[0001] The invention relates to a device and method for ca ptu ring a nd

concentrating of C0 ₂ from gaseous streams.

[0002] US 2001/0022955 describes a reactor having active regenerable packing for treati ng gas, incl uding also capturi ng of C0 ₂ , said reactor packing com prises at least one bed of active pa rticles, especial ly of adsorbent, said bed bei ng a nnular, wherein gas is treated in a cycle which comprises at least one treatment phase, i n the course of which a gas to be treated is caused to circulate th rough the packaging, and at least one phase for regenerating the packing, for exam ple by a TSA process (Temperatu re Swi ng Adsorption or modulated tem perature

adsorption) or a PSA process (Pressu re Swi ng Adsorption or modulated pressu re adsorption).

[0003] The regeneration (i n the desorption mode) is done by entering

regeneration gas i nto the central space, passing th rough the bed in a genera lly radial and centrifugal ma nner, thus arriving into outer space from which it is evacuated into the atmosphere. Regeneration comprises a phase of flushing with a dry a nd decarbonated regeneration gas. The adsorption /desorption cycles are done by switching flow of one reactor from one mode to a nother mode or by using 2 u nits with one in adsorption mode and another in desorption mode.

[0004] WO 2017/053062 descri bes apparatuses, systems, and methods for performi ng two stage separation of C0 ₂ from a gaseous stream. The fi rst and second stage adsorbent ca n be a rranged radially about a centra l axis

concentrical ly for space and efficiency considerations. The first stage adsorbent being steam sensitive a nd a second stage adsorbent being stea m insensitive. The method comprising a fi rst C0 ₂ adsorption; desorbing C0 ₂ from the fi rst stage adsorbent forming a fi rst C0 ₂ -rich strea m and contacting the first C0 ₂ -rich stream with a second stage stea m i nsensitive adsorbent such that C0 ₂ is adsorbed in the second stage adsorbent and a second C0 ₂ -lean stream is formed; and desorbing C0 ₂ from the second stage adsorbent thereby formi ng a second C0 ₂ rich stream wherein the second C0 ₂ rich stream has a higher C0 ₂ concentration by mol. % than the first C0 ₂ -rich strea m. Desorption can be done by a temperature swi ng process using hot purge gas, for exa mple nitrogen. [0005] There is a need for a cost-effective process and device to capture and concentrate C0 ₂ from gaseous streams such as combustion gas, flue gas, tail gas or air, preferably air.

[0006] According to the invention this has been achieved by providing a device for the capturing and concentration of C0 ₂ comprising a vessel C comprising one or more tubular, ring shaped compartments B comprising a space between an inner and an outer circle containing a solid sorbent capable of capturing C0 ₂ from a gaseous stream, wherein in an adsorption mode the gaseous stream is introduced in the inner space A of the compartment B and flows through the compartment B, and wherein in a desorption mode a desorption stream is introduced directly into the space between the inner and outer circle of the compartment B and an insert D is used in the inner space A to prevent gasses flowing through the inner circle of compartment B.

[0007] It has been found that, when dealing with large flows of gasses, especially in the case of air, it is of great importance to minimise the pressure drop and optimize the mass transfer at relatively high gas velocities and that therefore mass transfer in solid-gas systems is superior to liquid gas systems where the mass transfer efficiency is significantly lower, often because of the formation of gas bubbles. Therefore, for this invention a solid sorbent is utilized in a solid-gas contacting device.

[0008] It is an import advantage that in the device of the invention gaseous streams can be contacted with a solid sorbent at relatively high gas velocities while ensuring a low pressure drop and a good gas-solid mass transfer. Further advantages are a lower energy consumption and improved separation efficiency of C0 ₂ from air and faster adsorption/desorption cycles. Higher gas velocities allow a lower surface area, so hence a reduced footprint and cost of the equipment.

[0009] The adsorbent becomes saturated and needs to be regenerated after some adsorption time by a desorption step. Regeneration comprises flushing the adsorbent with a regeneration gas (the desorption gas stream) that will take up the C0 ₂ from the sorbent. In desorption mode preferably the temperature and humidity are increased, pressure is reduced, and steam is injected, preferably in a down flow, to desorb C0 ₂ from the solid sorbent in compartment B. [0010] In the prior art methods and devices, the regeneration in the desorption mode is done by entering regeneration gas into the central space passing through the sorbent in a generally radial and centrifugal manner, arriving into the outer space of the vessel and by consequence, the C0 ₂ in the desorption gas stream will be less concentrated. The same applies if the adsorption /desorption cycles are done by switching flow of one reactor from one mode to another mode or by using 2 units with one in adsorption mode and another in desorption mode.

[0011] In the device of the invention a higher efficiency and higher concentration of C0 ₂ in the desorption stream can be achieved as in a desorption mode a desorption stream is introduced directly into the space between the inner and outer circle of the compartment B and an insert D is used in the inner space A to prevent gasses flowing through the inner circle of compartment B. The device is more compact, more efficient and cost effective.

[0012] The invention is further described by reference to the drawings in Figure 1 to 5.

[0013] A gaseous stream containing C0 ₂ [ see Figure 1, inlet Gj is introduced in the inner circle of the compartment for adsorption [depicted as A, Figure 1] and flows through the ring-shaped compartment filled with a C0 ₂ sorbent [Figure 1, B] to the outer ring [Figure 1, C]. Where gaseous stream with depleted C0 ₂ level exits the compartment on the outer circle of the ring [Figure 1, Gj.

[0014] Diameter of the inner space [defined as D _a in Figure 1] is preferably at least 2 times thickness of the ring [defined as D _b in Figure 1].

[0015] When desorbing, steam is introduced via the inlet S _: [Figure 3] during which step C0 ₂ is desorbed and together with steam exits the ring [defined as S ₀ + C0 ₂ , Figure 3].

[0016] During desorption step an insert [see D, Figure 3] is introduced in the inner space A to reduce the volume of the inner space. Simultaneously a jacket [see J, Figure 3] is placed at the outer edge of the sorbent containing

compartment to prevent cross sectional flow. Steam is introduced in compartment B directly by means of inlet Si and evacuated in the opposite side of the ring So. [0017] In the embodiment of Figure 3, a part of the ring-shaped compartment (B) that is not covered by the insert (D) forms a C0 ₂ adsorption section, and a part of the ring-shaped compartment (B) that is covered by the insert (D) and preferably also Jacket (J) forms a C0 ₂ desorption section. The desorption gas stream is introduced into the desorption section of the ring-shaped compartment (B), preferably in a top down flow mode and exiting at the bottom of the C0 ₂ desorption section. In this embodiment adsorption and desorption steps can be done in the same compartment B and simultaneous. The insert and jacket can be rotated radially over the compartment B to move the desorption section (arrow in Figure 3).

[0018] One or more adsorption compartments B can be placed in one vessel C to minimise the cost of the installation [see Figure 4].

[0019] Figure 5a illustrates the device during adsorption mode wherein the expandable insert D, preferably a balloon, is contracted in the centre of the inner space A and the outer expandable Jacket J is extended against the outer wall of vessel C leaving an open space for the gas flow to move through the compartment B. Herein it is preferred that the outer pressure PI is atmospheric (1 bar) and pressure P2 in Vessel C is higher than PI such that the outer expandable jacket J is expanded away from the outer circle of compartment B is and the pressure P3 in the inner space A enclosed by compartment B is higher than P2 such that the gaseous stream flows through the compartment B and expandable insert D is shrunk away from the inner circle of compartment B. It is noted that in Figures 5 a - c the pressure Pd inside flexible insert D is indicated to be PI. That is preferred but not necessary as long as Pd has the same relation towards P2, P3 and P4 as PI. So in adsorption mode Pd is lower than P3 and in desorption mode Pd is higher than P3 or P4.

[0020] Figure 5b illustrates the device during adsorption mode wherein the air is evacuated from the system through output So, while the air input and output are closed leading to a vacuum in the system (P2 and P3 lower than PI). This vacuum will cause a difference in pressure between the in- and outside of the expandable insert D and jacket J causing expandable insert D to expand and press against the inner circle of compartment B and the outer expandable jacket J to shrink around the outer circle of the compartment B. [0021] Fig 5c illustrates the inflated expandable insert D occupying the dead space in the inner space A of compartment B, and the expandable jacket J pressed against the outer circle of the compartment, thus effectively isolating the sorbent bed to be desorbed by vacuum steam stripping at low pressure P4.

[0022] After desorption the releasing of the vacuum will relax the expandable insert D and jacket J back into the starting position illustrated in Figure 5a for operation in adsorption mode. The adsorption-desorption cycle can be very easily switched in this way.

[0023] The compartment B can be a cylindrical double wall compartment wherein the walls have perforations to permit air to flow through and containing solid adsorbent between the inner and outer circular walls. The compartment B can also be a porous solid compartment, preferably a honeycomb, or one or more porous carpets or fabrics comprising sorbent capable of capturing C0 ₂ from the gaseous stream. With gas flow through the inner or outer circle of the

compartment B, it is meant to indicate the direction of the gas flow in cross- sectional view (Figure 2). This is also meant to include the gasses flowing through the inner and outer surface of the compartment B (as in Figure 1), i.e. through the inner and outer walls of a double walled compartment or through the inner and outer surface of a porous solid compartment, carpet or fabric.

[0024] In the device the following process steps are preferably performed:

1 the gaseous stream, preferably air, is flowing through the

compartment B from inside space A out during the adsorption of C0 ₂

2 temperature and humidity are increased, pressure is reduced, and steam is injected preferably in a down flow, to desorb C0 ₂ from the solid sorbent in compartment B,

3 temperature and humidity from Step 2 are decreased where after Step 1 commences.

[0025] In the device, in desorption mode, the desorption gas stream coming from the compartment B, preferably in down flow, can be vented from the vessel C wherein the compartment B is placed. Preferably, in desorption mode the desorption gas stream, preferably steam, is introduced directly in compartment B, preferably in down flow, by means of an inlet Si and evacuated at the opposite side So of the compartment B. [0026] To anticipate and prevent condensation of steam on the sorbent, this process might require a preheating step which can be done by means of electrical heating. The insert D optionally in combination with the jacket J can be used for heating and/or cooling the compartment B to avoid steam condensation. For the same reason the process may require reduced pressure, resulting in the fact that materials and construction are chosen accordingly.

[0027] The device can be operated in a fractional desorption mode, separating the desorbed fractions according to their purity. For example, when C0 ₂ concentration is low at the start of the desorption, a fraction of the desorption stream comprising desorbed C0 ₂ at the start is collected separately from the later higher C0 ₂ content stream.

[0028] Suitable sorbents are described in the prior art Dl and D2 described above. Suitable sorbents and methods for adsorption/desorption processes of C0 ₂ that can be used in this invention are described in WO2014012963,

WO2014012966, WO2015071443, WO2015082567, WO2016050944 and

WO2017148782 from ANTECY B.V. Preferably the sorbent is a non-amine material, for instance a potassium carbonate.

[0029] It is preferred that the insert D also reduces the volume of the inner space A, preferably for at least 25, 50 or 75 %. This drives out air in the inner space A and reduces leaking of air into the desorption gas stream and thus reduces dilution of the C0 ₂ therein.

[0030] In a preferred embodiment of the device according to the invention a jacket J is used opposite to the insert D at the outer circle of the compartment B, to also prevent cross sectional flow through the outer circle of the compartment B. As a desorption stream Si is introduced directly into the space between the inner and outer circle of the compartment B, the desorption stream is forced to flow between the insert D and jacket J resulting in higher concentration (less dilution) of C0 ₂ in the desorption stream So.

[0031] As described below in more detail insert D and jacket J can be a metal or polymeric material shaped to fit the inner or outer circle of the compartment B, but can also be a flexible material, for example a flexible expandable insert, for example a balloon type of insert, or a flexible flap that can cover part or all of the surface of the inner or outer circle of compartment B. The flexible flap can be pressed against at least part of the inner or outer circle of the compartment B either by vacuum suction or by gas flow pressure or a combination thereof. The flexible expandable insert, preferably a balloon can be inflated and deflated.

[0032] In a particularly preferred embodiment of the device according to the invention insert D prevents gasses flowing through part of the inner circle of compartment B, preferably a part having a radial size between 10 and 280°, preferably between 150 and 210°, more preferably about 180 ⁰ (as in Figure 3), wherein insert D creates a desorption zone where it covers the inner circle of compartment B and an adsorption zone where it does not cover the inner circle of compartment B. The insert D and jacket J can together form a double walled cylinder section with a radial size between 10 and 280°, preferably between 150 and 210°, more preferably about 180°.

[0033] The insert D, preferably together with jacket J, can be rotated around a central longitudinal axis to radially move over compartment B, thus creating a continuously movable desorption and adsorption zone within one compartment B. The insert D and the outer jacket J can rotate simultaneously to facilitate continuous process.

[0034] Preferably a nitrogen cushion is applied between the adsorption section and the desorption section of compartment B to purge residual gasses from the sorbent material and prevent dilution with air from inner space A. This nitrogen cushion can be applied by injecting nitrogen gas into the compartment B from the edges of the insert D and/or jacket J, for example from a perforated tube or slit positioned along the edge of insert D and/or jacket J (see dots on edge of jacket in Figure 3).

[0035] In another embodiment, the insert D prevents gasses to flow through the entire inner circle of compartment B and preferably also having a jacket J at the outer circle of the compartment B to prevent gasses to flow through the entire outer circle of compartment B. The insert D and jacket J together form a double walled cylinder wherein the walls are spaced to enclose compartment B, which double walled cylinder is placed over the compartment B in desorption mode. [0036] In another embodiment, insert D is an expandable insert, preferably a balloon, which in desorption mode can expand towards the inner circle of compartment B to prevent gasses flowing through the inner circle of compartment B and which in adsorption mode shrinks back to allow gasses to flow through the inner circle of compartment B.

[0037] The device according to the invention preferably comprises a pressure control unit operating the device

a) in adsorption mode to provide pressure P3 in the inner space A and higher than pressure P2 which is the pressure in a space outside compartment B wherein P2 and P3 are higher than atmospheric pressure PI and the pressure Pd inside the expandable insert D, wherein Pd is preferably about equal to PI, such that the insert D is shrunk and the gaseous stream flows from the inner space A through the compartment B and

b) in desorption mode to provide low pressure P3 and P2 both lower than PI and Pd such that the such that the insert D is expanded to prevent gasses flowing through the inner circle of compartment B and

c) providing pressure P4 lower than Pd and PI, to desorb C0 ₂ from the sorbent in compartment B, optionally while supplying steam and preferably in down flow mode,

d) repeating steps a) to c).

[0038] The device preferably also comprises a jacket J in the form of an expandable jacket, preferably a balloon, that in adsorption mode expands away from the outer circle of compartment B to allow gasses to flow through

compartment B and that in desorption mode shrinks towards the outer circle of compartment B to prevent gasses to flow through compartment B.

[0039] In the above embodiment the device comprises a pressure control unit operating the device

a) in adsorption mode to provide pressure P3 in the inner space A and higher than pressure P2 which is the pressure in a space outside compartment B and inside jacket J and wherein P2 and P3 are higher than atmospheric pressure PI and the pressure Pd in the expandable insert D, wherein Pd is preferably about equal to PI, such that the insert D is shrunk, jacket J is expanded and the gaseous stream flows from the inner space A through the compartment B and b) in desorption mode to provide low pressure P3 and P2 both lower than PI and Pd such that the such that the insert D is expanded, and that jacket J is shrunk to prevent gasses flowing through the inner and outer circle of compartment B and

c) providing pressure P4 lower than PI and Pd, to desorb C0 ₂ from the sorbent in compartment B, optionally while supplying steam and preferably in down flow mode,

d) repeating steps 1 to 3.

[0040] The invention also relates to a process for the effective capturing and concentration of C0 ₂ using a device according to anyone of the embodiments herein described, wherein preferably the adsorption and desorption process is operated in a continuous mode.

[0041] The invention is further described in the following embodiments 1 to 15:

1. A device for the effective capturing and concentration of C0 ₂ comprising a tubular, ring shaped compartment containing a solid sorbent capable of capturing C0 ₂ from a gaseous stream.

2. The device from embodiment 1 wherein a gaseous stream is introduced in the inner part of the compartment and flows through the compartment.

3. The device from embodiments 1 and 2 wherein one or more C0 ₂ adsorbing compartments are placed inside one vessel.

4. The device from embodiments 1 to 3 wherein gaseous streams coming from the compartment are vented from the vessel wherein the compartment is placed.

5. The device from embodiment 1 wherein the compartment is a porous solid carpet capable of capturing C0 ₂ from the gaseous stream.

6. The device from embodiments 1 to 5 where the gaseous stream is air.

7. The device from embodiments 1 to 3 in which the following process is performed:

Step 1) gas is flowing through the compartment from inside out during the adsorption of C0 ₂ .

Step 2) temperature and humidity are increased, pressure is reduced, and steam is injected to desorb C0 ₂ .

Step 3) temperature and humidity from Step 2 are decreased where after Step 1 commences.

8. The device from embodiments 1 to 7 wherein desorption is performed in a down flow. 9. The device from embodiments 1 to 7 wherein desorption stream is introduced directly into the space between inner and outer circle of the ring- shaped compartment.

10. The device from embodiment 7 wherein during the desorption step an insert is used to prevent gasses flowing through the inner circle and to drive out residual gases and to reduce the dead space.

10a The device from Embodiment 7 wherein the insert can be heated to enable desorption.

11. The device from Embodiments 7 to 9 wherein the insert can be rotated.

11a The device from Embodiment 7 to 9 wherein the device rotates around the insert.

12. The device from embodiments 1-11 in which the process takes place in a fractional desorption mode, separating the desorbed fractions according to their purity.

13. The device from embodiments 1-12 in which a nitrogen cushion is applied between the C0 ₂ adsorption section (from air) and the desorption section to purge residual gasses from the sorbent material.

14. The device from embodiments 1-13 in which the sorbent is a non-amine material, for instance a potassium carbonate.

15. The device from embodiments 1-14 in which the adsorption/desorption process is operated in a continuous mode.