Distillation Apparatus And Method For Extraction Of Volatile Components From Biological Material, Especially From Plants

Abstract

The invention refers to a distillation apparatus (100) for extraction of volatile components from biological material (50), especially from plants, comprising a housing (10) defining a sample chamber (S), a drum (30) arranged in the sample chamber (S), the drum (30) defining a receiving chamber (R) for receiving the biological material (50), and at least one microwave generator (70) for irradiating the biological material (50) with microwave radiation when received in the drum (30); wherein the drum (30) is rotatably arranged in the sample chamber (S) about a rotation axis (H) which is oriented substantially horizontally.

Claims

1. Distillation apparatus (100) for extraction of volatile components from biological material (50), especially from plants, comprising: a housing (10) defining a sample chamber (S), a drum (30) arranged in the sample chamber (S), the drum (30) defining a receiving chamber (R) for receiving the biological material (50), and at least one microwave generator (70) for irradiating the biological material (50) with microwave radiation when received in the drum (30); wherein the drum (30) is rotatably arranged in the sample chamber (S) about a rotation axis (H) which is oriented substantially horizontally.

2. Distillation apparatus (100) according to claim 1, wherein the receiving chamber (R) is configured to receive at least one flexible receptacle (51) into which the biological material (50) is loaded, the receptacle (51) preferably being a bag such as a cotton bag.

3. Distillation apparatus (100) according to claim 1, wherein a bottom space (B) of the sample chamber (S) is configured to be filled with a liquid (L) such as water, and wherein the drum (30) is arranged such that part of the receiving chamber (R) is arranged in the bottom space (B) so as to immerse in the liquid (L) when the bottom space (B) is filled with said liquid (L).

4. Distillation apparatus (100) according to claim 3, wherein the housing (10) comprises an opening (O) for accessing the drum (30), the opening (O) being selectively closable by a door (11), and wherein the opening (O) is preferably positioned above the bottom space (B), if present.

5. Distillation apparatus (100) according to claim 1, comprising: a plurality of microwave generators (70), preferably three microwave generators (70); wherein the main emission directions (M) of the microwave generators (70) are substantially orthogonal and preferably not-intersecting, and wherein each main emission (M) direction is preferably either substantially perpendicular or substantially parallel to the rotation axis (H) of the drum (30).

6. Distillation apparatus (100) according to claim 1, further comprising: at least one heating element (90), such as a heating pad (90), wherein the heating element (90) is arranged and configured to heat an inner wall (15) of the housing (10) defining the sample chamber (S).

7. Distillation apparatus (100) according to claim 1, further comprising: at least one condenser configured to condense the volatile components, wherein the condenser is fluidly connected to the sample chamber (S) via an outlet (14) and arranged downstream of the sample chamber (S).

8. Distillation apparatus (100) according to claim 7, further comprising: a collection vessel configured for collecting the condensed volatile components, the collection vessel being fluidly connected to and arranged downstream of the condenser, wherein the collection vessel preferably is configured for separating the condensed volatile components from residual liquid, such as condensed water, wherein the collection vessel preferably is fluidly connected to the sample chamber (S) via an inlet to return the condensed residual liquid to the sample chamber (S), wherein the inlet preferably is at a location different from the outlet (14).

9. Distillation apparatus (100) according to claim 1, further comprising: at least one temperature sensor (21, 22) provided to monitor a process temperature at at least one desired location of the apparatus (100), wherein in case of the collection vessel be provided, preferably the temperature sensor is provided to monitor the temperature of the condensed volatile components as the process temperature, and/or a control unit to control the process of the apparatus (100), preferably based on process parameters like the process temperature.

10. Distillation apparatus (100) according to claim 1, wherein the drum (30) has a drum wall (31) defining the receiving chamber (R), the drum wall (31) preferably extending circumferentially about the rotation axis (H), and/or wherein the drum (30), preferably its drum wall (31) if present, is at least partially permeable to microwave radiation and/or liquid and/or the volatile components, and/or wherein the drum (30) comprises at least one carrier protruding towards the receiving chamber (R) to facilitate a tumbling motion of the biological material (50) or receptacle (51), if present, when the drum (30) is rotating.

11. Method for extracting volatile components from biological material (50), especially from plants, comprising: loading (S1) the biological material (50) into a receiving chamber (R) of a drum (30) being arranged in a sample chamber (S), in which the drum (30) is arranged rotatably about a rotation axis (H) being oriented substantially horizontally, irradiating (S2) the biological material (50) with microwave radiation while the drum (30) is rotating, and collecting (S3) the volatile components.

12. Method according to claim 11, further comprising: filling (S1b) a bottom space (B) of the sample chamber (S) with liquid (L), preferably water, wherein part of the receiving chamber (R) immerges in the liquid (L) so that the biological material (50) is wetted, preferably continuously or periodically wetted, with the liquid (L) during rotation of the drum (30), and/or pre-wetting (S0) the biological material (50) with a liquid, preferably water, prior to loading it into the drum (30) and/or in the filled bottom space (B), if present, preferably outside of irradiation of the biological material (50) with microwave radiation.

13. Method according to claim 11, further comprising: heating (S1b) at least one inner wall (15) of a housing (10) defining the sample chamber (S).

14. Method according to claim 11, wherein the step of collecting (S3) of the volatile components comprises condensing the volatile components in a condenser, which is fluidly connected to and arranged downstream of the sample chamber (S), wherein the condensed volatile components are preferably collected in a collection vessel being fluidly connected to and arranged downstream of the condenser, wherein the collected volatile components are preferably separated from residual liquid, such as condensed water, and wherein the residual liquid is preferably returned to the sample chamber (S), if desired, and/or wherein the method further comprises monitoring a process temperature of the method, and controlling the method, preferably the irradiation (S2) of the biological material (50) and/or the heating (S1b) of the at least one inner wall (15), based on the monitored process temperature, wherein controlling the method based on the monitored process temperature preferably comprises stopping the irradiation (S2) of the biological material (50) and/or stopping the heating (S1b) of the at least one inner wall (15) in case a define threshold value of the monitored process temperature is underrun or exceeded, and further preferably comprises continuing the irradiation (S2) of the biological material (50) and/or continuing the heating (S1b) of the at least one inner wall (15) in case the process temperature again rises over or drops below the said threshold value, wherein in case of the collection vessel be provided, preferably at least the temperature of the condensed volatile components is monitored as the process temperature.

15. Method according to 111 claim 11, wherein the biological material (50) is provided, preferably filled, in a flexible receptacle (51), preferably a bag such as a cotton bag, prior to being loaded into the receiving chamber (R), and/or wherein the biological material (50) is in a fresh or pre-processed state, such as (freeze-) dried, frozen and/or cut, prior to being loaded into the receiving chamber (R), and/or wherein the biological material (50) is plant material from the biological family Cannabaceae, and wherein the volatile component preferably is from the group of terpenes.

Description

BRIEF DISCUSSION OF THE DRAWINGS

[0054] FIG. 1 shows a schematic front view of a distillation apparatus according to an embodiment of the present invention.

[0055] FIG. 2 shows a sectional front view of a distillation apparatus according to another embodiment of the present invention.

[0056] FIG. 3 shows a flow chart of a distillation method according to an embodiment of the present invention.

DETAIL DESCRIPTION OF THE INVENTION

[0057] A distillation apparatus 100 according to the present invention is schematically shown in FIGS. 1 and 2. The distillation apparatus 100 is an apparatus 100 for extraction of volatile components such as terpenes from biological material 50 such as plants, for example from the biological family Cannabaceae. The apparatus 100 comprises a housing 10 which defines a sample chamber S. A drum 30 is arranged in the sample chamber S. The drum 30 defines a receiving chamber R for receiving the biological material 50. The drum 30 is rotatably arranged in the sample chamber S about a rotation axis H, which is oriented substantially horizontal. The drum 30 is, for example, driven by a motor that is preferably arranged outside of the sample chamber S. The apparatus 100 further comprises at least one microwave generator 70 for irradiating the biological material 50 with microwave radiation, when the biological material 50 is received in the drum 30.

[0058] The biological material 50 may be positioned in the receiving chamber R as loose material or in a flexible receptacle 51, as shown in FIGS. 1 and 2. The flexible receptacle 51 is easy to handle and may be prepared in advance and then transported to the distillation apparatus 100, e.g. in a tray 13. The receptacle 51 can be a bag made from cotton and may be reusable.

[0059] As particularly shown in FIG. 2, the sample chamber S preferably has a bottom space B that may be filed with a liquid L. The type of liquid L used depends on the specific extraction, i.e. on the process parameters and type of biological material. However, it is preferred that water is used as the liquid L. The bottom space B may be filed with the liquid L from a liquid reservoir 80 fluidly connected to the sample chamber S. The liquid reservoir 80 may, for example, be a water container. A pump 82 may be provided and configured to selectively transfer the liquid from reservoir 80 to the bottom space using suitable valves 81, 83. A separate reservoir 86 may be used for a different liquid to be used for influencing the extraction or for containing a cleaning liquid to be used for cleaning the apparatus 100 in-between some or all extraction cycles. To release the liquid L from the bottom space, a collection container 85 may be fluidly connected to the bottom space, selectively closable and openable by a valve 84.

[0060] In a preferred embodiment, a level sensor 20 can be provided to monitor the filling level of the bottom space B. Also, temperature sensors 21, 22 may be provided to monitor a process temperature at at least one or a plurality desired location(s) of the apparatus 100. The process temperature can be the temperature in the sample chamber S (e.g. by temperature sensor 21 as exemplarily shown in FIG. 2) and/or in the receiving chamber and/or in the bottom space (e.g. by temperature sensor 22 as exemplarily shown in FIG. 2), preferably of the liquid filled in the bottom space B.

[0061] The apparatus 100 may comprise a control unit (not shown) to control the process of the apparatus 100; preferably dependent on particular process parameters like process temperatures (e.g. temperatures in the chamber(s), of the liquid and/or of the biological material), e.g. based on the data received by the sensors 20 to 22, and/or the type and/or amount of biological material, and the like. Hence, the filling level of the bottom space B can be controlled during operation or a cleaning cycle be carried out automatically. Also, the microwave generators 70 can be controlled to be operated for a most efficient and effective distillation process.

[0062] The drum 30 is preferably arranged such that part of it—i.e. a bottom part thereof—immerses in the liquid L in the bottom space B, when it is filled with the liquid L. Therefore, in this case, when the drum 30 rotates, there is always a segment of the drum 30 entering the liquid L and another segment not in the liquid L. The dwell time of the segment in the liquid L depends on the rotational speed of the drum 30 and can be freely adjusted and also preferably controlled by the control unit.

[0063] As shown in FIG. 1, the housing 10 may comprise an opening O via which the drum 30 or its receiving chamber R can be accessed. It is preferred that the drum 30 is fixedly installed in the apparatus 10, so that the receiving chamber R remains in place for loading and unloading of the biological material 50. The opening O may be selectively closable by a door 11 of the housing 10. The door 11 is preferably attached by a hinge. Preferably, the opening O is positioned above the bottom space B, i.e. the lowermost part of the opening O is preferably higher than the uppermost portion of the bottom space B, so that the door 11 may be opened even if the bottom space B is maximum filled with the liquid L. The door 11 may further include a sealing 12 for sealing the sample chamber S against the environment of the apparatus 10 when being closed. Further means for promoting a tight close of the door 11 may be provided, such as springs, cabinet bolts, lever closures etc. The door 11 may also be optically transparent but non-transparent for microwave radiation to provide better monitoring of the extraction process. A door sensor (not shown) may be provided to monitor the closed state of the door 11. The control unit may be configured to prohibit or stop a process, particularly an operation of the microwave generators 70, if the door sensor monitors the door 11 not being in a closed or locked state.

[0064] The apparatus 100 may also comprise more than one microwave generator 70, i.e. a plurality of microwave generators 70, as best shown in FIG. 2. The microwave generators 70 may, for example, be magnetrons. The microwave generators 70 have a main emission direction M, in which the microwave radiation is emitted into the sample chamber S. When a plurality of microwave generators 70 are used, it is preferred that the main emission directions M are substantially orthogonal and preferably not-intersecting with each other. This can be achieved by placing the microwave generators 70 at different sides of the housing 10. The main emission direction M may, for example, correspond to the longitudinal direction of a microwave generator's waveguide. If using three microwave generators 70, these sides preferably corresponding to three axes of Cartesian coordinates. Note that the leftmost and uppermost microwave generators 70 as shown in FIG. 2 are preferably placed in different depths relative to the picture plane, so that their axes M are not intersecting. Furthermore, as shown in FIG. 2, each main emission direction M is preferably also either substantially perpendicular or substantially parallel to the rotation axis H of the drum 30.

[0065] The apparatus 100 may further comprise at least one heating element 90, as shown schematically in FIG. 2. For example, such a heating element 90 may be a heating pad 90. The heating element 90 preferably is arranged and configured to heat an inner wall 15 of the housing 10 defining the sample chamber S. Here, the heating element 90 preferably is provided on/at the housing 10 to be in direct thermal contact with the inner wall 15. By heating the inner wall 15, condensation on the inner wall 15 can be avoided and heating can be made more efficient. The heating element 90 can also be controlled by the control unit.

[0066] While not explicitly shown in the figures, the apparatus 100 may further comprise one or more condensers configured to condense the volatile components. The condenser is preferably fluidly connected to the sample chamber S via an outlet 14 and arranged downstream of the sample chamber S. The condenser is preferably water-cooled. The fluid stream exiting the outlet 14 may be split into a plurality of streams, each fluidly connected to one of a plurality of condensers—preferably arranged in parallel—for increasing cooling capacity. To facilitate the volumetric flow rate of the fluid exiting the outlet 14, the condenser may further include a pump which may also be controlled by the control unit.

[0067] The volatile components condensed to a liquid (or solid) by the condenser are preferably collected in a collection vessel (not shown), such as a glass flask. It is also preferred that the collection vessel is configured for separating the condensed volatile components from residual liquid, such as condensed water. This separation may be done by using an elongated collection vessel, in which the condensed volatile components separate from residual liquid due to their different density and/or miscibility. For example, a commercial (glassware) separation system may be used. Preferably, the collection vessel or separation system can preferably be fluidly connected to the sample chamber S via an inlet (not shown) to return the condensed residual liquid, such as the condensed water, to the sample chamber S. Preferably, the return of liquid can be controlled by the control unit, e.g. by controlling a valve in a return piping. Preferably, the inlet is at a location different from the outlet 14, in order not to impede to cooling capacity of the condenser.

[0068] A vacuum pump (not shown) may be fluidly connected to the apparatus, e.g. the sample chamber and/or the condenser and/or the collection vessel, if present, so that the distillation process can be carried out under vacuum. The vacuum pump may be controlled by the control unit as well.

[0069] A temperature sensor (not shown) may be provided to monitor the temperature of the condensed volatile components, e.g. in the collection vessel, as the process temperature. Based on said process temperature, the control unit may control the process of the apparatus 100, e.g. by controlling the at least one microwave generator 70 and thus the irradiation of the biological material 50 and/or by controlling the at least one heating element 90 and thus the heating of the at least one inner wall 15. This will be described in more detail with respect to the method for extracting volatile components from biological material 50 herein below.

[0070] The drum 30 preferably has a drum wall 31 which defines the receiving chamber R. The drum wall 31 preferably extends circumferentially about the rotation axis H of the drum 30. The drum wall 31 may be one-piece or multi-piece. For example, the drum wall 31 may be made from a plurality of rods 32, extending in the axial direction of the drum 30 and fastened to circular end members 33 of the drum 30, as exemplarily shown in FIGS. 1 and 2. In another embodiment the drum wall 31 may be made of a mesh material or the like. The drum 30 and preferably its drum wall 31 is at least partially permeable to microwave radiation and/or liquid and/or the volatile components. This can, for example, be achieved by using rods or mesh material as described above. Preferably, the drum 30 is made from a non-metallic material in order not to interact with the microwave radiation. The drum 30 may be made from microwave transparent material, e.g. PTFE, ceramics, glass or the like.

[0071] The drum 30 and in particular the drum wall 31 may comprises one or more carriers protruding towards the receiving chamber R to facilitate a tumbling motion of the biological material 50 or receptacle 51, when the drum 30 is rotating. Such a carrier may, for example, be a protrusion formed on the drum wall 31 extending, for example, in a radial direction towards the rotational axis of the drum 30. Preferably, the rods 32 may act as the carriers, if present. The carrier thus acts as a carrier for biological material 50 or receptacle 51 contacting the protrusion, until contact is lost when the drum 30 has rotated far enough for the contact to be become instable. The biological material 50 or receptacle 51 then falls down from a particular height. This repeated motion of being carried for only part of the rotation and thus being lifted up, losing contact with the carrier and falling down thus forms a tumbling motion.

[0072] In the following, a method for extracting the volatile components from the biological material 50 according to the present invention and preferably by use of the apparatus 100 as described herein above is described.

[0073] An example for a method according to the present invention including further optional steps is shown in FIG. 3. The method comprises step S1, which includes loading the biological material 50 (preferably be received or filled in the receptacle 51) into the receiving chamber R of the drum 30 being arranged in the sample chamber S, in which the drum 30 is arranged rotatably about the rotation axis H being oriented substantially horizontally. Preferably after loading of the drum 30 is completed, rotation of the drum 30 is started in step S1a. In step S2, the biological material 50 is irradiated with microwave radiation while the drum 30 is rotating. In step S3, the volatile components are collected; for example by condensation and subsequent collection preferably in the collection vessel.

[0074] For example, the method according to the present invention allows heating water within the biological material, so that the cells of the biological material are distended and, for example, their glands and oleiferous receptacles are ruptured to free volatile components.

[0075] As described above, the bottom space B of the sample chamber S may be filled with the liquid L. This is preferably done in step S1b prior to step S2, i.e. prior to the irradiation. It is also possible to (e.g. continuously or successively or periodically or otherwise in a preferably controlled manner) keep filling the bottom space B of the sample chamber S during extraction, e.g. to maintain a constant liquid volume in the bottom space B. By filling the bottom space B with liquid L, it is possible to wet the biological material 50 to a desired degree for extraction and preferably maintain this state during extraction, thus increasing the amount of liquid available for evaporation and promoting breakage of cell walls, while further increasing microwave absorption of the biological material 50.

[0076] If desired, the biological material 50 may be pre-wetted with a liquid, preferably water, prior to loading it into the drum 30 in step S0. In addition or alternatively, the biological material 50 may also be pre-wetted in the filled bottom space B, preferably outside of irradiation of the biological material 50 with microwave radiation. Other pre-processing steps for the biological material 50 are also possible, such as cutting. If the biological material 50 is loaded into the receptacle 51, this may be done at step S0.

[0077] It is possible to heat the inner wall 15 of the housing 10 in order to reduce condensation thereon, as described above. The inner walls 15 are preferably heated continuously throughout the whole extraction process, and preferably to a temperature higher than the boiling point at least of the volatile components, preferably also of the liquid L for a given pressure in the sample chamber S. Heating of the inner walls 15 is preferably started in step S1b, but may also be a separate step.

[0078] As described, the volatile components may be condensed for collecting them, preferably by using a condenser and collecting the volatile components in the collection vessel described above. This may also be part of Step S3. As already described, the collected volatile components are preferably separated from residual liquid, such as condensed water, and the residual liquid is preferably returned to the sample chamber S.

[0079] The method may further comprise monitoring a process temperature of the method, and controlling the method, preferably the irradiation S2 of the biological material 50 and/or the heating S1b of the at least one inner wall 15, based on the monitored process temperature. In this regard, controlling the method based on the monitored process temperature may preferably comprise stopping the irradiation S2 of the biological material 50 and/or stopping the heating S1b of the at least one inner wall 15 in case a define threshold value of the monitored process temperature is underrun or exceeded. More preferred, controlling the method based on the monitored process temperature may additionally comprise continuing the irradiation S2 of the biological material 50 and/or continuing the heating S1b of the at least one inner wall 15 in case the process temperature again rises over or drops below the said threshold value. In case of the collection vessel be provided, preferably at least the temperature of the condensed volatile components is monitored as the process temperature.

[0080] When extraction is finished, the sample chamber S may be emptied in step S4, for example by opening the door 11 and manually or automatically removing the biological material 50 or receptacle 51 from the drum 30. Prior to loading the receiving chamber R of the drum 3o with a new batch of biological material 50 or new receptacle 51, it is preferred that a cleaning cycle is performed in optional step S5. This can be done, for example, by using ethanol or other cleaning liquid provided in container 86 and transferred into the sample chamber S, for example through a nozzle or the like, via pump 82. The cleaning cycle S5 may or may not include heating the sample chamber S to a defined temperature. The cleaning liquid can be removed to the collection container 85 via valve 84 and the extraction method can be started again. It is preferred that a cleaning cycle is only done when different types of biological material are to be used, for example when changing from one plant type to another. If the same biological material is used for two consecutive batches, no cleaning cycle is necessary.

[0081] The present invention allows to extract volatile components from substantially any biological material 50. The state of the biological material 50 may be in principle arbitrary and especially a fresh or pre-processed state, such as (freeze-)dried, frozen and/or cut. The present invention can be advantageously applied to plants or parts thereof, such as herbs, spices, fruits such as citrus fruits, flower buds etc. It is preferred that the biological material 50 is plant material from the biological family Cannabaceae, and the volatile component preferably is from the group of terpenes.