Adsorption device for adsorbing CO2, elemental analyzer, and method for removing CO2 from fluid flow

Abstract

To provide: an adsorption device for removing CO2 from a sample gas of an elemental analysis device, the adsorption device capable of effectively and efficiently regenerating an adsorbent material; an elemental analysis device comprising the adsorption device; and a method for removing CO2 from a gas stream.SOLUTION: A CO2 adsorption device 1 for use in an elemental analysis device includes: a filter 11 having an inlet 111 for a fluid, an outlet 112 for the fluid, and an adsorbent material through which the fluid can flow; and a heating device 12 for heating the adsorbent material. In the CO2 adsorption device, the heating device extends along a longitudinal axis X, and the filter is arranged coaxially with the longitudinal axis and at least partially radially surrounds the heating device. In addition, an elemental analysis device includes: a combustion reactor for burning a sample; an optional reduction reactor; an optional water separator; and a detector.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an adsorption device for adsorbing CO2, an elemental analyzer equipped with the adsorption device, and a method for removing CO2 from a fluid flow, particularly a gas flow.

Background Art

[0002] The present invention relates to the field of elemental analyzers. Elemental analyzers are used to measure the content of specific chemical elements in a sample. Such devices are used, for example, to measure the nitrogen content in organic samples, particularly food samples. The nitrogen content can be used, for example, to draw conclusions regarding the protein content of a food sample.

[0003] In the elemental analysis of an organic sample, first the organic sample is decomposed into elemental gas components by combustion. Thereby, combustion gases of different compositions of combinations of gas substances are generated depending on the sample. The main gases are COx, water vapor, elemental nitrogen, and nitrogen oxides. In order to decompose the combination of COx and NOx and react them into a more manageable combination, the combustion gas (also called the sample gas) is first passed through a catalyst and then, as a second step, usually through a reduction reactor. Thereafter, water is usually removed from the flow of the sample gas by one or more water traps. In a further step, CO2 is removed from the sample gas flow by an adsorption device that adsorbs CO2. The sample gas flow thus obtained essentially contains only elemental nitrogen, and its concentration in the sample gas flow can be measured in a final step by a detector, usually a thermal conductivity detector.

[0004] Known adsorption devices contain an adsorbent that binds CO2 from the sample gas stream. For example, natural and synthetic zeolites, also known as molecular sieves, are used as adsorbents. CO2 binds to the surface of the adsorbent at room temperature. Once the adsorbent is completely saturated with CO2, it needs to be regenerated before it can be used again. Regeneration is achieved by heating the adsorbent, preferably to a temperature of 220 °C or higher. At high temperatures, the adsorbent releases the bound CO2. To completely remove the CO2, a purge gas stream is also passed through the adsorbent. After regeneration, the adsorbent is cooled and can be reloaded.

[0005] Patent specification EP2013615B1 discloses a CO2 adsorption device comprising a filter made of an adsorbent and a heating device for heating the adsorbent. The filter is formed by a U-shaped tube with the adsorbent disposed inside. The heating device consists of heating wires spirally wound around the outside of the U-shaped tube. Thus, the adsorbent can be externally heated by the heating device for regeneration. The adsorption device further comprises a valve device by which the sample gas stream and the purge gas stream can be alternately passed through the filter, and the purge gas stream is passed through the filter in a direction opposite to that of the sample gas stream.

[0006] Object of the Invention The object of the present invention is to provide an improved adsorption device for adsorbing CO2, in particular an adsorption device in which the regeneration of the adsorbent is carried out more effectively and efficiently. Thereby, the bound CO2 can be flushed out of the adsorbent as completely as possible with a minimum of energy and time. Furthermore, the adsorption device needs to enable complete adsorption of CO2 from the sample gas stream. Finally, it is desirable that the adsorption device is simple and inexpensive to manufacture and maintain.

[0007] Detailed Description of the Invention To solve this problem, the present invention discloses an adsorption device for adsorbing CO2 used in an elemental analyzer, an elemental analyzer, and a method for removing CO2 from a fluid stream.

[0008] Adsorption Device The CO2 adsorption device used in the elemental analyzer according to the present invention includes a filter having a fluid inlet, a fluid outlet, and an adsorbent through which the fluid can pass, and a heating device for heating the adsorbent. This adsorption device is characterized in that the heating device extends along the longitudinal axis, the filter is arranged coaxially with the longitudinal axis, and at least partially surrounds the heating device in the radial direction.

[0009] As a result of the filter, and thus the adsorbent present in the filter, at least partially surrounding the heating device in the radial direction, the heat released radially outward by the heating device, and thus the heating power, is utilized better. This results in a difference between the adsorption device according to the present invention and the adsorption device disclosed in EP2013615B1, where the heating device is arranged outside the filter in the radial direction and the heat released radially outward cannot be used for heating the adsorbent.

[0010] Also, the adsorption device according to the present invention achieves a highly homogeneous heat distribution within the adsorbent. This improves the regeneration performance. In the adsorption device according to the present invention, the regeneration of the adsorbent is performed quickly and completely.

[0011] The design of the adsorption device according to the present invention also facilitates the assembly and maintenance of the heating device and the filter. For example, the heating device can be inserted into a corresponding axial receptacle of the filter and thus separated from the filter again. On the other hand, in the adsorption device according to EP2013615B1, since the heating device is composed of a heating wire spirally wound around a U-shaped tube, a great deal of effort is required to separate the heating device from the filter.

[0012] The terms "inlet" and "outlet" are each used to represent an opening of the filter through which the fluid can flow into and out of the filter. In this specification, unless otherwise explicitly stated, these terms do not imply any restrictions regarding the direction of the flow. Thus, during the operation of the adsorption device, it is also possible to direct the fluid from the opening designated as the "outlet" to the opening designated as the "inlet", and vice versa.

[0013] The filter at least partially surrounds the heater radially, where the radial direction is defined with respect to the longitudinal axis. It is not essential for the filter to completely cover the radial surface of the heater, and it is also possible for the filter to leave a gap, for example, through which air can circulate between the outer radial side of the filter and the radial surface of the heater.

[0014] The filter can at least partially or completely surround the heating device radially. Preferably, the filter covers an angular range of at least 45°, more preferably at least 90°, even more preferably at least 180° in a projection plane perpendicular to the longitudinal axis. Here, the projection plane is considered, that is, the cross-section of the filter is projected onto a plane perpendicular to the longitudinal axis to determine the degree of radial enclosure. Most preferably, the filter covers an angular range of 360°, that is, completely surrounds the heater.

[0015] The heating device preferably extends along a straight longitudinal axis and is, for example, rod-shaped. In this case, the straight longitudinal axis is also the longitudinal axis of the heating device. This embodiment has the advantage that a rod-shaped longitudinal axis can be easily inserted into and withdrawn from a corresponding receptacle in the filter.

[0016] In one embodiment, the filter forms a receptacle extending along the longitudinal axis, and the heating device extends along a straight longitudinal axis and is configured to be removably insertable into the receptacle.

[0017] However, it is also possible for the heating device to have the shape of a curved rod. For example, the heater may be U-shaped. Such a curved rod has a curved longitudinal axis. In this case, the longitudinal axis along which the heater extends is curved, and the shape of the filter follows the curvature of the longitudinal axis.

[0018] In one embodiment, the filter is arranged spirally around the heating device along the longitudinal direction. The spiral filter surrounds the axial cavity in which the heating device is arranged. In this embodiment, the filter completely surrounds the heating device in the radial direction. In this embodiment, there is a gap between the turns of the spiral filter, and air can circulate through this gap between the outer radial side of the filter and the surface of the heating device. Thereby, the surface area of the filter available for heat exchange can be increased in proportion to the amount of adsorbent used. Thereby, the absorption of heat released from the heating device is promoted, and a uniform temperature distribution within the adsorbent becomes possible. Further, in this embodiment, the cooling of the adsorbent after regeneration can be performed more rapidly.

[0019] In this embodiment, the filter is preferably in the form of a spiral tube, and an inlet and an outlet are arranged at its ends. Preferably, the inlet and the outlet are arranged at the opposite ends with respect to the longitudinal axis of the filter in this way.

[0020] The tube is a container for holding the adsorbent. The tube can be made of, for example, glass, stainless steel or plastic, and glass is the most preferred material. In the case of plastic, it is necessary to select a heat-resistant material or pay attention to appropriately lowering the temperature for the regeneration of the adsorbent. The spiral tube is filled with the adsorbent to such an extent that the adsorbent can be heated by the heater, but it is not necessary to completely fill it with the adsorbent. In the case of a curved heater, for example, a U-shaped bar heater, the spiral filter is also curved and follows the curvature of the heater.

[0021] The diameter of the tube is preferably from 5 mm to 50 mm, particularly preferably from 6 mm to 15 mm. With this diameter, an optimal heat distribution is achieved within the adsorbent.

[0022] Preferably, the heating device in this embodiment is rod-shaped such that the longitudinal axis is a straight line. In this way, it becomes possible to insert the heating device into the axial cavity of the spiral filter. This facilitates the assembly of the entire adsorption device. The adsorption device can be easily disassembled by a corresponding method, and in this case, the heating device is simply pulled out from the spiral filter. This facilitates the maintenance of the entire adsorption device.

[0023] In another embodiment, the filter comprises a first chamber, and the adsorbent is disposed within the first chamber. In this embodiment, the first chamber surrounds a cavity extending along the longitudinal axis. The heating device is disposed within the cavity. In this embodiment, the filter completely surrounds the heating device in the radial direction.

[0024] In this embodiment, it is possible but not essential for the filter to completely cover the radial surface of the heating device. This means that the filter leaves no gap through which air can circulate in the radial direction. Therefore, the heat radiated in the radial direction is almost completely absorbed by the filter and can be used for heating the adsorbent. In this way, the energy efficiency of the adsorption device can be increased.

[0025] In a variant of this embodiment, the filter has only the first chamber in which the adsorbent is disposed. This chamber preferably extends along the longitudinal axis. This chamber surrounds the axial cavity in which the heating device is disposed. Preferably, in this variant, the inlet and the outlet are disposed at opposite ends of the chamber with respect to the longitudinal axis such that the fluid can flow unidirectionally through the adsorbent.

[0026] In a further modification, the filter has, in addition to the first chamber, a second chamber in fluid communication with the first chamber. The second chamber surrounds an axial cavity in which the heating device is disposed and is arranged radially between the first chamber and the cavity. Preferably, both the first chamber and the second chamber are coaxially arranged with respect to the longitudinal axis, both surround the axial cavity, the second chamber is arranged radially inside and the first chamber is arranged radially outside.

[0027] In this embodiment, the adsorbent can be arranged in either the outer first chamber, the inner second chamber, or both chambers. In a preferred embodiment, the adsorbent is arranged only in the outer first chamber.

[0028] In this embodiment, the inlet is connected to one of the two chambers and the outlet is connected to the other of the two chambers. For example, the inlet is connected to the outer first chamber and the outlet is connected to the inner second chamber, or the inlet is connected to the inner second chamber and the outlet is connected to the outer first chamber. In this case, the inlet and the outlet are preferably arranged at the same end of the filter with respect to the longitudinal axis. The fluid connection between the first chamber and the second chamber is preferably at the end of the filter opposite to the longitudinal axis. Thus, it is possible for the fluid flow to first flow through one chamber in one direction and then through the other chamber in the opposite direction.

[0029] In a preferred embodiment, the adsorbent is arranged only in the outer first chamber, and the inlet and outlet of the filter are arranged such that the fluid flow first flows through the inner second chamber and then only later through the outer first chamber. In this way, the fluid flow is first heated by the heating device in the inner second chamber close to the heating device. Then, the heated fluid flow passes through the outer first chamber and heats the adsorbent. Thus, a uniform temperature distribution is formed in the adsorbent by the fluid flow.

[0030] In a preferred embodiment of all filter variants, the adsorption device further comprises a cooling device for cooling the adsorbent. With the help of the cooling device, after regeneration, the adsorbent can be cooled to the temperature required for CO2 adsorption in a short time and brought into an operable state.

[0031] The cooling device is preferably a fan. The fan blows air in the direction of the filter so that the adsorbent in the filter is cooled. The air used for cooling is preferably at room temperature. However, the fan can also be equipped with additional cooling units, such as a water-cooling unit and a heat exchanger, so that the air used for cooling can be cooled to a temperature below room temperature. Preferably, the fan and the filter are arranged such that air is guided onto the filter in a radial direction with respect to the longitudinal axis.

[0032] The use of a fan is particularly preferred in combination with the above-described spiral filter because the air used for cooling can circulate between the turns of the spiral filter. This improves the heat exchange between the air used for cooling and the filter, and the adsorbent is cooled more quickly. This effect is particularly pronounced when the air used for cooling is directed radially towards the filter.

[0033] Preferably, the air used for cooling is guided from the fan onto the filter through a flow path. The flow path does not necessarily have to run in a straight line and can be designed such that the air used for cooling is guided around one or more corners. For example, the fan can be arranged axially above or below the filter so that the air used for cooling first exits the fan in a direction parallel to the longitudinal axis. Thereafter, the air used for cooling is deflected through the flow path and hits the filter from the radial direction.

[0034] The flow path is preferably formed by a housing that at least partially surrounds the filter and the heating device. The cooling device can be at least partially surrounded by the housing or can be arranged outside the housing. Preferably, the housing consists of a plurality of internal thin plate walls in which one or more flow paths are formed.

[0035] The heating device for heating the adsorbent is preferably an electric heating device. Using an electric heating device has the advantage that heating and cooling can be carried out quickly. This makes it possible to shorten the cycle time in the regeneration of the adsorbent.

[0036] In one embodiment, the heating device is formed by a heating wire spirally arranged around a rod-shaped base. The spiral heating wire enables uniform supply of heat to the adsorbent.

[0037] As described above, the heater may be rod-shaped such that the longitudinal axis is straight, or may be rod-shaped with a curved longitudinal axis that also curves. Therefore, the rod-shaped base may be straight or may have a curved shape. In the case of a curved rod-shaped base, the helix of the heat transfer wire also follows the curvature of the rod-shaped base. However, the use of a straight rod-shaped base is preferred.

[0038] The rod-shaped base is preferably formed from an electrically non-conductive material. It is also possible for the rod-shaped base to have at least one electrically non-conductive surface. The rod-shaped base is preferably tubular and particularly preferably formed by a mica tube.

[0039] The use of a tubular rod-shaped base has the advantage that further functional elements can be arranged within the rod-shaped base. In a preferred embodiment, a temperature sensor is arranged within the rod-shaped base and this is used to control the heating device.

[0040] In a preferred embodiment, the adsorption device comprises a first valve unit connected to the inlet. This unit enables the first fluid and the second fluid to be alternately supplied to the filter. Preferably, the valve unit consists of at least two valves. This makes it possible to supply the analysis fluid to the filter via one valve and the flushing fluid to the filter via another valve.

[0041] In a further embodiment, the adsorption device further has a second valve unit connected to the outlet and capable of alternately passing the fluid from the filter to different uses. Thereby, for example, it becomes possible to alternately direct the fluid from the filter to a downstream detector or a further outlet.

[0042] By the first and second valve units, it is possible to alternately pass the analysis fluid through the filter and then through a downstream detector, or to pass the flushing fluid through the filter and then through a further outlet. Further, for example, it is also possible to pass the flushing liquid through the detector in order to measure the amount of combined CO2.

[0043] The analysis fluid and the flushing fluid do not have to flow through the filter in the same direction. It is also possible to pass the flushing fluid through the filter in a direction opposite to that of the analysis fluid. In this case, the flushing fluid is led to the filter via the outlet of the adsorption device and led out from the filter via the inlet of the adsorption device, and the analysis fluid is led to the filter via the inlet of the adsorption device and further led to the detector via the outlet of the adsorption device. However, it is equally possible for both the analysis fluid and the flushing fluid to be introduced into the adsorption device from the inlet of the adsorption device and discharged from the adsorption device through the outlet, passing through the filter in the same direction.

[0044] In a further embodiment, the inlet and outlet of the filter each have a connecting element through which the inlet and outlet can be fluid-tightly connected to a valve or valve unit, respectively. In this embodiment, each valve or valve unit is not itself part of the adsorption device. Preferably, the two connecting elements enable a detachable connection to each valve or valve unit. In this way, the adsorption device can be connected in a simple manner to a valve unit provided outside the adsorption device. In this way, the adsorption device can be manufactured in the form of a module that can be easily incorporated into an existing elemental analysis device.

[0045] Any material that can adsorb CO2 from a fluid flow can be used as an adsorbent. Preferably, molecular sieves are used as the adsorbent. Particularly preferably, the adsorbent consists of natural or synthetic zeolite. To improve the adsorption characteristics, the adsorbent can also be coated. Preferably, the adsorbent is in the form of granules. The average particle size of the granules is preferably selected to be as small as possible to maximize the specific surface area of the adsorbent. However, too small a particle size will have an adverse effect on the service life of the adsorbent. Preferably, the particle size of the adsorbent ranges from 1 mm to 3 mm. Preferably, the measured size of the zeolite structure ranges from 8 μm to 15 μm. In this particle size range, a particularly advantageous ratio of adsorption capacity to service life is achieved.

[0046] In addition to the adsorbent for adsorbing CO2, the filter can include additional adsorbents that adsorb, in particular, water and sulfur-containing compounds, especially SO2. These are preferably arranged upstream with respect to the flow direction of the analysis fluid from the adsorbent for CO2 adsorption. By means of these additional adsorbents, impurities that lead to damage of the adsorbent for CO2 adsorption can be removed from the analysis fluid. For example, silica gel or aluminum oxide can be used to adsorb water. For the adsorption of sulfur-containing compounds, especially SO2, silica gel or activated carbon can be used, for example.

[0047] The adsorption device is preferably intended for use in an elemental analyzer, preferably an elemental analyzer for analyzing organic samples, most preferably an elemental analyzer for analyzing food samples, and most preferably an elemental analyzer for determining the nitrogen content in food samples. However, the adsorption device is also suitable for other applications where it is necessary to remove CO2 from a fluid.

[0048] The adsorption device is designed to adsorb CO2 from any fluid. The fluid may contain liquid and gaseous components. Further, the fluid may contain solid particles, such as soot particles, as long as the particle size and amount of the solid particles do not lead to an obstruction of the adsorbent. Preferably, the fluid is a gas or a gas mixture, particularly preferably a gas mixture that may contain water vapor. Particularly preferably, the fluid consists only of gaseous components.

[0049] Elemental analyzer The elemental analyzer according to the present invention comprises a combustion reactor for combusting a sample, an optional reduction reactor, an optional water separator, and a detector. The elemental analyzer is characterized in that it comprises the above-described adsorption device for adsorbing CO2, and a valve control unit for alternately guiding the analysis fluid from the combustion reactor through the adsorption device to the detector or through the adsorption device to the flushing fluid.

[0050] In a preferred embodiment, the elemental analyzer is a device for analyzing organic samples, particularly food samples. The food sample may be, for example, food consumed by humans or feed consumed by animals. Preferably, the elemental analyzer is used to measure the nitrogen content in the sample. Particularly preferably, it is an analyzer for measuring the nitrogen content in food samples.

[0051] Preferably, the reduction reactor is arranged downstream of the combustion reactor and upstream of the adsorption device. Preferably, a copper reactor is used as the reduction reactor, and copper functions as a catalyst for the reduction reaction. Optionally, another catalyst arranged in or upstream of the reduction reactor may also be used. By means of the reduction reactor, nitrogen oxides in the analysis fluid generated in the combustion reactor are reduced to elemental nitrogen.

[0052] The optional water separator is arranged downstream of the combustion reactor and, if present, preferably downstream of the reduction reactor. The water separator is arranged upstream of the adsorption device. The water separator is used to remove the water present in the analysis fluid from the analysis fluid.

[0053] The elemental analyzer includes at least one of the adsorption devices described above. Preferably, the elemental analyzer consists of two or more adsorption devices, more preferably two to twelve adsorption devices, and most preferably four to eight adsorption devices. In a particularly preferred embodiment, the elemental analyzer consists of six adsorption devices. With a plurality of adsorption devices, it is possible to shorten the cycle time of the elemental analyzer. For example, first, a first sample can be burned, and the resulting analysis solution can be passed through the first adsorption device. Then, a second sample can be burned, and the resulting analysis fluid can be passed through the second adsorption device, and during that time, the first adsorption device can be regenerated.

[0054] The elemental analyzer includes a valve control unit that can alternately guide the analysis fluid and the flushing fluid formed in the combustion reactor to the adsorption device. Preferably, the valve control unit can alternate between a plurality of operating states. For example, in the first operating state, the valve control unit guides the analysis fluid from the combustion reactor through the adsorption device to the detector. In the second operating state, the valve control unit passes, for example, the flushing fluid through the adsorption device and guides it to the outlet of the flushing fluid. Preferably, the flushing fluid does not pass through the detector. In the third operating state, for example, the inlet and outlet of the adsorption device are closed, and the fluid communication between the adsorption device and the remaining functional units of the elemental analyzer is blocked.

[0055] In one embodiment, the flushing liquid can also pass through the detector or another detector to detect CO2 or carbon. In this way, the amount of combined CO2 or carbon can be measured, and conclusions regarding the carbon content in the analysis fluid and the sample can be drawn.

[0056] In one embodiment, the elemental analyzer includes at least two adsorption devices, and the valve control unit is configured to pass the analysis fluid in parallel over two or more adsorption devices. In this way, it is possible to double the adsorption capacity.

[0057] In a further embodiment, when there are a plurality of adsorption devices, the valve control unit is configured such that the analysis fluid of similar samples always passes over the same adsorption device. In this way, it is possible to minimize or completely eliminate systematic measurement errors that may occur due to individual differences between the adsorption devices. Preferably, for this purpose, the valve control unit comprises an electronic storage device that stores identification data of the sample and the adsorption device. Therefore, based on the identification data of the sample, it is possible to assign the sample to a specific adsorption device.

[0058] Preferably, the elemental analyzer comprises a control unit that controls the valve control unit and the heating device of the adsorption device. Preferably, the control unit also controls a cooling device, if any, that cools the adsorbent of the adsorption device. In this way, the valve control unit is preferably connected to the heating device such that the heating device operates only when the analysis fluid does not pass through the adsorption device. Further, the valve control unit is preferably connected to a cooling device (if any) that cools the adsorbent such that the cooling device operates only after the flushing fluid has been passed through the adsorption device.

[0059] The elemental analyzer comprises a detector that detects at least one component of the analysis fluid. Preferably, it is a detector that detects the gaseous components of the analysis fluid. Particularly preferably, it is a detector that detects elemental nitrogen and / or carbon in the analysis fluid. In one embodiment, the detector is a thermal conductivity detector. Preferably, the detector comprises a chromatography device that separates the remaining components of the analysis fluid. Particularly preferably, it is a gas chromatography device.

[0060] Method for removing CO2 from a fluid The method for removing CO2 from the fluid flow according to the present invention has the following steps: Providing the above-described adsorption device for adsorbing CO2; Passing the fluid flow containing CO2 through the adsorption device such that CO2 is adsorbed from the fluid flow by the adsorbent; Stopping the fluid flow containing CO2; Heat the adsorbent with a heating device, flow a flushing fluid through the adsorbent, and wash away the adsorbed CO2 from the adsorbent; and Stop the flow of the flushing fluid.

[0061] This method is suitable for removing CO2 from any fluid flow. The fluid flow may contain liquid and gas components. Further, the fluid flow may contain solid particles, such as soot particles, as long as the particle size and amount of the solid particles do not lead to obstruction of the adsorbent. Preferably, the fluid flow is a gas or a gas mixture, particularly preferably a gas mixture that may contain water vapor. Particularly preferably, the fluid flow consists only of gas components.

[0062] In one embodiment, the fluid flow is an analysis fluid obtained by combustion of a sample, preferably an organic sample, more preferably a food or feed sample. Preferably, the fluid flow is obtained by the following steps: Combust the sample in a combustion reactor to obtain an analysis fluid; Pass the analysis fluid through a reduction reactor to reduce the oxidation components of the analysis fluid; Pass the analysis fluid through a water separator to remove water from the analysis fluid.

[0063] Preferably, the fluid flow containing CO2 is passed through the adsorbent device at a temperature of 10°C to 40°C, preferably 15°C to 30°C, more preferably 18°C to 25°C, such that CO2 is adsorbed from the fluid flow by the adsorbent.

[0064] After the fluid flow containing CO2 has been passed through the adsorption device, the adsorbed CO2 is washed away from the adsorbent by heating the adsorbent with a heating device and passing a flow of flushing fluid through the adsorption device. Preferably, the adsorbent is heated to a central temperature between 100°C and 300°C, preferably 150°C and 250°C, more preferably 180°C and 220°C thereby. In a particularly preferred embodiment, the adsorbent is first heated to a predetermined core temperature, and then the flow of flushing fluid passes through and through the adsorbent.

[0065] The flushing fluid used is preferably a fluid that does not itself contain components adsorbed by the adsorbent or components that chemically react with the adsorbent. Preferably, the flushing fluid is a noble gas, such as helium or argon. In a preferred embodiment, helium is used as the flushing fluid.

[0066] In a preferred embodiment, the adsorbent device comprises the cooling device described above. In this case, the method includes an additional step of cooling the adsorbent by the cooling device after the adsorbed CO2 is purged from the adsorbent. During the cooling of the adsorbent by the cooling device, the flow of the flushing fluid may be interrupted or may continue to pass through the adsorbent.

Brief Description of the Drawings

[0067] Further features of the present invention will be described with reference to the drawings described below.

Figure 1

Figure 2

Figure 3

Figure 4

[0068] FIGS. 1 and 2 show a first embodiment of the adsorption device 1. The adsorption device 1 has a filter 11, a heating device 12, and a cooling device 13.

[0069] The filter 11 has a tubular shape spirally wound around the rod-shaped heating device 12. The filter 11 completely surrounds the rod-shaped heating device 12 in the radial direction. At both ends of the tube, there are an inlet 111 and an outlet 112 of the filter 11.

[0070] An adsorbent, which is not itself shown in the drawings, is disposed within the inner cavity 113 of the tube.

[0071] Since the heating device 12 extends along the longitudinal axis x and is a linear rod-shaped heating device, the spiral filter 11 can be inserted into the rod-shaped heating device 12 in a simple manner. In this way, the heating device 12 is accommodated in the axial cavity of the spiral filter 11.

[0072] The heating device 12 consists of a heating wire 121 spirally wound around a rod-shaped base 122. The rod-shaped base 122 is made of a tube, preferably a mica tube, and a temperature sensor 123 is arranged inside it. The temperature of the heating device 12 can be determined and controlled by the temperature sensor 123.

[0073] The cooling device 13 is axially arranged with respect to the longitudinal axis x below the heating device 12 and the filter 11. The fan 13 has an outlet 131 through which the air used for cooling can be discharged axially with respect to the longitudinal axis x.

[0074] The suction device 1 further has a housing 14 in which the heating device 12 and the filter 11 are arranged. The fan 13 is connected to the housing 14 outside the housing 14. The housing 14 does not completely surround the heating device 12 and the filter 11, but is open on the side facing the viewer in FIGS. 1 and 2. On the back side, the housing 14 has an outer wall 142. Inside the housing, a plurality of thin plate-shaped inner walls 141 are formed, and a plurality of flow paths 143 are formed in the inner walls 141. Through the flow paths 143, the air discharged from the fan 13 is guided to the filter 11 so as to collide with the filter 11 radially with respect to the longitudinal axis x.

[0075] The connecting means 144 are formed on each of the inner walls 144. These connecting means 144 can be used to couple the housing 14 to a second suction device. For this purpose, the protrusions 144 can engage with corresponding receptacles provided on the outer wall 142 of the second suction device. In this way, a plurality of suction devices 1 can be mechanically coupled to each other.

[0076] In the illustrated embodiment, the inlet 111 and the outlet 112 of the filter 11 each have connecting means. By means of these connecting means, the inlet 111 and the outlet 112 can each be fluid-tightly connected to a valve device (not shown).

[0077] Figures 3 and 4 show another adsorption device 2 according to the second embodiment.

[0078] The adsorption device 2 has a filter 21 and a rod-shaped heating device not individually shown in Figures 3 and 4. The heating device can be composed of a rod-shaped base and a heat transfer wire spirally arranged around the rod-shaped base, as depicted in Figures 1 and 2.

[0079] The filter 21 includes an outer first chamber 214 and an inner second chamber 213. The first chamber 214 and the second chamber 213 surround an axial cavity 25 in which a heater can be disposed. The cavity 25 has an open bottom, and a rod-shaped heating device can be inserted into the cavity 25.

[0080] Both the heating device and the filter 21 extend along the longitudinal axis x. The first chamber 214 and the second chamber 213 are each coaxially arranged with respect to this longitudinal axis x. At the upper end of the filter 21 with respect to the longitudinal axis x, there are an inlet 211 and an outlet 212. The inlet 211 forms the upper opening of the inner second chamber 213. The outlet 212 forms the upper opening of the outer first chamber 214. The inner second chamber 213 is in fluid communication with the outer first chamber 214 via a gap at the lower end 215 of the filter. In this way, the fluid can enter the outer first chamber 214 through the inlet 211 and the inner second chamber 213 and finally pass through the outlet 212.

[0081] In this embodiment, the adsorbent may be disposed in either the outer first chamber 214 and / or the inner second chamber 213. Preferably, the adsorbent is disposed in the outer first chamber 214.

[0082] In this embodiment, the inlet 211 and the outlet 212 each have connection means by which the inlet 211 and the outlet 212 can be connected to the valve in a fluid-tight manner.

Description of the reference numerals

[0083] 1, 2 Adsorption device 11, 21 Filter 111, 211 Inlet 112, 212 Outlet 113 Inner cavity 213 Second chamber 214 First chamber 12 Heating device 121 Heating wire 122 Rod-shaped base 123 Temperature sensor 13 Cooling device 131 Outlet opening 14 Housing 141 Inner wall 142 Outer wall 143 Flow path 144 Connection means 25 Cavity x Vertical axis

Claims

1. CO used in an elemental analysis device ２ An adsorption device (1) for adsorbing A filter (11) having an inlet (111) for the fluid, an outlet (112) for the fluid, and an adsorbent through which the fluid can pass, a heating device (12) for heating the adsorbent, comprising: the heating device (12) extends along the longitudinal axis (x), the filter (11) is arranged coaxially with the longitudinal axis (x) and is arranged spirally around the heating device (12) along the longitudinal direction, the filter (11) forms a receptacle extending along the longitudinal axis, and is configured to be removably insertable into the receptacle, the inlet (111) and the outlet (112) are arranged on opposite sides with respect to the longitudinal axis (x) of the filter (11), characterized in that the adsorption device (1).

2. The adsorption device (1) further comprises a cooling device (13) for cooling the adsorbent, characterized in that the adsorption device (1) according to claim 1.

3. The cooling device (13) is formed by a fan, characterized in that the adsorption device (1) according to claim 2.

4. The heating device (12) is formed by a heating wire (121) arranged spirally around a rod-shaped base (122), characterized in that the adsorption device (1) according to claim 1.

5. The rod-shaped base (122) includes a temperature sensor (123), characterized in that the adsorption device (1) according to claim 4.

6. The adsorption device (1) includes a first valve connected to the inlet (111) and capable of alternately guiding a first fluid and a second fluid into the filter (11), characterized in that the adsorption device (1) according to claim 1.

7. An elemental analyzer comprising a combustion reactor for combusting a sample, an optional reduction reactor, an optional water separator, and a detector, CO ２ comprising the adsorption device (1) according to any one of claims 1 to 6, which adsorbs The elemental analyzer passes the analysis fluid from the combustion reactor through an adsorption device (1) that adsorbs the CO ２ and sends it to the detector, or alternately performs a valve control unit that sends a flushing fluid through the adsorption device (1) that adsorbs the CO ２ and includes characterized in that the elemental analyzer.

8. The flushing fluid can also pass through the detector or through another detector that detects CO or carbon in the flushing fluid. ２ The elemental analyzer according to claim 7, characterized in that it can also pass through the detector or through another detector that detects CO or carbon in the flushing fluid.

9. At least two COs ２ The elemental analyzer according to claim 7, further comprising an adsorption device (1) for adsorbing, wherein the valve control unit is configured to allow the analysis fluid to pass through two or more adsorption devices in parallel.

10. A method for removing CO from a fluid flow ２ which comprises CO ２ providing the adsorption device (1) according to any one of claims 1 to 6 that adsorbs CO ２ Passing a fluid stream containing CO through the adsorption device (1) so that CO ２ is adsorbed from the fluid stream by the adsorbent; the step of stopping the flow of the fluid containing the CO ２ and the step of stopping the flow of the fluid containing the CO The adsorbent is heated by the heating device (12), and a flow of a flushing fluid is passed through the adsorption device so that the adsorbed CO ２ is washed away from the adsorbent; a step of stopping the flow of the flushing fluid comprising a method.

Images