FIELD OF INVENTION

The present invention is in relation to the field of extraction techniques. The extraction in particular is related to counter-current extraction wherein separation of compounds involves serial extraction using solvent. The present invention provides a system and method of extraction from various solid raw materials using volatile solvents in less time, economically. The system involves simple construction, comprising series of chambers further comprising filter and extractor chamber, interconnected with one another through heat exchangers and pumps. The complete extraction involves optimization of quantities and flow rate of raw material and solvent mixture at specific temperature. The whole system works on software through SCAD A.

BACKGROUND OF INVENTION

Counter-current extraction involves extraction from raw material using solvent. The importance of said extraction method is ubiquitously acknowledged in the pharmaceutical, chemical, food industries and in nutraceuticals. Owing to the high need, lot of impetus has been put forth in the development and modification of the apparatus to improve the productivity, reduce the cost, and orient to be environmentally benign in the extraction process.

In conventional methods, required quantity of raw material is made into a bed at the bottom of the chamber and solvent is added from the top of the chamber. The chamber is provided with a steam jacket and maintained at stipulated temperature depending upon the nature of extraction. The solvent percolates through the bed and the percolated solvent is being recirculated through the chamber. This process is continued for a few hours. The main disadvantage of such method is that the solvent would come in contact with the raw material for a few minutes only and also that the most part of the solvent would be in contact with the centre portion of the raw material whereas the side portion of the material would be in contact with the solvent for a very minimal period and minimal volume. Hence, this leads to insufficient contact and thereby inefficient extraction of the product. After stipulated time the solvent is taken out and a fresh lot of solvent is added onto the same bed and the extraction process is continued. This is repeated to ensure proper extraction of the product. The entire process is time-consuming because of repeated extractions. Also, the energy consumption and solvent consumption is very high in this process. This process is manual, and removal of raw material bed also poses difficulty. To overcome these drawbacks, present invention provides an extraction/separation method and apparatus which is more efficient, consuming less energy, less consumption of solvent and posing no risk from high temperature.

Patent document US2547577 describes an apparatus for counter current extraction; the apparatus is cumbersome to be handled routinely for the extractions.

Considering the importance of the extraction techniques in the domains of pharmaceutical, chemical, petrochemical industries, food and neutraceuticalsthere is a need to develop extraction technique which can overcome the limitations of long timelines, huge quantity of solvents and cumbersome methodologies. The present invention aims at overcoming such limitations by developing a simple, efficient system and method for cost effective process of extractions. SUMMARY OF INVENTION

Accordingly, the present invention provides a system and method for continuous extraction/separation for extracting the required product from various materials using counter current extraction. The extraction system includes series of chambers as per requirement and interconnected through heat exchanges and other pipings to transfer material and solvent from one chamber to another to and extract at end. The complete extraction is possible by optimizing quantity and flow rate of extraction solvent and raw material. The entire system operates through software.

Typically a system for extraction (A) from a material, comprising battery of chambers (B), wherein each chamber (B) comprise filter (1) and extractor (3); wherein, the chambers (B) are interconnected through piped heat exchangers (2) and pump (4) for circulation of solvent stored in chamber (Y); and a centrifuge extruder (5) connected to the extractor (3) for removal of spent out (Z); and valves(6); wherein, the system (A) is functionalised either by a software or manually.

A method for extraction from a material, said method comprising steps of loading material into a chamber (B) of system (A), wherein system (A) comprise battery of chambers (B), wherein each chamber (B) comprise filter (1) and extractor (3); wherein the chambers (B) are interconnected through piped heat exchangers (2) and pump (4) for circulation of solvent stored in chamber (Y); and a centrifuge extruder (5) connected to the extractor (3) for removal of spent out (Z); and valves (6) the system (A) is functionalised either by a software or manually; circulating solvent from chamber (Y) through the chamber (B) comprising the material for extraction to obtain extract solution; removing the extract solution from chamber (B) into the extractor and passing the extracted material to the subsequent chamber (B); circulating the solvent in chamber (Y) into the chamber (B) containing the extracted material; optionally repeating the steps (b), (c) and (d) till completion of extraction; circulating the extract solution from last chamber to the first chamber; and pooling the extract solutions in extractors and processed to separate the extract from the solution to obtain the extract from the material.

BRIEF DESCRIPTION OF FIGURES The features of the present invention can be understood in detail with the aid of appended figure. It is to be noted however, that the appended figure illustrates only typical embodiments of this invention and are therefore not to be considered limiting of its scope for the invention.

Figure 1 : Schematic of extraction system (A)

Figure 2: HPLC graph showing 34% assay value of Chlorogenic acid from Green coffee bean

DESCRIPTION OF INVENTION

The embodiments herein and the various features of the system are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawing and detailed in the following description. The illustrations used herein are intended to merely facilitate an understanding of ways in which the embodiments herein may be prescribed and further to enable those skilled in the art to practice the embodiment herein. Accordingly, the example should not be construed as limiting the scope of the embodiments herein.

The present invention is in relation to a system for extraction (A) from a material, comprising battery of chambers (B), wherein each chamber (B) comprise filter (1) and extractor (3); wherein

the chambers (B) are interconnected through piped heat exchangers (2) and pump (4) for circulation of solvent stored in chamber (Y); and a centrifuge extruder (5) connected to the extractor (3) for removal of spent out (Z); and valves(6)

wherein, the system (A) is functionalised either by a software or manually.

In an embodiment of the present invention, the number of chambers (B) in the system can vary from two chambers to eight chambers.

In still another embodiment of the present invention, the piped heat exchangers (2) are insulated. In yet another embodiment of present invention, the chamber (Y) is connected to the first chamber of the battery of chamber (B).

In yet another embodiment of present invention, the software is Supervisory Control and Data Acquisition (SCADA) software or customised software.

In yet another embodiment of present invention chambers (B), insulated heat exchangers (2) are of stainless steel.

The present invention is also in relation to a method for extraction from a material, said method comprising steps of a) loading material into a chamber (B) of system (A),

wherein

system (A) comprise battery of chambers (B), wherein each chamber (B) comprise filter (1) and extractor (3); wherein

the chambers (B) are interconnected through piped heat exchangers (2) and pump (4) for circulation of solvent stored in chamber (Y); and a centrifuge extruder (5) connected to the extractor (3) for removal of spent out (Z); and valves (6) the system (A) is functionalised either by a software or manually;

b) circulating solvent from chamber (Y) through the chamber (B) comprising the material for extraction to obtain extract solution;

c) removing the extract solution from chamber (B) into the extractor and passing the extracted material to the subsequent chamber (B);

d) circulating the solvent in chamber (Y) into the chamber (B) containing the extracted material;

e) optionally repeating the steps (b), (c) and (d) till completion of extraction;

f) circulating the extract solution from last chamber to the first chamber; and

g) pooling the extract solutions in extractors and processed to separate the extract from the solution to obtain the extract from the material.

In an embodiment of present invention, the material is selected from plants, crude drug materials and the like.

In another embodiment of present invention, the solvent is selected from water, methanol, ethanol hexane and ethyl acetate. In still another embodiment of present invention, the solvent is optionally preheated to temperature of extraction from the material. In still another embodiment of present invention, the extraction is automated by software integrated with the system (A).

In still another embodiment of present invention, the process of the separation is selected from evaporation, distillation, spray drying and the like. The present invention discloses a system (A) as in schematic figure 1 for extraction from various solids including but not limiting to plant material, crude drug and petroleum products.

The system (A) comprises a battery of chambers (B), wherein the chamber (B) further comprises filter (1) and extractor (3), as per requirement, for illustration a system with four chambers is shown in the figure 1, the chambers/vessels (B) are connected to only an extractor (3) at one end to introduce the fresh solvent (Y) and at the other end raw material (X) from which relevant material has to be extracted is introduced. The chambers(B) are connected through piped, preferably doubly piped heat exchangers (2) and pump (4). The centrifuge extruder (5) is connected to the extractor from which spent out (Z) is removed.

The chambers (B), insulated heat exchangers (2) can be of material selected from metal or polymeric material, like for example stainless steel.

In the extraction process, the solvent can be added into any filter and spent raw material can be removed from any extractor (3).

A single chamber is associated with an extractor (3), a recirculation pump (4), a heat exchanger (2), a diversion valve (6) and a solid-liquid separator (1). In the process of extraction, required quantity of the raw material is continuously introduced in to the first chamber at a designed rate using a vibro feeder (9) and required quantity of solvent added continuously in to the chamber at designed rate using a dosing pump (10). The raw material and solvent mixture is pumped through the heat exchangers (2) continuously, which are maintained at required temperature based on the nature of solvent and the extraction material. After specified time, the solid and solvent mixture is pumped into the second chamber using a diversion valve (6). The said step is repeated in accordance with the requirement through any number of chambers. The volume of mixture, equivalent to the volume pumped into any chamber would be drawn into the succeeding chamber from the preceding chamber. The process continues till last chamber. In last chamber, fresh solvent adds to ensure complete extraction of the product. After stipulated time, the extracted solvent is taken out from one end and the solid matter is removed from the other end. The solid matter is pressed into a cake and disposed.

In the system the chamber (B) are connected with recirculation loops of material like stainless steel and the number of chamber (B) are customised as per the requirement. The system also offers advantage is that the solvent can be added into any chamber and spent raw material can be removed from any of the chamber (B) as valves are provided at the bottom of the each chamber (B).

In the system (A) the entire process is interlinked and controlled through a customised or standard supervisory control like Supervisory Control and Data Acquisition (SCADA) or similar data acquisition software. The software controls the setting up of temperature, time, rate of addition of raw material and solvent and opening and closing of diversion valve. Everything is automated and there is no manual intervention in the whole process, however in case of any troubleshoot, manual intervention is possible. The system (A) and process offer specific advantages of usage of less quantity of solvent as the same is circulated along with the raw material, the continuous current extraction is done around 25°C or at temperature which spares the thermo labile constitutes from exposure to heat, in case of crude material may be extracted as many times as required, as per the requirement in the extraction the chambers can be installed. However, before the material is discharged, it is treated with fresh solvent providing maximum extraction. Thus the system solves the problem with respect to material handling and the associated problem relating to of material loss and material contamination.

Typically the extraction process involves introduction of the raw material in to the first chamber (B) at suitable rate and required quantity of solvent is added continuously in to the chamber at desired rate from the top. The chamber(s) (B) are provided with heating jackets. The rate of addition of raw material and solvents are optimized depending on the raw material and solvent used. The raw material and solvent mixture thus formed in the chamber(B) is pumped through the heat exchangers (2) continuously, which are maintained at stipulated temperature required for relevant extraction. After, say stipulated time, the solid and solvent mixture is passed through the solid liquid separator (1) which separates the solid which is pumped into the second chamber and the liquid is collected as an extract. The solid comes in contact with the fresh solvent in the second chamber (B) and extraction is carried on. Similarly after stipulated time the mixture is pumped in to the third chamber through separators from the second chamber and this process goes on. In the mean while after the raw material and solvent mixture (solution) is pumped to the second chamber, fresh lot of raw material and solvent is introduced into the first chamber, which is the volume of mixture equivalent to the volume pumped into the second chamber. The process continues such that first chamber receives fresh raw material and the solvent and the last chamber receives fresh solvent and extracted material (which is present in the previous chamber and this has been in the extraction process from the first chamber.) During this process the raw material and solvent is in continuous agitation, thereby enhancing the effective extraction.

Experimental:

Materials and construction

The material of construction (MOC) of the chambers (B), heat exchangers (2), valves (6), and interconnecting loops is preferably of Stainless Steel 316. Water or organic solvents selected from a group comprising methanol, ethanol, hexane and Ethyl acetate are used. The avoidable solvents are strong acids. Diversion valves (6) are provided to transfer the material from one chamber (B) to another chamber (B). Good safety measures are provided to protect the explosion of chambers due to increase in the pressure. The chambers, heat exchangers and other relevant parts are thermally insulated. Pressure transducers (8) and thermocouples (7) are provided to monitor the pressure and temperature respectively.

Example

A.Extraction of Chlorogenic acid from Green Coffee Beans

Materials: Arabica Green coffee beans are grinded to coarse powder and passed through sieve. Care is taken that the powder is neither fine nor very coarse (powder should pass 60# mesh).

Solvent used for extraction: 80% Ethanol -about 10 liters used for complete extraction.

Optimized temperature for extraction: 60°C. Number of chambers in the system: 6

Presence of Water is ensured in the thermocouple and switched on. The temperature of water in the thermostat is maintained at 60° C.

1 kg of green coffee bean powder is weighed and kept ready. The valves of the system(A) is suitably opened or closed as per requirement and the system is switched on. 1 liter of 80% Ethanol is charged into in each chamber of the system and heated the solvent to 60°C. Once the required temperature is attained, add weighed green coffee bean powder and the solvent in to the first chamber of the system as per the optimized flow rate. The mixture of green coffee bean powder and 80% Ethanol gets agitated and heated up. After 10 minutes, this mixture is passed through a solid liquid separator. The liquid is collected and then the solid part moves to the second chamber and comes in contact with the fresh solvent and extraction continues. The same process continues until the raw material reaches the final chamber and then after complete extraction, the raw material is removed a spent. The solvent used in the last chamber flows in the counter direction and reaches the first chamber after the complete extraction. This final extract is collected and processed further.

After 1 hour the system is switched off and mixture is unloaded into a container. The mixture is allowed to cool to 25°C-30°C and then filtered.

The filtrate is spray dried. About 100 gm of powder is obtained. Aliquot amount of the dry powder is weighed and analyzed for the content of Chlorogenic acid by HPLC (samples in triplicate) and the assay is found to be 34% (Figure 2). B. Extraction of Curcnminoids from Cnrciimin:

Dried Curcumin roots are pulverized and made in to powder.

Solvent used for extraction: Ethanol (About 15 liters used for complete extraction)

Optimized temperature for extraction: 70°C Number of chambers in the system: 6

Sufficient water in the thermostat controller is ensured and switch on. The temperature of water in the thermostat is heated to 70°C.

1 kg of Curcumin powder is weighed and kept ready. All the valves of the system are properly opened up or closed as per requirement and switched on. About 1 liter of Ethanol is charged in each chamber of the system and the solvent is heated to 70°C. Once the required temperature is attained, weighed Curcumin powder is added in to the first chamber of the system as per the optimized flow rate. The mixture of Curcumin powder and Ethanol gets agitated and heated up. The mixture circulates through the system.

After 10 minutes, this mixture is passed through a solid liquid separator. The liquid is collected and then the solid part moves to the second chamber and comes in contact with the fresh solvent and extraction continues. The same process continues until the raw material reaches the final chamber and then after complete extraction, the raw material is removed a spent. The solvent used in the last chamber flows in the counter direction and reaches the first chamber after the complete extraction. This final extract is collect and processed further. After 1 and half hours the system is switched off and mixture is unloaded into a container. The mixture is allowed to cool to about 25 °C and then filtered. The filtrate is spray dried and approximately 32 gm of Curcumin powder obtained. Aliquot amount of the powder is weighed and analyzed for the content of total Curcuminoids by HPLC (samples in triplicate) and the assay is found to be 95.2%.

C.Extraction of Hydroxy citric acid from Garcinia cambogia:

Dried fruits and rinds are cut into small pieces and are dried at 60°C and then used for extraction.

Solvent used for extraction: Water (About 10 liters used for complete extraction)

Optimized temperature for extraction: 60°C Number of chambers in the system: 6 Sufficient water in the thermostat controller is ensured and switch on. The temperature of water in the thermostat is heated to 60°C.

1 kg of dried fruits and rinds are weighed and kept ready. All the valves of the system are properly opened up or closed as per requirement and switched on. 1 liter of Water is charged into each chamber of the system and heated to 60°C. Once the required temperature is attained, weighed dried fruits and rinds is added in to the solvent in first chamber of the system as per the optimized flow rate. The mixture of dried fruits, rinds and Water gets agitated and heated up. The mixture circulates through the system.

After 10 minutes, this mixture is passed through a solid liquid separator. The liquid is collected and then the solid part moves to the second chamber and comes in contact with the fresh solvent and extraction continues. The same process continues until the raw material reaches the final chamber and then after complete extraction, the raw material is removed a spent. The solvent used in the last chamber flows in the counter direction and reaches the first chamber after the complete extraction. This final extract is collect and processed further.

After 1 hour the system is switched off and mixture is unloaded into a container. The mixture is allowed to cool to about 25 °C and then filtered. The filtrate is spray dried and approximately 180 gm of extract of Garcinia cambogia powder is obtained. Aliquot amount of the powder is weighed and analyzed for the content of Hydroxy citric acid by HPLC (samples in triplicate) and the assay is found to be 48.6%.

D.Extraction of Withanolides from Withania somnifera (Ashwagandha):

Dried roots of Ashwagandha are cut into small pieces and pulverized. Solvent used for extraction: Water (About 10 liters used for complete extraction)

Optimized temperature for extraction: 70°C Number of chambers in the system: 6

Sufficient water in the thermostat controller is ensured and switch on. The temperature of water in the thermostat is heated to 70°C. 1 kg of dried roots is weighed and kept ready. All the valves of the system are properly opened up or closed as per requirement and the system is switched on. 1 liter of Water is charged in to each chamber of the system and heated to 70°C. Once the required temperature is attained, weighed dried roots is added in to the solvent in first chamber of the system as per the optimized flow rate. The mixture of dried roots and Water gets agitated and heated up. The mixture circulates through the system. After 10 minutes, this mixture is passed through a solid liquid separator. The liquid is collected and then the solid part moves to the second chamber and comes in contact with the fresh solvent and extraction continues. The same process continues until the raw material reaches the final chamber and then after complete extraction, the raw material is removed a spent. The solvent used in the last chamber flows in the counter direction and reaches the first chamber after the complete extraction. This final extract is collect and processed further.

After 1 and half hours the system is switched off and mixture is unloaded into a container. The mixture is allowed to cool to about 25 °C and then filtered.

The final extract is obtained in the form of a powder. The Aliquot amount of the powder is weighed and analyzed for the content of Withanolides by HPLC (samples in triplicate) and the assay is found to be 1.2% for Withanolide IV and 0.8% for Withanolide V.

The present invention thus provides a simple, efficient and cost-effective method for extracting from various types of raw materials and can be suitably adopted for industrial scale extractions effortlessly. The system can be completely automated offering high advantage of saving the man power. The system is highly beneficial for extraction of plant material, crude drug and the like.