Patent Application
20230293612
The present application relates to the extraction of phytochemicals, more specifically to methods and systems for the selective extraction of phytochemicals from biomass.
In the Cannabis industry, extraction of essential Cannabis oils such as THC, CBD, and other cannabinoids, has become a focus for developing smokeless consumable products. Current means of extraction involve solvent or non solvent based methods. Solvent based methods include the use of hydrocarbons, supercritical fluids such as carbon dioxide, and ethanol as solvents. Non-solvent based methods include rosin pressing, dry sifting, or ice water extraction. Each process can produce a different type of recovered product (crude oil, rosin, hash, keif, etc.) depending on the conditions of the set up.
Drying of the biomass is critical for driving up the potency and is usually done at room temperature and at a humidity of between 55-65%. Drying of cannabis results in a reduction of water content from ˜70% by weight when harvested to 10-15% by weight when dried. Large harvests can occupy significant space when drying the biomass. Typical harvest drying times can range from 5 to 15 days. Low THC content materials are problematic for current solvent extraction technologies as it diminishes the yield and thus requires more material to be processed. This ultimately drives up cost and post processing handling. Such drying and processing typically represents around 25-30% of the total cultivation facility footprint. Solvent extraction technologies rely on high potency feedstock to be able to extract as much cannabinoids as possible with as little solvent required. However, solvent extractions add on the resources required, including material, infrastructure and money, as well as on the environmental footprint.
Drying is a critical step for forming a product that can be used for solvent extraction. Too high of a moisture content reduces throughputs and increases the amount of solvent required reducing throughput and increasing cost of operations. Additionally, solvent extraction processes are unable to selectively isolate individual constituents within the essential oils within their extraction step and rather will extract all soluble compounds (i.e. waxes, fats, paraffins). Furthermore, several post processing steps are required to achieve the final product such as winterization. Lastly, in the case of hydrocarbon and ethanol extraction, removal of the solvent from the product is an extremely important step in the process. Hydrocarbons and ethanol are highly flammable substances and are toxic if consumed. As such, residual amounts of solvents in extraction products represent a hazard to consumers.
In summary, there are many drawbacks in the current extraction techniques. For example, solvent extraction may have limited extraction efficiencies and throughputs based on feed stock composition; solvents used can be dangerous (flammable, combustible); some solvent may be trapped in the biomass and unable to be recovered. Non-solvent extraction may present low processing rates, may require large equipment foot print and be labour intensive. As such, there is a need to develop multi-use and versatile technology applicable to drying the harvested crop, to extraction of crude phytochemicals without the need for solvents, selective separation of cannabis components, and requiring limited pre and post-processing.
In certain embodiments, the present disclosure applies low temperature heat to a product while maintaining a vacuum to promote volatilization of the phytochemicals to be separated and recovered as individual components from the biomass or as an emulsion in an infused edible oil product.
It has been surprisingly shown herein that the methods and systems of the present application provide for high selectivity of extraction of different phytochemicals which are obtained in high yield and high purity. Comparable methods and systems did not display the same properties, highlighting the surprising results obtained with the methods and systems of the application.
Accordingly, the present application includes a method for extracting one or more phytochemicals from a biomass, the method comprising: placing the biomass into a thermal chamber, the thermal chamber connected to an eductor through a suction connection, and a discharge port of the eductor connected to a concentrate tank; generating a vacuum in the thermal chamber by circulating a motive fluid through the eductor; heating the biomass to volatilize one or more phytochemicals in the biomass; condensing the one or more volatilized phytochemicals by contact of the volatilized phytochemicals with the motive fluid; and collecting the motive fluid and the one or more condensed phytochemicals into the concentrate tank.
The present application also includes a system for the extraction of one or more phytochemicals from a biomass, the system comprising: a thermal chamber for receiving the biomass; an eductor, connected to the thermal chamber through a suction connection, for circulating a motive fluid thereby creating a vacuum within the system, the eductor comprising a discharge port; a heating source for heating the biomass within the thermal chamber to volatilize one or more phytochemicals; a concentrate tank connected to the discharge port of the eductor for recovering the motive fluid and the one or more condensed phytochemicals; wherein the one or more volatilized phytochemicals are condensed by contact with the motive fluid.
In some embodiments, the biomass is selected from the group consisting of flowers, leaves, wood, bark, roots, seeds, peel, and combinations thereof.
In some embodiments, the biomass is selected from the group consisting of cannabis, lavender, peppermint, spearmint, tea tree, patchouli, eucalyptus, and citrus. In some embodiments, the biomass is cannabis.
In some embodiments, the one or more phytochemicals are selected from the group consisting of terpenes, cannabinoids, essential oils or flavonoids.
In some embodiments, the one or more phytochemicals are selected from the group consisting of tetrahydrocannabinolic acid (THCa), tetrahydrocannabinol (THC), cannabidiolic acid (CBDa), cannabidiol (CBD), cannabigerolic acid (CBGa), cannabigerol (CBG), cannabichromenic acid (CBCa), cannabichromene (CBC), cannabinolic acid (CBNa), cannabinol (CBN), cannabigerovarinic acid (CBGVA), tetrahydrocannabivarin carboxylic acid (THCVA), tetrahydrocannabivarin (THCV), cannabidivarinic acid (CBDVA), cannabidivarin (CBDV), cannabichromevarinic acid (CBCVA), cannabichromevarin (CBCV), limonene, linalool, pinene, myrcene, caryophyllene, pulegone, cineole, terpineol, cymene, apigenin, quercetin, annflavin A, sitosterol and combinations thereof.
In some embodiments, the biomass is a raw feedstock, a partially dried feedstock or a dried feedstock.
In some embodiments, the method and system further comprises drying the biomass in the thermal chamber. In some embodiments, drying the biomass comprises heating the biomass at a temperature of 30° C. to 100° C.
In some embodiments, heating the biomass to volatilize one or more phytochemicals is through indirect heating selected from conductive, convective and radiative heat transfer means. In some embodiments, heating the biomass to volatilize one or more phytochemicals is at a temperature from 30° C. to 300° C. In some embodiments, the temperature is near or lower than the boiling point of the one or more phytochemicals.
In some embodiments, after collecting the one or more condensed phytochemicals into the concentrate tank, the one or more condensed phytochemicals are recovered in a recovery tank.
In some embodiments, after recovering the one or more condensed phytochemicals into the recovery tank, heating is carried out at a second temperature to volatilize a second one or more phytochemicals. In some embodiments, the second temperature is near or lower than the boiling point of the second one or more phytochemicals.
In some embodiments, the eductor further comprises a circulation system for circulating the motive fluid into a closed loop. In some embodiments, the circulation system comprises a circulation pump. In some embodiments, the circulation pump collects the motive fluid from the concentrate tank to return the motive fluid to the eductor.
In some embodiments, the vacuum is at 15-29″ HgVac.
In some embodiments, the motive fluid is selected from N2, CO2, compressed air, steam, water, oil and ethanol.
In some embodiments, the method and system further comprises separating the motive fluid from the one or more condensed phytochemicals.
The present application further includes use of a method or a system of the present application in the manufacture of an extract.
In some embodiments, the extract is an essential oil from the group consisting of cannabis, lavender, peppermint, spearmint, tea tree, patchouli, eucalyptus, and citrus.
In some embodiments, the extract is a cannabis extract.
The present application also provides an extract obtained by the method or system of the present application
Other features and advantages of the present application will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the application, are given by way of illustration only and the scope of the claims should not be limited by these embodiments, but should be given the broadest interpretation consistent with the description as a whole
The embodiments of the application will now be described in greater detail with reference to the attached drawings in which:
Unless otherwise indicated, the definitions and embodiments described in this and other sections are intended to be applicable to all embodiments and aspects of the present application herein described for which they are suitable as would be understood by a person skilled in the art.
The term “and/or” as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that “at least one of” or “one or more” of the listed items is used or present.
As used in the present application, the singular forms “a”, “an” and “the” include plural references unless the content clearly dictates otherwise.
In embodiments comprising an “additional” or “second” component, such as an additional or second compound, the second component as used herein is chemically different from the other components or first component. A “third” component is different from the other, first, and second components, and further enumerated or “additional” components are similarly different.
As used in this application and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “include” and “includes”) or “containing” (and any form of containing, such as “contain” and “contains”), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.
The term “consisting” and its derivatives as used herein are intended to be closed terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, and also exclude the presence of other unstated features, elements, components, groups, integers and/or steps.
The term “consisting essentially of”, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and/or steps as well as those that do not materially affect the basic and novel characteristic(s) of these features, elements, components, groups, integers, and/or steps.
The term “suitable” as used herein means that the selection of the particular composition or conditions would depend on the specific steps to be performed, the identity of the components to be transformed and/or the specific use for the elements, but the selection would be well within the skill of a person trained in the art.
The present description refers to a number of chemical terms and abbreviations used by those skilled in the art. Nevertheless, definitions of selected terms are provided for clarity and consistency.
The terms “about”, “substantially” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies or unless the context suggests otherwise to a person skilled in the art.
The term “aq.” as used herein refers to aqueous.
The term “phytochemicals” as used herein refers to chemical compounds produced by plants, including for example carotenoids, polyphenols which include phenolic acids, flavonoids, stilbenes/lignans, anthocyanins, flavones, flavanones, isoflavones, catechins, epicatechins, and proanthocyanidins; terpenes/terpenoids, cannabinoids; essential oils; or any other chemicals of plant origin.
The term “biomass” as used herein refers to plant material used as feedstock for further processing.
The term “eductor” as used herein refers to a type of pump which works on the “venturi effect” to pump out air, gas or liquid from a specified area, requiring only a motive fluid (or driving fluid) for its operation, not requiring any moving parts. When the motive fluid is passed through the eductor at the required capacity (which depends on the design of the eductor), a low pressure or vacuum is created, enabling the eductor to suck liquid or gas from a certain area.
The term “volatilization” or “volatilized” used herein refers to the process of the phase transition of a compound between the liquid phase or semi-solid phase to the gaseous phase or vapour. One may also refer to vaporization or evaporation interchangeably.
It has been surprisingly shown herein that the methods and systems of the present application provide for high selectivity of extraction of different phytochemicals which are obtained in high yield and high purity. Comparable methods and systems did not display the same properties, highlighting the surprising results obtained with the methods and systems of the application.
Accordingly, the present application includes a method for extracting one or more phytochemicals from biomass, the method comprising placing the biomass into a thermal chamber, the thermal chamber connected to an eductor through a suction connection, and a discharge port of the eductor connected to a concentrate tank; generating a vacuum in the thermal chamber by circulating a motive fluid through the eductor; heating the biomass to volatilize one or more phytochemicals; condensing the one or more volatilized phytochemicals by contact with the motive fluid; and collecting the motive fluid and the one or more condensed phytochemicals into the concentrate tank.
The present application further includes a system for the extraction of one or more phytochemicals from biomass, the system comprising: a thermal chamber for receiving the biomass; an eductor connected to the thermal chamber through a suction connection, for circulating a motive fluid thereby creating a vacuum within the system, the eductor comprising a discharge port; a heating source for heating the biomass within the thermal chamber to volatilize one or more phytochemicals; a concentrate tank connected to the discharge port of the eductor for recovering the motive fluid and the one or more condensed phytochemicals; wherein the one or more volatilized phytochemicals are condensed by contact with the motive fluid.
In some embodiments, the biomass is selected from the group consisting of flowers, leaves, wood, bark, roots, seeds, peel, and combinations thereof. In some embodiments, the biomass is selected from the group consisting of cannabis, lavender, peppermint, spearmint, tea tree, patchouli, eucalyptus, and citrus. Any biomass comprising desired phytochemicals to be extracted would be suitable and within the purview of a skilled person.
In some embodiments, the one or more phytochemicals are any compounds contained in the biomass, for example the one or more phytochemicals are selected from the group consisting of terpenes, essential oils, cannabinoids and flavonoids. In some embodiments, the one or more phytochemicals are selected from the group consisting of tetrahydrocannabinolic acid (THCa), tetrahydrocannabinol (THC), cannabidiolic acid (CBDa), cannabidiol (CBD), cannabigerolic acid (CBGa), cannabigerol (CBG), cannabichromenic acid (CBCa), cannabichromene (CBC), cannabinolic acid (CBNa), cannabinol (CBN), cannabigerovarinic acid (CBGVA), tetrahydrocannabivarin carboxylic acid (THCVA), tetrahydrocannabivarin (THCV), cannabidivarinic acid (CBDVA), cannabidivarin (CBDV), cannabichromevarinic acid (CBCVA), cannabichromevarin (CBCV), limonene, linalool, pinene, myrcene, caryophyllene, pulegone, cineole, terpineol, cymene, apigenin, quercetin, annflavin A, sitosterol and combinations thereof. In some embodiments, the one or more phytochemicals are selected from the group consisting essential oils from cannabis, lavender, peppermint, spearmint, tea tree, patchouli, eucalyptus, and citrus.
In some embodiments, the biomass is a raw feedstock, a partially dried feedstock or a dried feedstock. The biomass may be dried or partially dried prior to extraction according to the methods and systems of the present application. For example, dried or partially dried biomass may contain about 10-20% of water based on total weight of biomass. In some embodiments, the water content may be 10-15%. However, the biomass may be a raw feedstock, for example containing 60-80% of water based on total weight of biomass. In some embodiments, the water content may be 60-75%, or 65-70%.
In some embodiments, raw feedstock may be directly used and dried directly in the thermal chamber. The direct drying as part of the methods and systems of the present application may reduce overall costs of extraction by reducing necessary infrastructure for drying, reducing time required for drying, reducing required resources such as equipment, energy and money, and thus improving the overall process.
In some embodiments, drying the biomass comprises heating the biomass at a temperature of 30° C. to 100° C. In some embodiments, drying the biomass is made at a temperature between 30 to 90° C., between 30° C. to 70° C., or between 30° C. to 50° C.
In some embodiments, heating the biomass to volatilize one or more phytochemicals is done through indirect heating selected from conductive, convective and radiative heat transfer means. For example, ceramic heaters, heated media such as oil baths, salt baths and sand baths, heated mantles, forced hot air, induction heaters, microwaves, or any heating means know in the art.
In some embodiments, the thermal chamber is made of glass, ceramic, stainless steel or an alloy of steel, a refractory material or any material that would be food grade compatible. The thermal chamber may be provided with a rotary connection motor to allow the chamber to be rotated for better heat transfer from the indirect heating source. In some embodiments, the thermal chamber is connected with an eductor through a suction connection which is a fixed, non-rotating assembly. An exemplary eductor is shown in
In some embodiments, the methods and systems may further include additional condensation means or cooling means to accelerate the condensation of the one or more phytochemicals. In some embodiments, the one or more condensed phytochemicals may be further recovered from the concentrate tank into a recovery tank.
In some embodiments, the eductor further comprises a circulation system for circulating the motive fluid into a closed loop. In some embodiments, the circulation system comprises a circulation pump. The closed loop may comprise the eductor, the circulation pump, the concentrate tank and a piping system for continuously circulating the motive fluid from the concentrate tank to the input of the eductor. In some embodiments, the circulation pump collects the motive fluid from the concentrate tank to return the motive fluid to the eductor.
In some embodiments, the vacuum generated by the eductor is at 15-29″ HgVac. In some embodiments, the vacuum generated is between 20 and 28″ HgVac, or between 25 and 28″ HgVac.
In some embodiments, the parameters of the methods and systems may be precisely controlled through various systems including valves, sensors, controllers, etc. For example, thermocouplers may be provided on the system to monitor temperatures at various stages and heating may be adjusted accordingly. In some embodiments, pressure sensors may be provided and the pressure at which the motive fluid enters the eductor and/or the back pressure at which the motive fluid exits the eductor may be controlled, for example through pressure valves, through the speed at which the circulation pump circulates the motive fluid, or any suitable devices known in the art. A skilled person would readily appreciate that various configurations including sensors and controllers may be used. In some embodiments, the monitoring and controlling of the parameters is made automatically according to predetermined extraction threshold for specific biomass and specific phytochemicals.
In some embodiments, the motive fluid is selected from N2, CO2, compressed air, steam, water, oil and ethanol, or any suitable motive fluid within the purview of a skilled person in the art. In another embodiment, the oil is coconut oil, olive oil, canola oil, vegetable oil or any other edible oil.
In one embodiment, the motive fluid and the condensed phytochemicals form an emulsion or an infusion. In one embodiment, when the motive fluid is an edible oil (for example, olive oil, vegetable oil, coconut oil, canola oil etc.), the condensed phytochemicals form an emulsion or infusion product with the edible oil.
In some embodiments, heating the biomass to volatilize one or more phytochemicals is conducted at a temperature from 30° C. to 300° C. In some embodiments, the temperature is from 30° C. to 200° C., or from 30° C. to 100° C. In some embodiments, the temperature is selected to be near the boiling point of one or more specific phytochemicals to extract so that the other phytochemicals may remain in the biomass and optionally be later extracted. In some embodiments, the temperature is slightly below the boiling point of the phytochemical, or significantly below the boiling point of the phytochemical.
In some embodiments, after recovering the one or more condensed phytochemicals into the recovery tank, heating is carried out at a second temperature to volatilize a second one or more phytochemicals. For example, selective extraction may be conducted to volatilize THCa or THC, which may be condensed and collected into the recovery tank, and the biomass may further be heated at a second temperature to volatilize CBDa or CBD. For example, the first temperature may be near or below the boiling point of THCa, which is 105° C. In some embodiments, the first temperature may be from 90-105° C., from 80-100° C., from 70-90° C., or from 60-80° C. In some embodiments, the second temperature may be near or below the boiling point of a second phytochemicals. For example, the second temperature may be near or below the boiling point of CBD, which is between 160-180° C. In some embodiments, the second temperature may be from 140-160° C., from 120-140° C., from 100-120° C., or from 80-100° C. In some embodiments, the temperature may be selected to avoid chemical reactions or degradation of phytochemicals, for example the decarboxylation of tetrahydrocannabinolic acid (THCa) into tetrahydrocannabinol (THC) or cannabidiolic acid (CBDa) into cannabidiol (CBD). In some other embodiments, the temperature may be selected to induce such chemical reactions. Thus, the methods and systems of the present application may allow for the selective extraction of different phytochemicals comprised in a biomass by precise control of the temperature and vacuum, as explained above.
For example, parameters for the selective extraction may be based on the boiling points of various phytochemicals, presented in Tables 1 and 2. As such, the temperature and vacuum may be selected and precisely controlled according to parameters of the one or more phytochemical isolate desired for extraction.
In some embodiments, the one or more condensed phytochemicals is recovered from the concentrate tank to a recovery tank while the motive fluid is returned to the eductor. In other embodiments, the motive fluid is recovered together with the condensed phytochemicals. For example, an oil, such as coconut oil, olive oil or an edible oil, may be used as a motive fluid and collected as an infusion. In some embodiments, the method further comprises separating the motive fluid from the one or more condensed phytochemicals to form a desired phytochemical product with high purity and little degradation.
In one embodiment, the process is able to extract at least 80%, or at least 85%, or at least 90% of the desired phytochemical from the biomass. In one embodiment, when the biomass is cannabis, the process is able to extract at least about 85% of THC from the cannabis. In another embodiment, the THC extract is free from organic solvents.
The methods and systems of the application have been shown useful in selectively extracting phytochemicals from biomass to provide extracts of high purity in a high yield.
Accordingly, the present application includes use of the methods and systems in the manufacture of an extract.
The present application also includes extracts obtained from the present methods and systems.
In some embodiments, the extract is from a cannabis biomass.
The following non-limiting examples are illustrative of the present application.
Infusion process
An exemplary system for an infusion process is shown in
This method and system advantageously provide for the direct infusion/emulsification of decarboxylated cannabinoids into an edible oil. No solvents are required; thus, there is no loss of solvent to the biomass during extraction. The precise temperature and pressure control allow for more focused recoveries of cannabinoids and less undesired phytochemicals (for examples plant waxes) which are inevitably recovered during solvent extractions. The number of steps to form the final extract product is considerably reduced as compared to crude oil recovery from solvent extractors.
i. Gas Motive Fluid Liquid Separation
An exemplary system for a direct recovery process is shown in
This method and system advantageously provide for no solvents being in contact with the biomass at any time, and a single step is necessary to recover crude oil with high efficiencies (<1% residual cannabinoids in the remaining biomass feed stock)
ii. Oil and Motive Fluid Liquid Separation
An additional exemplary system is shown in
A similar exemplary system is shown in
iii. Evaporative Separation
Another exemplary system for recovering phytochemicals from biomass is shown in
This method and system advantageously provide minimal losses of ethanol during the process. The circulating ethanol can be highly concentrated with crude oil prior to removal of the ethanol thus reducing the amount of ethanol required per mass of feed stock; in theory, all ethanol used can be recovered.
Cannabis biomass was treated in an exemplary system according to an infusion process of the present application as described in the above Examples. Analyses were conducted for measuring the content of some phytochemicals in the biomass prior the extraction and remaining in the treated biomass. Analysis was performed on HPLC-UV, with a limit of quantitation (LOQ), i.e. the lowest level of analyte that can be accurately quantified, of about 0.10%. Initial content of some cannabinoids and remaining content in the treated biomass are given in Table 5.
These results demonstrate that almost 85% of all THC was extracted from the cannabis biomass, thus showing the high yield of recovery that may be achieved.
Based on the combination and difference in the boiling points of the cannabinoid isolates THC and CBD at atmospheric pressure and at negative pressure based on −15 inHg vacuum, the selective extraction of the phytochemicals may be achieved. Using a Nomograph, the boiling point (BP) of organic compounds can be estimated when the vacuum pressure is known.
BPTHC@760 Torr (1 atm)=about 160° C.
BPTHC@381 Torr (−15 inHg)=about 127° C.
BPCBD@760 Torr (1 atm)=about 180° C.
BPCBD@381 Torr (−15 inHg)=about 150° C.
Given the temperature difference in boiling points of the cannabinoid isolates at atmospheric and vacuum pressures, the ability to precisely control processing temperature in the extraction vessel, and the ability to precisely control and vary the amount of vacuum in the extraction system, at −15 inHg or higher, the targeting of the cannabinoid isolate THC can be achieved effectively at about 127° C., 33° C. lower than the BPTHC at atmospheric pressure.
Research has also shown that the decarboxylation of the cannabinoids, such as THCa to THC starts to occur at temperature of about 120° C., but can occur over longer periods at temperatures of 80-90° C. (Ref. Tallon et. al. Extraction and fractionation of cannabinoids from Cannabis Sativa). Using the methods described above, water can be removed from the biomass at temperatures of less than 15° C. at 20 Torr, well below the temperatures required for decarboxylation.
The following procedure may be used to determine the selectively of the present methods and systems and recover cannabinoid isolates, specifically THC and CBD.
While the applicant's teachings described herein are in conjunction with various embodiments for illustrative purposes, it is not intended that the applicant's teachings be limited to such embodiments as the embodiments described herein are intended to be examples. On the contrary, the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents, without departing from the embodiments described herein, the general scope of which is defined in the appended claims.
The present application claims priority to U.S. patent application No. 63/057,071, which was filed on Jul. 27, 2020, the contents of which are incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2021/051028 | 7/23/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63057071 | Jul 2020 | US |
