a biogas plant.

14. A process according to claim 13, wherein the process further comprises a step of feeding at least a fraction of the tail gas recycle stream (32) from the synthesis section (30) back to the synthesis sections (30).

15. A process according to claim 13 or 14, wherein the process comprises a step of removing carbon dioxide from the synthesis gas stream (11) to provide a carbon dioxide lean synthesis gas stream (21) and a carbon dioxide rich off-gas stream (23); wherein said carbon dioxide lean synthesis gas (21) is fed to the synthesis section (30) and said carbon dioxide rich off-gas stream (23) is recycled to the reformer section (10).

16. A process according to any one of the claims 13-15, wherein the process comprises a step of feeding at least a fraction of the tail gas recycle stream (32) from the synthesis section (30) to a purge section (50) to provide a nitrogen-rich purge stream (51) and a liquid hydrocarbon stream (52), wherein said liquid hydrocarbon stream (52) is recycled back to the synthesis section (30).

17. A process according to any one of the claims 13-16, wherein the step of refining comprises a step of hydrocracking at least a fraction of the stabilized condensate stream (31) and the liquid wax stream (38) to provide the jet fuel fraction stream (41) and a C3- Cs fraction (47), and wherein the step of refining further comprises a step of aromatization of a second fraction of the second liquid hydrocarbon recycle stream (34C) and / or a C3-C8 fraction stream from distillation unit(s) of the refinery (47) from a hydrocracker unit (40A) to provide an aromatic stream (48).

18. A process according to claim 17, wherein the process comprises a step of blending the jet fuel fraction stream (41) with the aromatic stream (48) to provide a jet fuel product (61).

19. A process according to any one of the claims 13-18, wherein the process produces the jet fuel fraction (41) or a jet fuel product (61) with and overall carbon utilization of more than 90% or between 97-98% or more than 97% or more than 98% or more than 98.5% or more than 98.75% or about 99% or above 99%.

20. A process according to any one of the claims 13-19, wherein the process is a process for producing the jet fuel fraction (41) or a jet fuel product (61) in a plant (100) according to any one of claims 1 to 12.

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