Microwave device for extracting volatile substances

Abstract

An apparatus for extracting a liquid composition from organic material comprises: (i) a MW cavity (2), a MW extraction chamber (9) having an inlet opening (17a) and an outlet opening (17b) for said organic material and a collection opening (3a) at its bottom for collecting the liquid composition; a MW cavity (2) comprising a microwave generation chamber (13) separated from the MW extraction chamber (9); (ii) at least one microwave generator (14) arranged to heat the organic material in the MW extraction chamber (9); (iii) an inlet tunnel (16a) opening into the inlet opening (17a) of the MW extraction chamber (9) and an outlet tunnel (16b) extending from the outlet opening (17b) of the MW extraction chamber (9); (iv) Conveyor means (15) for transporting organic material through said entrance tunnel (16a), said MW extraction chamber (9) and said exit tunnel (16b).

Description

[Technical Field]

[0001] The present invention relates to the field of fragrances, flavors, and industrial raw materials. More specifically, the present invention relates to microwave-assisted extraction of extracts for producing or formulating fragrances, flavors, and / or industrial raw materials.

[0002] Background technology Microwave (MW) extraction represents a beneficial, environmentally friendly method for extracting compounds from natural biomass without the use of solvents. It is particularly advantageous for extracting volatile substances and food-grade compounds.

[0003] In industrial applications, continuous MW extraction is usually preferred over batch processing.

[0004] Unfortunately, existing continuous microwave extraction equipment for solids / liquids does not provide safe extraction conditions for the operator and / or other workers in the vicinity. Indeed, the human body, which is mainly composed of water, is particularly sensitive to microwaves, especially the brain, lungs, heart, and eyes. It is essential to limit the human body exposure level to a specific absorption rate (SAR) of less than 0.4 W / kg averaged over the whole body, and for industrial microwave ovens operating in the 2450 MHz frequency band, this is 50 W / m 2 (5mW / cm 2 ) power density should not exceed (Directive 2004 / 40 / EC, ICNIRP, 1998).

[0005] The usual way to protect operators is to provide them with some personal protective equipment or to reduce the time they are exposed to microwaves when the device is operating.

[0006] There is a need to provide safer working conditions for industrial-scale extraction using microwave equipment.

[0007] Operators also face the risk of burns due to the increased temperature of the equipment, which not only exposes the operator to combustion but also creates hot spots in the raw material, reducing the quality of the extraction. In fact, uniformity of raw material processing is also a challenge during microwave extraction. Hot spots can burn the raw material, produce unpleasant odors, and reduce the quality of the extraction.

[0008] Another major problem associated with the temperature rise of the equipment is that it limits the operating time of the equipment, and existing microwave extraction equipment typically requires the extraction line to be shut down periodically to allow the equipment to cool, which is a major limitation in terms of productivity.

[0009] There is a need for a microwave device that not only provides safer working conditions for workers but also provides uniform treatment of raw materials in a continuous extraction process.

[0010] Summary of the Invention One aspect is an apparatus for extracting a liquid composition from an organic material, comprising: MW cavity, an MW extraction chamber having an inlet opening and an outlet opening for the organic material and a collection opening at its bottom for collecting the liquid composition; a MW cavity comprising a microwave generation chamber separated from a MW extraction chamber; at least one microwave generator positioned to heat the organic material in the MW extraction chamber; an inlet tunnel opening into the inlet opening of the MW extraction chamber and an outlet tunnel extending from the outlet opening of the MW extraction chamber; and conveyor means for transporting the organic material through an entrance tunnel, an MW extraction chamber and an exit tunnel.

[0011] The MW cavity, in particular the microwave generation chamber, may comprise at least one microwave generator.

[0012] The at least one microwave generator may be located outside the MW cavity.

[0013] The at least one microwave generator may be connected to the microwave generating chamber via at least one waveguide.

[0014] In one embodiment, at least part of the entrance tunnel and / or at least part of the exit tunnel are located outside the MW cavity, in other words the MW cavity preferably does not include or accommodate at least part of the entrance tunnel and / or at least part of the exit tunnel.

[0015] In one embodiment, the conveyor means extends into and out of the MW cavity, and therefore the MW cavity does not contain or house the complete conveyor means.

[0016] The conveyor means may extend along a path, only part of which extends into the MW cavity, the remainder of which may extend laterally and / or below the MW cavity.

[0017] At least the exit tunnel may be provided with cooling means for at least partially cooling the walls of the exit tunnel.

[0018] The exit tunnel may be positioned such that liquid condensing in the exit tunnel flows towards the bottom of the MW extraction chamber.

[0019] The entrance tunnel and / or the exit tunnel may be equipped with at least one microwave trap.

[0020] The microwave trap may extend along and / or cover at least 10%, or at least 25%, or at least 50%, or at least 75%, or at least 90%, or 100% of the longitudinal extension of the entrance tunnel, the longitudinal extension preferably being parallel to the extension and / or conveying direction of the conveyor means within the entrance tunnel.

[0021] The microwave trap may extend along and / or cover at least 10%, or at least 25%, or at least 50%, or at least 75%, or at least 90%, or 100% of the longitudinal extension of the exit tunnel, the longitudinal extension preferably being parallel to the extension and / or conveying direction of the conveyor means within the exit tunnel.

[0022] The microwave trap may be an absorptive, reactive, or hybrid microwave trap.

[0023] The entrance tunnel and / or the exit tunnel may contain two microwave traps, the microwave trap closer to the MW extraction chamber being a reactive trap and preferably the microwave trap further from the MW extraction chamber being an absorptive trap.

[0024] A microwave transparent cover can hermetically separate the MW extraction chamber from the microwave chamber.

[0025] The apparatus may comprise means for reducing the pressure in the MW extraction chamber and directing the produced vapor to a condenser for condensing the vapor.

[0026] The means for reducing pressure may be arranged to reduce the pressure below the conveyor means, e.g. to provide a vacuum below the conveyor means, thereby (i.e. by pressure differential) providing a (e.g. downward) flow through the conveyor means and / or towards a collection opening and / or towards the bottom of the MW extraction chamber, e.g. to collect the liquid composition in liquid and / or vapour form.

[0027] The pressure reducing means may be a condenser.

[0028] The organic material placed on the conveyor means may be heated from above by at least one microwave generator (e.g., at least one microwave generator is positioned above the conveyor means), and optionally, a pressure drop may be applied on the opposite side of the conveyor means, i.e., below the conveyor means.

[0029] By heating the organic material on the conveyor means, the pressure in the MW extraction chamber can be increased, which can help direct the generated vapor to a condenser for condensation. For example, the pressure can be increased above the conveyor means. This can provide a (e.g., downward) flow through the conveyor means and / or towards the collection opening and / or towards the bottom of the MW extraction chamber, due to the lower pressure below the conveyor means (which can be reduced using said means for reducing pressure), for example, to collect the liquid composition in liquid and / or vapor form.

[0030] The conveyor means comprises, at least inside the MW extraction chamber and the exit tunnel, a conveyor belt having a longitudinal axis which may have an inclination of between 0.5 degrees and 60 degrees from the horizontal plane.

[0031] The steam nozzles in the MW extraction chamber are preferably located on the side wall of the MW extraction chamber above or near the conveyor belt.

[0032] The bottom of the inlet tunnel and / or the outlet tunnel may be positioned at a higher level than the bottom of the MW extraction chamber, preferably by means of a step.

[0033] The entrance tunnel may include a top wall and / or a bottom wall, with one or more side walls extending from each of the top wall and / or the bottom wall. Optionally, the one or more side walls extend from the top wall to the bottom wall. Thus, the top wall and / or the bottom wall, on the one hand, and the one or more side walls, on the other hand, define a passageway through which the conveyor means extends.

[0034] At least some of the microwave traps of the entrance tunnel may be located i) on the top wall and / or bottom wall(s), and / or ii) on one or more side walls. At least some of the microwave traps may be located on the top wall. At least some of the microwave traps may be located on the bottom wall. At least some of the microwave traps may be located on one or more side walls.

[0035] The exit tunnel may include a top wall and / or a bottom wall, with one or more side walls extending from each of the top wall and / or bottom wall. Optionally, the one or more side walls extend from the top wall to the bottom wall. Thus, the top wall and / or bottom wall on the one hand and the one or more side walls on the other hand define a passageway, and the conveyor means extends through the passageway.

[0036] At least some of the microwave traps of the exit tunnel may be located i) on the top wall and / or bottom wall(s), and / or ii) on one or more side walls. At least some of the microwave traps may be located on the top wall. At least some of the microwave traps may be located on the bottom wall. At least some of the microwave traps may be located on one or more side walls.

[0037] Optionally, each tunnel may completely surround a conveyor means, such as a conveyor belt, in other words, each tunnel may completely surround a respective portion of the path along which the conveyor means extends.

[0038] The apparatus may have an external housing arranged to ensure reduced loss of volatile substances and / or to ensure reduced loss of microwaves, i.e., to shield microwaves. The external housing may include or house the MW extraction chamber, inlet tunnel, outlet tunnel, and / or conveyor means.

[0039] The apparatus may have an input end and an output end, through which the conveyor means can be loaded and through which the conveyor means can be discharged. The input end may be provided by an external housing. The output end may be provided by an external housing.

[0040] The MW cavity, in particular the MW extraction chamber and the microwave generation chamber, can include one or more components, all of which are microwave transparent. This provides the advantage of reducing hot spots in the MW cavity and providing a uniform microwave field. Furthermore, a reduction in microwave-impermeable materials is achieved. The one or more components can include conveyor rollers of the conveyor means, nozzles (such as steam nozzles), and / or handling structures (such as hand grips). In one embodiment, all (mechanical) components located in the MW cavity are microwave transparent.

[0041] In summary, the device offers, inter alia, the following advantages: Extracting liquid from the raw material particularly well, either via conveyor means or by condensation of the steam, which liquid can be used in products used as flavorings and / or fragrances; avoiding the loss of vapors, in particular by means of pressure reduction means, a transparent cover and / or an external housing, to ensure a reduced loss of volatile substances; avoiding microwave losses, in particular by means of an inlet and / or outlet tunnel, preferably having a microwave trap and / or an external housing, which may at least help to avoid such losses; Reducing hot spots and especially uniform microwave fields within the MW cavity, which may be increased by using materials within the cavity (extraction chamber and / or generation chamber) made of microwave transparent materials, such as materials for conveyor rollers, nozzles, hand grips, etc.; This reduces microwave-opaque materials.

[0042] Another aspect is a method for extracting a liquid composition from an organic material, comprising: (a) introducing an organic material into a central chamber, the chamber being positioned to receive microwave radiation from at least one microwave generator; (b) reducing the pressure in the MW extraction chamber to below atmospheric pressure; (c) optionally spraying the organic material with water vapor; (d) collecting the water vapor condensed by the condenser and collecting the liquid produced from the MW extraction chamber and the condenser in a collection tank; (e) removing the treated organic material from the central chamber.

[0043] Yet another aspect relates to a method for extracting a liquid composition from an organic material by using an apparatus as described above.

[0044] The method can include increasing the pressure in the central chamber (i.e., the MW extraction chamber) to a pressure higher than atmospheric pressure. The increased pressure can also be in a different section from the section where the pressure is reduced. For example, the central chamber can be divided into upper and lower sections, e.g., by a conveyor means, where the organic material is positioned to receive microwave radiation and the pressure is increased in the upper section, and reduced in the lower section, e.g., to provide a vacuum. This results in a flow (e.g., downward) from the upper section into the lower section, e.g., through the conveyor means, to collect the water vapor and / or liquid.

[0045] The reduced pressure results in a decrease in pressure below the organic material in the central chamber, e.g., a vacuum is provided below the organic material, which (i.e., by pressure differential) can convey the organic material and / or provide a flow (e.g., downward) toward the bottom of the condenser and / or MW extraction chamber, e.g., to collect the liquid composition in liquid and / or vapor form in a collection tank.

[0046] The pressure reducing means may be a condenser.

[0047] For example, organic material in a central chamber disposed on a conveyor means can be heated by microwave radiation from above (e.g., at least one microwave generator is disposed above the conveyor means and / or the organic material in the central chamber), and optionally, pressure can be reduced on the opposite side of the organic material and / or conveyor means, i.e., below the organic material and / or conveyor means.

[0048] By heating the organic material in the central chamber, preferably on the conveyor means, the pressure in the central chamber can be increased, which can help direct the vapor to the condenser to condense the generated steam or water vapor. For example, the pressure can be increased relative to the organic material and / or the conveyor means. This can provide a flow through the conveyor means and / or towards the bottom of the condenser and / or collection tank and / or MW extraction chamber (e.g., downwards) at a lower pressure than the organic material and / or the conveyor means (which can be reduced by using a means for reducing the pressure), for example, to collect the liquid composition in liquid and / or vapor form in the collection tank.

[0049] One aspect is an apparatus for extracting a liquid composition from an organic material, comprising: (i) an MW cavity, - an MW extraction chamber having an inlet opening and an outlet opening for the organic material and a collection opening at its bottom for collecting the liquid composition; a microwave generation chamber separated from a MW extraction chamber; (ii) at least one microwave generator positioned to heat the organic material in the MW extraction chamber; (iii) an inlet tunnel opening into the inlet opening of the MW extraction chamber and an outlet tunnel extending from the outlet opening of the MW extraction chamber; (iv) An apparatus comprising an entrance tunnel, a conveyor means for transporting the organic material through the MW extraction chamber and an exit tunnel. Description of the Invention [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of a first embodiment of the device. [Figure 2] FIG. 2 is a longitudinal cross-sectional view of a second embodiment of the device. [Figure 3]FIG. 10 is a longitudinal cross-sectional view of a third embodiment of the device.

[0051] MODE FOR CARRYING OUT THE INVENTION Throughout the following description and drawings, corresponding like parts are identified by the same reference numerals, and specific details are set forth to provide a more thorough understanding to those skilled in the art. However, to avoid unnecessarily obscuring the present disclosure, well-known elements may not be shown or described in detail. Accordingly, the description and drawings should be regarded in an illustrative sense, rather than a restrictive sense.

[0052] The extraction device 1 comprises a MW cavity 2, whereby the organic material is heated by microwaves generated by one or more microwave generators 14, causing substances to be released from the organic material and extracting a liquid composition containing said substances, which then leaves the MW cavity 2 and is then collected in a collection tank 3.

[0053] Apparatus 1 has an input end 4 and an output end 5 of a travel path for organic material through the apparatus, with an organic feedstock loading module 6 at input end 4 and a processed organic material discharge module 7 at output end 5. According to one embodiment, apparatus 1 has an outer housing 8 on a support frame (not shown).

[0054] The MW extraction chamber 9, which is open on both sides, extends axially into an inlet tunnel 16a and an outlet tunnel 16b at its inlet opening 17a and outlet opening 17b, respectively. A microwave-transparent cover 10 made of a microwave-transparent material forms a ceiling within the MW extraction chamber 9.

[0055] According to the present invention, the microwave transparent material, such as the microwave transparent cover or microwave transparent layer or microwave transparent conveyor means, comprises 1,2-polybutadiene (PBD, 1,2-polybutadiene), polyisoprene, polybutadiene-polyisoprene copolymer, polyetherimide (PEI, polyetherimide), polytetrafluoropolymer such as fluoroethylene (PTFE, polytetrafluoroethylene), polyimide, polyetheretherketone (PEEK, polyetherimide), polyamideimide, polyethylene terephthalate (PET, polyethylene naphthalate), polycyclohexylene terephthalate, polybutadiene-polyisoprene copolymer, polyphenylene ether, alkylated polyphenylene ether polymers based on polyphenylene ether, or combinations thereof. Combinations of high and low polarity may be used, including, but not limited to, epoxy and poly(phenylene ether), epoxy and poly(etherimide), cyanate, ester and poly(phenylene ether) {cyanate ester and poly(phenylene ether)}, and 1,2-polybutadiene and polyethylene. Preferably, the microwave transparent layer comprises PEEK and / or PTFE (PEEK / PTFE-5).

[0056] The MW extraction chamber 9 has a bottom 11 that may be inclined relative to a horizontal plane, and the collection duct opening 3a is preferably located close to a side wall 12 of the MW extraction chamber 9 for collecting the liquid, and if inclined, is preferably located at the lower end of the bottom 11 of the MW extraction chamber 9. The side wall 12 is provided with openings having substantially the size of the inlet and outlet tunnels, which communicate with the inlet and outlet tunnels 16a and 16b, respectively. Typically, the inner surfaces of the side wall 12 and bottom 11 of the MW extraction chamber 9 comprise a material that reflects microwaves, such as a metal, typically copper, steel, aluminum, lead-tin, zinc, brass, gold or silver.

[0057] At least the bottom of the MW extraction chamber and / or the exit tunnel may be horizontal or preferably inclined and preferably flat.

[0058] The longitudinal extension of each of the inlet and / or outlet tunnels is preferably at least 20%, preferably at least 40%, more preferably at least 60% of the longitudinal extension of the MW cavity, etc.

[0059] The longitudinal extension may be an extension of the conveyor means in the entrance tunnel, the MW extraction chamber and / or the exit tunnel and / or an extension parallel to the conveying direction.

[0060] The longitudinal extension of the inlet tunnel is preferably at least 200%, preferably at least 400%, more preferably at least 600% of the diameter of the inlet opening in the side wall of the MW cavity. The longitudinal extension of the outlet tunnel is preferably at least 200%, preferably at least 400%, more preferably at least 600% of the diameter of the outlet opening in the side wall of the MW cavity.

[0061] The longitudinal extension of each of the inlet and / or outlet tunnels is preferably at least 200%, preferably at least 400%, more preferably at least 600% of the average diameter of the inlet and outlet openings in the side wall of the MW cavity.

[0062] The longitudinal extension of each of the inlet and / or outlet tunnels is preferably less than 150%, preferably less than 100%, more preferably less than 80% of the longitudinal extension of the MW cavity, etc.

[0063] The cross section of the inlet and / or outlet tunnel is preferably smaller than the cross section of the MW cavity, preferably by at least 20%, or at least 40%. Each of the cross-sectional surfaces may extend perpendicular to the respective longitudinal extension and / or conveying direction of the conveyor means, along which the conveyor means convey the organic material through the inlet tunnel, the MW extraction chamber and the outlet tunnel.

[0064] Preferably, the entrance and exit tunnels extend centrally and axially through the microwave cavity, and the conveyor belt 15 is located in the lower half of these tunnels.

[0065] The cross-sectional shape of the entrance and exit tunnels may be rounded or, preferably, rectangular.

[0066] Above the microwave-transparent cover 10 and the microwave extraction chamber 9 is a microwave generation chamber 13. The microwave generation chamber 13 a) houses one or preferably several microwave generators 14 that generate microwave radiation that traverses the MW-transparent cover 10 separating the microwave generation chamber 13 from the MW extraction chamber 9, or b) is connected to or houses at least a portion of one or preferably several waveguides that are respectively connected to one or preferably several microwave generators 14, which may be located outside the microwave generation chamber 13. The microwave-transparent cover 10 airtightly separates the MW extraction chamber from the microwave chamber, e.g., so that neither vapors nor volatile substances can leak from the MW extraction chamber 9 into the microwave generation chamber 13. The microwave generation chamber 13 is sealed from the MW extraction chamber 9 but not from the atmosphere; it is therefore filled with air and is at atmospheric pressure. A motor-driven microwave agitator (not shown) is preferably provided in the microwave generation chamber 13 to disperse the generated microwaves and facilitate uniform microwave distribution in the MW extraction chamber 9. A typical microwave agitator comprises a motor having an output shaft and a stirring blade with a holder connected to the output shaft at its middle, with wings extending radially outward. The teachings of EP 1 566 986 are incorporated by reference with regard to possible implementations of such a MW agitator.

[0067] The conveyor means comprises at least one conveyor belt 15, conveyor rollers 15a, 15b, 7a for guiding and supporting the conveyor belt(s), and a conveyor drive control system necessary to continuously transport the organic material extracted from the loading module 6 through the entrance tunnel 16a to the MW cavity 2, the MW extraction chamber 9 and the exit tunnel 16b at a controlled speed. In the MW extraction chamber 9, the conveyor belt 15 extends substantially parallel to the cover 10 so that the organic material loaded on top of the conveyor belt 15 is in close proximity to or direct contact with the cover 10. The conveyor belt 15 extends into the loading and unloading modules 6, 7, as will be described below, forming a continuous loop, for example by running underneath the MW cavity 2 and the entrance and exit tunnels 16a, 16b. The conveyor belt 15 is made permeable to the liquid extracted from the raw materials, for example, by having pores or other openings or structural features that retain the treated organic material but allow the liquid to drain by gravity. Typically, the conveyor belt can contain pores having an average diameter (d) of 0.001 to 30 mm, preferably 0.01 to 20 mm. During the MW thermal extraction process, the organic material remains on the conveyor belt while the liquid drains from the organic material and reaches the bottom of the MW extraction chamber 9.

[0068] The path of the conveyor belt 15 may be inclined, preferably upwards in the direction of travel, at least inside the MW extraction chamber and / or the exit tunnel. The inclinations in these sections may be the same or different. Preferably, the non-zero inclinations are substantially the same in the entrance tunnel, the MW extraction chamber, and the exit tunnel.

[0069] The MW extraction chamber 9 is equipped with at least one steam nozzle(s). To facilitate the extraction of soluble compounds from the organic material, steam is injected into the MW extraction chamber 9 by nozzles 18 preferably located in one or both of the closed side wall(s) of the MW extraction chamber 9 (positioned perpendicular to the open side wall) and below the cover 10, preferably substantially at the level of the organic material above the conveyor belt 15. Some nozzles may be located below the level of the conveyor belt 15. The addition of steam is particularly important when extracting compounds from dry biomass or from biomass with reduced moisture levels, such as seeds or berries or spices.

[0070] The loading module 6 has an organic material feed distributor 6a, such as a hopper, which is positioned above the conveyor belt 15 and configured to drop the organic material to be processed onto the conveyor belt 15. The conveyor belt 15 runs over conveyor rollers 15a within the loading module 6. Advantageously, the conveyor rollers are made of or incorporated into a microwave transparent material.

[0071] A raw material supply tank (not shown) is connected to the raw material supply distributor 6a via a supply conduit. A supply controller can be provided to control the flow of raw material into the distributor. The supply tank is at atmospheric pressure. The raw material is generally solid organic material such as biomass fruits, flowers, leaves, seeds, etc., or in the form of small pieces that can be loaded onto the conveyor belt 15 by a conduit, auger, or other transfer device that can then convey the material into the conveyor belt 15.

[0072] The entrance tunnel 16a, which opens into the entrance 17a of the MW extraction chamber 9, is particularly advantageous in that the organic material is packed or thickened in the light of the tunnel before reaching the MW extraction chamber 9, reducing leakage of microwaves outside the MW cavity 2. The entrance tunnel 16a may be of a lower height than the height of the MW extraction chamber 9 and the exit tunnel.

[0073] To avoid loss of water vapor and thus loss of volatiles extracted from the raw material, the loading module 6, in particular the feed distributor 6a, can be sealed to the feed tank. The interior of the loading module is open to the MW cavity 2 and is therefore under reduced pressure during operation of the device. An observation window (not shown) in the outer housing 8 allows visual inspection inside the loading module 6 and thus inside the MW extraction chamber 9.

[0074] An exit tunnel 16b extends from the exit opening 17b of the MW extraction chamber 9 to facilitate cooling of the treated organic material and to complete the extraction of remaining volatiles before reaching the evacuation module 7.

[0075] The bottom of the outlet tunnel 16b is preferably inclined towards the MW cavity 2 and is preferably located at a higher level, preferably by a downward step relative to the bottom of the MW cavity 2, to facilitate the flow of condensed liquid back into the MW cavity 2 and into the outlet opening 17b located at its bottom. To facilitate the flow of liquid from the walls of the outlet tunnel 16b into the MW extraction chamber 9, the central axis of the MW cavity 2 and therefore the central axis of the outlet tunnel 16b is inclined from the ground by 0, 5 and 40 degrees, preferably 2 to 10 degrees.

[0076] The outlet tunnel 16b may have its own outlet duct (not shown) at its bottom, which may communicate with a tank, for example a collection tank 3, which is in fluid connection with the collection duct 3b at the bottom of the MW extraction chamber 9.

[0077] Advantageously, a cooling system 19 is provided, for example in the side walls and / or ceiling and / or bottom of the exit tunnel 16b, to accelerate the cooling of the raw material and the condensation of volatile substances on the side walls of the exit tunnel 16b.

[0078] The entrance tunnel 16a and the exit tunnel 16b also reduce the level of microwaves leaking out of the MW extraction chamber 9. To further facilitate reducing microwave leakage from the MW extraction chamber 9, microwave traps 20 are located in at least the exit tunnels, and preferably in both the entrance tunnel 16a and the exit tunnel 16b. Typically, the microwave trap 20 is an absorptive trap, a reactive trap, or a hybrid trap; preferably, the microwave trap 20 is a hybrid trap.

[0079] Reactive traps are characterized by a set of metal parts, typically cylinders, arranged to attenuate wave leakage. The number of metal parts, their height, diameter, and positioning are related to the geometry of each device.

[0080] The absorber trap adapted to the present invention has the properties of a microwave absorbing plate. Typically, the microwave absorbing plate is dielectrically heated by microwave leakage and is advantageously coupled to a cooling system 19. The absorber trap according to the present invention contains a metal or mineral powder selected from ferrite powder, carborundum powder, alumina powder, calcium oxide powder, magnesia powder, titanium oxide powder, zirconia powder, silica powder, kaolin, feldspar, gypsum, graphite, or a combination thereof. The metal or mineral powder has an average diameter of 5 to 100 μm. Typically, the absorber trap contains a mixture of a metal or mineral powder and an insulating material, advantageously a mixture of a metal powder and an insulating material. The insulating material is a natural or synthetic polymer, typically rubber, and the metal powder is ferrite powder.

[0081] According to another embodiment, the sorbent trap is a cooling system 19, which comprises a network of pipes, typically polymer pipes (eg polyvinyl chloride), carrying a liquid sorbent, advantageously water.

[0082] Advantageously, the trapping system is a hybrid trap, which is a mixture of a reactive trap and an absorptive trap.

[0083] Examples of reactive, absorptive or hybrid traps suitable for the present invention are described in CN202282884, CN214481362, CN102752892 or US4182946.

[0084] According to a first embodiment of the tunnel (described with respect to the entrance tunnel in Figures 1 and 2), a reactive microwave trap is located in a first section of the tunnel adjacent to the MW extraction chamber 9, and an absorptive microwave trap is located in a second section of the tunnel, away from the MW extraction chamber 9. According to this embodiment, the cooling system may be limited to the section of the exit tunnel away from the MW cavity (described with respect to the entrance tunnel in Figure 1), or a cooling system may be added along the entire exit tunnel (described with respect to the entrance tunnel in Figure 1). According to another embodiment, the microwave trap may be located in the section of the tunnel closest to the central chamber. Similarly, according to this second embodiment, the cooling system may be located only on the outer wall of the tunnel with the microwave trap (described with respect to the exit tunnel in Figure 2) or along the entire tunnel (described with respect to the exit tunnel in Figure 1). According to another embodiment, the cooling system is located on the outer wall of the tunnel(s) except for the bottom of the tunnel(s).

[0085] Microwave traps 20 in the entrance tunnel 16a and exit tunnel 16b effectively trap microwaves escaping from the MW extraction chamber 9, and the external housing 8 of the device is optional in terms of its MW shielding, which nevertheless remains highly advantageous for some raw materials for safety, microbiological, and extraction yield reasons.

[0086] According to another embodiment, the MW cavity 2 is equipped with doors (not shown), preferably sliding doors, at the inlet 17a and outlet 17b of the MW extraction chamber 9. Such doors are advantageous for operating in batch mode.

[0087] Advantageously, the central axis of the conveyor belt is inclined to promote the flow of liquid from the processed raw material along the conveyor belt to the MW extraction chamber 9. Typically, the conveyor belt may be inclined at least within the MW extraction chamber 9, preferably at least from the entrance 17a of the MW extraction chamber 9 to the opening 16c of the exit tunnel 16b, and optionally from the entrance 17a of the MW extraction chamber 9 to the discharge module 7. Some means may be arranged to stop the liquid flowing along the belt from going beyond the entrance opening 17a of the MW extraction chamber 9. For example, the bottom of the entrance tunnel is arranged at a higher level than the bottom of the MW extraction chamber 9. Typically, the axis of the conveyor belt is inclined from the ground at 0, 5 and 60 degrees, preferably 2 to 10 degrees.

[0088] It is particularly advantageous for the conveyor belt 15 to extend below the MW cavity 2 to form a continuous loop, so that the liquid extract from the organic material is gravity-discharged through the conveyor belt 15 at the bottom of the MW extraction chamber 9. Nevertheless, another continuous loop can be envisaged laterally or within the MW cavity. A collection system can be envisaged for scraping the surface of the belt free of raw material before it leaves the MW extraction chamber 9. It is also particularly advantageous for a cooling system 19a to be arranged within the wall of the MW cavity in order to maintain the liquid extract in liquid form and facilitate its collection in the collection duct 3a. The cooling system 19a is also particularly advantageous for continuous operation of the apparatus.

[0089] As the organic raw material is in intimate contact with the upper walls of the inlet tunnel 16a, the cover 10 of the MW extraction chamber 9 and the outlet tunnel 16b, said upper walls are advantageously protected by a microwave transparent layer comprising a heat-resistant material.

[0090] The discharge module 7 has conveyor rollers 7a that guide the conveyor belt 15. A material collector 7c is positioned below the outward rollers to receive processed material coming from the exit tunnel 16b and dropping from the conveyor belt 15. The drive roller(s) 7a are rotated by a motor (not shown) to drive the conveyor belt 15. The discharge module 7 is contained within the apparatus and surrounded by an outer housing 8 (FIGS. 1 and 2), which is fixed and sealed to the output end 5 of the apparatus 1, and an observation window (not shown) may be positioned to allow visual inspection within the discharge module. The discharge module opens to the MW extraction chamber 9 via the exit tunnel 16b and is therefore under reduced pressure during operation of the apparatus.

[0091] Optionally, an auger conveyor 7b is positioned below the material collector 7c to receive the processed material therefrom. A vacuum seal between the lower end of the material collector 7c and the auger conveyor 7b maintains the vacuum within the MW extraction chamber 9 and the auger conveyor 7b. The auger 7b is driven by a motor (not shown). An outlet valve (not shown) at one end of the auger conveyor 7b may be positioned to remove the processed material from the apparatus 1. Such a valve functions as an airlock to allow removal of the processed product. A container (7d), advantageously vacuum-sealed, for receiving the processed product is attached to the valve. One valve opens once to allow the container 7d to receive the product from the auger 7b, while the other valve closes to allow the filled container to be removed from that valve. The two valves are alternately opened and closed to allow the auger 7b to operate continuously.

[0092] A cooling system may be provided around the collection duct 3b and the tank 3.

[0093] A pump 3d is connected to the tank 3 to suck the water vapor produced in the MW extraction chamber 9 into a collection duct 3b. The tank may therefore be at a lower pressure than the MW extraction chamber. Ideally, a condenser is placed in front of the vacuum pump 3d. The collection duct 3b is connected to a condenser 3c, which is connected to the tank 3 in which all the liquid extracted from the raw material is stored.

[0094] The water vapor sucked from the MW extraction chamber 9 is condensed by the condenser 3c and the resulting liquid is stored in the tank 3.

[0095] Vacuum pump 3d reduces the pressure in apparatus 1, or at least in MW extraction chamber 9, to below atmospheric pressure, preferably between 0.99 and 0.001316 atm, and even more preferably between 0.55 and 0.01316 atm. This pressure difference is particularly advantageous in that it limits the loss of water vapor and therefore the loss of volatiles from apparatus 1, or at least MW extraction chamber 9. Extraction of volatiles from the MW extraction chamber also reduces the exposure of the volatiles to heat and therefore potential degradation.

[0096] Alternatively, the tank 3, pump 3d and condenser 3c may be within the external housing 8 of the device (see Figure 2).

[0097] As mentioned above, the apparatus includes one or several cooling units (not shown), each equipped with a compressor, a cooling fan, and a refrigerant pump, connected to convey a refrigerant via refrigerant pipes extending along any and / or all walls of the MW extraction chamber 9, the inlet tunnel 16a, the outlet tunnel 16b, the collection duct 3b, and / or the tank 3.

[0098] According to the present invention, the apparatus 1 includes a programmable logic controller (PLC) programmed and connected to control the operation of the system, including controlling the inflow of raw materials, a motor, a microwave generator, a vacuum pump, and a coolant pump.

[0099] The extraction apparatus 1 operates in the following manner. The coolant pump, microwave generator, motor, and raw material supply controller are all operated under the control of a PLC. The organic material to be processed is fed onto a conveyor belt 15 and transported through an inlet tunnel 16a and an inlet opening 17a into the MW extraction chamber 9 beneath the cover 10. The microwave generator generates microwaves having a central frequency between 0.3 and 300 GHz, preferably between 0.5 and 5.2 GHz, 0.8 and 3 GHz, or 0.9 and 2.5 GHz. Typically, the microwave generator is a variable frequency microwave generator. Advantageously, the microwave generator generates microwaves having a central frequency of 2450 MHz at a power between 300 W and 6000 W, preferably between 1000 W and 3000 W. According to another embodiment, the microwave generator generates microwaves having a central frequency of 915 MHz at a power between 300 W and 6000 W, preferably between 1000 W and 3000 W. The processing time can range from 0.1 to 20 kg / h, typically 0.5 to 12 kg / h. Typically, the processing time can be approximately 5 minutes to 2.5 hours, preferably 8 minutes to 2 hours, and even more preferably 10 minutes to 1 hour. The liquid flows through the conveyor belt 15 to the bottom of the MW extraction chamber 9, where it is collected in the collection opening 3a and stored in the tank 3. Steam condenses on the side walls of the MW extraction chamber 9 or the exit tunnel 16b, flows to the side walls of the MW extraction chamber 9, and reaches the collection duct opening 3a at the bottom of the MW extraction chamber 9. Extraction of volatile substances is enhanced by radiation and facilitated by steam sprayed onto the raw material by the nozzles 18. Steam is drawn from the MW extraction chamber 9 and from the entrance tunnel 16a and / or exit tunnel 16b into the collection duct 3b, where it is condensed by the condenser 3c and stored in the tank 3. The processed material falls into a material collector 7c and travels to an auger conveyor 7b where it is removed from the system through outlet valve 5.

Claims

1. 1. An apparatus for extracting a liquid composition from an organic material, comprising: A MW cavity (2), a MW extraction chamber (9) having an inlet opening (17a) and an outlet opening (17b) for said organic material and a collection opening (3a) at its bottom for collecting the liquid composition; a MW cavity (2) comprising a microwave generation chamber (13) separated from the MW extraction chamber (9); at least one microwave generator (14) arranged to heat the organic material in the MW extraction chamber (9); an inlet tunnel (16a) opening into the inlet opening (17a) of the MW extraction chamber (9) and an outlet tunnel (16b) extending from the outlet opening (17b) of the MW extraction chamber (9); and conveyor means (15, 15a, 15b, 7a) for transporting organic material through said entrance tunnel (16a), said MW extraction chamber (9) and said exit tunnel (16b).

2. 2. The apparatus of claim 1, wherein the microwave generation chamber (13) comprises the at least one microwave generator (14).

3. 3. The apparatus according to claim 1, wherein one, more or all of the outlet tunnel (16b), the MW extraction chamber (9) and the duct (3b) connected to the collection opening (3a) are provided with cooling means.

4. 4. The apparatus according to claim 1, wherein the outlet tunnel (16b) is arranged such that liquid condensing in the outlet tunnel (16b) flows towards the bottom of the MW extraction chamber (9).

5. 5. Apparatus according to any one of claims 1 to 4, wherein the entrance tunnel (16a) and / or the exit tunnel (16b) comprises at least one microwave trap.

6. The apparatus of claim 5 , wherein the microwave trap is an absorptive, reactive, or hybrid microwave trap.

7. 7. Apparatus according to any one of claims 1 to 6, wherein the entrance tunnel (16a) and / or the exit tunnel (16b) comprise two microwave traps, the microwave trap closer to the MW extraction chamber (9) being a reactive trap and preferably the microwave trap further from the MW extraction chamber (9) being an absorptive trap.

8. 8. Apparatus according to any one of claims 1 to 7, wherein a microwave-transparent cover (10) hermetically separates the MW extraction chamber (9) from the microwave generation chamber (13).

9. 9. The apparatus according to any one of claims 1 to 8, comprising means for reducing the pressure in the MW extraction chamber (9) and directing the produced steam to a condenser of the apparatus (1) for condensing the steam.

10. 10. Apparatus according to any one of claims 1 to 9, wherein the conveyor means comprises a conveyor belt (15) having a longitudinal axis inclined at least inside the MW extraction chamber (9) and the exit tunnel (16b) from the horizontal plane between 0.5 and 60 degrees.

11. 11. Apparatus according to any one of claims 1 to 10, wherein the bottom of the MW extraction chamber (9) and / or the outlet tunnel (16b) has an inclination of between 0.5 and 60 degrees from the horizontal plane, with a lower end preferably towards the inlet opening of the MW extraction chamber (9).

12. 12. Apparatus according to any one of claims 1 to 11, wherein the MW extraction chamber (9) comprises at least one steam nozzle(s), preferably arranged on a side wall of the MW extraction chamber (9) above or near the conveyor belt (15).

13. 13. Apparatus according to any one of claims 1 to 12, wherein the bottom of the inlet tunnel (16a) and / or the outlet tunnel (16b) is arranged at a higher level than the bottom of the MW extraction chamber (9), preferably via a step.

14. 1. A method for extracting a liquid composition from an organic material, comprising: (a) introducing the organic material into a MW extraction chamber, the MW extraction chamber being positioned to receive microwave radiation from at least one microwave generator; (b) reducing the pressure in the MW extraction chamber to below atmospheric pressure; (c) optionally spraying the organic material with water vapor; (d) collecting the water vapor condensed by the condenser and collecting the liquid produced from the MW extraction chamber and the condenser in a collection tank; (e) removing the treated organic material from the MW extraction chamber.

15. A method for extracting a liquid composition from organic material by using a device (1) according to any one of claims 1 to 13.

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