DAC MATERIALS

Abstract

Method for separating gaseous carbon dioxide from air, in particular from ambient atmospheric air (1), by cyclic adsorption/desorption using a sorbent material (3), wherein said sorbent material (3) is a solid inorganic or organic, non-polymeric or polymeric support material functionalized on the surface with amino functionalities capable of reversibly binding carbon dioxide, with a specific BET surface area, preferably measured by nitrogen adsorption, in the range of 1-20 m2/g.

Claims

1. A method for separating gaseous carbon dioxide from a gas mixture, said gas mixture containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide, by cyclic adsorption/desorption using a sorbent material adsorbing said gaseous carbon dioxide in a unit, wherein the method comprises at least the following sequential and in this sequence repeating steps (a)-(e): (a) contacting said gas mixture with said sorbent material to allow at least said gaseous carbon dioxide to adsorb on said sorbent material by flow-through through said unit under ambient atmospheric pressure conditions and ambient atmospheric temperature conditions in an adsorption step; (b) isolating said sorbent material with adsorbed carbon dioxide in said unit from said flow-through while maintaining the temperature in said sorbent material; (c) injecting a stream of saturated or superheated steam by flow-through through said unit and thereby inducing an increase of the temperature of said sorbent material to a temperature between 60 and 110° C., starting desorption of CO2; (d) extracting at least desorbed gaseous carbon dioxide from said unit and separating gaseous carbon dioxide from steam by condensation downstream of said unit; (e) bringing the sorbent material to ambient atmospheric temperature conditions; wherein said sorbent material is a solid inorganic or organic, non-polymeric or polymeric support material functionalized on the surface with amino functionalities capable of reversibly binding carbon dioxide, with a specific BET surface area, in the range of 1-20 m2/g.

2. Method according to claim 1, wherein said sorbent material has a specific BET surface area, measured by nitrogen adsorption, in the range of 2-15 m2/g.

3. Method according to claim 1, wherein said sorbent material has a pore diameter distribution, measured by Mercury intrusion, such that 90% of the pore volume is in the range of 50-300 nm, and/or wherein said sorbent material has a pore volume distribution, measured by Mercury intrusion, such that the maximum pore volume is at a pore diameter in the range of 80-150 nm, and/or wherein said sorbent material has a total pore volume, measured by Mercury intrusion, in the range 0.05-0.50 cm3/g.

4. Method according to claim 1, wherein said sorbent material has a nitrogen content in the range 5-50 wt. % for dry sorbent material.

5. Method according to claim 1, wherein said gas mixture is ambient atmospheric air.

6. Method according to claim 1, wherein the solid inorganic or organic, non-polymeric or polymeric support material is an organic or inorganic polymeric support.

7. Method according to claim 1, wherein the solid inorganic or organic, non-polymeric or polymeric support material is in the form of at least one of monolith, layer or sheet, hollow or solid fibres, or wherein the solid inorganic or organic, non-polymeric or polymeric support material is in the form of solid particles embedded in a porous or non-porous matrix.

8. Method according to claim 1, wherein the gas mixture is passing through the sorbent material in step (a) with a relative humidity of at least 70%.

9. Method according to claim 1, wherein the sorbent material has a water retention in the range of 3-60 weight percent, and/or a bulk density (EN ISO 60 (DIN 53468)) in the range 750-400 kg/m3.

10. Method according to claim 1, wherein step (d) is carried out in that still contacting the sorbent material with steam by injecting and/or circulating saturated or superheated steam into said unit, thereby flushing and purging both steam and CO2 from said unit, while regulating the extraction and/or steam supply to essentially maintain the temperature in the sorbent at the end of the preceding step (c) and/or to essentially maintain the pressure in the sorbent at the end of the preceding step (c).

11. Method according to claim 1, wherein it is using a unit containing said sorbent material, the unit and the sorbent material being able to sustain a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and the unit being openable to flow-through of the gas mixture, and for contacting it with the sorbent material for the adsorption step.

12. Method according to claim 1, wherein said unit is evacuable to a vacuum pressure of 400 mbar(abs) or less, and wherein step (b) includes isolating said sorbent with adsorbed carbon dioxide in said unit from said flow-through while maintaining the temperature in the sorbent and then evacuating said unit to a pressure in the range of 20-400 mbar(abs), wherein in step (c) injecting a stream of saturated or superheated steam is also inducing an increase in internal pressure of the reactor unit, and wherein step (e) includes bringing the sorbent material to ambient atmospheric pressure conditions and ambient atmospheric temperature conditions.

13. Method according to claim 1, wherein step (e) is carried out exclusively by contacting said ambient atmospheric air with the sorbent material under ambient atmospheric pressure conditions and ambient atmospheric temperature conditions to evaporate and carry away water in the unit and to bring the sorbent material to ambient atmospheric temperature conditions.

14. Method of using a sorbent material having a solid inorganic or organic, non-polymeric or polymeric support material functionalized on the surface with amino functionalities capable of reversibly binding carbon dioxide, with a specific BET surface area, measured by nitrogen adsorption, in the range of 1-20 m2/g, for separating gaseous carbon dioxide from a gas mixture.

15. Unit for separating gaseous carbon dioxide from a gas mixture, comprising at least one reactor unit containing sorbent material suitable and adapted for flow-through of said gas mixture, wherein the reactor unit comprises an inlet for said gas mixture, and an outlet for said gas mixture, during adsorption, wherein the reactor unit is heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and the reactor unit being openable to flow-through of the gas mixture, and for contacting it with the sorbent material for an adsorption step.

16. Method according to claim 1, wherein said sorbent material has a specific BET surface area, measured by nitrogen adsorption, in the range of 4-10 m2/g.

17. Method according to claim 1, wherein said sorbent material has a pore diameter distribution, measured by Mercury intrusion, such that 95% of the pore volume is in the range of 50-300 nm, or in the range of 50-250 nm, and/or wherein said sorbent material has a pore volume distribution, measured by Mercury intrusion, such that the maximum pore volume is at a pore diameter in the range of 100-150 nm, wherein 90% or 95% of the total pore volume of the distribution is in a window of −50 nm and +150 nm around the diameter of said maximum of the pore volume distribution and/or wherein said sorbent material has a total pore volume, measured by Mercury intrusion, in the range 0.15-0.35 cm3/n.

18. Method according to claim 1, wherein said sorbent material has a nitrogen content in the range 9-15 wt. % or 10-12 wt. %, in each case for dry sorbent material.

19. Method according to claim 1, wherein the solid inorganic or organic, non-polymeric or polymeric support material is an organic polymeric support, in particular a polystyrene based material, including a styrene divinylbenzene copolymer, to form the sorbent material surface functionalised with primary amine, including methyl amine and benzylamine moieties, or is a non-polymeric inorganic support, selected from the group consisting of: silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), titania (TiO.sub.2), magnesia (MgO), clays, as well as mixed forms thereof, including silica-alumina (SiO.sub.2—Al.sub.2O.sub.3), or mixtures thereof.

20. Method according to claim 1, wherein the solid inorganic or organic, non-polymeric or polymeric support material is styrene divinylbenzene copolymer, to form the sorbent material surface functionalised with benzylamine moieties, and wherein the solid polymeric support material is obtained in an emulsion polymerisation process.

21. Method according to claim 1, wherein the solid inorganic or organic, non-polymeric or polymeric support material is in the form of at least one of monolith, layer or sheet, hollow or solid fibres in woven or nonwoven structures, hollow or solid particles in the form of essentially spherical beads with a particle size (D50) in the range of 0.30-1.25 mm.

22. Method according to claim 1, wherein the gas mixture is passing through the sorbent material in step (a) with a relative humidity of at least 75%.

23. Method according to claim 1, wherein the sorbent material has a water retention in the range of 3-30 weight percent or 5-30 weight percent and/or a bulk density (EN ISO 60 (DIN 53468)) in the range 450-650 kg/m3.

24. Method according to claim 11, wherein the unit comprises an array of individual adsorber elements, each adsorber element comprising at least one support layer and at least one sorbent layer comprising or consisting of at least one sorbent material, where said sorbent material offers selective adsorption of CO2 in the presence of moisture or water vapor, wherein the adsorber elements in the array are arranged essentially parallel to each other and spaced apart from each other forming parallel fluid passages for flow-through of gas mixture.

25. Method according to claim 1, wherein said unit is evacuable to a vacuum pressure of 400 mbar(abs) or less, and wherein step (b) includes isolating said sorbent with adsorbed carbon dioxide in said unit from said flow-through while maintaining the temperature in the sorbent and then evacuating said unit to a pressure in the range of 20-400 mbar(abs), wherein in step (c) injecting a stream of saturated or superheated steam is also inducing an increase in internal pressure of the reactor unit, and wherein step (e) includes bringing the sorbent material to ambient atmospheric pressure conditions and ambient atmospheric temperature conditions, and wherein after step (d) and before step (e) the following step is carried out: (d1) ceasing the injection and, if used, circulation of steam, and evacuation of the unit to pressure values between 20-500 mbar(abs), or in the range of 50-250 mbar(abs) in the unit, thereby causing evaporation of water from the sorbent and both drying and cooling the sorbent.

26. Method according to claim 14, using a temperature, vacuum, or temperature/vacuum swing process, including using a process in which injecting a stream of saturated or superheated steam by flow-through is used for inducing an increase of the temperature of the sorbent material to a temperature between 60 and 110° C., starting the desorption of CO2.

27. Unit according to claim 15, wherein at the gas outlet side of said device for separating carbon dioxide from water, there is at least one of a carbon dioxide concentration sensor and a gas flow sensor for controlling the desorption process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

[0080] FIG. 1 shows a schematic representation of a direct air capture unit;

[0081] FIG. 2 shows N2 adsorption/desorption isotherms of HSA-CPFA and LSA-CPFA at 77 K;

[0082] FIG. 3 shows the pore size distribution measured by Hg porosimetry of HSA-CPFA and LSA-CPFA;

[0083] FIG. 4 shows the adsorption capacity of the sorbents HSA-CPFA and LSA-CPFA at 30° C. and 60% RH;

[0084] FIG. 5 shows the desorption capacity of the sorbents HSA-CPFA and LSA-CPFA after air adsorption at increasing RH values;

[0085] FIG. 6 shows the adsorption capacity of the sorbents HSA-ISAP and LSA-ISAP at 30° C. and 60% RH.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0086] In one embodiment, low surface area cross-linked polystyrene sorbent functionalized with amino groups (LSA-CPFA) functionalized with primary aminoalkyl functional groups in the form of beads of a styrene-divinylbenzene cross-linked polymer with an average particle size (d50) between 0.01-1.50 mm, functionalized with benzylamine units bound to the polymeric matrix, where the amine is a free base, is utilized as DAC sorbent in a packed bed configuration.

[0087] In another embodiment of the present invention, LSA-CPFA functionalized with primary aminoalkyl functional groups is used in the form of a monolith structure to filter CO2 from a gas mixture or preferably ambient air.

[0088] In another embodiment of the present invention, LSA-CPFA functionalized with primary aminoalkyl functional groups is used in the form of powder coated on a filter structure such as, but not limited to, a monolith, a laminate, fibers, polymers, metal structures.

[0089] In another embodiment of the present invention LSA-CPFA functionalized with primary aminoalkyl functional groups is used for capturing carbon dioxide from atmospheric air where the desorption step is performed by increasing the temperature of the sorbent and applying vacuum and/or saturated and superheated steam, and/or by applying temperature vacuum swing and by using a warm fluid wherein the warm fluid can be, but is not limited to, saturated and superheated steam. In such a method preferably at least a part of the desorption of CO2 is performed at a pressure in the range of 50-1000 mbarabs preferably of 100-950 mbarabs and at a temperature in the range of 50-150° C.

[0090] The low surface area material can be produced using a process as follows:

[0091] 300 g of deionized water and 10 g of dispersant is added to a three-neck 1 L flask equipped with a thermometer and a reflux condenser at room temperature. To this mixture, a mixture containing 150 g of styrene, 25 g of divinylbenzene, 1.5 g of benzoyl peroxide and 90 g of pore-forming agent, which can be isooctane, toluene, wax or a mixture of thereof, is added under stirring. The temperature is increased to 70° C. for 3 h, then up to 80° C. for 4 h and completed at 95° C. for 7 h, after which the formation of the beads has occurred. The suspension is cooled down to room temperature. The beads are filtered and are then washed three times with an equivalent volume of acetone. 100 g of styrene-divinylbenzene and 220 mL of chloromethyl ether are added to a 1 L flask and left to swell for 3 h at room temperature. To this mixture, 3 g of zinc chloride is added and the temperature is increased to 45° C. for 16-24 h. The chloromethylated beads are then filtered and washed three times with an equivalent volume of methyl alcohol.

[0092] To obtain the aminomethylated polymer, the chloromethylated beads are treated in the following way. 100 g of chloromethylated beads and 100 g of deionized water are mixed, and then 40 g of a 200 g/L ammonia solution is added to the beads over 3 h maintaining the temperature between 3-30° C. The reaction mixture is then held for 3 h at 40° C. After cooling, 30 g of sodium hydroxide is added and the mixture is distilled. The beads are filtered and washed with hot water for 3 h.

Specific Examples

[0093] In this example section, two samples have been analyzed and compared: one with high surface area as disclosed in the prior art e.g. of the type Lewatit VP OC1065 as available from Lanxess, Germany, having a BET surface area >25 m2/g, which is herein after referred to high surface area polymer (HSA-CPFA); and the second one with low surface area, <25 m2/g which is herein after referred to as low surface area polymer (LSA-CPFA).

Pore Size, Pore Volume and Specific Surface Area of Sorbents:

Method for the Specific Surface Area Measurements:

[0094] Nitrogen adsorption measurements were performed at 77 K on a Quantachrome ASiQ. The mass of the sample used was between 0.2-1.0 g. Since the samples contain a significant amount of water, it is important to use a treatment that does not alter their intrinsic porosity and pore structure. Therefore, prior to degassing, the samples were treated using the elutropic row method, which comprises removing water and replacing it with organic solvents with lower boiling point in the following order: methanol, acetone, and n-heptane. 2 g of samples was place in a chromatography column with a frit and flushed with 20 cm3 of each solvent in decreasing polarity order. The sample was then spread out on a petri dish and placed in a vacuum oven at 40° C. for 24 hours. After that, the sample was degassed at 70° C. under vacuum for twelve hours before measurement.

[0095] BET (Brunauer, Emmett und Teller) surface area analysis was used applying the method ISO 9277.

[0096] Results for the specific surface area measurements are presented in FIG. 2 and are given in the below table 1:

TABLE-US-00001 TABLE 1 Specific surface area calculated and determined by N2 adsorption measurements using the BET method. Sample ID SBET/m.sup.2 g.sup.−1 HSA-CPFA 45 LSA-CPFA 7

[0097] Mercury Porosimetry Measurements:

[0098] Mercury porosimetry measurements were performed to analyze the pore sizes and pore volumes not accessible through N2 adsorption measurements. In order to perform mercury porosimetry measurements the following parameters were used: [0099] Mercury surface tension: 0.48 N/m [0100] Mercury contact angle: 150° [0101] Test method: PASCAL (Pressurized by Automatic Speed-up and Continuous Adjustment Logic) [0102] Max. pressure: 400 MPa [0103] Increase speed: 6-19 MPa/min [0104] Preparation: Degassing for 130 min. (also ensured <0.03 kPa reached)

[0105] Prior to Hg intrusion, the samples were degassed under vacuum at 70° C. for 12 h.

[0106] The results of Hg porosimetry analysis are presented in FIG. 3 and summarized in the following table 2:

TABLE-US-00002 TABLE 2 Porosity data obtained by Hg intrusion Sample ID Total pore volume/cm.sup.3 g.sup.−1 Diameter pore/nm HSA-CPFA 0.57 20-60 LSA-CPFA 0.29  50-300

Elemental Analysis:

[0107] Elemental analysis of the materials was carried out using a LECO CHN-900 combustion furnace. Prior to the measurement, the samples were treated under N2 flow (2 L/min) at 90° C. for 2 h.

TABLE-US-00003 TABLE 3 Elemental analysis results of HSA-CPFA Element Nr. 1/wt. % Nr. 2/wt. % Nr. 3/wt. % Average/wt. % C 79.70 80.41 78.55 79.55 H 8.06 8.10 8.43 8.01 N 8.46 8.43 7.91 8.27

TABLE-US-00004 TABLE 4 Elements analysis results of LSA-CPFA Element Nr. 1/wt. % Nr. 2/wt. % Average/wt. % C 78.59 78.56 78.58 H 8.26 8.25 8.26 N 10.88 10.99 10.94

Adsorption Measurements:

[0108] 6 g of dry sample was filled into a cylinder with an inner diameter of 40 mm and a height of 40 mm and placed into a CO2 adsorption/desorption device, where it was exposed to a flow of 2.0 NL/min of air at 30° C. containing 450 ppmv CO2, having a relative humidity of 60% corresponding to a temperature of 30° C. for a duration of 600 min. Prior to adsorption, the sorbent bed was desorbed by heating the sorbent to 94° C. under an air flow of 2.0 NL/min. The amount of CO2 adsorbed on the sorbent was determined by integration of the signal of an infrared sensor measuring the CO2 content of the air stream leaving the cylinder. The CO2 cumulative curves are shown in FIG. 4. As we can see, LSA-CPFA sorbent presents a much higher cumulative CO2 capacity compared to HSA-CPFA.

[0109] The results of the CO2 adsorption measurements are summarized in Table 5.

TABLE-US-00005 TABLE 5 CO2 adsorption capacity for the sorbents CO.sub.2 capacity/mmol Sample ID CO.sub.2 per g of dry sorbent HSA-CPFA 1.4 LSA-CPFA 1.9

Cyclic Adsorption/Desorption Measurements:

[0110] The cyclic adsorption/desorption capacity was measured in consecutive runs at relative humidity of the ambient air larger than 70%. The desorption process was performed using a warm fluid to increase the temperature of the sorbent. In this specific example, saturated steam was employed. The sorbent bed was first adsorbed for 120 min using ambient air.

[0111] Once the adsorption was completed, the pressure of the system was brought down to 200 mbara. As soon as the pressure is reached, saturated steam is supplied to the sorbent bed up to reaching a temperature of ca 95° C. This cycle was repeated multiple times and the results for HSA-CPFA and LSA-CPFA are shown in FIG. 5.

[0112] By applying the aforementioned process and using air with RH in the range 75-99%, the desorption capacity of HSA-CPFA shows a constant decay. Within 25 cycles at high humidity it was observed a 50% decay, while the desorption capacity of LSA-CPFA shows a surprisingly stable outcome for at least 25 consecutive cycles at high relative humidity.

[0113] The sorbent material can generally also be a solid inorganic non-polymeric support material functionalized on the surface with amino functionalities capable of reversibly binding carbon dioxide, with a specific BET surface area, in the range of 1-20 m2/g.

[0114] Silica (SiO2), alumina (Al2O3), silica-alumina (SiO2-Al2O3), titania (TiO2), magnesia (MgO), clays, mixtures of the above are possible.

[0115] As for the organic polymeric materials, preferably for these organic or organic, non-polymeric support materials the total pore volume, measured by mercury intrusion, is in the range of 0.05-0-50 cm3/g and/or the pore diameter distribution, measured by mercury intrusion, is such that 90%, preferably 95% of the pore volume it is in the range of 50-300 nm.

[0116] For the case of silica microspheres having these porosity characteristics, they can be produced using the following scheme:

[0117] Monodisperse colloidal SiO2 was prepared by the seeded growth method. The seeds, commercially available Ludox AS-40 silica sol particles, were added to a mixture of ammonia (2 mol/L), deionised water (6 mol/L), and ethanol to form a suspension. Tetraethylorthosilicate (TEOS, 2.2 mol/L) was added to the mixture under stirring at a controlled speed while keeping the reaction mixture at 25° C. The monodisperse SiO2 particles were obtained by the growth of seeds. Monodisperse SiO2 microspheres with diameters of 500 nm were obtained and then calcined at 700° C. for 2 h, and followed by a hydrothermally treatment at 220° C. for 5 h to recover the surface silanol groups which were lost during the calcination.

[0118] The resulting silica material has a specific surface area of 10 m2/g, a median pore diameter of 95 nm, a total pore volume determined by Hg intrusion porosimetry of 0.23 cm3/g, and an average particle size of 500 μm.

[0119] For the case of alumina microspheres having these porosity characteristics, they are commercially available, for example, from Saint Gobain Nor Pro—catalyst carriers. Alpha-alumina not having surface hydroxyl groups can be used for modification by impregnation.

[0120] For the case of titania microspheres having these porosity characteristics, they are commercially available from Saint Gobain Nor Pro—catalyst carriers. Rutile titania not having surface hydroxyl groups can be used for modification by impregnation.

[0121] A method to prepare macroporous (anatase) TiO2 via hard templating with polystyrene microspheres is as follows:

[0122] 290 nm polystyrene microspheres were obtained by first washing the styrene monomer with m1 of NaOH solution and distilled water for four times each until the pH value of styrene was neutral. Next, 160 m1 of distilled water and 6 m1 of washed styrene were introduced in a 250 m1 three-necked flask, and nitrogen was bubbled for 15 min to remove the oxygen in the system. Then the solution was heated to 70° C., and 10 m1 of K2S2O8 (0.007 g/mL) was added to the above solution. Under a nitrogen atmosphere, the reaction was continued for 28 h with vigorous magnetic stirring. A colloidal solution of polystyrene microspheres was obtained, followed by centrifuging and washing with deionized water and ethanol for three times. Finally, white powder PS microspheres were obtained after drying in air at 30° C. The macroporous titania is obtained by dissolving Ti(OC4H9)4 in anhydrous ethanol while stirring at 45° C. After that, deionized water and acetylacetone were added to the ethanol for a hydrolysis polycondensation reaction. 290 nm polystyrene microspheres were added to the solution. In this case, the molar ratio of the composition of the TiO2 sol was 1:25:2:1:0.2 of Ti(OC4H9)4:ethanol:H2O:acetylacetone:polystyrene microspheres. The resulting homogeneous composite sol was further stirred for 2 h at room temperature and aged for about 48 h, before calcination under pure oxygen at 500° C. for 3 hours. The final macroporous (anatase) titania has an average pore diameter (determined by Hg intrusion porosimetry) of 260 nm, a specific surface area of 42 m2/g and a pore volume (determined by Hg intrusion porosimetry) of 0.28 cm3/g.

[0123] For the case of clay having these porosity characteristics, they can be produced using the following scheme:

[0124] 290 nm polystyrene microspheres are used as hard template for the preparation of macroporous clay particles. 3 g of polystyrene microspheres were added to 50 mL and sonicated for 10 min, then 6 g of kaolin powder was added and the solution further sonicated for 30 min. Then the solution was left to settle for 4 h before it was poured on a tray and dried for 24 h at 50° C., followed by calcination under pure oxygen at 600° C. for 5 hours. The final macroporous clay particles have an average pore diameter (determined by Hg) of 260 nm, a specific surface area of 20 m2/g and a pore volume (determined by Hg) of 0.2 cm3/g. Clays can be surface modified by impregnation.

[0125] Surface functionalisation of the solid inorganic or organic, non-polymeric or polymeric support material as defined above can generally be obtained by impregnation, or grafting.

[0126] Possible procedures are as follows:

[0127] Impregnation of solid inorganic or organic, non-polymeric or polymeric support material particles with amino-polymer:

[0128] For the preparation of 60 g of a sorbent with 20 wt. % low molecular weight polyethylenimine (PE1800, Mw=800, or PE12000, Mw=2000) loading on a support (e.g. silica or alumina or titania), to an aqueous mixture of 12 g of PE1800 or PE12000, 48 g of support are added and the suspension is stirred at 25° C. at 30 rpm for 3 h. After impregnation, the excess liquid is removed using a rotary evaporator set at 150 mbar and 50° C.

Grafting of an Amino-Polymer onto Silica Particles:

[0129] In a typical functionalization process, the silica particles are first dried for 12 h at 120° C. under vacuum. 2 g of dried silica are stirred with 200 mL of toluene for 3 hours, and then 1 g of 3-aminopropyltrimethoxysilane (APS) is added to the solution and stirred for 24 hours. The resulting material is then filtered, washed with 200 mL toluene, and dried for 12 h at 90° C. under vacuum at a pressure of ca. 100 mbar.

[0130] Specific example for an inorganic support material impregnated with an amino-polymer:

[0131] In this example section, two commercially available alumina supports have been impregnated with an amino-polymer according to the method detailed above. Those samples have been analyzed and compared: one with high surface area, having a BET surface area >25 m2/g, which is herein after referred to high surface area sorbent (HSA-ISAP, which stands for high-surface area inorganic supported amine polymer); and the second one with low surface area, <25 m2/g which is herein after referred to as low surface area sorbent (LSA-ISAP which stands for low-surface area inorganic supported amine polymer).

[0132] Results for the specific surface area measurements, with the measurement conditions as detailed above, are given in the below table 6:

TABLE-US-00006 TABLE 6 Specific surface area calculated and determined by N2 adsorption measurements using the BET method. Sample ID SBET/m.sup.2 g.sup.−1 HSA-ISAP 82 LSA-ISAP 10

[0133] The results of Hg porosimetry analysis, with the measurement conditions as detailed above, are summarized in the table 7: t,?

Table 7: Porosity data obtained by Hg intrusion

[0134] The results of the CO2 adsorption measurements, with the measurement conditions as detailed above, are summarized in Table 8. The CO2 cumulative curves are shown in FIG. 6.

TABLE-US-00007 TABLE 8 CO2 adsorption capacity for the sorbents taken after 600 min of adsorption. CO.sub.2 capacity/mmol Sample ID CO.sub.2 per g of dry sorbent HSA-ISAP 0.6 LSA-ISAP 0.8

TABLE-US-00008 LIST OF REFERENCE SIGNS 1 ambient air, ambient air inflow structure 2 outflow of ambient air behind adsorption unit in adsorption flow-through mode 3 sorbent material 4 steam, steam inflow structure for desorption 5 reactor outlet for extraction 6 vacuum unit/separator 7 wall 8 reactor unit