Cleaning of co 2 containing feed gases

Abstract

The present invention relates to a process for cleaning a CO2-rich gas feed, in particular for removing sulfur-containing impurities, and optionally oxygen.

Description

[0001] CLEANING OF CO2CONTAINING FEED GASES

[0002] TECHNICAL FIELD

[0003] The present invention relates to a process for cleaning a CO2-rich gas feed, in particular for removing sulfur-containing impurities and oxygen (O2).

[0004] BACKGROUND

[0005] Carbon dioxide (CO2) is commercially available in different grades. Typically, “food grade” or “beverage grade” CO2has a purity of 99.9%. However, for processes involving catalytic conversion of CO2to other chemical products (e.g. power-to-X), impurities such as sulfur- containing compounds in the CO2stream may poison the synthesis catalyst, even when present at concentrations of 0.00001 % (100 ppb) or even lower. Oxygen (O2) will only rarely be an actual poison for the catalyst, but the ability to oxidize the catalyst materials may lead to structural damage to the catalyst leading to mechanical or catalytic degradation if present in higher concentrations, e.g. higher than 100 ppm.

[0006] Despite the high purity of certain CO2sources, it has been discovered that further purification is required to avoid catalyst poisoning or degradation of downstream synthesis catalysts.

[0007] Sulfur compounds are well-known as catalyst poisons, which react with the active material on the catalysts and render them catalytically inactive. For some catalysts, oxygen (O2) is also a critical substance leading to catalyst degradation and e.g. a downstream Cu-based methanol catalyst is prone to oxidation by oxygen and therefore high concentrations of oxygen present in the CO2(or H2) feed gases to a methanol plant have to be removed at a position upstream the methanol catalyst.

[0008] Systems and processes for purification of CO2streams are known from e.g. EP2457636, CN112999843, US2007028764, US200702877, US2022333015 and CN112957872.

[0009] 03118-WO Applicant’s co-pending patent application PCT / EP2024 / 060944 discloses a process for cleaning a CCh-rich gas feed via H2 addition, with first a O2 hydrogenation over a first catalyst and then removal of a sulfur-containing impurity over a second catalyst / absorbent.

[0010] The catalyst / absorbent systems developed to remove sulfur impurities from CO2 have been found to be sensitive to relatively high oxygen concentrations as well, and a solution has now been developed to remove the O2 from the CO2 gas already as part of the sulfur removal process, thus suitably simultaneously with the removal of sulfur-containing impurities.

[0011] SUMMARY

[0012] It has been found by the present inventor(s) that sulfur (S) impurity removal of CO2 feeds is necessary and can be carried out upon addition of some hydrogen, by retaining sulfur impurities e.g. by adsorption on a metal-promoted guard material to such a degree, that the cleaned CCh-rich gas stream has a very low content of sulfur-containing impurities, such as <500 ppb. It has also been found that the metal-promoted guard material is capable of hydrogenating at least a part of O2 to H2O in the CCh-rich gas feed and / or in the hydrogen being added, and thus it is now possible to combine the O2 and S-containing impurity removal, such as SO2 removal, utilizing the same guard material.

[0013] It has also been discovered that any oxygen in the CO2 feed can influence the sulfur retainment capacity and mechanical integrity of a metal promoted guard material.

[0014] So, in a first aspect the present invention relates to a process for cleaning a CCh-rich gas feed, said CCh-rich gas feed comprising at least 60 vol% CO2 and one or more sulfur- containing impurities; wherein said process comprises the step of:

[0015] - passing the CCh-rich gas feed together with a first hydrogen-rich gas feed over a guard material, and retaining, such as adsorbing, one or more sulfur-containing compounds on said guard material, to provide a cleaned CCh-rich gas stream;

[0016] 03118-WO and wherein the CCh-rich gas feed, and / or the first hydrogen-rich gas feed, additionally comprise(s) oxygen (O2) of which at least a part is hydrogenated to water (H2O) on the guard material.

[0017] Preferably, the step of “passing the CCh-rich gas feed together with a first hydrogen-rich gas feed over a guard material” means: directly passing the CCh-rich gas feed together with a first hydrogen-rich gas feed over a guard material,

[0018] The term “directly” means that there are no units or process steps changing the composition of the associated gas(es).

[0019] The O2 is hydrogenated and leaves the guard material as water vapor.

[0020] A process for production of a syngas stream utilizing the leaned CCh-rich gas stream is also provided.

[0021] A process is also provided for production of a synthetic fuel stream by converting said syngas stream to at least one synthetic fuel stream.

[0022] Additional aspects are presented in the following description text, figures and claims.

[0023] For the purposes of the present application, the term “synthetic fuel stream” is used interchangeably with the term “synthetic fuel” and is at least one of: MeOH (methanol), DME (dimethyl ether), methane (CH4), aviation fuel, kerosene, gasoline and diesel. The aviation fuel may also be sustainable aviation fuel (SAF), i.e. aviation fuel which is produced based on sustainable resources.

[0024] For the purposes of the present application, the term “and / or” means at least one of the associated three options. For instance, MeOH and / or DME means at least one of: MeOH, DME, MeOH and DME.

[0025] For the purposes of the present application, the term “aspect” and “embodiment” may be used interchangeably.

[0026] 03118-WO For the purposes of the present application, the term “present application” or “application” may be used interchangeably with the term “present invention” or “invention”, respectively.

[0027] For the purposes of the present application, the term “retaining” or “retained” in connection with the guard material is used interchangeably with any of the terms: adsorption and / or absorption, or respectively, adsorbed and / or absorbed. The term is also meant to include the chemical binding of a sulfur-containing impurity in the guard material, e.g. by forming ZnS, CuS and CU2S.

[0028] For the purposes of the present application, the term “sulfur-containing impurities” may be used interchangeably with the term “sulfur-containing compounds” or “sulfur compounds”.

[0029] For the purposes of the present application, the term “purification” and “cleaning” may be used interchangeably. For instance, the term “purification reactor” which refers to the reactor vessel where the purification takes place, may be used interchangeably with the term “cleaning reactor”.

[0030] Other definitions are provided in connection with one or more of above and below embodiments.

[0031] LEGENDS

[0032] Figure 1 (Fig. 1) shows a simple process layout a process layout according to an embodiment of the invention.

[0033] Figure 2 (Fig. 2) shows a process layout according to another embodiment of the invention.

[0034] Figure 3 (Fig. 3) shows a process layout according to yet another embodiment of the invention.

[0035] Figure 4 (Fig. 4) shows experimental SO2 and O2 removal efficiencies from the experiment described in Example I.

[0036] 03118-WO Figure 5 (Fig. 5) shows experimental SO2 and O2 removal efficiencies from the experiment described in Example II.

[0037] DETAILED DISCLOSURE

[0038] For the purposes of the present application, any given percentages for gas content are %, ppm (parts per million) or ppb (parts per billion) by volume. All feeds are preheated as required. Unless specified, the concentrations will be given on dry basis, i.e. without taking any water present into account.

[0039] The term “at least a part” or “at least a portion” of a certain item, the item being a process stream, a conduit associated with the process stream, or a compound, or a molecule, means a portion of the item or the entire item.

[0040] A cleaned CCh-rich gas stream is defined as the outlet stream from the CO2 cleaning process, in which minimum 95% of the combined sulfur containing impurities in the feed is removed, or the sum of sulfur containing impurities in the cleaned CCh-rich gas stream is lower than 500 ppb (parts per billion by volume), preferably lower than 100 ppb and most preferably lower than 50 ppb or lower than 10 ppb.

[0041] The sum of sulfur-containing impurities in the cleaned CCh-rich gas stream should be understood as sulfur-equivalents, i.e. 100 ppb SO2 correspond to 100 ppb sulfur whereas 100 ppb CS2 correspond to 200 ppb sulfur.

[0042] Similarly, and suitably in addition to sulfur removal, cleaned CCh-rich gas stream is defined as the outlet stream from the CO2 cleaning process, in which minimum 95% of the oxygen in the feed is hydrogenated, or the O2 concentration in the cleaned CCh-rich gas stream is lower than 200 ppm, preferably lower than 100 ppm and most preferably lower than 50 ppm.

[0043] Accordingly, in an embodiment, a cleaned CCh-rich gas stream is defined as the outlet stream from the CO2 cleaning process, in which:

[0044] - minimum 95% of the combined sulfur containing impurities in the feed is removed, or the sum of sulfur containing impurities in the cleaned CCh-rich gas stream is lower than 500 ppb

[0045] 03118-WO (parts per billion by volume), preferably lower than 100 ppb and most preferably lower than 50 ppb or lower than 10 ppb; and

[0046] - minimum 95% of the oxygen in the feed is hydrogenated, or the O2 concentration in the cleaned CO2 gas stream is lower than 200 ppm, preferably lower than 100 ppm and most preferably lower than 50 ppm.

[0047] Syngas is used as reference for synthesis gas, a gas mixture comprising hydrogen, carbon monoxide, carbon dioxide, methane and typically water as steam. It is referred to as syngas / synthesis gas because it is the feed for a downstream catalytic synthesis leading to the desired product. In some applications the feed downstream the referred purification can be mixed with additional hydrogen and be used as synthesis gas e.g. for methanol synthesis. In other applications, the purified gas is converted, after mixing with additional hydrogen and optionally steam, in a reverse water gas shift reactor (RWGS), methanation reactor, or combined RWGS and methanation reactor, to form the final synthesis gas for the synthesis of the final product.

[0048] The proposed solution according to the invention ensures that the feed gases for any downstream conversion to synthesis gas and further synthesis to chemicals, herein also referred to as synthetic fuels, like MeOH, DME, FT (Fischer Tropsch) synthetic fuels, TIGAS based gasoline etc. will be unproblematic with regard to sulfur and oxygen poisoning of the downstream synthesis catalyst. This will ensure that operation can be made over time and allow catalyst lifetime as expected for industrial catalyst.

[0049] In a first aspect, therefore, said process for cleaning a CO2-rich gas feed is provided.

[0050] In an embodiment, the CO2-rich gas feed provided to the process comprises at least 70 vol% CO2, or at least 80 vol% CO2, or at least 90 vol% CO2, such as at least 95 vol% CO2, such as at least 99 vol% CO2, preferably at least 99.5 vol% CO2, more preferably as at least 99.9 vol% CO2. The CO2-rich gas feed is thus, in an embodiment, already of high purity prior to the process of the present invention.

[0051] The term “high purity” means in connection with this embodiment, at least 95 vol% CO2.

[0052] 03118-WO More generally, for the purposes of the present application, the term “high purity” with respect to a given compound, means at least 95 vol% of the compound.

[0053] Suitably, the CCh-rich gas feed is derived from a renewable source, such as:

[0054] - combustion or gasification of a lignocellulosic biomass such as wood products, algae, grass, forestry waste and / or agricultural residue;

[0055] - combustion or gasification of municipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public, such as mixed municipal waste given in Ell Directive 2018 / 2001 (RED II), Annex IX, part A;

[0056] - microbial conversion of nitrogen-rich renewable feedstock such as manure or sewage sludge;

[0057] - fermentation of hydrocarbon(sugar) rich feed streams such as corn, sugar cane and beets;

[0058] - Direct Air Capture (DAC).

[0059] Thus, for instance, The CCh-rich gas feed can also be obtained from said direct air capture (DAC) processes, metallurgical processes, cement production or fossil fuel combustion.

[0060] The CO2 concentration in most of the above-mentioned gas streams may typically be too low for further chemical processing and a concentration step is required to increase the CO2 concentration to the desired value as mentioned above.

[0061] This concentration step is often called a carbon capture process, and the process can take several forms. The most commonly used process includes an absorption step in which the CO2 is absorbed into an alkaline liquid and the CO2 loaded liquid is passed to a desorbing step in which the CO2 is desorbed from the alkaline liquid, producing a concentrated CO2 stream and a CO2 depleted alkaline liquid, which is then returned to the absorption step.

[0062] In e.g. combustion processes, the flue gas from a furnace / boiler will, besides CO2, SO2, N2, H2O, O2, also contains relatively low concentrations of NOx, originating from either fuelbound nitrogen and / or from N2 in the atmosphere. Depending on the cleaning steps of the

[0063] 03118-WO flue gas and the degree of carryover and retainment in the carbon capture process (concentration step), the CO2 rich stream can contain both O2, SO2 and NOx.

[0064] NOx typically describes both NO, NO2 and N2O, which are the species normally found in combustion processes. NO is typically the dominant species in the combustion process but may not be it in the CO2-rich gas stream as NO is poorly soluble in the aqueous solutions of the carbon capture process, whereas NO2 is much more soluble and thus easier transported to the CO2 rich gas stream.

[0065] The guard material as described in the present invention is capable of hydrogenating O2 and reducing SO2 to H2S by means of reaction with H2 and thus NOx may also become hydrogenated / reduced on the guard material. Those reactions are:

[0066] NO + 2.5 H2-> NH3+ H2O

[0067] NO2+ 3.5 H2-> NH3+ 2 H2O

[0068] N2O + 4 H2-> 2 NH3+ H2O

[0069] From these chemical reactions, it is observed that both water and ammonia may be formed on the guard material. Neither water nor ammonia are retained on the guard material and therefore they may become part of the cleaned H2-and-CO2 rich gas stream. The NH3can under certain conditions become an issue as CO2, H2O and NH3can react and form ammonium bicarbonate (NF HCOs) and / or ammonium carbamate (NH4COONH2), or methyl amines, which can solidify and result in (local) plugging, corrosion and fouling. This typically takes place at high pressure and low temperature.

[0070] If deemed necessary, the NH3can be removed from the H2-and-CO2 rich gas stream by means of e.g. a water washing or a water condensation step, where the readily soluble NH3is transferred from the gas phase to the liquid phase and will leave the process via the aqueous stream i.e. condensate stream.

[0071] 03118-WO Suitably, the first hydrogen-rich gas feed is derived from a renewable source, such as electrolysis of water / steam powered by any of: wind, solar, hydro power, geothermal, thermonuclear energy.

[0072] Suitably, the first hydrogen-rich gas feed is derived from a reforming unit, optionally after further hydrogen enrichment such as after water-gas shift (WGS) and hydrogen purification e.g. in a pressure swing adsorption (PSA) unit and / or a membrane unit. The reforming unit is supplied with a hydrocarbon gas feed or a pre-reformed hydrocarbon gas feed. The hydrocarbon gas feed is for instance natural gas.

[0073] It is understood that the term “suitably” may be used interchangeably with the term “optionally”, i.e. it refers to an optional embodiment.

[0074] It is understood that the use of the article “a” or “an” in connection with an embodiment or an item, means “one or more” or interchangeably “at least one”.

[0075] The CC>2-rich gas feed comprises one or more sulfur-containing impurities. In an embodiment, the one or more sulfur-containing impurities within the CCh-rich gas feed are selected from organosulfur compounds such as thiols, sulfides, disulfides, sulfones, sulfoxides and thioketones, CS2, COS, SO3, SO2 and H2S, preferably H2S and SO2, most preferably SO2.

[0076] In an embodiment, the guard material is active in reduction of SO2 to H2S and retainment of H2S, as well as catalytically active in the hydrogenation of O2, and is preferably a Cu-Zn-AI guard material. Advantageously, the following reactions take place in the guard material: 2 H2+ O2-> 2 H2O; SO2+ 3 H2-> H2S + 2 H2O; ZnO + H2S -> ZnS + H2O.

[0077] In an embodiment, the guard material is arranged within a reactor vessel, said reactor vessel being arranged to receive said CO2-rich gas feed and said first hydrogen-rich gas feed, optionally in admixture, and provide said cleaned CO2-rich gas stream.

[0078] For instance, the guard material is arranged as a fixed bed. For instance, the reactor vessel is arranged as an adiabatic reactor. For instance, the reactor vessel is arranged as a cooled reactor.

[0079] 03118-WO In an embodiment, the sulfur containing impurity is SO2 and the concentration of SO2 in the CC>2-rich gas feed is 0.1-50 ppm SO2, such as 0.2-10 ppm SO2, such as 1-10 ppm SO2, such as 0.5-5 ppm SO2, such as 1-5 ppm SO2.

[0080] The CC>2-rich gas feed may also comprise water. However, high concentrations of water can lim it / inhibit the uptake of sulfur-containing compounds on the guard material and limiting the water concentration provides for a more efficient operation of the guard system. Accordingly, in an embodiment, the content of H2O in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed, e.g. after mixing of said feeds, is no more than 10 vol%, preferably no more than 5.0 vol%, preferably no more than 1.0 vol%, e.g. approximately 0.5 vol%.

[0081] It is understood that the term “combined feed of the CCh-rich gas feed and the hydrogen-rich gas feed” means the resulting stream of mixing the CCh-rich gas feed and the first hydrogenrich gas feed prior to being passed over the guard material.

[0082] The CC>2-rich gas feed may - in many cases - comprise oxygen (O2). Oxygen may also contaminate, poison or lead to degradation of downstream catalysts and guard material, so any oxygen in the CO2-rich gas feed should be reduced or eliminated. The total content of O2 in the CO2-rich gas feed, is 50-10,000 ppm O2, such as 50-5,000 ppm O2, such as 100- 3,000 ppm O2.

[0083] Generally, the process comprises the step of: passing the CCh-rich gas feed together with the first hydrogen-rich gas feed over a guard material, retaining e.g. adsorbing one or more sulfur-containing compounds on said guard material and hydrogenating the O2 on the guard material, to provide a cleaned CCh-rich gas stream.

[0084] The CC>2-rich gas feed to be purified may be first mixed with the first hydrogen-rich gas feed, which acts as a reductant for one or more sulfur-containing impurities, and optionally for oxygen, in the CCh-rich feed.

[0085] In an embodiment, the first hydrogen-rich gas feed comprises O2 and the process comprises a prior hydrogenating step for of said first hydrogen-rich gas. The first hydrogen-rich gas feed is preferably supplied to an Ch-hydrogenation reaction zone. Preferably, in connection

[0086] 03118-WO with this embodiment, the total content of H2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed corresponds to a ratio of at least 2 moles H2 per mole CO2, such as 2-5 moles H2 per mole CO2, for instance 2.5-4.5 moles H2 per mole CO2 or 3-4 moles H2 per mole CO2, or 2.8-3.2 moles H2 per mole CO2.

[0087] The first hydrogen-rich gas feed can itself also contain O2, depending on the origin. In some electrolysis processes, there can be some carryover of O2 to the first hydrogen-rich gas feed stream, resulting in up to 0.5-2 vol% O2, such as 1 vol% O2 in the hydrogen-rich gas feed stream. The O2 can be (catalytically) hydrogenated in the first hydrogen-rich gas feed stream before the first hydrogen-rich gas feed is mixed with the CCh-rich gas feed, or the first hydrogen-rich gas feed is mixed directly with the CCh-rich gas feed whereby the O2 from the first hydrogen-rich gas feed is hydrogenated on the guard material for sulfur and oxygen removal.

[0088] Suitably, this, together with any moisture present in any of the feed gases, results in the above-mentioned content of H2O in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed, e.g. after mixing of said feeds, being no more than 10 vol%, preferably no more than 5.0 vol%, preferably no more than 1.0 vol%, e.g. approximately 0.5 vol%.

[0089] Suitably, the Ch-hydrogenation reaction zone comprises a hydrogenation catalyst, wherein:

[0090] - the hydrogenation catalyst comprises an alumina and / or silica carrier impregnated with a metal, such as: Cu, Mn, Pt, Pd, or combinations thereof; or

[0091] - the hydrogenation catalyst comprises a Cu / Zn / AI based material; or

[0092] - the Ch-hydrogenation reaction zone is arranged as a fixed bed of hydrogenation catalyst pellets or as one or more layers of monolithic type hydrogenation catalyst, and the hydrogenation catalyst comprises an alumina and / or silica carrier impregnated with Pt and / or Pd.

[0093] A hydrogenation catalyst comprising an alumina and / or silica carrier impregnated with Pt and / or Pd enables operation at a lower temperature than e.g. the Cu / Zn / AI based material.

[0094] In an embodiment, the first hydrogen-rich gas feed to the process comprises at least 98 vol% H2 such as at least 99 vol% H2 such as at least 99.5 vol% H2.

[0095] 03118-WO In an embodiment, the content of O2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed is 50-20,000 ppm O2 such as 50-5,000 ppm O2, such as 100- 3,000 ppm O2.

[0096] In an embodiment, more than 95% of the O2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed is hydrogenated; or the concentration of O2 in the cleaned CCh-rich gas stream is < 200 ppm, such as < 100 ppm, such as < 50 ppm.

[0097] In an embodiment, hydrogen is suitably added such that, the total content of H2 in the combined feed of the CCh-rich gas feed and the hydrogen-rich gas feed, e.g. after mixing of said feeds, is 0.2-10 vol% H2 such as 0.5-3 vol% H2 or 2-3 vol% H2.

[0098] The advantage of this embodiment is that addition of H2 is controlled, so as to limit undesired side reactions, e.g. methanol formation while still having a sufficient H2 to ensure high degree of hydrogenation of any oxygen, NOx and the sulfur impurities. With such little content of H2 in the inlet flow to the reactor vessel, there is lower risk of methanol formation. This enables to expand the range of temperatures under which at least sulfur-containing impurities are retained without risking methanol formation. The higher the temperature, the higher at least the S-retainment. Furthermore, with this embodiment the total gas flow is kept at a minimum, thus providing the smallest possible reactor and equipment size.

[0099] In an embodiment, the total content of H2 in the combined feed of the CO2 rich gas feed and the first hydrogen-rich gas feed, e.g. after mixing of said feeds, corresponds to a ratio of at least 2 moles H2 per mole CO2, such as 2-5 moles H2 per mole CO2, for instance 2.5-4.5 moles H2 per mole CO2 or 3-4 moles H2 per mole CO2 or 2.8-.3.2 moles H2 per mole CO2.

[0100] In an embodiment, the first hydrogen-rich gas feed is added to the CCh-rich gas feed in an amount corresponding to the feed composition to the downstream process for production of synthesis gas, or synthetic fuels e.g. methanol. As an example, in the production of methanol, the feed composition to the methanol process is suitably around 75 vol% H2, 25 vol% CO2 (12 wt% H2 and 88 wt% CO2), corresponding to a ratio of 3 moles H2 per mole of CO2 or within the range 2.8-3.2 moles H2 per mole of CO2. Where renewable natural gas

[0101] 03118-WO (RNG, which is a methane-rich product) is the final product, the initial H2 / CO2 molar ratio is suitably around 4.

[0102] The advantage of this embodiment is that H2 and CO2 can be mixed and preferably compressed prior to the CO2 cleaning. The CO2 cleaning process can be located downstream the compression step or between intermediate compression steps, whichever is best suited with regard to cost, water concentration, risk of carbonate formation on the guard material and risk of formation of undesired side products such as water and methanol. Appended Fig. 3 shows a particular embodiment. Another advantage of this embodiment is that any O2 present in the first hydrogen-rich gas feed also becomes hydrogenated. H2 provided from electrolysis of water / steam, for instance, can contain varying amounts of O2, as recited earlier, depending on the operation of the electrolyser.

[0103] The one or more sulfur-containing compounds retained, e.g. adsorbed onto the guard material are typically selected from COS, SO2 and H2S, preferably SO2. The guard material is suitably active in retaining, e.g. adsorption and / or absorption of SO2 and H2S as well as catalytically active in the hydrogenation of O2, and is preferably a Cu-Zn-AI guard material. In the presence of H2, the guard material is capable of catalytically reducing the SO2 in the CO2-rich gas feed to H2S, which is much more efficiently retained e.g. adsorbed on the guard than the SO2. Again, the guard is also capable of reacting oxygen content in the CO2 feed stream with hydrogen to form water, i.e. hydrogenation of O2.

[0104] The process provides a cleaned CCh-rich gas stream. This cleaned CCh-rich gas stream comprises for instance:

[0105] - less than 500 ppb (< 500 ppb), such as less than 100 ppb, preferably less than 50 ppb sulfur (sulfur-containing impurities), or preferably less than 25 ppb sulfur, more preferably less than 10 ppb;

[0106] - less than 200 ppm O2, such as less than 100 ppm O2, preferably less than 50 ppm O2.

[0107] The guard material used in the process is suitably located within a reactor vessel, said reactor vessel being arranged to receive the CCh-rich gas feed and the first hydrogen-rich gas feed, optionally in admixture, and provide said cleaned CCh-rich gas.

[0108] 03118-WO In an embodiment, the guard material is a Cu-Zn-AI guard material, having a chemical composition of 25-60 wt% Cu, 15-70 wt% Zn, and 1-20 wt% Al, such as 2-20 wt% Al e.g. 2- 10 wt% Al or 2-15 wt% Al. It may comprise minor amounts of at least one of K, Cs and C. The elements will either be found in a reduced or oxidised state.

[0109] In a particular embodiment, the guard material is coprecipitated Cu / ZnO / alumina-based guard material, in which Cu is ~ 40 wt%, ZnO is ~30 wt% and alumina ~10 wt%.

[0110] For the purposes of the present application, the sign ~ means + / -10% . For instance, Cu can be 40, 36 or 44 wt% i.e. within 10%; or 42, 38 wt% i.e. within 5%.

[0111] The CO2 cleaning process is preferably operated in the pressure range 1-120 bar, such as 1-100 bar or 1-90 bar, preferably 1-50 bar, depending on the pressure of the CCh-rich gas feed stream and the pressure of the downstream conversion process. Further, to provide the best compromise between high catalytic / retention e.g. catalytic / adsorption efficiency and low tendency for carbonate formation and evolution of undesired side reactions, such as water and methanol formation, the CO2 cleaning process is preferably operated in the interval 120- 250°C.

[0112] Accordingly, in an embodiment, the step of passing the CCh-rich gas feed and first hydrogen-rich gas feed over the guard material, takes place at a temperature in the interval 120-250°C and a pressure in the interval 1-120 bar.

[0113] For instance, the temperature is 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, or 240°C.

[0114] Preferably, as recited in an embodiment of the invention, the content of H2 in the combined gas to the reactor vessel is no higher than 2-3 vol% H2, so that the risk of methanol formation is less pronounced even at higher temperatures than e.g. 180°C, thereby further enhancing at least the S-retainment in the guard material.

[0115] The temperature is understood as reaction temperature in an isothermal reactor, or inlet temperature in an adiabatic reactor. In an adiabatic reactor the adiabatic temperature increase is preferably not greater than 50°C.

[0116] 03118-WO For instance, the pressure is 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 bar.

[0117] In an embodiment, more than 95% of the one or more sulfur containing impurities are retained on the guard material or the total concentration of sulfur-containing impurities in the cleaned CCh-rich gas stream is < 500 ppb, such as < 100 ppb, or such as < 50 ppb, or such as < 10 ppb.

[0118] Other values the sulfur-containing impurities in the cleaned CO2-righ gas stream may also apply, as recited in connection with other embodiments.

[0119] More generally, for the purposes of the present application, individual values of an item within a range, may be combined with individual values of the same item within a different range.

[0120] For instance, where the total content of O2 in the combined feed of the CO2-rich gas feed and the first hydrogen-rich gas feed is 50-20,000 ppm O2 such as 50-5,000 ppm O2, such as 100-3,000 ppm O2, this includes 50-3,000 ppm O2 or 5,000-20,000 ppm O2.

[0121] As recited above, in an embodiment, the CCh-rich gas feed is derived from a renewable source such as:

[0122] - combustion or gasification of a lignocellulosic biomass such as wood products, algae, grass, forestry waste and / or agricultural residue;

[0123] - combustion or gasification of municipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public, such as mixed municipal waste given in Ell Directive 2018 / 2001 (RED II), Annex IX, part A;

[0124] - microbial conversion of nitrogen-rich renewable feedstock such as manure or sewage sludge;

[0125] - fermentation of hydrocarbon(sugar) rich feed streams such as corn, sugar cane and beets;

[0126] - Direct Air Capture (DAC)

[0127] The term “derived from a renewable source” means that the process further comprises a prior step according to the above, e.g. a prior step of combustion or gasification of a

[0128] 03118-WO lignocellulosic biomass such as wood products, algae, grass, forestry waste and / or agricultural residue.

[0129] As recited above, the cleaned CCh-rich gas stream is sufficiently pure that the risk of catalyst poisoning of downstream processes is significantly reduced.

[0130] Accordingly, in an embodiment, where the content of H2 in the cleaned CO2-rich gas is too low for use as syngas, for instance where the molar ratio of H2:CO2 is below 2, the process further comprisies:

[0131] - providing a second hydrogen-rich gas feed, optionally obtained from the process of electrolysis of water / steam in one or more electrolysis unit(s);

[0132] - reacting at least a portion of the cleaned CCh-rich gas stream with the second hydrogen-rich gas feed, to provide at least one syngas stream; or reacting at least a portion of the cleaned CCh-rich gas stream feed with the second hydrogen-rich gas feed directly in: a methanol converter in the presence of a methanol synthesis catalyst, or a methanation reactor in the presence of a methanation catalyst; or supplying the cleaned CCh-rich gas stream to a solid oxide electrolysis (SOE) unit to provide a CO-and-CCh gas mixture and combining at least a portion thereof with the second hydrogen-rich gas feed into a at least one syngas stream.

[0133] It is understood that the term “water / steam” means water or steam. Water is supplied as feed to a low temperature electrolysis units i.e. so-called PEM / Akali water electrolysis, while steam is supplied as feed to a solid oxide electrolysis (SOE) unit, which operates at high temperatures, for instance in range 700-900°C.

[0134] It is understood that the term “directly in: a methanol converter in the presence of in a methanol synthesis catalyst, or a methanation reactor in the presence of a methanation catalyst” means without the production of synthesis gas by use of reverse water gas shift (RWGS).

[0135] The invention enables, in an embodiment, purifying a CO2-rich gas feed gas by eliminating at least the sulfur-impurity(ies) along with O2, prior to being supplied to e.g. a solid oxide cell

[0136] 03118-WO (SOE) unit for producing a gas mixture of CO and CO2. This gas mixture of CO and CO2 is suitably combined with the second hydrogen-rich gas feed into the at least one syngas stream comprising CO, CO2 and H2. Where the syngas is further converted to methanol, the presence of CO in the syngas enables less H2 consumption and less water formation in connection with the methanol synthesis and the cost of separation, typically by distillation, will therefore be lower. Further, since the methanol catalyst performance is also sensitive to water, that the catalyst volume in the methanol reactor is reduced. Where the syngas is further converted to synthetic fuels via a Fischer-Tropsch (FT) process, the presence of CO in the syngas enables to eliminate the need of RWGS to convert some of the CO2 to CO. Optionally, the at least a portion of the gas mixture of CO-and-CO2 gas mixture from the SOE unit may be combined with a portion of the first hydrogen-rich gas feed, or a second hydrogen-rich gas feed. This hydrogen-rich gas feed is for instance from a water / steam electrolysis unit such as a SOE unit.

[0137] In an embodiment:

[0138] - the step of reacting said portion of the cleaned CO2-rich stream feed with the second hydrogen-rich gas feed, to provide at least one syngas stream is carried out in the presence of a catalyst active in reverse water gas shift (RWGS), preferably in an electrically heated reactor for RWGS (e-RWGS).

[0139] RWGS, methanol synthesis and methanation are well known in the art. For details on e- RWGS, which is a more recent technology, reference is given to e.g. applicant’s WO 2022079098.

[0140] The RWGS increases the CO content in the syngas and further serves to e.g. adjust, the module “M” of the syngas (M=(H2-CO2) / (CO+CO2)) on molar basis, for e.g. downstream methanol synthesis in a methanol converter. For downstream methanol synthesis M is preferably 2.0-2.1. For downstream Fischer-Tropsch (FT) process the molar ratio of H2 / CO is preferably 2.

[0141] In an embodiment, RWGS is conducted to provide the at least one syngas stream for downstream methanation. The H2 / CO molar ratio is suitably around 4, as earlier recited. After RWGS, the H2 / CO molar ratio of the syngas is suitably around 3 disregarding CO2 (or said ratio (H2-CO2) / (CO+CO2) is 3), in line with the methanation reaction:

[0142] 03118-WO CO+3H2->CH4+H2O

[0143] An integrated process can also take place, in which CO2cleaning, syngas production and subsequent downstream syntheses occur. Accordingly, in an embodiment, the process comprises producing a synthetic fuel stream by further converting said at least one syngas stream to at least one synthetic fuel stream which is at least one of: MeOH (methanol), DME (dimethyl ether), methane, aviation fuel, kerosene, gasoline and diesel fuel.

[0144] Again, it is understood that the term “synthetic fuel stream” is used interchangeably with the term “synthetic fuel” and is at least one of: MeOH (methanol), DME (dimethyl ether), methane, aviation fuel, kerosone, gasoline and diesel. The aviation fuel may also be sustainable aviation fuel (SAF), i.e. aviation fuel which is produced based on sustainable resources.

[0145] For the purposes of the present application, the term “aviation fuel” is regarded as a different synthetic fuel than “kerosene”. The term “aviation fuel” may be used interchangeably with the term “jet fuel” and includes SAF, in compliance with specific standards for use in jet fuel engines. The term “kerosene” is broader and refers to a flammable hydrocarbon liquid often used as a fuel or solvent.

[0146] In one aspect, the process of converting said at least one syngas stream to at least one synthetic fuel stream is a Fisher-Tropsch (FT) process, which provides the synthetic fuel stream. In another aspect, the process of converting said at least one syngas stream to at least one synthesis fuel stream is a TIGAS process, which provides a synthetic fuel stream. In yet another aspect, the process of converting said at least one syngas stream to at least one synthesis fuel stream is a methanol-to-jet fuel (MTJ) process, which provides at least an aviation fuel, suitably SAF, as the synthetic fuel stream.

[0147] Accordingly, in an embodiment, the process of converting said at least one syngas stream to at least one synthetic fuel stream is: a Fisher-Tropsch (FT) process; or a process whereby the syngas stream is first converted to methanol and / or DME, and subsequently to gasoline, e.g. via a TIGAS process, or aviation fuel e.g. via a methanol-to-jet fuel (MTJ) process.

[0148] The FT, TIGAS and MTJ processes are well-known in the art.

[0149] 03118-WO In an embodiment, the step of converting said at least one syngas stream to at least one synthetic fuel stream is a Fisher-Tropsch (FT) process, and a recycle stream from the FT- process, such as FT-tail gas or hydrogenated FT-tail gas, is supplied upstream the RWGS, e.g. upstream the e-RWGS.

[0150] Specific embodiments

[0151] Fig. 1 shows a simple layout of one embodiment of the process 100 of the invention. A CO2- rich gas feed 101 comprising O2 is mixed with a first hydrogen-rich gas feed 103, optionally comprising O2, and passed as mixed (combined) feed gas 105 over a guard material 112 in reactor vessel 110. Sulfur-containing compounds are retained e.g. adsorbed and O2 is hydrogenated on the guard material 112 and a cleaned CO2-rich gas stream 107 is outputted.

[0152] Fig. 2 shows a layout for production of a syngas stream. In the process 100, the reactor vessel 110, CO2-rich gas feed 101 , first hydrogen-rich gas feed 103, mixed feed gas 105 and cleaned CO2-rich gas stream 107 are according to Fig. 1. Subsequently, a second hydrogen-rich gas feed 109 is mixed with the cleaned CO2-rich stream feed 107 into a raw syngas 111 and then converted in a syngas section 120 optionally comprising a reverse water gas shift (RWGS) reactor; or directly in: a methanol reactor or a methanation reactor. For instance, the reaction of the cleaned CO2-rich gas stream 107 with the second hydrogen-rich gas feed 109 is carried out in the presence of a catalyst 122 active in RWGS, thereby providing at least one syngas stream 113. The at least one syngas stream 113 is suitably further converted in syngas conversion section 130 to at least one synthetic fuel stream 115, such as aviation fuel, kerosene, gasoline and diesel fuel. This conversion step in 130 is for instance a Fisher-Tropsch (FT) process (FT synthesis process).

[0153] In Fig. 3 one embodiment of the layout of the CO2 gas purification process 100 is shown. The CO2 -rich gas feed 101 comprising O2 and one or more sulfur-impurities is mixed with an amount of a H2 rich gas 103 (first hydrogen feed), optionally comprising O2. The mixed feed gas 105 is supplied to a compressor 102 in which the pressure is increased. Thereby, H2 and CO2 are mixed and compressed as mixed feed gas 105’ prior to the CO2 cleaning in the downstream sulfur and oxygen removing reactor vessel (reactor) 110. The high-pressure

[0154] 03118-WO (HP) mixed feed gas 105’ is then preheated in a heat exchanger 104 and the heated HP mixed feed gas 105” is supplied to said reactor 110. In the reactor 110 a guard material 112 is provided, removing sulfur impurities and hydrogenating O2. The outlet 107 comprising the cleaned CCh-rich gas withdrawn from the reactor 110 is substantially free of oxygen and sulfur impurities and can be further processed to syngas 113 or other downstream products, as shown in Fig. 2. It is understood that the cleaned CCh-rich stream 107 in Fig. 1 and 2 corresponds to outlet stream 107 in Fig. 3.

[0155] EXAMPLES

[0156] Experiments have been carried out in a laboratory fixed bed reactor at isothermal condition to test the combined SO2 and O2 removal efficiency of the guard material. The fixed bed reactor is placed in an electrically-heated oven and heated to the desired operating temperature. Two internal thermocouples measure the inlet and exit temperatures in the catalytic bed. The oven is equipped with external thermocouples controlling the temperature zones in the oven. These zones are controlled by internal thermocouple readings to obtain isothermal reaction condition in the fixed bed.

[0157] The guard material is placed in the SilcoNert 2000™ coated stainless-steel reactor on a grid and the reactor is aligned to be in the center of the electrical oven. Feed gases are mixed from gas cylinders using mass flow controllers controlling feed of the individual gases. These include nitrogen (N2), hydrogen (H2), carbon dioxide (CO2), 2 vol% O2 in N2, and 100 ppm sulfur dioxide in methane (SO2 in CH4). Liquid water is supplied via a pump, passing through an evaporator and mixed with the feed gas upstream of the fixed bed reactor.

[0158] The guard material used is a coprecipitated Cu (~40 wt%) / ZnO (~30 wt%) / alumina- (~10 wt%) based guard material.

[0159] The guard material was loaded into the reactor as industrial-sized tablets, each tablet was separated with a 2 mm glass sphere to improve the tablet’s surface exposure to the reactor feed gas. This so-called Single Pellet String reactor is loaded with 30 tablets, simulating the top layer of an industrial fixed bed guard reactor.

[0160] 03118-WO Before measuring SO2 and O2 removal from the CCh-richfeed gas, the guard material was reduced in 2% H2 in N2 at 220°C and 3 barg.

[0161] EXAMPLE (I)

[0162] The first experiment was carried out at an operating pressure of 30 barg and at 150°C.

[0163] The approximate composition of the combined feed gas to the reactor, herein referred to as process gas, was 60 vol% H2, 20 vol% CO2, 10 vol% CH4, 10 vol% N2 with the impurity concentrations of 7 ppm SO2 and 2,500 ppm O2. No water was added to the process gas.

[0164] The process gas flow was 40 Nl / h (0°C, 1 atm).

[0165] The process gas simulates a plant, wherein all the H2 is mixed into the CO2 stream prior to process gas purification (as depicted in Fig. 3) and passing the purified gas i.e. the clean CC>2-rich gas stream to a downstream synthesis gas plant. The presence of CH4 and N2 in the reactor feed was a consequence of using mixtures of SO2+CH4 and O2+N2, necessary for safety reasons in the experiments.

[0166] The sulfur feed and exit gas concentration were measured on Agilent 7890A GC system equipped with an Ol 5380 pulsed flame photometric detector (PFPD). The O2 concentration was measured with a TecMicro analyzer (0-5,000 ppm O2) from TecSense GmbH.

[0167] In Fig. 4, the relative O2 and SO2 concentrations at the reactor outlet are shown as a function of time on stream of the experiment. The relative concentrations are defined as the outlet concentration divided by the inlet concentration, i.e. a relative concentration of 0% correspond to complete removal / conversion, whereas 100% correspond to no removal / conversion. For an adsorbent / absorbent, it is expected that the relative outlet concentration starts at a low value (preferably 0%) and over time increase and ultimately the relative outlet concentration reaches 100% when the adsorbent / absorbent become fully saturated. For a catalyst, the relative outlet concentration should ideally stay constant over time. However, poisoning / deactivation of the catalyst will result in a gradual increase in relative concentrations over time.

[0168] 03118-WO The O2 is added after 5 hours of time on stream and SO2 is added to the process gas after 37 hours. For the first ~ 60 hours thereafter there is no SO2 or O2 leaving the reactor. After that, both the relative O2 and SO2 concentration slowly starts increasing to values of 40% and 25%, respectively, until the experiment is ended after 275 hours on stream.

[0169] The SO2 is retained on the tablets and the sulfur can be found on the tablets when carrying out post experiment analyses on the spent guard material.

[0170] The O2 is believed to be hydrogenated to H2O and carried out of the reactor as water vapor. The reason for the increase in relative O2 concentration at the reactor outlet is due to deactivation of the guard material’s catalytic sites active in O2 hydrogenation.

[0171] It is easier and simpler to continuously monitor the O2 concentration at the reactor outlet compared to measuring sulfur compounds, which typically require gas sampling and analysis by gas chromatograph. For the presented experimental conditions, it was effective to use the O2 breakthrough from the guard reactor as an indicator to the sulfur saturation of the guard material, i.e. an alarm that the guard material is exhausted and new guard material is required.

[0172] EXAMPLE (II)

[0173] A second experiment, which resembles the example above, has been carried out with some slightly changed conditions. The second experiment was carried out at an operating pressure of 30 barg and at 180°C.

[0174] The approximate process gas composition was 60 vol% H2, 20 vol% CO2, 10 vol% CH4, 10 vol% N2 with the impurity concentrations of 8 ppm SO2 and 2,500 ppm O2. Water was added to give 0.5 vol% in the process gas.

[0175] The process gas flow was 40 Nl / h (0°C, 1 atm).

[0176] In Fig. 5, the relative O2 and SO2 concentrations at the reactor outlet are shown as a function of time on stream of the experiment.

[0177] 03118-WO The O2 was added after 5 hours of time on stream and SO2 is added to the process gas after 10 hours. For the first - 160 hours thereafter there is practically no SO2 or O2 leaving the reactor. After that, both the relative O2 and SO2 concentration slowly starts increasing to values of 1% and 13% until the experiment is ended after 340 hours on stream.

[0178] The SO2 is retained on the tablets and the sulfur can be found on the tablets when carrying out post experiment analyses on the spent guard material.

[0179] Comparing Fig. 4 and 5 with somewhat comparable process gas conditions, it became clear that the guard material had a significantly higher SO2 capture capacity when operated at 180°C compared to 150°C as the time on stream before SO2 breakthrough was significantly higher at 180°C. Also, it seemed that the O2 hydrogenation activity was not as significantly affected by the saturation of the guard material with sulfur as the relative O2 concentration stayed low for the entire time on stream, although there was a very gradual increase in O2 leaving the reactor.

[0180] A drawback of operating at higher temperatures such as higher than 180°C is the risk of increasing (undesired) side product formation as the guard material also become increasingly active in the Reverse Water Gas Shift (RWGS) reaction, forming CO and H2O, and in methanol (CH3OH) formation. Besides forming these products, a large degree of e.g. methanol formation could result in overheating the guard material as the methanol formation enthalpy is highly exothermic.

[0181] The examples show that there is efficient removal of O2 and SO2 impurities in a H2+CO2 containing feed gas stream for extended periods (time on stream, TOS), while at the same time minimizing the risk of undesired by-product formation such as methanol.

[0182] 03118-WO

Claims

24CLAIMS1 . A process for cleaning a CCh-rich gas feed, said CCh-rich gas feed comprising at least 60 vol% CO2, and one or more sulfur-containing impurities; wherein said process comprises the step of:- passing the CCh-rich gas feed together with a first hydrogen-rich gas feed over a guard material, and retaining one or more sulfur-containing compounds on said guard material, to provide a cleaned CCh-rich gas stream; and wherein the CCh-rich gas feed, and / or the first hydrogen-rich feed, additionally comprise(s) oxygen (O2) of which at least a part is hydrogenated to water (H2O) on the guard material.

2. The process according to claim 1 , wherein the CCh-rich gas feed provided to the process comprises at least 70 vol% CO2, or at least 80 vol% CO2, or at least 90 vol% CO2, such as at least 95 vol% CO2, such as at least 99 vol% CO2, preferably at least 99.5 vol% CO2, more preferably as at least 99.9 vol% CO2.

3. The process according to any one of the preceding claims, wherein the one or more sulfur-containing impurities within said CCh-rich gas feed are selected from organosulfur compounds such as thiols, sulfides, disulfides, sulfones, sulfoxides and thioketones, COS, SO3, SO2 and H2S, preferably H2S and SO2, most preferably SO2.

4. The process according to any one of the preceding claims, wherein the guard material is active in reduction of SO2 to H2S and retainment of H2S, as well as catalytically active in the hydrogenation of O2, and is preferably a Cu-Zn-AI guard material.

5. The process according to any one of the preceding claims, wherein the guard material is arranged within a reactor vessel, said reactor vessel being arranged to receive said CO2-rich gas feed and said first hydrogen-rich gas feed, optionally in admixture, and provide said cleaned CO2-rich gas stream.03118-WO6. The process according to any one of the preceding claims, wherein the sulfur containing impurity is SO2 and the concentration of SO2 in the CCh-rich gas feed is 0.1-50 ppm SO2, such as 1-10 ppm SO2, such as 1-5 ppm SO2.

7. The process according to any of the preceding claims, wherein the content of H2O in the combined feed of the CCh-rich gas feed and the hydrogen-rich gas feed, is no more than 10 vol%, preferably no more than 5.0 vol%, preferably no more than 1.0 vol%, e.g. approximately 0.5 vol%.

8. The process according to any of the preceding claims, wherein the first hydrogen-rich gas feed comprises O2 and the process comprises a prior hydrogenating step of said first hydrogen-rich gas.

9. The process according to any of the preceding claims, wherein the first hydrogen-rich gas feed to the process comprises at least 98 vol% H2 such as at least 99 vol% H2, such as at least 99.5 vol% H2.

10. The process according to any one of the preceding claims, wherein the total content of O2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed is 50-20,000 ppm O2 such as 50-5,000 ppm O2, or such as 100-3,000 ppm O2.

11. The process according to any of the preceding claims, wherein: more than 95% of the O2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed is hydrogenated; or the concentration of O2 in the cleaned CCh-rich gas stream is < 200 ppm, such as < 100 ppm, or such as < 50 ppm.

12. The process according to any one of the preceding claims, wherein the total content of H2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed is 0.2-10 vol% H2 such as 0.5-3 vol% H2 or 2-3 vol% H2.

13. The process according to any one of claims 1-11 , wherein the total content of H2 in the combined feed of the CCh-rich gas feed and the first hydrogen-rich gas feed corresponds to a ratio of at least 2 moles H2 per mole CO2, such as 2-5 moles H2 per mole03118-WOCO2„ for instance 2.5-4.5 moles H2per mole CO2or 3-4 moles H2per mole CO2, or 2.8-3.2 moles H2per mole CO2.

14. The process according to any of the preceding claims, wherein the guard material is a Cu-Zn-AI guard material, having a chemical composition of 25-60 wt% Cu, 15-70 wt% Zn, and 1-20 wt% Al.

15. The process according to any of the preceding claims, wherein the step of passing the CO2-rich gas feed and first hydrogen-rich gas feed over the guard material, takes place at a temperature in the interval 120-250°C and a pressure in the interval 1-120 bar.

16. The process according to any of the preceding claims, wherein more than 95% of the one or more sulfur containing impurities are retained on the guard material or the total concentration of sulfur-containing impurities in the cleaned CO2-rich gas stream is < 500 ppb, such as < 100 ppb, or such as < 50 ppb, or such as <10 ppb..

17. The process according to any one of the preceding claims, wherein the CO2-rich gas feed is derived from a renewable source such as:- combustion or gasification of a lignocellulosic biomass such as wood products, algae, grass, forestry waste and / or agricultural residue;- combustion or gasification of municipal waste, in particular the organic portion thereof, where the municipal waste is defined as a feedstock containing materials of items discarded by the public, such as mixed municipal waste given in Ell Directive 2018 / 2001 (RED II), Annex IX, part A;- microbial conversion of nitrogen-rich renewable feedstock such as manure or sewage sludge;- fermentation of hydrocarbon(sugar) rich feed streams such as corn, sugar cane and beets.- Direct Air Capture (DAC)18. The process according to any one of the preceding claims 1-12, 14-17, further comprising:- providing a second hydrogen-rich gas feed, optionally obtained from the process of electrolysis of water / steam in one or more electrolysis unit(s);03118-WO27- reacting at least a portion of the cleaned CCh-rich gas stream with the second hydrogen-rich gas feed, to provide at least one syngas stream; or reacting at least a portion of the cleaned CCh-rich gas stream with the second hydrogen-rich gas feed directly in: a methanol converter in the presence of a methanol synthesis catalyst, or a methanation reactor in the presence of a methanation catalyst; or supplying the cleaned CCh-rich gas stream to a solid oxide electrolysis (SOE) unit to provide a CO-and-CCh gas mixture and combining at least a portion thereof with the second hydrogen-rich gas feed into a at least one syngas stream.

19. The process according to claim 18, wherein:- the step of reacting said portion of the cleaned CCh-rich stream feed with the second hydrogen-rich gas feed, to provide at least one syngas stream is carried out in the presence of a catalyst active in reverse water gas shift (RWGS), preferably in an electrically heated reactor for RWGS (e-RWGS).

20. The process according to any of preceding claims 18-19, comprising producing a synthetic fuel stream by further converting said at least one syngas stream to at least one synthetic fuel stream which is at least one of: MeOH (methanol), DME (dimethyl ether), methane, aviation fuel, kerosene, gasoline and diesel fuel.

21. The process according to claim 20, wherein the step of converting said at least one syngas stream to at least one synthetic fuel stream is:- a Fisher-Tropsch process; or- a process whereby the syngas stream is first converted to methanol and / or DME, and subsequently to: gasoline, e.g. via a TIGAS process, or aviation fuel, e.g. via a methanol-to- jet fuel (MTJ) process.

22. The process according to claim 21 , wherein the step of converting said at least one syngas stream to at least one synthetic fuel stream is a Fisher-Tropsch (FT) process, and wherein a recycle stream from the FT-process, such as FT-tail gas or hydrogenated FT- tail gas, is supplied upstream the RWGS, e.g. upstream the e-RWGS.03118-WO

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