Site-based carbon capture

Abstract

Apparatus 10 for carbon capture from a heating appliance, wherein the heating appliance heats and conveys air through the appliance for receipt by the apparatus. The apparatus comprises a housing of at least two parts, 44 and 42. The housing may have a first (rear) face for communicating with the appliance and a second (front) face comprising outlet 20 for out letting air having passed through a carbon capture cartridge. The cartridge contains a carbon capture material, located within and forming part of the apparatus. The carbon sequestering material may be a zeolite, melamine or melamine derivative such as nitrogen doped melamine. The apparatus may comprise sensors for detecting temperature and carbon dioxide and a processor. The heating appliance may be a boiler or air conditioning unit (HVAC). The apparatus may be retrofitted to an existing appliance.

Description

The present invention relates to site-based carbon capture and in particular a capture solution to enable the scavenging of carbon dioxide locally, i.e. on site. Background Carbon capture is becoming increasingly important, so as to reduce the carbon dioxide load on the atmosphere. Whi 1st there are many projects for carbon capture in powerplants, and separate carbon capture facilities dedicated to that role, around 26 percent of carbon dioxide emissions United Kingdom, for example, comes from households. By way of example a hydrocarbon fuel domestic boiler may release around 2.2 tons of carbon dioxide annually. There is therefore a need for a simple and practical solution to enable carbon capture from domestic premises, households and related situations. These situations provide several challenges; efficient carbon capture substrates and efficient management of the systems given that the average domestic premises does not have a high degree of technical competence or diligence in maintenance. Many installations also have considerable remaining useable life and therefore the opportunity to retrofit carbon capture to an existing installation would be beneficial. There is therefore a need to provide a site-based carbon capture apparatus and method, to address these issues. Carbon capture and systems for carbon capture are known, relevant examples being disclosed in WO2021097425. This discloses carbon capture from the atmosphere and use of the captured carbon in carbonated drinks. WO2014059961 is cited as a representative example of one of the many chemistries available for carbon capture, in this case ammonium and urea carbonate derivatives are used for the capture and processing of carbon dioxide. CA2998917A1 discloses another means for chemical carbon capture using anhydrous metal hydroxides from which the heat evolved in creating metal carbonate is also used to supplement a heating system. A similar process is known using nitrogen doped melamine-based substrates, such as disclosed in CN114345298. LIS11,738,301 discloses a regeneratable carbon capture method using zeolites for the absorption and desorption of carbon dioxide. LIS11,766,636 discloses a modular carbon capture system using transportation container type units as the basic module, WO2023235744A1 discloses a similar modular system. As can be seen, there are a plurality of mechanisms for carbon capture, the sequestered carbon dioxide can then be directly re-used, transformed into another chemical substance, or absorbed onto a substrate for subsequent desorption after transport. The present invention The present invention in its various aspects is as set out in the appended claims. The present invention provides an apparatus and method for carbon capture suitable for use in domestic premises, the apparatus and method comprising the provision of a replaceable unit of carbon capture material, monitoring sensors and a notification system for the user. The apparatus of the present invention is preferably configured for attachment to an air conditioning unit (HVAC). The attachment to the air conditioning unit is preferably on the outlet of an air conditioning unit. This is advantageous as the absorption of carbon dioxide by substrates, a particularly preferred substrate being melamine based, generally occurs at elevated temperature and the presence on the outlet of air conditioning provides this. The air-conditioning unit is preferably configured to provide an outlet temperature in the range of 40 degrees centigrade to 60 degrees centigrade for said activation. In a preferred form of the present invention the outlet is subsequently admixed with ambient air so is to produce an exit temperature of between 20 and 40 degrees centigrade. This enables the higher temperature required for carbon capture to be achieved whilst providing an outlet temperature within the normal comfort zone of a user. The present invention may be an air conditioning unit where the apparatus is integral to the unit, or the apparatus may be a retrofit attachment. The apparatus of the present invention is preferably configured for attachment to a domestic central heating boiler. The attachment to the boiler is preferably on the outlet, the flue, of the boiler. This is advantageous as the absorption of carbon dioxide by substrates, a particularly preferred substrate which is melamine based, generally occurs at elevated temperature and the presence on the outlet of air conditioning provides this. The boiler unit is preferably configured to provide an outlet temperature in the range of 40 degrees centigrade to 60 degrees centigrade for said activation. In a preferred form of the present invention the outlet is pre heat scavenged using a heat exchanger to harvest heat energy before the carbon capture step and again preferably subject to heat scavenged using a heat exchanger to harvest heat energy after. It may also be further admixed with ambient are so is to produce an exit temperature of between 20 and 40 degrees centigrade. This enables the high temperature required for carbon (dioxide) capture to be achieved without loss of energy. The present invention may be an boiler unit where the apparatus is integral to the unit, or the apparatus may be a retrofit attachment. Preferably, and alternatively in the case of the boiler the outlet of the flue gas is used directly with the carbon capture substrate, thereby providing a potential absorption temperature of between 100 and 200 degrees centigrade, followed by the conventional flue gas heat recovery. This provides the benefits of high temperature for absorption already present in the system with the energy efficiency of the subsequent heat scavenging of the flue gas. Alternatively partial heat scavenging may occur, to provide an intermediate temperature as mentioned in the previous paragraph. As can be seen, there are two main preferred applications of the present invention and a general principle of the present invention covers both, i.e. air conditioning and a boiler as representing appliances providing forced airflow (so that it is not required to be provided in the apparatus) and increased air temperature (so as to avoid unnecessary heat generation). The apparatus of the present invention preferably comprises one or more temperature sensors, the apparatus of the present invention preferably comprises a processor and control electronics so as to enable one or more of sensors to be read, actions to be undertaken based upon sensor readings and external communications to be undertaken, such as external communications with a portable computer cell phone or similar. Temperature sensors may be located in the inlet and / or outlets of the apparatus and in particular may be located in a replaceable cartridge of the apparatus. This enables the determination of an action is related to the optimum temperatures mentioned above to be monitored and acted upon, such as by the controller of the apparatus. This enables more effective carbon capture to take place based upon the combination of appliance and carbon capture material. This is particularly so when the controller is configured to interact with the appliance so is to adapt the operating parameters, such as throughput of the appliance for optimisation of carbon capture such as to avoid saturation of carbon capture uptake rate at a given (high) flow rate or to permit back diffusion from the external atmosphere into the Carbon capture material at a given (low) flow rate.an optimum flow rate for the apparatus is such as between 0.1 and 2 metres per second, preferably between 0.2 and one metres per second. This flow rate is flow rate through the device as a whole, whereas an input, such as from a flute may be at a higher flow rate, that flow rate being reduced by means of a manifold, either actual or implicit, as the output of the flue is distributed over a wider area of carbon capture material, such as in the replaceable cartridge. The replaceable cartridge of the present invention therefore preferably has a larger cross-section than the inlet. For optimum flow the outlet of the apparatus has the same cross-section as that of the replaceable cartridge, so is to avoid back pressure. The apparatus of the present invention preferably provides a replaceable unit of carbon capture material. This is preferably in the form of a container which is slotted into the apparatus so that the chemical composition of the carbon capture material is isolated from the user in the form of a readily replaceable unit. In a preferred form of the present invention and air conditioning unit or boiler comprises two such replaceable units, the appliance outlets (or a divided single outlet) being channelled through both units, with the units being separately and individually replaceable. This enables the staggering of replacement so that even if one unit becomes saturated the other unit can continue to function without interruption of the appliance. An important option for the present invention is that the apparatus comprises monitoring means for the carbon dioxide. In the present document air conditioning (such as HVAC) or boiler is referred to as the appliance. The apparatus of the present invention may incorporate the appliance, or preferably may be added to the appliance, such as a retrofit. The present invention may monitor the carbon dioxide output from the appliance. This information may be used to regulate the flow of outlet gas from the appliance so as to avoid saturating the take-up rate of the carbon capture material. This is an aspect which is often been overlooked as whilst complex and high cost very high surface area materials may be used to allow very fast carbon capture it can be more efficient to use lower surface area materials but at lower flow rates, as designing for maximum flow rates may be inefficient. To perform carbon capture a carbon capture material is required, such as preferably present in a replaceable cartridge, as described above. The preferred form of carbon capture material is a regeneratable carbon capture material. I.e. material which absorbs carbon dioxide and then in a subsequent process, either chemical or physical, evolves carbon dioxide so that it may be otherwise processed such as in a remote facility, which enables this action to be carried out on a larger scale and hence potentially more efficiently. The replaceable cartridge of the present invention preferably slots into a housing of the apparatus of the invention, whether or not the apparatus of the invention is attached to appliance. In slotting into the housing, the replaceable cartridge preferably comprises a sealing aperture for sealing the inlet of the cartridge to an outlet of the appliance, either directly or by sealing first to the housing and housing itself sealing to the appliance. Preferably the replaceable cartridge comprises an elastomeric seal for ensuring an efficient sealing process. This is advantageous as the replaceable cartridge can be taken away for processing and the seal can then be inspected and easily renewed removing the requirement to do so locally at individual installations of the apparatus of the invention. The replaceable cartridge preferably comprises an inbuilt detector for the level of carbon dioxide present in the carbon capture material of the cartridge. Again, this is advantageous as the sensor can be tested, calibrated, or replaced during processing of the carbon capture material such as in parallel to the regeneration process. The replaceable cartridge preferably interfaces with a controller of the apparatus of the invention for the purposes of communicating data, or at least electrical signals, representative of the carbon dioxide stored in the cartridge. In addition to or alternative to sensors providing a measure of the carbon dioxide stored in the cartridge then a sensor detecting the carbon dioxide on the inlet and on the outlet may be provided, again these are interfaceable with the controller of the apparatus so that the efficiency of the cartridge may be evaluated and the cumulative store of carbon dioxide determined. The interface of the replaceable cartridge preferably comprises a plug and socket combination distributed between the cartridge and the rest of the apparatus and is preferably present on an, in use, lower side of the cartridge so that in placing the cartridge in the apparatus, the relevant connection is made. The plug is preferably in the cartridge to reduce the potential for damage. As mentioned, in the apparatus of the invention preferably comprises a controller. The controller is configured to monitor the signals from sensors of the apparatus. The sensors of the apparatus may be in the replaceable cartridge, as previously mentioned, or the equivalent inlet and outlet carbon dioxide level sensors may be present in the inlets and outlets of the apparatus, such as in the form of a housing of the apparatus for an equivalent purpose. Preferably, both sets of sensors are present to provide redundancy and to detect leaks. This is enabled since a mismatch between the inlet and outlet carbon dioxide for the cartridge in the inlet and outlet carbon dioxide for the apparatus may be determinant of a leak bypassing the cartridge. In addition, the sensors of the present invention located as previously mentioned relevant to carbon dioxide, may also optionally include a carbon monoxide sensor. This may be linked to a warning system of the apparatus and enable the carbon capture material to also capture the carbon monoxide for improved safety. The controller of the apparatus is preferably configured to be communicable with a further, external, computer means to communicate relevant data, such as usage, capacity remaining, efficiency and temperature. The controller of the apparatus and / or the external computer means may be configured to predict when a replaceable cartridge needs to be replaced and automatically place an order for a replacement. In a configuration of the present invention where a plurality of cartridges, such as two, are used in the usages to be staggered then the controller may be configured to carry out this process. The carbon capture material may be provided using any suitable material. As mentioned, a regeneratable material is preferred. Suitable regeneratable materials of the present invention are zeolite, melamine, and their derivatives. The preferred material is melamine. The melamine is preferably doped with nitrogen compounds, such as amines, as this enables more effective low-temperature adsorption and desorption. The preferred melamine is melamine doped with (i.e. treated with), DETA (diethylenetriamine), to bind carbon dioxide. In particular, melamine with cyanuric acid added during the polymerization reaction increases the pore size dramatically and radically improved carbon dioxide capture efficiency such that nearly all the carbon dioxide in a simulated flue gas mixture can be absorbed rapidly. The preferred form of melamine carbon capture material of the present invention is therefore a macro porous melamine. Drawings The present invention is illustrated by means of the following drawings in which like features are designated with like numerals. The figures provide: figure 1 shows a schematic in notional cross section of a central heating boiler (appliance) with an outlet passing through a wall and the outlet being fed into a carbon capture apparatus of the present invention; figure 2 shows a schematic in notional cross section of a HVAC (heating ventilation air-conditioning, otherwise stated as air conditioning) appliance fed into a carbon capture apparatus of the present invention; figure 3 shows a side view of a carbon capture apparatus of the present invention; figure 4 shows a perspective view from the front I carbon capture apparatus of the present invention; figure 5 shows a schematic of a base of the housing of the carbon capture units of the present invention; figure 6 shows a carbon capture cartridge of on for use in the present invention; and figure 7 shows the location of the carbon capture cartridge in the housing. The features of the drawings are listed as follows: 10 carbon capture apparatus of the present invention; 20 outlet for air which has been scrubbed of carbon dioxide; 22 slats of outlet; 24 gauze covered outlet; 30 external inlet to boiler, absent when used with air conditioning; 40 casing of the apparatus of the present invention being a housing of two parts; 42 lower housing; 44 upper housing; 46 joint between housings; 48 strengthening rib; 50 inlet to carbon capture apparatus suitable for accommodating flue 110 of boiler 100 or outlet 160 of HVAC 150; 52 well of housing for accommodating cartridge; 60 inlet to cartridge (detail concealed); 62 upper face of cartridge providing space above in upper housing 44 for the accommodation of control electronics; 64 rear face of cartridge; 66 end face of cartridge; 68 outlet apertures of cartridge; 70 carbon capture cartridge of the present invention; 72 cartridge local located in lower housing; 74 recessed foldable handle of carbon capture cartridge; 76 cartridge nested in lower housing of the casing; 78 arcuate lower (side) face of cartridge; 100 boiler; 110 flue, outlet of the boiler; 120 wall to which the boiler is attached and with aperture for flue; 150 HVAC; 160 outlets of HVAC; 170 inlet of HVAC; and 180 ceiling to which the HVAC is attached. Similar features are numbered similarly between the drawings, features of the same type but unnumbered carry the same numbering. Detailed description The present invention provides a carbon capture apparatus, particularly for use in combination with a domestic (i.e. appliance associated with a domicile, such as a house or small office) appliance which produces heat and forced air circulation. Two specific examples of such appliance are a domestic boiler and a domestic air conditioning unit. Figure 1 shows a schematic, in notional cross section, of a central heating boiler 100 (appliance) with an outlet 110 passing through a wall 120 and the outlet 110 being fed into a carbon capture apparatus 10 of the present invention. The apparatus further provides a conduit 30 to provide an external, ambient air, inlet to the boiler such as to accommodate a balanced flue of the boiler. This conduit passes straight to the unit and its function is to facilitate a retrofit to existing appliance, such as a balanced flow inlet / outlet of a boiler. This apparatus feature is not required when associated with an air conditioning appliance and so therefore provides more compact apparatus. This conduit also provides a convenient source of ambient air for the cooling of flue gases after and before exiting the apparatus passing through the carbon capture material, as described previously. This is advantageous over using earth from inside the premises as it avoids the issue of potential mixing of combusted gases with air in an occupied environment (with the attendant risks regarding carbon monoxide). Figure 2 shows a schematic, in notional cross section, of a HVAC (heating ventilation air-conditioning) unit 150, otherwise stated as air conditioning appliance fed into a carbon capture apparatus 10 of the present invention by means of an outlet 160, the year having been taken into the unit our time inlet 170. The air conditioning unit is secured to a surface, such as a ceiling 180. The present invention also encompasses the combination of boiler and / or air conditioning with the carbon capture units to provide a broader meaning of the apparatus of the present invention. However, the present invention is preferably a separate unit for retrofit onto an existing appliance. This is particularly useful as a large number of boilers are installed and it is not environmentally acceptable to simply replace them during their operational lifetime. The presence apparatus allows a retrofit by attaching the apparatus of the present invention to an existing appliance. Figure 3 shows a side view of a carbon capture apparatus 10 of the present invention. The apparatus 10 comprises a casing 40 in the form of a housing having a lower portion 42 and an upper portion 44. The lower portion 42 is preferably configured for securing either to a wall as a means of support or to the appliance. The lower portion 42 also comprises an inlet, a sealing member for sealing the apparatus inlet to the outlet of the appliance for conveying of air / gas / flue gas, such as containing carbon dioxide for capture using the apparatus of the invention. An important and common feature of the appliance to which the apparatus is intended to be connected, or is connected in use is that it provides forced air movement (such as by means of a fan). This obviates the need for creating forced air movement within the apparatus itself. This provides a more efficient and practical apparatus for use in domestic premises. An important and common feature of the appliance to which the apparatus is intended to be connected, or is connected in use, is that it provides a source of air at elevated temperature (such as in conjunction with a heat exchanger). Most recyclable carbon capture materials, such as melamine, require air to be at elevated temperature, such as a greater than 40 degrees centigrade so as to activate the carbon capture process. This enables the carbon capture to occur locally upon activation rather than being a passive ambient process not associated with a given activity. This is important in terms of attributing environmental responsibility which is a key element in improving the environment. Creating an elevated temperature locally solely for the purpose of carbon capture is inefficient in itself, and may give rise, either directly or indirectly, to a carbon footprint from the activity. Therefore, the present invention utilises the elevated temperature already obtained from the flue outlet of a boiler or from the outlet temperature of an air-conditioner. Referring again to figure 3, the upper housing 44 is configured to be removable so as to access inside the apparatus for the purposes of maintenance and to replace the carbon capture material. This has enabled by a joint 46 between the housings enabling lifting off of the upper housing. As mentioned, air is inlet on one side of the housing and on a side remote from the inlet side is outlet through feature 20. This outlet is preferably equipped with flaps to produce a one-way flow so as to prevent back flow from the environment, such as externally on a windy day, which would serve to cool the carbon capture material and thus inhibit its activity. When the apparatus of the present invention is used in conjunction with the boiler then a boiler will typically have a plurality of heat exchangers. The first heat exchanger is configured to extract heat from a flame source, such as burning gas, and then a subsequent heat exchanger to extract further heat so as to provide a cool outlet stream of high energy efficiency. In the present invention, the apparatus is preferably juxtaposed in an apparatus comprising the boiler between the primary and secondary heat exchangers so as to use the elevated heat after first heat exchange to activate the carbon capture source and to recoup the remaining heat energy afterwards by means of the secondary heat exchanger. Such boilers with multiple heat exchangers are typically termed condenser boilers. When the apparatus of the present invention is used in conjunction with an air conditioning unit the apparatus may preferably comprise the appliance, for the purposes of providing an inlet stream of air at elevated temperature such as in the range 40 to 60 degrees centigrade. This air is then admixed with ambient air to provide a final outlet below 30 degrees centigrade. This provides effective activation of carbon capture material in combination with a safe and comfortable outlet temperature suitable for conditioning the ambient are in a room. Figure 4 shows a perspective view from the front of a carbon capture apparatus of the present invention. This view is to contextualise the previous information and to note that the housing, particularly upper housing preferably comprises a plurality of strengthening ribs 48 so that the housing may be made of a relatively thin and flexible material, such as an injection moulded plastics material so that it is light and readily detached. Such attachment gives rise to the image shown in - Figure 5 which shows the lower housing 42 were the rear of the housing 54 for abutting, and attaching to the appliance or a building surface for support comprises an inlet aperture for the forced air movement from the boiler or air conditioning unit. This enters a well of the housing, or more preferably parts, such as the cartridge placed in the well of the housing. As can be seen from the cross section (the end plate of the lower housing is omitted) an arcuate basis provided as this enables parts such as the aforementioned cartridge 70 to be readily and accurately slotted into the housing for rapid and simple exchange of a cartridge to renew the carbon capture material. Figure 6 shows the aforementioned carbon capture cartridge. The cartridge 70 comprises a rear face 64 with an inlet aperture 60 (not visible), but see corresponding aperture 50, and a front face with outlet apertures 68. Exit air from the appliance is pushed through aperture 50 which is in communication with aperture 60, preferably sealed by means of a sealing member to convey inlet her into the cartridge 70, the air then passes through the carbon capture medium (not shown) and exits through a plurality of apertures 68 distributed over the whole of the front face of the cartridge. This enables the air to diffuse over the whole internal volume of the cartridge. The cartridge is generally an elongate cuboid with a lower front side face 78 being arcuate, this enables the cartridge to be readily lowered into the housing such as when placing a replacement cartridge in the apparatus by means of removing the upper housing 44, lifting out the cartridge 70 and replacing a further cartridge 70 as a replacement. The aforementioned shape enables the cartridge to be largely self-locating with the large rear face enabling optimum use of space and the arcuate portion providing a self-locating action were the vertical force / weight of the cartridge serves to push the cartridge rearward so that the apertures 50 / 60 becoming communication, as preferably sealed by elastomeric sealing member. This enables accurate her tight sealing of the cartridge into the apparatus for use with the appliance without the need for any further clips et cetera. The cartridge preferably comprises recessed handle 74 in the centre of the upper face 62 of the cartridge 70. This both provides an ergonomic means to lift out the cartridge but also enables the self-centring and self-locating of the cartridge in the lower housing 42. The cartridge 70 has a flat upper face 62 above this in conjunction with the arcuate upper housing 44 a space is created for the provision of control electronics such as for the aforementioned monitoring and alerting of usage. Sensors for the carbon dioxide in the earth are preferably present adjacent the rear and front faces of the cartridge such that they interface with the aforementioned control electronics by means of a plug and socket arrangement engaged when the cartridge is placed in the housing. This enables the sensors to be recalibrated when the cartridge is refurbished and for sensors to be updated and / or tailored to the particular composition of the carbon capture material. This makes the approach of the present invention potentially carbon capture material agnostic. In addition to the common outside sensors are preferably temperature sensors included and more preferably feedback from the temperature sensors to the control electronics and more preferably to the appliance so as to enable an inlet of the appropriate temperature for effective carbon capture. Figure 7 shows the location of the carbon capture cartridge in the housing, during the aforementioned self-locating action as the rear faces of the cartridge and housing are brought into contact.

Claims

25Claims1. An apparatus for carbon capture from a heating appliance, wherein the heating appliance:a. conveys air through the appliance for receipt by the apparatusb. that air is heated when whilst passing through the appliancethe apparatus comprising a casing comprising a housing of at least two parts, the housing having a first (rear) face for communicating air exiting from the appliance into the apparatus and a second (front) face comprising outlets for out letting air having passed through a carbon capture cartridge, the cartridge containing carbon capture material, located within and forming part of the apparatus wherein the appliance is configured for a flow rate from the heating appliance flow rate between 0.1 and 2 metres per second.

2. The apparatus of claim 1 when the apparatus is configured for direct attachment to the heating appliance and heating appliance is a domestic heating appliance.

3. The apparatus of claim 1 or 2 wherein the cartridge is a replaceable cartridge.

4. The apparatus of any of claims 1, 2 or 3 wherein the cartridge locates in and substantially fills a lower, in use, housing of said two parts of the housing.

5. The apparatus of any preceding claim wherein the cartridge is an elongate cuboid having an, in use, lower side face which is arcuate for slotting into a lower portion of the housing.

6. The apparatus of any preceding claim wherein the apparatus is configured to receive, in use, the heated air the appliance to activate a carbon capture material located within the cartridge.

7. The apparatus of any preceding claim wherein the cartridge is a plurality of independently replaceable cartridges simultaneously locatable in the apparatus.15 04 258. The apparatus of claim 7 wherein the apparatus is configured to selectively use the cartridges so as to stagger use thus configuring the apparatus so that the cartridges will not become simultaneously saturated.

9. The apparatus of claim 7 or claim 8 where the independently replaceable cartridges comprise different carbon capture materials having different optimal temperatures for carbon capture, the apparatus being configured to selectively convey incoming air to one or other of the cartridges to optimise carbon capture efficiency, such as based on air temperature.

10. The apparatus of any preceding claim wherein the carbon capture material is a regeneratable carbon capture material for the capture of carbon and subsequent release to regenerate the material, such as for reuse.

11. The apparatus of claim 10 wherein the carbon capture material is melamine or a melamine derivative or a zeolite or zeolite derivative.

12. The apparatus of claim 11 wherein the melamine derivative is a nitrogen doped melamine derivative.

13. The apparatus of claim 12 wherein the carbon capture material is a macroporous carbon capture material.

14. A method of carbon capture comprising retrofitting an apparatus of any of clams 1 to 13 to the boiler appliance.

15. A kit of parts comprising an apparatus of any of claims 1 to 13 equipped for the fitting of an apparatus of the present invention to the boiler appliance.19

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