CLIAMS:1. Method for extracting useful compounds from selected species of plants comprises of following steps;
Delivering an extraction fluid from a delivery system for extracting the useful compounds from the plants;
Pumping the extraction fluid from the delivery system to a heating means;
Extracting the useful compounds from the plant species by treating the plant species with the extraction fluid in an extractor at the supercritical condition;
Separating the extracted compounds in a separator;
Collecting the compound in a first collecting means;

2. Method for extracting useful compounds from selected species of plants comprises of following steps;
Delivering an extraction fluid from a delivery system for extracting the useful compounds from the plants;
Pumping the extraction fluid from the delivery system to a heating means;
Extracting the useful compounds from the residual plant matter by retreating the plant species with the extraction fluid in an extractor at the sub-critical condition.
Separating the extracted compounds in a separator;
Collecting the compound in a second collecting means;

3. Method for extracting useful compounds from selected species of plants comprises of following steps;
Delivering an extraction fluid from a delivery system for extracting the useful compounds from the plants;
Pumping the extraction fluid from the delivery system to a heating means;
Extracting the useful compounds from the plant species by treating the plant species with the extraction fluid in an extractor at the supercritical condition;
Separating the extracted compounds in a separator;
Collecting the compound in a first collecting means;
and
Delivering an extraction fluid from the delivery system for extracting the useful compounds from the plants;
Pumping the extraction fluid from the delivery system to the heating means;
Extracting the useful compounds from the residual plant matter by retreating the plant species with the extraction fluid in the extractor at the sub-critical condition;
Separating the extracted compounds in a separator; and
Collecting the compound in a second collecting means in order to increase the extraction rate.

4. Method of extracting various products from plant species of claim 3, where in the fluid used in the extraction process can be carbon dioxide or the like.

5. Method of extracting various products from plant species of claim 3, where the plant species can be selected from the group comprising Michelia nilagirica known as champa flower, Pandanus fascicularis LAM known as kewada flower, Vetiveria zizanioides (L.) known as vetiver flower, fennel seed (foeniculum vulgare), fenugreek seed (trigonella foenum), jatamansi (nardostachys jatamansi), kuonch beej (mucuna prur ita), kapur kachri (hedychium spicatum buch.-ham), mango ginger (curcuma amada roxb), marigold flower (tagetes patula l), nagarmotha (cyperus scariosus r.br), sugandhbala (valeriana walli.chii dc), tobacco (nicotiana tabacum l), turmeric powder (curcuma longa l) and thereof.

6. Method for extracting useful compounds from selected species of plants using both supercritical and sub-critical fluid.

7. The product extraction process comprises of;
A delivery system used for storing or delivering fluid,
A pumping means for pumping fluid,
A heating means for heating plant materials with desired pressure, temperature and thereof,
An extractor unit for extracting required plant products,
And a separating unit used for separating extracted products.
,TagSPECI:Field of the invention
[0001] The present invention relates to a method of treating plant species with different conditions like supercritical and sub-critical conditions to increase the extraction rate of different useful compounds like medicines, fragrances and thereof.

Background of the invention
[0002] Champa flower belongs to the magnolia family (Magnoliaceae) its botanical name is Michelia nilagirica and it is known by several names such as Champaca Flower, Frangipani, champa, and champak sapu. This is a gorgeous subtropical tree with deep fragrant flowers and is best known for its strongly fragrant yellow or white flowers. These flowers are used in Southeast Asia for several purposes and it is primarily used in the preparation of perfumes.

[0003] There are different extraction techniques that are conventionally used to extract products from botanical species through hydro-distillation, steam distillation, solvent extraction or like. However, the hydro and steam distillation have several drawbacks, where steam distillation is suitable for lighter plant compounds because high temperature damages the volatile matter in the plant compounds and may lead to break-down of thermally-labile components, promoting hydration reaction of chemical constituents, this requires a post-extraction process to remove water and incomplete extraction of essential oils from plant materials. Solvent extraction is another type of extraction technique which overcomes the drawbacks of hydro-distillation or steam distillation and it is particularly suitable for extraction of heavier plant compounds but the major disadvantage with this technique is it leaves solvent residue in extracted essential product which makes unfavorable. In conventional extractions using organic solvent has been widely practiced to obtain efficient natural product extracts, but still it stands with few drawbacks, such as low selectivity, high energy costs, and the possible loss of volatile compounds during removal of the solvent.

[0004] Supercritical CO2 acts as a good solvent for the purpose of extracting plant materials from seeds, roots, flowers, leaves and barks. The solvency of supercritical CO2 can be easily varied by controlling pressure and temperature. Super-critical fluid (SCF) extraction is an extraction process utilizing a fluid as an extractant at temperatures and pressures exceeding its critical temperature and pressure. It is possible to separate a multi component mixture when a super-critical fluid is used as an extractive solvent by capitalizing on both the differences in component volatilities (i.e., salient features of distillation) and the differences in the specific interaction between the mixture components and the SCF solvent. The application of SCF solvents is based on the experimental observations that many gases exhibit enhanced solvating power when compressed to conditions above the critical point.

[0005] Super-critical fluid extraction (SFE), which has received much interest in its use and further development for industrial applications, is a method that offers some advantages over conventional methods, especially for the palm oil industry. SC-CO2 refers to super-critical fluid extraction (SFE) that uses carbon dioxide (CO2) as a solvent which is nontoxic, inexpensive, non flammable and non polluting super-critical fluid solvent for the extraction of natural products. Almost 100% oil can be extracted and it is regarded as safe, with organic solvent-free extracts having superior organoleptic process.

[0006] CO2 is one of the most commonly used super critical fluids (SCF) because it has low critical temperature (31.1°C) and critical pressure (73.8 bars). It is abundantly available at low cost and odor less, colorless, non toxic, non inflammable, non corrosive in nature.

[0007] Sub-critical CO2 extract of flowers has given superior products with improved yield of desirable components with minimum amount of waxy components. But bulk volume of the flowers is large in comparison to the yield the floral fragrance. So, for commercial scale production, very large sub-critical CO2 extraction unit is needed.

[0008] Reference “comparison of subcritical CO2 extraction with conventional methods of extraction to isolate the flower fragrance from Michelia champaca Linn” P. K .Rout et al. explains about extraction of champa flower oil by using sub-critical CO2 extraction process but this reference doesn’t explain about a combined process for flower oil extraction using both super-critical fluid CO2 and sub-critical fluid CO2.

[0009] The PCT application No. WO2007107856 applied by Yannick et al. explains about extraction of champa flower oil by using super-critical CO2 extraction process but this patent doesn’t focus on the combined process of using both sub-critical CO2 extraction process and super-critical CO2 extraction process for extracting compounds from champa flower.

[0010] Another reference “Subcritical and super critical fluid extraction: A critical review of its analytical usefulness” by A. N. Mustapa et al., Journal of Chemical and Natural Resources Engineering, Special Edition: 164-180 © FKKKSA, explains about extraction of palm oil by using sub-critical R134a and super-critical CO2 extraction process but this reference doesn’t explain about extraction of other oils.

[0011] Reference “Supercritical and subcritical carbon dioxide extraction of Indian orange peel oil” by Omprakash H.Nautiyal et al., Journal of Chemical and technology, Volume 9, Issue 1, explains about 000extraction of orange peel oil by compound process using both sub-critical CO2 and super-critical CO2 extraction process but this reference doesn’t explain about different products or oil extract’s from various plants or leaves or roots.

[0012] Therefore, there is a need in the art for an improved extraction process facilitates maximum extraction of useful products from any part of any plant .

[0013] In order to overcome the above disadvantages in extraction of useful compounds from plant species a combined use of super-critical fluid extraction (SFE) and sub-critical fluid extraction (SE) is among the more promising extraction methods. These extraction techniques provide higher selectivity, shorter extraction times and more specifically do not use any toxic organic solvents.

Objects of the Invention

[0014] The object of the present invention is to extract various useful compounds from plant species using a combination of supercritical and sub-critical fluid extraction process.

[0015] The other object of the present invention is to use carbon dioxide or the like as an extraction fluid.

[0016] The other objective of the present invention is to provide maximum recovery in the extraction process.

[0017] The other objective of the present invention is to extract products from both heavier and lighter plant species.

[0018] Further other objective of the present invention is to eliminate the residual solvents in the extract.

Summary of the Invention

[0019] The present invention discloses a method for extracting useful compounds from selected species of plants which includes delivering an extraction fluid from a delivery system for extracting the useful compounds from the plants, pumping the extraction fluid from the delivery system to a heating means by using pumping means, extracting the useful compounds from the plant species by treating the plant species with the extraction fluid like carbon dioxide in an extractor at the supercritical condition, separating the extracted compounds in a separator and collecting the compounds in a first collecting means. Method of retreating the selected or residual species of plants for the extraction of useful compounds includes delivering an extraction fluid from a delivery system for extracting the useful compounds from the plants, pumping the extraction fluid from the delivery system to a heating means, extracting the useful compounds from the residual plant matter by retreating the plant species with the extraction fluid in an extractor at the sub-critical condition to separate the extracted compounds in a separator and collecting the compounds in a second collecting means.

[0020] The plant species can be selected from the group of plant species comprising Michelia nilagirica known as champa flower, Pandanus fascicularis LAM known as kewada flower, Vetiveria zizanioides (L.) known as vetiver flower, fennel seed (foeniculum vulgare), fenugreek seed (trigonella foenum), jatamansi (nardostachys jatamansi), kuonch beej (mucuna prurita), kapur kachri (hedychium spicatum buch.-ham), mango ginger (curcuma amada roxb), marigold flower (tagetes patula l), nagarmotha (cyperus scariosus r.br), sugandhbala (valeriana walli.chii dc), tobacco (nicotiana tabacum l), turmeric powder (curcuma longa l) and thereof

[0021] Further in the present invention the fluid used in extraction process can be carbon-dioxide or the like.

[0022] Initially plant species is fed into extractor and super-critical process is started by keeping the pressure and temperature above supercritical parameters and this super-critical carbon-dioxide extraction technology facilitates a uniform bed that allows reasonable heat & mass transfer as the surface area of the plant species is either wet and/or dried to increase the surface area for better penetration of the fluid heavier compounds are extracted which can be further used as medicinal products. Then after the botanical extract from supercritical fluid CO2 extract is again fed into cleaned extractor and further processed by keeping pressure and temperature below supercritical parameters and the extraction is carried until the recovery is negligible. This gives an enhanced yield and extractability from plant species. Varying pressure and temperature as per the requirement of the process would change in density and help in optimum yield.
Description of Drawings

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an exemplary embodiment of the invention, and, together with the description, serve to explain the principles of the invention:

[0024] Fig. 1 shows a schematic view of a process design according to exemplary embodiment of the present invention.

Detailed Invention disclosure

[0025] The present invention is described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0026] According to the exemplary embodiment shown in Fig.1 comprises of a delivery system 101 that stores fluid and delivers an extraction fluid, a pumping means 102 provided for pumping fluid, a heating means 103 provided for heating the fluid to the required temperature and pressure, an extractor unit 104 used for feeding plant species, and a separating means 105 for separating the compounds, and a collecting means (not shown) for collecting compounds and thereof. Where, the extractor unit 104 also includes tank (not shown), shredder (not shown) and thereof.

[0027] According to fig. 1 Initially CO2 from the cylinder is allowed to pass through the preheat-exchanger to bring it to the fluid state and later is stored and delivered from the delivery system 101 to the heating means through a pumping means 102. Where the heating means 103 heat and treat the extraction fluid to maintain required temperature and pressure. Plant species either dry or wet which can be conventionally milled or reduced to small pieces is weighed and charged into the extractor unit 104. The extraction temperature is set by switching on the thermostat. Once the reservoir is full with fluid state CO2, then the CO2 feed will stop. Then the pumping means 102 is activated to start the process. Accordingly, the pressure and temperature of the plant is set for every cycle by a heater 103. The extraction is carried out under the set parameters of temperatures and pressures of super critical fluid CO2 process and extraction is carried out till the recovery is negligible. During supercritical fluid CO2 extraction process carried in the extractor unit 104, where the extract of heavier compounds is timely collected in a container (not shown) preferably made of stainless steel from the separating means 105. Further after the completion of the supercritical process the extractor unit 104 is clean or washed well without any residues left over.

[0028] In sub-critical fluid CO2 extraction process, the separated plant extract from supercritical fluid CO2 extraction is fed into the extractor unit 104. The CO2 fluid is maintained at subcritical temperatures by adjusting the temperature at the heater zone 103. Once the set pressure and temperature are below supercritical parameters of extraction, then the subcritical fluid CO2 extraction is started in extractor unit 104 and the extraction is carried out until recovery is negligible. After extraction, botanical extract of lighter compounds is timely collected in a stainless-steel container (not shown) after completion of supercritical and sub-critical process the useful plant compound extract is collected in aluminum vessels.

[0029] The fluid delivery system 101 stores and delivers the fluid to the heating means 103 through a pumping means 102 then dry or wet plant species (not shown) which can be shredded is fed into the extractor unit 104 and thereof the extractor unit 104 is treated with super critical and sub-critical fluid extraction means.

[0030] Supercritical CO2 acts as a good solvent for the purpose of extracting plant materials from seeds, roots, flowers, leaves and barks and thereof. The solvency of supercritical CO2 can be easily varied by controlling pressure and temperature.

[0031] CO2 at higher pressure and temperature i.e. above supercritical parameters is suitable for extraction of heavier plant materials. Also, higher pressure and temperature ensures more complete extraction as compared to lower pressure and temperature.

[0032] Subcritical CO2 has pressure and temperature lower than supercritical CO2. It is suitable for extraction of lighter plant materials, typically volatile compounds, when compared to supercritical CO2. However, subcritical CO2 does not ensure as complete a recovery of plant material as in supercritical CO2.

[0033] Heavier plant extracts are typically denser and more viscous and closer in properties to the native plant. They are generally used for flavouring and medicinal purpose. Lighter plant extracts are typically free flowing liquid and suitable for aromatic applications.

[0034] Heavier compounds of champa extract are collected from the extractor after completion of supercritical fluid CO2 extraction and is kept separately in an aluminum can with appropriate marking.

[0035] Lighter compounds of champa extract are collected from the separator after completion of sub-critical fluid CO2 extraction and are kept separately in an aluminum can with appropriate marking.

[0036] This process is advantageous in good recovery compared to traditional extraction / distillation methods, availability of heavier plant compounds for medicinal usages, Lighter plant compounds for aromatic usages and extracts are free of any residual solvents

[0037] The plant compound extract is not limited to the above described procedure and it can be done in any way using either as a combination process of super-critical and sub-critical fluid CO2 extraction or anyone of the condition is used to attain the required concentration of the extract.

[0038] The plant species used can be of any variety like champa flower (Michelia nilagirica), Kewada (Pandanus fascicularis LAM), Vetiver (vetiveria zizanioides, etc for extraction of various products.

[0039] In alternative embodiment any single process either Sub-critical or Super-critical fluid CO2 extraction process is used to extract products from different plants or flowers such as Fennel Seed (Foeniculum vulgare), Fenugreek Seed (Trigonella foenum), Jatamansi (Nardostachys jatamansi), Kuonch Beej (Mucuna prurita), Kapur Kachri (Hedychium spicatum BUCH.-HAM), Mango Ginger (Curcuma amada ROXB), Marigold Flower (Tagetes patula L), Nagarmotha (Cyperus scariosus R.BR), Sugandhbala (Valeriana wallichii DC), Tobacco (Nicotiana tabacum L), Turmeric Powder (Curcuma longa L).

[0040] While we have shown and described only a few examples herein, it is understood that numerous changes and modifications as known to those skilled in the art could be made to the present invention. The scope of the present invention is not only limited to any particular industry and it can be applied or used in any management system within the spirit of the invention.