Molded bodies made of silicon dioxide, having increased stability by virtue of mixtures of pyrogenic and precipitated silicic acid

Abstract

The invention relates to a sorbent for CO2, comprising a molded body (i) made of at least one pyrogenic silicic acid and at least one precipitated silicic acid, wherein the weight proportion of the total amount of the at least one precipitated silicic acid to the total mass of the at least one pyrogenic silicic acid and the at least one precipitated silicic acid is 20-60 wt.%, preferably 30-50 wt.%, and at least one sorption agent (ii) for CO2, the sorption agent being used to functionalize the molded body. The invention also relates to the production of said sorbent and to the use thereof as a fixed-bed sorbent for the chemisorption of CO2.

Description

[0001] WA12454S / Wi

[0002] Molded bodies made of silicon dioxide with increased stability due to mixtures of pyrogenic and precipitated silica

[0003] The present invention relates to a sorbent for CO2, comprising a molded body (i) of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the total mass of the at least one pyrogenic silica and the at least one precipitated silica (=total silica mass) is 20-60 wt.%, preferably 30-50 wt.%, and at least one sorbent (ii) for CO2 with which the molded body is functionalized, the production of this sorbent, and the use of this sorbent as a fixed-bed sorbent in the chemisorption of CO2.

[0004] Climate change and global warming are considered the most serious environmental problems of our time. It is now widely accepted that the main cause of global warming is the release of so-called greenhouse gases into the atmosphere. One important greenhouse gas is carbon dioxide (CO2), which is released primarily during the combustion of fossil fuels such as coal, oil, and natural gas. Together, these fossil fuels cover about 80% of global energy needs. Because fossil fuels remain relatively inexpensive and easy to use, and no satisfactory alternatives are yet available to replace them to the necessary extent, they are expected to remain our primary energy source for the foreseeable future.It is therefore all the more important to channel CCt emissions into innovative technologies capable of storing CO2 as a valuable resource and / or using it as a feedstock for further processes. WA12454S / Wi.

[0005] 2

[0006] “Carbon Capture and Storage” (CCS) is a representative of such technologies, in which CO2 is captured either from the environment or directly at the sources of fossil CO2 emissions of an industrial or energy-related nature, processed, compressed and transported to a storage site.

[0007] In contrast to the pure storage purpose of CCS, “Carbon Capture and Utilization” (CCU) concerns the capture of CO2, especially from combustion exhaust gases, and its subsequent use in further chemical processes, such as the conversion to methanol.

[0008] Another method for obtaining CO2 is "Direct air capture" (DAC), in which CO2 is extracted from the ambient air.

[0009] All these technologies require that CO2 can be (reversibly) sorbed onto a solid sorbent. This sorbent is typically used as a fixed-bed sorbent in sorption columns, through which the gas from which CO2 is to be removed flows.

[0010] Solid sorbent materials are currently used in the form of finely divided powders, which, however, have disadvantages for sorption columns. The use of finely divided powders in the columns leads to an undesirably high pressure drop, accompanied by turbulence and the discharge of the sorbent from the column.

[0011] Instead of using finely divided powders, EP2102131A1 teaches larger metal oxide particles, which, however, are not functionalized and therefore unsuitable for selectively adsorbing CO2 from gas mixtures. WA12454S / Wi

[0012] Processes for producing stable shaped bodies from metal oxides are also described in WO 2008 / 071611 Al and WO 2008 / 071612 Al. In these processes, an aqueous dispersion of the metal oxide is prepared, which is then made "solid" by the addition of a coagulant. The coagulant is a basic salt that decomposes below the sintering temperature and does not melt. Coagulation is initiated by increasing the pH value. This solidified mass is then shaped, for example, by extrusion. The resulting green bodies are dried and subsequently sintered to strengthen the supports. For the reliable use of these shaped bodies in sorption columns with low pressure drop and minimal turbulence, the following should be considered:

[0013] Strength can, however, be further increased.

[0014] It would therefore be desirable to provide a CO2 sorbent that overcomes the disadvantages associated with powdered sorbent materials, i.e., when used as a fixed-bed sorbent in a sorption column, exhibits high strength, results in low pressure drop, and minimizes turbulence or even carry-out of the sorbent from the column. Simultaneously, CO2 should be reversibly bound with high sorption efficiency and capacity.

[0015] The problem according to the invention is solved by the first aspect of the present invention, namely a sorbent for CO2, in particular a solid sorbent, comprising

[0016] (i) a shaped body (i) made of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the total mass of the at least one precipitated silica in the total mass of WA12454S / Wi at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%, preferably 30-50 wt.%; and

[0017] (ii) at least one sorbent (ii) for CO2 with which the molded body (i) is functionalized.

[0018] “Functionalised” within the meaning of the invention means, for example, that the shaped body (i) is impregnated and / or coated with the sorbent (ii).

[0019] Pyrogenic silica is a colloidal material made of amorphous silicon dioxide and is therefore also called pyrogenic silicon dioxide. To produce pyrogenic silicon dioxide, a volatile silicon halide (e.g.,

[0020] Silicon tetrachloride is injected into an oxyhydrogen flame of hydrogen and air. Under the influence of the water produced during the oxyhydrogen reaction, this substance hydrolyzes to silicon dioxide. After leaving the flame, the silicon dioxide enters a so-called coagulation zone, where the primary particles and primary aggregates agglomerate.

[0021] Precipitated silica is another amorphous form of silicon dioxide and differs from pyrogenic silicon dioxide, particularly in its production. To produce precipitated silica, for example, commercially available sodium silicate is reacted with acid (e.g., sulfuric acid) at a pH between 7.5 and 10.5. The pH is then adjusted to 3.0 to 5.0, and the precipitated silica is filtered, washed, and dried.

[0022] Preferably, the at least one pyrogenic silica is exactly one type of pyrogenic silica. WA12454S / Wi

[0023] Preferably, the at least one precipitated silica is exactly one type of precipitated silica.

[0024] In a particular embodiment, the shaped body (i) is a shaped body (i) made of a pyrogenic silica and a precipitated silica, wherein the weight fraction of the precipitated silica in the total mass of the pyrogenic silica and the precipitated silica is 20-60 wt.%, preferably 30-50 wt.%.

[0025] In a particularly preferred embodiment, the molded body (i) comprises a mixture of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%, preferably 30-50 wt.%.

[0026] In particular, the shaped body (i) consists of a mixture of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%, preferably 30-50 wt.%.

[0027] Preferably, the molded body is sintered at a sintering temperature Ts .

[0028] The strength of metal oxide molded parts is typically improved by sintering at high temperatures. However, this process also leads to a reduction in porosity and specific surface area (WA12454S / Wi), and thus a significant decrease in the CO2 sorption capacity of these materials.

[0029] Surprisingly, it has been shown that the inventive mixture of pyrogenic and precipitated silica in the molded body ensures that the molded body has excellent mechanical properties (expressed via the compressive strength and / or breaking load of the molded body) without significantly reducing the porosity and associated specific surface area.

[0030] The porosity is crucial for the CO2 sorption efficiency of the molded bodies. Sufficiently high sorption efficiencies, as required by the present invention, are achieved, for example, when the pore volume of the molded bodies according to the invention is reduced by less than 20%, preferably less than 15%, compared to a molded body made exclusively from pyrogenic silica. Due to the drastically improved mechanical properties when using a mixture of pyrogenic and precipitated silica in the molded body, such reductions in pore volume (caused by the addition of precipitated silica, which, however, provides stability) are acceptable. Acceptable pore volumes, as required by the present invention, are also at least 1.10 mL / g in a particularly preferred embodiment.

[0031] High strength combined with acceptable pore volumes offers the advantage of efficient CO2 sorption and optimal flow-mechanical properties in the sorption column, such as low pressure drop, no carryover of the sorbent from the column, etc. WA12454S / Wi

[0032] Additionally, it is possible to sinter the carriers at a lower temperature, thereby reducing production costs.

[0033] In the context of the present invention, sintering refers to a treatment of a green body (easily machinable blank) formed, for example, by extrusion, in order to transform it into a solid finished body. The green body can sometimes be dried at lower temperatures before sintering.

[0034] Ts is preferably in a range of 800-1200 °C, more preferably in a range of 900-1100 °C .

[0035] A preferred sorbent comprises shaped bodies having dimensions in one, two or three dimensions, more preferably in two or three dimensions, particularly in all three dimensions in the range of 0.5 mm to 30 mm, preferably 1.0 mm to 15 mm.

[0036] Preferably, the sorbent according to the invention has the same dimensions as the corresponding molded body.

[0037] When a gas mixture flows through powder beds known in the prior art, a high pressure drop occurs between the sides facing the gas source and those facing away from it. A coarser shaped body having the dimensions according to the invention is advantageous because the pressure loss (= pressure drop) when flowing through such a bed is reduced.

[0038] The sorbent according to the invention is therefore particularly well suited as an efficient fixed-bed sorbent for CCU, CCS or DAC, since – in contrast to finely divided powders – it results in a lower pressure drop and little turbulence or even carryover of the sorbent from the sorption column. Only when using the WA12454S / Wi

[0039] 8 In the molded body according to the invention, efficient CCt adsorption is possible.

[0040] The molded bodies according to the invention also exhibit improved mechanical stability and improved long-term stability. In contrast to powdered sorbents, the molded bodies according to the invention do not tend to agglomerate or clump together when impregnated (= functionalized with sorbent) and do not require complex grinding.

[0041] Surprisingly, it has been shown that particularly good adsorption efficiencies can be achieved in the sorption column only if the mechanical properties (compressive strength and / or breaking load) of the sorbent according to the invention are observed.

[0042] It is preferred that the sorbent has a compressive strength of at least 2 N / mm². 2 , preferably at least 8 N / mm 2 , exhibits .

[0043] The compressive strength according to the invention can be determined using all methods known in the field, for example with the aid of a material testing machine, such as the Texture Analyser XT plus from Winopal.

[0044] It is preferred that the sorbent in the form of cylindrical bodies has a breaking load of at least 70 N, preferably at least 80 N.

[0045] The breaking load is determined as is standard practice in the field, for example using Texture Analyser XT plus from Winopal, as described in the examples. WA12454S / Wi

[0046] 9

[0047] Molded bodies whose mechanical properties do not correspond to those of the invention cannot withstand the CCt pressure in the adsorption column sufficiently and are destroyed, exhibiting, for example, spalling. Destroyed molded bodies again lead to the same disadvantages that also occur when using sorption powders in the sorption column (e.g., higher pressure drop, turbulence, carryout).

[0048] The molded body according to the invention can be highly pure. Highly pure within the meaning of the invention means that it is essentially free of inorganic and organic impurities. Preferably, the sum of impurities (all metals as well as carbon, phosphorus, and sulfur) is less than 400 ppm, more preferably less than 250 ppm, particularly preferably less than 100 ppm, even more preferably less than 50 ppm, and even more preferably less than 20 ppm, even more preferably less than 10 ppm, and most preferably less than 1 ppm, based on the total mass of the molded body. Impurities can be quantified using all conventional analytical methods, for example, XRF, AAS, ICP-OES, or ICP-MS. If necessary, the molded body must be dissolved in a suitable solvent, e.g., hydrofluoric acid, before analysis. In a particular embodiment, the molded bodies are essentially spheres, ellipsoids, cylinders, or hollow cylinders (e.g.,Tubes), wagon wheels, honeycombs or cuboids, preferably cylinders or hollow cylinders. It is also clear to a person skilled in the art that the geometry described does not represent perfect geometric bodies, so deviations from the ideal geometry are possible. WA12454S / Wi.

[0049] 10

[0050] The shaped bodies preferably have an aspect ratio of at most 15, more preferably of at most 10, most preferably of at most 6.

[0051] It has also been found that the aforementioned aspect ratio has a particularly positive effect on the suitability of the molded body in a sorption column, as the already low pressure drop when using the molded bodies according to the invention can be reduced even further due to this aspect ratio. Molded bodies whose aspect ratio exceeds that of the invention are no longer practical to handle in reaction / sorption columns and tend to break. Fractures are disadvantageous because they result in very small molded body fragments, which cause a high pressure drop and turbulence in the column, as well as discharge from the column.

[0052] The molded body is preferably composed of silica agglomerates. The agglomerates are preferably composed of aggregates of a plurality of primary silica particles.

[0053] In a preferred design, the BET surface area of ​​the sorbent lies in the range of 30 to 500 m². 2 / g, especially in the range of 50 to 400 m 2 / g .

[0054] The BET surface area can be determined using measurement methods known in the field. The BET surface area is preferably determined using nitrogen according to DIN 66131.

[0055] Preferably, the molded bodies are characterized by a high pore volume, which is between 1.10 ml / g and 1.8 ml / g, preferably between 1.10 ml / g and 1.7 ml / g, and particularly preferably between 1.10 ml / g and 1.6 ml / g. WA12454S / Wi

[0056] 11

[0057] These high pore volumes give the sorbent according to the invention the advantage that it can be functionalized with a particularly large amount of sorbent, which significantly increases the sorption capacity for CO2.

[0058] If the pore volume exceeds the ranges mentioned above, the molded bodies are too fragile and tend to break when used in a sorption column. This results in the formation of very small molded body fragments and thus a high pressure drop. Fragments with a smaller pore volume than specified have too small an internal surface area and therefore lead to low sorption efficiencies and capacities.

[0059] The determination of the pore volume and pore size is carried out using methods known in the field, for example by means of Hg porosimetry, for example as described in ISO 15901 - 1.

[0060] In a preferred embodiment, the silicon dioxide of the molded body has a mesoporous structure, in particular a mesoporous structure with an irregular pore structure.

[0061] The irregular pore structure of the silica, according to the preferred embodiment described above, is retained in the molded body. This pore structure creates channels within the molded body, defining its inner surface.

[0062] The functionalization with the sorbent is preferably located on the inner surfaces of the molded bodies according to the invention.

[0063] Mesoporous solids, according to the IUPAC definition, are porous materials with pore diameters between 2 nm and 50 nm. WA12454S / Wi

[0064] 12

[0065] It is known to those skilled in the art that mesoporous silica is usually produced by a complex template-based synthesis. Silica produced in this way is characterized by a defined, channel-like pore structure. In contrast, the molded bodies according to the invention are based on silica, which is characterized by an irregular pore structure. In this context, "irregular pore structure" means that the pores within the silica extend asymmetrically and / or randomly without any recognizable repeating sections, either with or without at least one branch and / or division.

[0066] Silica with such an irregular pore structure offers economic advantages, for example, as it is far cheaper and easier to produce than silica with a predefined and regular channel structure. Surprisingly, it has also been shown that the CO2 adsorption efficiency of the silica molded bodies according to the invention with an irregular pore structure can significantly exceed the adsorption efficiency of silica molded bodies with a defined, uniform pore structure, since silica with an irregular pore structure is less prone to clogging and blockage of the channels by sorbents. Thus, the inner surfaces of the molded bodies according to the invention can be more homogeneous and completely functionalized, thereby increasing the adsorption capacity of the molded bodies according to the invention for CO2.Sufficient capacities for efficient CO2 sorption are preferably at least 20 mg CO2 per gram of sorbent (corresponding to approximately 0.45 mmol CO2), more preferably at least 40 mg CO2 per gram of sorbent. WA12454S / Wi.

[0067] 13

[0068] In a preferred embodiment, the at least one sorbent (ii) is able to undergo a reversible reaction with CO2, in particular a reversible sorption reaction.

[0069] The sorption reaction is specifically a chemisorption reaction. In this case, the CO2 is bound to the inner surface of the molded part by chemical bonding with the sorbent. By increasing the temperature and / or decreasing the pressure, the chemisorbed CO2 can be released from the molded part and thus driven off. This has the advantage that the CO2 can not only be removed from the gas phase (e.g., DAC, CCS), but can also be released again at any later time and, for example, fed into a process that uses CO2 as a feedstock (e.g., CCU), such as the conversion to methanol.

[0070] The at least one sorbent ( ii ) can be an inorganic or an organic sorbent .

[0071] In one embodiment, the shaped body (i) is functionalized with a mixture of an inorganic and an organic sorbent, in particular with a mixture of a carbonate and an organic amine.

[0072] The inorganic sorbent (ii) is preferably a carbonate, in particular selected from the group consisting of metal carbonate, metal hydrogen carbonate and mixtures thereof.

[0073] Preferably, the metal is selected from alkali metals and alkaline earth metals, in particular from Na and K.

[0074] The organic sorbent can be an organic monoamine or polyamine, wherein the polyamine has at least two N atoms per WA12454S / Wi

[0075] 14

[0076] The molecule comprises , which are separated by at least one carbon atom, in particular selected from the group , consisting of ethyleneamine, aminosilane, polyethyleneimine (PEI ) , polypropylenamine, polyvinylpyridine, polydimethylaminoethyl methacrylate , polyamidoamine, polyvinylamine and polyallylamine .

[0077] The ethyleneamine is preferably selected from the group consisting of ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetraamine (TETA), tetraethylenepentamine (TEPA), aminoethylethanolamine (AEEA), aminoethylpiperazine (AEP), piperazine (PIP), hydroxyethylpiperazine (HEP), pentaethylenehexamine (PEHA) and polyethylenepolyamine (PEPA).

[0078] The aminosilane is preferably selected from the group consisting of aminopropylsilane, [3-(2-Aminoethylamino)-propyl]-trimalkoxysilane, 3-[2-(2-Aminoethylamino)-ethylamino]-propyltrialkoxysilane, mixtures thereof and condensation products of 3-aminopropyltrialkoxysilane.

[0079] The polyamine can be silylated, for example obtained by reacting one or more amino groups of the polyamine with suitably functionalized alkoxysilanes, for example selected from the group consisting of 3-chloropropyl-trialkoxysilane, 3-chloropropyl-trialkoxysilane, glycidoxypropyl-trialkoxysilane and 1-socyanatopropyl-trialkoxysilane.

[0080] For the purposes of this application, ‘alkoxy group’ preferably means a Gl- to C4-alkoxy group, and in particular preferably an ethoxy or methoxy group.

[0081] The silylated polyamine can be obtained by silylation, either in isolation or in situ. WA12454S / Wi

[0082] 15

[0083] In a preferred embodiment, the sorbent according to the invention further comprises

[0084] (iii) at least one auxiliary substance (iii) selected from the group consisting of polymeric binders, silicon-containing binders such as silicates and silica sol, spreading agents and wetting agents.

[0085] The polyamine can be present in combination with at least one amino-functional alkoxysilane.

[0086] The at least one amino-functional alkoxysilane is preferably selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and 3-aminopropyltriisoproxysilane.

[0087] The amount of polyamine is preferably at least 50% by weight based on the total amount of polyamine and amino-functional alkoxysilane.

[0088] In a preferred sorbent, the amount of the at least one sorbent (ii) is 10 to 90 wt.%, preferably 25 to 80 wt.%, based on the total weight of the sorbent.

[0089] In a special version, the molded body of the sorbent is free of inorganic and organic chemical binders, such as glycerin, kaolin, sugar, starch, urea, wax, methylcellulose, magnesium stearate, graphite, aluminum stearate, polyethylene glycol or polyethylene oxide.

[0090] Another aspect of the present invention relates to a method for producing the sorbent according to the invention for WA12454S / Wi

[0091] 16

[0092] CO2, encompassing the following steps in the specified

[0093] Sequence :

[0094] (A) Providing a shaped body (i) from at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the totality of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%, preferably 30-50 wt.%;

[0095] (B) Impregnating the provided molded body with at least one sorbent (ii) for CO2 in order to functionalize the molded body.

[0096] In a preferred embodiment, the provision of the molded body in step (A) is carried out by the following steps in the specified order:

[0097] (Al) Providing a silica dispersion by dispersing at least one pyrogenic silica and at least one precipitated silica in a dispersing agent, wherein the weight fraction of the total mass of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%, preferably 30-50 wt.%;

[0098] (A2) Coagulation of the dispersion by raising the pH value;

[0099] (A3) Shaping the coagulated dispersion to produce a green body; and WA12454S / Wi

[0100] 17

[0101] (A4) Drying and subsequent sintering of the green body at a sintering temperature T s , in order to produce the sintered molded body .

[0102] The silica dispersion in step (Al ) can be provided by dispersing the at least one pyrogenic silica and the at least one precipitated silica in a common dispersant; or by dispersing the at least one pyrogenic silica and the at least one precipitated silica in separate dispersants and mixing the resulting dispersions of the at least one pyrogenic and the at least one precipitated silica together.

[0103] In the process according to the invention, a silica dispersion is therefore first produced in the first step (Al ).

[0104] This dispersion is coagulated in a next step (A2 ).

[0105] In the next step (A3), the coagulated dispersion can be transferred into a mold, resulting in a green body, i.e., a shaped blank made from the coagulated dispersion.

[0106] This green compact is transformed into a sintered body by drying and sintering according to step (A4). Only then is the body given the mechanical stability required for use in sorption columns.

[0107] Surprisingly, it has been shown that the use of a mixture of pyrogenic and precipitated silica gives the molded body excellent mechanical properties (such as compressive strength or breaking load) without limiting the porosity required for sorption efficiency. WA12454S / Wi

[0108] 18

[0109] The total amount of silica in the silica dispersion of step (Al ) can be 10-50 wt. -%, preferably 20-40 wt. -%, based on the total mass of the dispersion.

[0110] In a preferred method, the silica dispersion is provided in step (Al ) by stirring in the at least one silica using a dissolver disc and a butterfly insert.

[0111] The mixer used is therefore preferably equipped with a dissolver disc and a butterfly insert.

[0112] A dissolver disc is a stirring disc mounted in a mixer, rotatable around an axis, and immersed in the product to be dispersed. When the disc rotates, shear forces are generated that break down the product to be dispersed (in this case, at least one silicon dioxide).

[0113] A butterfly insert is a mixing organ with an open profile, which usually has at least three wings that have a high dispersing effect.

[0114] In a preferred method, the silica dispersion is provided in step (Al ) by stirring the total amount of silica into water in at least two portions, wherein the portion stirred in first is stirred in at a higher stirring speed of the dissolver disk and a lower stirring speed of the butterfly insert compared to the portion stirred in after.

[0115] The stirring according to the invention in step (Al) has the particular advantage that the silica produced thereby WA12454S / Wi

[0116] 19

[0117] Dispersion exhibits particularly good rheological properties, which results in easy handling.

[0118] It is preferred that the dispersing agent in step (Al) is water or an aqueous solution, preferably an aqueous solution with a pH value in the range of 1.0 to 7.0, preferably from 1.5 to 6.0, particularly preferably from 2.0 to 4.0.

[0119] The pH of the dispersant in step (Al) can be adjusted by adding acid, preferably by adding phosphoric acid.

[0120] The pyrogenic silicon dioxide provided in step (Al) is preferably in powder form. The powdered silicon dioxide preferably has aggregate sizes of 100 nm to 500 nm, measured by dynamic light scattering.

[0121] The precipitated silicon dioxide provided in step (Al) preferably has particle sizes in the range of 4.5 to 115 pm, preferably 4.5 to 40 pm, measured for example by laser diffraction particle size analysis (e.g. dynamic light scattering).

[0122] Mixing the silicon dioxide provided in step (Al) with the aqueous solution preferably produces a dispersion.

[0123] At the end of the dispersion process, the dispersions can also be freed from non-dispersible, unwetted and other coarse particles by sieving.

[0124] In a preferred method, the pH value is increased in step (A2) by 0.5-5.5 units, preferably using the WA12454S / Wi

[0125] 20

[0126] The target pH value after changing the pH value in step (A2) is in the range of 4.0 to 8.0, particularly preferably in the range of 5.5 to 7.0.

[0127] The pH increase in step (A2) is preferably achieved by adding suitable bases, in particular by adding a basic coagulant to the silica dispersion from step (Al) . Examples of basic coagulants are alkali and alkaline earth metal hydroxides, carbonates and mixtures thereof, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, magnesium carbonate, magnesium hydroxide carbonate, NH3 or mixtures thereof, in particular magnesium hydroxide carbonate.

[0128] In a preferred embodiment, during step (A2) the dispersion is first acidified to achieve a pH value < 4.0, and subsequently the reaction mixture is raised to a value > 4.0 with a base.

[0129] In the event that the pH value is only raised during step (A2), an aqueous solution with pH < 4.0 can already be used in step (Al) before the pH value is then raised to a value > 4.0 in step (A2).

[0130] The pH increase in step (A2) is preferably carried out by stirring and / or kneading. Planetary mixers or centrifugal mixers, for example, can be used for this purpose.

[0131] The increase in pH in step (A2) is accompanied by an increase in viscosity, so that a highly viscous mass is typically obtained. WA12454S / Wi

[0132] 21

[0133] The production of shaped bodies by forming in step (A3) is preferably carried out by extrusion, tableting, or pressing, particularly by extrusion. All equipment known to those skilled in the art, such as extruders, tablet presses, or piston extrusion presses, are conceivable. The geometry of the shaped body results from the respective forming tool selected. Geometries such as rings, pellets, cylinders, wagon wheels, honeycombs, spheres, etc., can be produced. The length of rings and pellets is preferably defined directly after forming using a cutting device.

[0134] After shaping, the molded part is dried in process step (A4). This is preferably carried out using methods known to those skilled in the art (e.g., climate chamber, drying oven, IR heating, microwave). Preferably, the drying takes place in a climate chamber under controlled humidity. Drying can be carried out at temperatures preferably between 25°C and 200°C, more preferably between 30°C and 100°C, and most preferably between 40°C and 80°C. The drying time depends on the ratio of silica to water, but is preferably between 2 and 48 hours. Process step (A4) can be carried out at atmospheric pressure of 1013 mbar or under reduced pressure. If the molded part is dried under reduced pressure in step (A4), the pressure can be reduced to 10 -3 mbar to normal pressure, in particular 10 -1 mbar to 800 mbar.

[0135] After drying, sintering takes place using methods known to experts.

[0136] The sintering step (A4) is also called calcination and can take place at a temperature Ts in the range of 800°C to 1200°C, particularly between 900°C and 1100°C. WA12454S / Wi

[0137] 22

[0138] Sintering is carried out particularly under gentle heating rates, for example 180 °C / h, and gentle cooling rates, for example 80 °C / h. These gentle heating and cooling rates ensure that the mechanical stability of the sorbents is not impaired, for example, due to the occurrence of mechanical stresses at excessively rapid heating and / or cooling rates.

[0139] Calcination in a furnace under an air atmosphere is preferred. An additional gas can be added to the air. Various protective gases are suitable for this purpose. All protective gases known to those skilled in the art are suitable; nitrogen, argon, or helium are particularly preferred. The air can also be completely replaced by the protective gas.

[0140] The sintering in step (A4) usually takes place for a period of 1-10 hours, preferably 4-8 hours.

[0141] Fine-pored molded bodies can be formed from finely divided silica by calcination. The proportion of pores with a diameter between 10 nm and 20 nm is typically more than 50%, preferably more than 70%, and particularly preferably more than 80%.

[0142] The at least one sorbent in the process according to the invention can be an inorganic or an organic sorbent.

[0143] The inorganic sorbent in the process according to the invention can be a carbonate, in particular selected from the group consisting of metal carbonate, metal bicarbonate and mixtures thereof. WA12454S / Wi

[0144] 23

[0145] The organic sorbent in the process according to the invention can be an organic monoamine or polyamine, wherein the polyamine comprises at least two N atoms per molecule, which are separated by at least one C atom, in particular selected from the group consisting of ethyleneamine, aminosilane, polyethyleneimine (PEI), polypropyleneamine, polyvinylpyridine, polydimethylaminoethyl methacrylate, polyamidoamine, polyvinylamine and polyallylamine.

[0146] The ethyleneamine in the process according to the invention can be selected from the group consisting of ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), aminoethylethanolamine (AEEA), aminoethylpiperazine (AEP), piperazine (PIP), hydroxyethylpiperazine (HEP), pentaethylenehexamine (PEHA) and polyethylenepolyamine (PEPA).

[0147] The aminosilane in the process according to the invention can be selected from the group consisting of aminopropylsilane, [3- (2- Aminoethylamino )-propyl ]-trialkoxysilane, 3- [2- (2- Aminoethylamino )-ethylamino ]-propyltrialkoxysilane, mixtures thereof and condensation products of 3-aminopropyltrialkoxysilane .

[0148] The polyamine in the process according to the invention can be silylated, for example obtained by reacting one or more amino groups of the polyamine with suitably functionalized alkoxysilanes, for example selected from the group consisting of 3-chloropropyl-trialkoxysilane, 3-chloropropyl-trialkoxysilane, glycidoxypropyl-trialkoxysilane and 1-isocyanatopropyl-trialkoxysilane. WA12454S / Wi

[0149] 24

[0150] The polyamine is obtainable in particular by silylation, which can be carried out in isolation or in situ.

[0151] Preferably, the at least one sorbent is present in liquid form during impregnation in step (B), for example as a solution, emulsion, or dispersion in a solvent or liquid medium, or in pure form. Within the scope of this invention, the sorbent is also referred to as the impregnating agent. The solvent or liquid medium is preferably removed after impregnation. In the process according to the invention, the at least one sorbent can be a solution of a metal carbonate, in particular potassium carbonate and / or sodium carbonate, in water, or a solution of a metal bicarbonate, in particular potassium bicarbonate and / or sodium bicarbonate, in water.

[0152] In a preferred process, the at least one sorbent is a saturated aqueous solution of potassium carbonate, sodium carbonate, potassium bicarbonate and / or sodium bicarbonate, preferably of potassium carbonate and / or potassium bicarbonate, more preferably of potassium carbonate.

[0153] In a preferred process, the amount of metal carbonate or metal hydrogen carbonate is 15-40 wt.%, preferably 15-33 wt.% of the total weight of the aqueous solution.

[0154] In a preferred process, the sorbent is present in the form of a solution of an organic sorbent, for example an organic amine, in a suitable solvent, wherein the amount of dissolved organic sorbent is preferably at least 30 vol.%, more preferably at least 60 vol.%. WA12454S / Wi

[0155] 25

[0156] The organic solvent preferably has a boiling point of no more than 200 °C, more preferably no more than 150 °C, in each case at 1013 mbar.

[0157] Examples of suitable solvents include water; alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-amyl alcohol, i-amyl alcohol; ethers, such as dioxane, tetrahydrofuran, diethyl ether, diisopropyl ether, diethylene glycol dimethyl ether; chlorinated hydrocarbons, such as dichloromethane, trichloromethane, tetrachloromethane, 1,2-dichloroethane, trichloroethylene; hydrocarbons, such as pentane, n-hexane, hexane isomer mixtures, heptane, octane, white spirit, petroleum ether, benzene, toluene, xylenes; ketones, such as acetone, methyl ethyl ketone, diisopropyl ketone, methyl isobutyl ketone (MIBK); esters, such as ethyl acetate, butyl acetate, propyl propionate, ethyl butyrate, ethyl isobutyrate; Carbon disulfide and nitrobenzene, or mixtures of these solvents.

[0158] The impregnation in step (B) is preferably carried out by bringing the molded body into contact with the at least one sorbent for CO2.

[0159] For impregnating the silica molded body, any prior art method suitable for the surface treatment of fillers or particles is generally appropriate. This is an advantage of the silica molded bodies according to the invention, as they are mechanically stable enough and, due to their size and shape, do not tend to agglomerate or stick together during drying.

[0160] In a preferred method, impregnation is carried out by mixing, spraying or soaking the molded body or by the incipient wetness method with the at least one WA12454S / Wi

[0161] 26

[0162] Liquid sorbents, especially using the incipient wetness method.

[0163] “Impregnation” within the meaning of this invention means the penetrating treatment with liquid, dissolved, emulsified or dispersed impregnating agents. The impregnating agent can be physically deposited on the inner and outer surface of the porous molded body or bond to it chemically, either wholly or partially.

[0164] The "incipient wetness method" is known in the literature in connection with the coating of support materials with a catalyst, and its principles are described in Marceau, E.; Carrier, X.; Chet, M., Impregnation and Drying. In Synthesis of Solid Catalysts, 2009; pp. 59-82. Surprisingly, it has been shown that the incipient wetness method is also suitable for coating the molded bodies according to the invention with the CO2 sorbent in such a way that CO2 binding sites are homogeneously distributed over the entire surface of the molded body. This allows particularly high sorption efficiencies to be achieved in the sorbent. In the incipient wetness method, the sorbent is usually dissolved or dispersed in a solution (e.g., aqueous or organic). This mixture can then be applied to the carrier material, which preferably has the same pore volume as the volume of the added mixture.Through capillary action, the mixture is drawn into the pores, leading to functionalization there.

[0165] Unlike the wet impregnation method, the incipient wetness method does not cause the particles to clump together, and the impregnating agent is deposited very homogeneously on the inner and outer surfaces of the molded body. WA12454S / Wi

[0166] 27

[0167] The impregnation in step (B) preferably takes place in a temperature range of 0-150 °C, preferably in a temperature range of 15-120 °C.

[0168] The impregnation in step (B) preferably takes place at normal pressure, under increased pressure or under reduced pressure.

[0169] Normal atmospheric pressure is usually 1013 mbar.

[0170] In the event that impregnation in step (B) takes place under increased pressure, the pressure can be a maximum of 2 bar.

[0171] In the event that impregnation in step (B) takes place under reduced pressure, the pressure can be 10 -3 mbar to normal pressure, in particular 10 -1 mbar to 500 mbar .

[0172] A preferred method is characterized in that the molded body has a mesoporous structure and the volume of the at least one sorbent for CO2 used is 80 to 120%, preferably 90 to 110%, more preferably 95-105% based on the total pore volume of the molded body.

[0173] Using such quantities of sorbent ensures that the inner surface of the molded body is homogeneously and completely functionalized with the sorbent. This results in high sorption efficiencies.

[0174] In a preferred method, the molded body is pre-impregnated at a pressure of 10 -3 up to 10 2 mbar treated; and / or dried. WA12454S / Wi

[0175] 28

[0176] The impregnation in step (B) of the provided molded body with at least one sorbent for CO2, in order to functionalize the molded body, is preferably carried out together with at least one impregnating agent, selected from wetting agent, emulsifier, colorant, binder, adhesion promoter, higher-grade alcohols and higher-grade polyols.

[0177] In a preferred embodiment, the molded body retains its shape, defined by the molding tool / mold, at the moment of manufacture. Deformations during and immediately after molding cause density differences and stresses that lead to defects (flaking, fine dust) on the molded body during the drying and sintering process. According to the invention, the manufactured carriers exhibit a flaking content of preferably less than 5 wt.%, more preferably less than 1 wt.%, and most preferably less than 0.5 wt.%. Flaking is disadvantageous because it leads to a high pressure drop in a column or reactor in the application.

[0178] The present invention is therefore directed in particular to a sorbent for CO2 obtainable by the inventive process for producing a sorbent for CO2, wherein the impregnation is preferably carried out using the incipient wetness method. This has the advantages already described in detail above of a particularly homogeneous distribution of the CO2 sorption sites and an associated outstanding sorption efficiency for CO2.

[0179] Another aspect of the present invention is directed towards the use of the inventive sorbent for CO2 for the reversible binding of CO2 from a gas mixture, in particular in the form of a fixed-bed sorbent, for example for CCU, CCS and / or DAC. WA12454S / Wi

[0180] 29

[0181] Reversible binding is achieved primarily through chemisorption. In this case, the CO2 is bound to the inner surface of the molded part by chemical bonding with the sorbent with which the molded part is functionalized. By increasing the temperature and / or decreasing the pressure, the chemisorbed CO2 can be released from the molded part and thus driven off. This has the advantage that the CO2 can not only be removed from the gas phase (e.g., DAC, CCS), but can also be released again at any later time and, for example, fed into a process that uses CO2 as a feedstock (e.g., CCU).

[0182] WA12454S / Wi

[0183] 30

[0184] Examples of implementation

[0185] Unless otherwise stated, the following examples were carried out at atmospheric pressure, i.e., at approximately 1013 mbar, and at room temperature, i.e., approximately 23°C or a temperature that occurs when the reactants come together at room temperature without additional heating or cooling, and describe the basic feasibility of the present invention without limiting it to the contents disclosed therein.

[0186] Determination of the breaking load

[0187] The breaking load of the molded parts was verified using a material testing machine. The Texture Analyser XT plus from Winopal was used for this purpose. The following parameters were used to measure the breaking load:

[0188] Test speed: 2.00 mm / sec; probe travel: 14.5 mm.

[0189] The target parameter is the displacement; that is, the sample is subjected to pressure until the set displacement of 14.5 mm is reached. A 6 mm diameter stainless steel punch is used as the tool. A 150 kg load cell was used for all measurements with the texture analyzer.

[0190] The cylindrical specimen was positioned in the apparatus so that the punch pressed against the lateral surface (not the cut surface); the result is the breaking load in Newtons (N). WA12454S / Wi

[0191] 31

[0192] Determination of CO2 adsorption capacity

[0193] The BELCAT II gas adsorption analyzer from Microtrac is used to determine the CO2 adsorption capacity. Typically, the temperature-programmed desorption (TPD) method is used, which works as follows.

[0194] For sample preparation, the substrate to be examined is heated to 200 °C under a continuous helium flow at a rate of 10 K / min and held at this temperature for 35 min.

[0195] For analysis, the sample is first rinsed with helium at 40°C. Then, CO2 is passed over the sample for 90 minutes at 40°C. If necessary, the CO2 can be humidified using a commercially available steam injection device (“Bubbier”).

[0196] The sample is treated in a helium stream at 40 °C for 30 minutes. Helium is used as the desorption gas. The temperature of the support is increased to 200 °C at a rate of 10 K / min (linear temperature gradient) and held at this temperature for 20 minutes.

[0197] The gas mixture is passed through a dry molecular sieve (3 α) to remove water and analyzed using a thermal conductivity detector (TCD) and mass spectrometry (MS). This allows the desorbed amount of CO2 to be determined. WA12454S / Wi

[0198] 32

[0199] Molded body

[0200] The molded body was made from hydrophilic pyrogenic silica HDK® S13 (BET surface area: 110-140 m²). 2 / g, tapped density : 50 g / ml; available from WACKER Chemie AG) and precipitated silica (see table).

[0201] Types of precipitated silica used (Sipernat® from Evonik):

[0202] Example 1:

[0203] General procedure for the production of slip A with

[0204] HDK® S13 (Silica Dispersion)

[0205] 3 kg of demineralized water are added and adjusted to a pH of 3 by adding 6 g of H3PO4. This is then mixed with a mixer.

[0206] A total of 1.6 kg of pyrogenic silica (WACKER HDK® S13) is stirred in using the dissolver disc and butterfly insert. This is done in 8 portions of approximately 200 g of silica each. During this process,

[0207] Portion with a stirring speed of 350 rpm

[0208] (Dissolver) and 74 rpm (Butterfly) started. Portion 2: 430 rpm

[0209] (Dissolver) and 42 rpm (Butterfly) Portion 3: 710 rpm

[0210] (Dissolver) and 60 rpm (Butterfly) Portion 4: 610 rpm

[0211] (Dissolver) and 46 rpm (Butterfly) Portion 5: 620 rpm

[0212] (Dissolver) and 60 rpm (Butterfly) Portion 6: 480 rpm

[0213] (Dissolver) and 87 rpm (Butterfly) Portion 7: 640 rpm WA12454S / Wi

[0214] 33

[0215] (Dissolver) and 97 rpm (Butterfly). Portion 8: 630 rpm

[0216] (Dissolver) and 73 rpm (Butterfly). Each portion is stirred for 5 minutes; after adding the last portion, stir for another 15 minutes. This dispersion has a solids content of approximately 35%.

[0217] Example 2:

[0218] General procedure for the preparation of slip B with Sipernat® 500 LS (silica dispersion)

[0219] 2 kg of demineralized water are added and adjusted to a pH of 3 by adding 4 g of H3PO4. A total of 900 g of precipitated silica (Sipernat® 500 LS) is stirred into a mixer with a dissolver disc and butterfly attachment. This is done in four portions of 340 g, 180 g, 280 g, and 100 g of silica. For the first portion, the stirrer is operated at a speed of

[0220] Started at 47 rpm (dissolver) and 109 rpm (butterfly). Portion 2:

[0221] 48 rpm (Dissolver) and 139 rpm (Butterfly). Portion 3: 110 rpm

[0222] (Dissolver) and 132 rpm (Butterfly). Portion 4: 109 rpm

[0223] (Dissolver) and 130 rpm (Butterfly). Portions 1 and 2 were each stirred for 5 minutes. Portions 3 and 4 were each stirred for 20 minutes. After adding the last portion, the mixture was stirred for another 15 minutes. This dispersion has a solids content of approximately 30%.

[0224] Example 3:

[0225] General procedure for the preparation of slip C with Sipernat® 50S (silica dispersion)

[0226] 3 kg of demineralized water are prepared and adjusted to a pH of 3 by adding 6 g of H3PO4. A total of 1.6 kg of precipitated silica (Sipernat® 50S) is stirred into a mixer with a dissolver disc and butterfly insert. This process is carried out by WA12454S / Wi

[0227] 34 in 3 portions of silica, each containing 750 g, 550 g, and 300 g. Portion 1 was started with stirrer speeds of 44 rpm (dissolver) and 38 rpm (butterfly). Portion 2: 45 rpm (dissolver) and 30 rpm (butterfly). Portion 3: 60 rpm (dissolver) and 50 rpm (butterfly). Portions 1 and 2 were each stirred for 5 minutes, followed by 5 minutes of stirring at an increased speed (70 rpm (dissolver), 40 rpm (butterfly)). Portion 3 was stirred for 40 minutes. After adding the last portion, the stirrer speed was increased to 100 rpm (dissolver) and 125 rpm (butterfly), and the mixture was stirred for another 40 minutes. This dispersion has a solids content of approximately 35%.

[0228] Example 4:

[0229] General procedure for the preparation of slip D with Sipernat® 22 S (silicic acid dispersion)

[0230] 2 kg of demineralized water are added and adjusted to a pH of 3 by adding 4 g of H3PO4. A total of 900 g of precipitated silica (Sipernat® 22 S) is stirred into a mixer with a dissolver disc and butterfly attachment. This is done in three portions of 277 g, 456 g, and 167 g of silica, respectively. For portion 1, the stirrer speeds are 260 rpm (dissolver) and 38 rpm (butterfly). Portion 2: 320 rpm (dissolver) and 50 rpm (butterfly). Portion 3: 750 rpm (dissolver) and 150 rpm (butterfly). Portions 1-3 are stirred for 5 minutes each. After adding the last portion, the mixture is stirred for 15 minutes. This dispersion has a solids content of approximately 30%. WA12454S / Wi

[0231] Example 5:

[0232] General procedure for the production of slip E with

[0233] Sipernat® 50 (silica dispersion)

[0234] 0.7 kg of demineralized water is added and adjusted to a pH of 3 by adding 1.4 g of H3PO4. A total of 280 g of precipitated silica (Sipernat® 50) is stirred into a mixer equipped with a dissolver disc and butterfly attachment. This is done in four portions of 86 g, 75 g, 86 g, and 33 g of silica, respectively. For portion 1, the mixers are started at 500 rpm (dissolver) and 150 rpm (butterfly). Portion 2: 1000 rpm (dissolver) and 200 rpm (butterfly). Portion 3: 1000 rpm (dissolver) and 200 rpm (butterfly). Portion 4: 200 rpm (dissolver) and 100 rpm (butterfly). Portions 1 and 2 are each stirred for 5 minutes. Portions 3 and 4 were each stirred in for 20 minutes. After adding the last portion, it was stirred for another 15 minutes. This dispersion has a solids content of approximately 28%.

[0235] Example 6: (not according to the invention)

[0236] Manufacturing of the molded part with 100% HPK® S13

[0237] 280 g of the slurry, which has gelled after a certain time, is stirred and liquefied twice at 2350 rpm for 20 seconds each time using a speed mixer. 3.1 g of magnesium hydroxycarbonate paste (25% in water) is added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. Then, 33 g of deionized water is added and blended again at 2350 rpm using a speed mixer. For extrusion, the mixture is filled into an empty cartridge, and strands are extruded using an electric cartridge extruder.

[0238] 36 pieces are extruded to a diameter of approximately 3.8 mm, which are then cut to a length of approximately 8 mm.

[0239] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 38 N per edge and a pore volume of 1.35 ml / g.

[0240] Example 7: (not according to the invention)

[0241] Production of the molded body with 10% Sipernat® 500 LS and 90% HPK®

[0242] S13

[0243] 33 g of slip B are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 257 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mixture is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0244] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies WA12454S / Wi are then sintered. They are heated at a rate of 180 °C / h to 930 °C and held at that temperature for 6 hours. This process yields carrier bodies with a breaking load of 57 N (based on the edge) and a pore volume of 1.27 ml / g (94% of the initial pore volume, 6% reduction).

[0245] Example 8:

[0246] Production of the molded body with 20% Sipernat® 500 LS and 80% HPK®

[0247] S13

[0248] 67 g of slip B are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 230 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mixture is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0249] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. They are heated at a rate of 180 °C / h to 930 °C and held at this temperature for 6 hours. This process yields carrier bodies with a breaking load of 75 N (at the edge) and a pore volume of 1.25 ml / g (93% of the initial pore volume, 7% reduction). WA12454S / Wi

[0250] 38

[0251] Example 9:

[0252] Production of the molded body with 30% Sipernat® 500 LS and 70% HPK®

[0253] S13

[0254] 100 g of slip B are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 200 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each time using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0255] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60°C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. They are heated at a rate of 180°C / h to 930°C and held at this temperature for 6 hours. This process yields carrier bodies with a breaking load of 81 N (based on the edge) and a pore volume of 1.22 ml / g (90% of the...).

[0256] (initial pore volume, 10% reduction).

[0257] Example 10:

[0258] Production of the molded body with 50% Sipernat® 500 LS and 50% HPK®

[0259] S13

[0260] 167 g of slip B are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 143 g of slip A, prepared according to WA12454S / Wi

[0261] After a certain amount of time has thawed, the mixture is added and mixed twice more at 2350 rpm for 20 seconds each using a speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) is added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0262] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 104 N per edge and a pore volume of 1.16 ml / g (86% of the initial pore volume, a 14% reduction).

[0263] Example 11:

[0264] Production of the molded part with 60% Sipernat® 500 LS and 40% HPK® S13

[0265] 200 g of slip B are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 114 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using a speed mixer. 2.5 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For WA12454S / Wi

[0266] 40

[0267] During extrusion, the mass is filled into an empty cartridge and strands with a diameter of about 3.8 mm are extruded using an electric cartridge press, which are then cut to a length of about 8 mm.

[0268] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 109 N per edge and a pore volume of 1.14 ml / g (84% of the

[0269] (Baseline pore volume, 16% reduction) .

[0270] Example 12: (not according to the invention)

[0271] Production of the molded body with 70% Sipernat® 500 LS and 30% HPK®

[0272] S13

[0273] 233 g of slip B are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 86 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm. WA12454S / Wi

[0274] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 125 N at the edge and a pore volume of 1.09 ml / g (81% of the initial pore volume, a 19% reduction).

[0275] Example 13: (not according to the invention)

[0276] Production of the molded body with 10% Sipernat® 50 S and 90% HPK®

[0277] S13

[0278] 29 g of slip C are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 257 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mixture is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0279] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C. WA12454S / Wi

[0280] Heated to 42°C and held for 6 hours. This yields carrier bodies with a breaking load at the edge of 68 N and a pore volume of 1.28 ml / g (95% of the initial pore volume, 5% reduction).

[0281] Example 14:

[0282] Production of the molded body with 20% Sipernat® 50 S and 80% HPK®

[0283] S13

[0284] 57 g of slip C are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 229 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0285] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is held for 6 hours. The resulting carrier bodies have a breaking load of 78 N per edge and a pore volume of 1.24 ml / g (92% of the

[0286] (Baseline pore volume, 8% reduction) . WA12454S / Wi

[0287] Example 15:

[0288] Production of the molded body with 30% Sipernat® 50 S and 70% HPK®

[0289] S13

[0290] 86 g of slip C are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 200 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0291] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60°C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. They are heated at a rate of 180°C / h to 930°C and held at this temperature for 6 hours. This process yields carrier bodies with a breaking load of 87 N (based on the edge) and a pore volume of 1.21 ml / g (90% of the initial pore volume, 10% reduction).

[0292] Example 16:

[0293] Production of the molded body with 50% Sipernat® 50 S and 50% HPK®

[0294] S13

[0295] 143 g of slip C are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 143 g of slip A, prepared according to WA12454S / Wi

[0296] After a certain amount of time has thawed, the mixture is added and stirred twice more at 2350 rpm for 20 seconds each using a speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) is added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0297] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 104 N per edge and a pore volume of 1.14 ml / g (84% of the initial pore volume, a 16% reduction).

[0298] Example 17:

[0299] Production of the molded body with 60% Sipernat® 50 S and 40% HPK® S13

[0300] 171 g of slip C are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 114 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using a speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For WA12454S / Wi

[0301] 45

[0302] During extrusion, the mass is filled into an empty cartridge and strands with a diameter of about 3.8 mm are extruded using an electric cartridge press, which are then cut to a length of about 8 mm.

[0303] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 115 N per edge and a pore volume of 1.10 ml / g (81% of the

[0304] (Baseline pore volume, 19% reduction) .

[0305] Example 18: (not according to the invention)

[0306] Production of the molded body with 70% Sipernat® 50 S and 30% HPK®

[0307] S13

[0308] 200 g of slip C are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 86 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.3 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm. WA12454S / Wi

[0309] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 121 N at the edge and a pore volume of 1.07 ml / g (79% of the initial pore volume, a 21% reduction).

[0310] Example 19: Production of the molded body with 20% Sipernat® 22 S and 80% HPK® S13

[0311] 67 g of slip D are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 230 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each time using a speed mixer. 2.4 g are then added to the liquid dispersion.

[0312] Magnesium hydroxycarbonate paste (25% in water) is added. This mixture is blended in a speed mixer at 2350 rpm for 20 seconds, which causes the mass to solidify. For the

[0313] During extrusion, the mass is filled into an empty cartridge and strands with a diameter of about 3.8 mm are extruded using an electric cartridge press, which are then cut to a length of about 8 mm.

[0314] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating at a rate of 180 °C / h to 930 °C, which is held for 6 hours. The resulting product is WA12454S / Wi.

[0315] Carrier body with a breaking load perpendicular to the edge of 70 N and a pore volume of 1.29 ml / g (96% of the initial pore volume, 4% reduction).

[0316] Example 20:

[0317] Production of the molded body with 40% Sipernat® 22 S and 60% HPK®

[0318] S13

[0319] 133 g of slip D are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 171 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0320] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 80 N per edge and a pore volume of 1.21 ml / g (90% of the

[0321] (Baseline pore volume, 10% reduction) . WA12454S / Wi

[0322] 48

[0323] Example 21:

[0324] Production of the molded body with 60% Sipernat® 22 S and 40% HPK®

[0325] S13

[0326] 200 g of slip D are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 114 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each time using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0327] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60°C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. They are heated at a rate of 180°C / h to 930°C and held at this temperature for 6 hours. This process yields carrier bodies with a breaking load at the edge of 121 N and a pore volume of 1.10 ml / g (81% of the total porosity).

[0328] (initial pore volume, 19% reduction).

[0329] Example 22: (not according to the invention)

[0330] Production of the molded body with 80% Sipernat® 22 S and 20% HPK®

[0331] S13

[0332] 267 g of slip D are stirred twice at 2350 rpm for 20 seconds each time using a speed mixer. 57 g of slip A, which follows WA12454S / Wi

[0333] After a certain period of time, the remaining ingredients are added and the mixture is stirred twice more at 2350 rpm for 20 seconds each using a speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) is added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0334] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 193 N at the edge and a pore volume of 0.68 ml / g (50% of the initial pore volume, 50% reduction).

[0335] Example 23:

[0336] Production of the molded body with 20% Sipernat® 50 and 80% HPK® S13

[0337] 71 g of slurry E are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 228 g of slurry A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using a speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using a speed mixer, causing the mass to solidify. For extrusion, the mixture is filled into an empty cartridge and WA12454S / Wi

[0338] 50 Using an electric cartridge press, strands with a diameter of about 3.8 mm are extruded, which are then cut to a length of about 8 mm.

[0339] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the relative humidity is reduced from 60% to 10% over a total of 38 hours. The green bodies are then sintered. This process involves heating them at a rate of 180 °C / h to 930 °C, which is then held for 6 hours. The resulting carrier bodies have a breaking load of 80 N per edge and a pore volume of 1.16 ml / g (86% of the

[0340] (Baseline pore volume, 14% reduction) .

[0341] Example 24: of rs with 40% 50 and 60% HDK® S13

[0342] 143 g of slip E are stirred twice at 2350 rpm for 20 seconds each using a speed mixer. 171 g of slip A, which has gelled after a certain time, are added and stirred again twice at 2350 rpm for 20 seconds each using the speed mixer. 2.4 g of magnesium hydroxycarbonate paste (25% in water) are added to the liquid dispersion. This mixture is blended at 2350 rpm for 20 seconds using the speed mixer, causing the mass to solidify. For extrusion, the mass is filled into an empty cartridge, and strands with a diameter of approximately 3.8 mm are extruded using an electric cartridge gun. These strands are then cut to a length of approximately 8 mm.

[0343] The extruded bodies are dried in a climate-controlled chamber using a drying program. The temperature is maintained at 60 °C and the humidity is reduced from 60% to 10% over the entire WA12454S / Wi cycle.

[0344] 51

[0345] The temperature is reduced for 38 hours. The green bodies are then sintered. This involves heating at a rate of 180 °C / h to 930 °C and holding that temperature for 6 hours. The result is...

[0346] Carrier body with a breaking load at the edge of 88 N and a pore volume of 1.11 ml / g (82% of the

[0347] (Baseline pore volume, 18% reduction) .

[0348] Summary of results: The reduction in pore volume is calculated in relation to example 6. WA12454S / Wi

[0349] 52

[0350] Example 25:

[0351] General procedure for the functionalization of silica

[0352] carrier

[0353] The functionalization of the support is achieved by spraying the functionalizing agent using a commercially available rotary evaporator. The silica mold is located in the rotating evaporator flask and is dried for 6 hours at an oil bath temperature of 140 °C and a pressure of 25 mbar before the functionalizing agent is added. For functionalization, a Teflon tube is connected to the vent valve of the rotary evaporator. The functionalizing agent is drawn in from the outside through this tube by applying a vacuum and then conveyed via another Teflon tube located inside the rotary evaporator, extending into the evaporator flask.

[0354] Immediately after spraying the functionalizing agent, the sprayed silica molded body is post-treated by rotation in an evaporator flask at normal pressure and room temperature for one hour, and then dried at an oil bath temperature of 80 °C and 25 mbar. WA12454S / Wi

[0355] Example 26:

[0356] Determination of the adsorption capacity of the carrier according to Example 14, functionalized with potassium carbonate

[0357] 10 g of the silica molded body with a pore volume of 1.24 mL / g from Example 14 are functionalized according to Example 25 by introducing 17.1 g of 30 wt% potassium carbonate into water. After functionalization, 15.8 g of the functionalized molded body are obtained. The adsorption capacity, determined by chemisorption, is 2.2 mmol CO₂ per gram of molded body.

[0358] Example 27:

[0359] Determination of the adsorption capacity of the carrier according to example

[0360] 15, functionalized with potassium carbonate

[0361] 10.0 g of the silica molded bodies with a pore volume of 1.21 mL / g from Example 15 are functionalized according to Example 25 by introducing 16.5 g of a 30 wt% potassium carbonate solution into water. After functionalization, 15.0 g of the functionalized molded body are obtained. The adsorption capacity, determined by chemisorption, is 2.1 mmol CO₂ per gram of molded body.

[0362] WA12454S / Wi

[0363] 54

[0364] The present invention is further characterized by the following points:

[0365] 1. Comprehensive CO2 sorbent

[0366] (i) a shaped body (i) made of at least one pyrogenic

[0367] Silica and at least one precipitated silica, wherein the weight fraction of the totality of the at least one precipitated silica to the total mass of the at least one pyrogenic silica and the at least one precipitated silica

[0368] (Total silica mass) 20-60 wt.%, preferably

[0369] 30-50 wt%; and

[0370] (ii) at least one sorbent (ii) for CO2 with which the molded body (i) is functionalized.

[0371] 2. Sorbens according to point 1, wherein the shaped body (i) is sintered at a sintering temperature Ts.

[0372] 3. Sorben according to any of the preceding points, wherein the formed body (i) is a formed body (i) of a pyrogenic silica and a precipitated silica, wherein the weight fraction of the precipitated silica in the total mass of the pyrogenic silica and the precipitated silica (total silica mass) is 20-60 wt.%, preferably 30-50 wt.%.

[0373] 4. Sorbens according to any of the preceding points, wherein the shaped body (i) comprises a mixture of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the at least one precipitated silica in the total mass of the at least WA12454S / Wi one pyrogenic silica and the at least one precipitated silica (total silica mass) 20-

[0374] 60 wt.%, preferably 30-50 wt.%.

[0375] 5. Sorben according to any of the preceding points, wherein the formed body (i) consists of a mixture of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica (total silica mass) is 20-60 wt.%, preferably 30-50 wt.%.

[0376] 6. Sorbens according to any of the preceding points, wherein the silicon dioxide of the molded body has a mesoporous structure, in particular a mesoporous structure with an irregular pore structure.

[0377] 7. Sorbens according to one of the preceding points, wherein the molded body has dimensions in at least one dimension in the range of 0.5 mm to 30 mm, preferably 1.0 mm to 15 mm .

[0378] 8. Sorbens according to one of the preceding points, wherein Ts is in a range of 800-1200 °C, in particular in a range of 900-1100 °C.

[0379] 9. Sorbens according to one of the preceding points, which has a compressive strength of at least 2 N / mm² 2 , preferably at least 8 N / mm 2 , and / or wherein the sorbent in the form of cylindrical bodies has a breaking load of at least 70 N, preferably at least 80 N. WA12454S / Wi

[0380] 56

[0381] 10. Sorbs according to one of the preceding points, wherein the BET surface of the Sorbs is in the range of 30 to 500 m 2 / g lies, especially in the range of 50 to 400 m 2 / G.

[0382] 11. Sorbens according to any of the preceding points, wherein the at least one sorbent (ii) is able to undergo a reversible reaction with CO2, in particular a reversible sorption reaction.

[0383] 12. Sorbent according to any of the preceding points, wherein the at least one sorbent (ii) is an inorganic or an organic sorbent.

[0384] 13. Sorben according to any of the preceding points, wherein the shaped body (i) is functionalized with a mixture of an inorganic and an organic sorbent, in particular with a mixture of a carbonate and an organic amine.

[0385] 14. Sorbs according to point 13, wherein the inorganic

[0386] (ii) sorbent is a carbonate, in particular selected from the group consisting of metal carbonate, metal hydrogen carbonate and mixtures thereof.

[0387] 15. Sorbent according to point 13, wherein the organic sorbent is an organic monoamine or polyamine, the polyamine comprising at least two N atoms per molecule separated by at least one C atom, in particular selected from the group consisting of ethyleneamine, aminosilane, polyethyleneimine (PEI), polypropyleneamine, polyvinylpyridine, polydime thylaminoethyl methacrylate,

[0388] Polyamidoamine, polyvinylamine, and polyallylamine. WA12454S / Wi

[0389] 16. Sorbens according to point 15, wherein the ethyleneamine is selected from the group consisting of ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetraamine (TETA), tetraethylenepentamine (TEPA), aminoethylethanolamine (AEEA), aminoethylpiperazine (AEP), piperazine (PIP),

[0390] Hydroxyethylpiperazine (HEP) , Pentaethylenehexamine (PEHA) and Polyethylenepolyamine (PEPA) .

[0391] 17. Sorbens according to point 15, wherein the aminosilane is selected from the group consisting of aminopropylsilane, [3- (2- Aminoethylamino ) -propyl] -trimalkoxysilane, 3- [2- (2-

[0392] Aminoethylamino ) -ethylamino] -propyltrialkoxysilane, mixtures thereof and condensation products of 3-Aminopropyltrialkoxysilane .

[0393] 18. Sorbens according to any of points 15-17, wherein the polyamine is silylated, for example obtainable by reacting one or more amino groups of the polyamine with suitably functionalized alkoxysilanes, for example selected from the group consisting of 3-chloropropyl-trialkoxysilane, 3-chloropropyl-trialkoxysilane, glycidoxypropyl-trialkoxysilane and isocyanatopropyl-trialkoxysilane.

[0394] 19. Sorbens according to point 18, wherein the silylated polyamine is obtainable by silylation, which is carried out in isolation or in situ.

[0395] 20. Sorbs according to one of the preceding points, furthermore comprehensively

[0396] (iii) at least one auxiliary material (iii) selected from the group consisting of polymeric binders, silicon WA12454S / Wi containing binders such as silicates and silica sol,

[0397] Spreading agents and wetting agents.

[0398] 21. Sorbs according to one of points 15-20, where the polyamine in

[0399] A combination with at least one amino-functional alkoxysilane is present.

[0400] 22. Sorbens according to point 21, wherein the at least one amino-functional alkoxysilane is selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and 3-

[0401] Aminopropyltriisoproxysilane .

[0402] 23. Sorbens according to point 21 or 22, wherein the amount of polyamine is at least 50% by weight based on the total amount of polyamine and amino-functional alkoxysilane.

[0403] 24. Sorben according to any of the preceding points, wherein the amount of the at least one sorbent (ii) is 10 to 90 wt.%, preferably 25 to 80 wt.%, based on the total weight of the sorbent.

[0404] 25. Sorben according to any of the preceding points, which has a proportion of flaking of less than 5 wt.%, preferably less than 1 wt.% and most preferably less than 0.5 wt.% based on the total weight of the sorbent.

[0405] 26. Method for producing a sorbent for CO2 according to any of points 1-25, comprising the following steps in the specified order:

[0406] (A) Providing a shaped body (i) made of at least one pyrogenic silica and at least one WA12454S / Wi

[0407] 59 precipitated silica, wherein the weight fraction of the total of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica (total silica mass) is 20-60 wt.%, preferably 30-50 wt.%;

[0408] (B) Impregnating the provided molded body with at least one sorbent (ii) for CO2 in order to functionalize the molded body.

[0409] 27. Method according to point 26, wherein the provision of the molded body (i) in step (A) is carried out by the following steps in the specified order:

[0410] (Al) Providing a silica dispersion by dispersing at least one pyrogenic silica and at least one precipitated silica in a dispersing agent, wherein the weight fraction of the total mass of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica (total silica mass) is 20-60 wt.%, preferably 30-50 wt.%;

[0411] (A2) Coagulation of the dispersion by raising the pH value;

[0412] (A3) Shaping the coagulated dispersion to produce a green body; and

[0413] (A4) Drying and subsequent sintering of the

[0414] green body at a sintering temperature T s , to produce the sintered molded body. WA12454S / Wi

[0415] 28. Method according to point 27, wherein the total amount of silica in the silica dispersion of step (Al) is 10-50 wt.%, preferably 20-40 wt.%, based on the total mass of the dispersion.

[0416] 29. Method according to one of points 27-28, wherein the provision of the silica dispersion in step (Al) is carried out by stirring in the at least one silica using a dissolver disc and a butterfly insert.

[0417] 30. Method according to point 29, wherein the provision of the silica dispersion in step (Al) is carried out by stirring the total amount of silica into water in at least two portions, the portion stirred in first being stirred in at a higher stirring speed of the dissolver disc and a lower stirring speed of the butterfly insert compared to the portion stirred in after.

[0418] 31. Method according to any one of points 27-30, wherein the dispersing agent in step (Al) is water or an aqueous solution, preferably an aqueous solution with a pH value in the range of 1.0 to 7.0, preferably from 1.5 to 6.0, particularly preferably from 2.0 to 4.0

[0419] 32. Method according to one of points 27-31, wherein the pH of the dispersant is adjusted in step (Al) by adding acid.

[0420] 33. Method according to one of points 27-32, wherein the pH of the dispersant is adjusted in step (Al) by adding phosphoric acid. WA12454S / Wi

[0421] 61

[0422] 34. Method according to any one of points 27-33, wherein the silica dispersion is provided in step (Al) by dispersing the at least one pyrogenic silica and the at least one precipitated silica in a common dispersing agent or by dispersing the at least one pyrogenic silica and the at least one precipitated silica in separate dispersing agents, and mixing the resulting dispersions of the at least one pyrogenic and the at least one precipitated silica together.

[0423] 35. Method according to one of points 27-34, wherein the pH is increased by 0.5-5.5 units in step (A2), wherein the target pH after the increase in step (A2) is preferably in the range of 4.0 to 8.0, particularly preferably in the range of 5.0 to 7.0.

[0424] 36. Method according to one of points 27-35, wherein the increase of the pH value in step (A2) is carried out by adding a basic coagulant to the silica dispersion, preferably by adding magnesium hydroxycarbonate.

[0425] 37. Method according to one of points 27-36, wherein the shaping in step (A3) is carried out by extrusion.

[0426] 38. Method according to any one of points 27-37, wherein the drying in step (A4) takes place at a temperature in the range of 25°C and 200°C, preferably between 30°C and 100°C, most preferably between 40°C and 80°C. WA12454S / Wi

[0427] 39. Method according to one of points 27-38, wherein the sintering in step (A4) takes place at a temperature T s in the range of 800-1200 °C, preferably 900-1100 °C.

[0428] 40. Procedure according to one of points 27-39, wherein the sintering in

[0429] Step (A4) is carried out at a heating rate of 100-250 °C / h, preferably 150-200 °C / h.

[0430] 41. Method according to one of points 27-40, wherein the sintering in

[0431] Step (A4) is carried out for a period of 1-10 hours, preferably 4-8 hours.

[0432] 42. Method according to one of points 27-41, wherein the at least one sorbent is an inorganic or an organic sorbent.

[0433] 43. Method according to point 42, wherein the inorganic sorbent is a carbonate, in particular selected from the group consisting of metal carbonate, metal hydrogen carbonate and mixtures thereof.

[0434] 44. Method according to point 42, wherein the organic sorbent is an organic monoamine or polyamine, wherein the polyamine comprises at least two N atoms per molecule separated by at least one C atom, in particular selected from the group consisting of ethyleneamine, aminosilane, polyethyleneimine (PEI), polypropyleneamine, polyvinylpyridine,

[0435] Polydimethylaminoethyl methacrylate, polyamidoamine,

[0436] Polyvinylamine and polyallylamine.

[0437] 45. Method according to point 44, wherein the ethyleneamine is selected from the group consisting of ethylenediamine (EDA), WA12454S / Wi

[0438] Diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), aminoethylethanolamine (AEEA), aminoethylpiperazine (AEP), piperazine (PIP), hydroxyethylpiperazine (HEP), pentaethylenehexamine (PEHA), and polyethylenepolyamine (PEPA).

[0439] 46. ​​Method according to point 44, wherein the aminosilane is selected from the group consisting of aminopropylsilane, [3- (2-

[0440] Aminoethylamino)-propyl]-trimalkoxysilane, 3-[2-(2-

[0441] Aminoethylamino ) -ethylamino] -propyltrialkoxysilane, whose

[0442] Mixtures and condensation products of 3-aminopropyltrialkoxysilane.

[0443] 47. Method according to any of points 44-46, wherein the polyamine is silylated, for example obtainable by reacting one or more amino groups of the polyamine with suitably functionalized alkoxysilanes, for example selected from the group consisting of 3-chloropropyl-trialkoxysilane, 3-chloropropyl-trialkoxysilane, glycidoxypropyl-trialkoxysilane and isocyanatopropyl-trialkoxysilane.

[0444] 48. Method according to point 47, wherein the polyamine is obtainable by silylation, which can be carried out in isolation or in situ.

[0445] 49. Method according to any of points 26-48, wherein the at least one sorbent is in liquid form during the impregnation in step (B), for example as a solution, emulsion or dispersion in a solvent or liquid medium or in pure form.

[0446] 50. Method according to point 49, wherein the at least one sorbent is a solution of a metal carbonate, WA12454S / Wi

[0447] 64 in particular potassium carbonate and / or sodium carbonate, in water or a solution of a metal hydrogen carbonate, in particular potassium hydrogen carbonate and / or

[0448] Sodium bicarbonate in water.

[0449] 51. Method according to point 49 or 50, wherein the at least one sorbent is a saturated aqueous solution of potassium carbonate, sodium carbonate, potassium hydrogen carbonate and / or sodium hydrogen carbonate, preferably of potassium carbonate and / or potassium hydrogen carbonate, more preferably of potassium carbonate.

[0450] 52. Method according to point 50 or 51, wherein the amount of metal carbonate or metal hydrogen carbonate is 15-40 wt.%, preferably 15-33 wt.% of the total weight of the aqueous solution.

[0451] 53. Method according to any of points 26-52, wherein the sorbent is in the form of a solution of an organic sorbent, for example an organic amine, in a suitable solvent, wherein the amount of dissolved organic sorbent is preferably at least 30 vol%, more preferably at least 60 vol%.

[0452] 54. Method according to one of points 26-53, wherein the impregnation in step (B) is carried out by bringing the molded body into contact with the at least one sorbent for CO2.

[0453] 55. Procedure according to one of points 26-54, wherein the

[0454] Impregnation in step (B) in a temperature range of WA12454S / Wi

[0455] 0-150 °C, preferably in a temperature range of 15-120 °C.

[0456] 56. Method according to one of points 26-55, wherein the impregnation in step (B) takes place at normal pressure, under increased pressure or under reduced pressure.

[0457] 57. Method according to any of points 26-56, wherein the impregnation is carried out by mixing, spraying or soaking the molded body or the incipient wetness method with the at least one sorbent in liquid form, in particular by means of the incipient wetness method.

[0458] 58. Method according to any of points 26-57, wherein the molded body has a mesoporous structure and the volume of the at least one sorbent for CO2 is 80 to 120%, preferably 90 to 110%, more preferably 95-105%, based on the total pore volume of the molded body.

[0459] 59. Method according to one of points 26-58, wherein the molded body is pre-impregnated

[0460] - at a suppression of 10 -3 up to 10 2 is treated in mbar; and / or

[0461] - is dried.

[0462] 60. Method according to any one of points 26-59, wherein in step (B) the provided molded body is impregnated with at least one CO2 sorbent to functionalize the molded body, together with at least one impregnation aid selected from wetting agent, emulsifier, dye, binder, adhesion promoter, higher alcohols and higher polyols. WA12454S / Wi

[0463] 66

[0464] 61. Use of the sorbent for CO2 according to one of points 1-25 for the reversible binding of CO2 from a gas mixture, in particular in the form of a fixed bed sorbent, for example for CCU, CCS and / or DAC.

Claims

WA12454S / Wi 67 Claims 1. Comprehensive CO2 sorbent (i) a shaped body (i) made of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the total mass of the at least one precipitated silica in relation to the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%; and (ii) at least one sorbent (ii) for CO2 with which the molded body (i) is functionalized.

2. Sorbens according to claim 1, wherein the molded body (i) is sintered at a sintering temperature Ts.

3. Sorben according to any of the preceding claims, wherein the weight fraction of the totality of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 30-50 wt.%.

4. Sorben according to any of the preceding claims, wherein the shaped body (i) consists of a mixture of at least one pyrogenic silica and at least one precipitated silica, wherein the weight fraction of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.% WA12454S / Wi 5. Sorbens according to any of the preceding claims, wherein the silicon dioxide of the molded body has a mesoporous structure.

6. Sorbens according to any one of claims 2-6, wherein Ts is in a range of 800-1200 °C.

7. Sorben according to any of the preceding claims, wherein the at least one sorbent (ii) is an inorganic or an organic sorbent.

8. Sorbens according to claim 7, wherein the inorganic sorbent (ii) is a carbonate.

9. Sorbens according to claim 7, wherein the organic The sorbent is an organic monoamine or polyamine, wherein the polyamine comprises at least two N atoms per molecule, which are separated by at least one C atom.

10. Sorbens according to any of the preceding claims, further comprising (iii) at least one auxiliary material selected from the group consisting of polymeric binders, silicon-containing binders such as silicates and silica sol, spreading agents and wetting agents.

11. A method for producing a sorbent for COs according to any one of claims 1-10, comprising the following steps in the specified order: (A) Providing a shaped body (i) made of at least one pyrogenic silica and at least one WA12454S / Wi precipitated silica, wherein the weight fraction of the total of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%; (B) Impregnating the provided molded body with at least one sorbent (ii) for CO2 in order to functionalize the molded body.

12. The method of claim 11, wherein the provision of the molded body (i) in step (A) is carried out by the following steps in the specified order: (Al) Providing a silica dispersion by dispersing at least one pyrogenic silica and at least one precipitated silica in a dispersing agent, wherein the weight fraction of the total mass of the at least one precipitated silica in the total mass of the at least one pyrogenic silica and the at least one precipitated silica is 20-60 wt.%; (A2) Coagulation of the dispersion by raising the pH value; (A3) Shaping the coagulated dispersion to produce a green body; and (A4) Drying and subsequent sintering of the green body at a sintering temperature T s , in order to produce the sintered molded body.

13. Method according to claim 11 or 12, wherein the pH value of the dispersion obtained after step (Al) is in the range of 1.0 WA12454S / Wi 70 to 7.0 and the pH value in step (A2) is raised to a value in the range of 4.0 to 8.

0.

14. Method according to one of claims 11-13, wherein the sintering takes place at a sintering temperature T s in the range of 800°C to 1200 °C is used.

15. Use of the sorbent for CO2 according to any one of claims 1-10 for the reversible binding of CO2 from a gas mixture.

Images