Abstract:
A continuous-flow extraction system and method for extracting oil from oil-bearing plant parts, or biomass, with liquid-phase hydrocarbon solvent in a continuous process, providing more than one extraction vessel so that one or more extraction vessels can be cleared of exhausted biomass and reloaded with biomass, while another one or more extraction vessels are undergoing the extraction process, optionally providing a de-waxer for use when needed, providing a primary jacketed separator vessel for flashing hydrocarbon solvent to a vapor phase and precipitating and collecting liquid plant extract, providing at least one secondary jacketed separator vessel for purification and refinement of vapor-phase hydrocarbon solvent and providing for re-liquefication of the solvent for the purpose of re-circulating and reusing the solvent, and providing for the heating, cooling, and pumping necessary to carry out the various steps.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of my co-pending application Ser. No. 15/190,977, filed on Jun. 23, 2016 for an “Apparatus for Extracting Oil from Oil-Bearing Plants,” which is a continuation-in-part of my previous application Ser. No. 14/470,494, filed on Aug. 27, 2014 for an “Apparatus for Extracting Oil from Oil-Bearing Plant Material,” issued as U.S. Pat. No. 9,399,180 on Jul. 26, 2016, which is a continuation-in-part of my previous application Ser. No. 13/734,915, filed on Jan. 4, 2013 (now abandoned), the full disclosures of which are hereby incorporated by reference and priority of which are hereby claimed. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention is a continuous-flow extraction system and method for extracting oil from oil-bearing plant parts, or biomass, with liquid-phase hydrocarbon solvent, in a continuous process, with re-circulation and reuse of the solvent. 
         [0003]    Presently, such extraction is performed on a batch basis, in part because there is a need to empty and clear the extractor vessel of spent and exhausted biomass, and to reload the vessel with fresh biomass. These processes in turn require a temporary shutdown of the extraction process. Additionally, present systems and methods do not provide for continuous regeneration of the used hydrocarbon solvent&#39;s properties, such that a smaller total amount of solvent can be used in an essentially closed, continuous loop. 
         [0004]    Plant oils have been extracted from plant material for centuries. Many plant oils are extracted from seeds by squeezing or crushing the seeds to force out the oil therefrom. Mechanical oil extractors or expellers are extensively used for obtaining cold-pressed oils where the temperature of starting material does not exceed 120-degrees Fahrenheit. In order to increase the oil output, the oil extraction methods provide for the addition of heat and pressure. 
         [0005]    In addition, plant oils can be extracted with the assistance of a chemical agent or solvent, such as hexane. Chemical extraction is cheaper and more efficient than mechanical extraction, at a large scale, leaving only 0.5-0.7% of the oil in plant solids, as compared to the 6-14% of mechanical extraction. 
         [0006]    Plant seeds and pods are not the only plant components that contain oil. Fibrous plant matter, including leaves, flowers, and so forth, contain significant amounts of plant oil that can be extracted and used in cosmetics, healthcare industries, and the like. Many solutions have been developed to provide plant oil extraction. 
         [0007]    For instance, U.S. Pat. No. 5,516,923 discloses a method of plant oil extraction, according to which grounded plant material is deposited into a reactor vessel, and vacuum is created in the reactor vessel. Liquid solvent is introduced into the reactor vessel and allowed to contact the plant material for a time sufficient to dissolve oil from the plant material, while the temperature in the reactor vessel is maintained at a level which prevents denaturing of constituent components of the plant oil and the plant material. Additional solvent vapors are introduced into the bottom of the reactor to cause mixing of the plant material and the solvent and separate fine particulate matter from heavier particles. Pressurized heated solvent vapors are introduced into the top of the reactor vessel while the liquid solvent and oil combination is being removed from the bottom of the reactor vessel through filters. To prevent clogging of filters in the bottom of the reactor vessel, pressurized solvent vapors are forced through the filters into the bottom of the reactor vessel. The solvent and oil combination is transferred into a separator vessel, wherein the solvent is vaporized and removed for recycling, while the oil is removed into a holding tank. 
         [0008]    U.S. Pat. No. 7,002,029 discloses a process for solvent extraction of oils, in an extraction chamber. According to this method, solvent mist with significant adiabatic cooling is introduced into the extraction chamber, whereby a pressure difference between the solvent inlet and outlet of the extraction chamber drives the solvent mist through the raw oil material. The solvent is fed to the extraction chamber at pressures exceeding the atmospheric pressure, and the outlet of the extraction chamber is subject to a partial vacuum. 
         [0009]    U.S. Application Publication No. 2003/0077367 discloses a process and system for extracting a solute from oil-bearing foodstuffs. This design uses a tubular membrane filter to separate a mass of the extracting medium and the foodstuffs into a miscella and foodstuffs of reduced oil content. In a batch or continuous process, after each extracting stage, the mass from the extraction vessel is conveyed to a membrane filter, which has pores along its cylindrical walls suitably sized to allow a miscella to pass as the permeate, while causing the foodstuffs of reduced oil content to be conveyed axially along the tubes and out of its ends as the retentate. This apparatus uses a heating jacket to provide heat by steam, either directly or indirectly. However, the heating jacket of this publication does not supply heat and cold to the interior of the separator vessel and the expansion filter and help evaporate and condense the solvent. 
         [0010]    U.S. Application Publication No. 2009/0028971 discloses a method utilizing compressed hydrocarbons. Residues from the crop and fruit treatment, especially from the treatment of pips and berries, are used as starting materials. The method is carried out without organic solvents, while applying low pressures and reduced extraction agent throughputs. Preferred extraction agents are ethane, propane, butane, and the mixtures thereof, with the extraction itself being carried out in batches at pressures of less than 50 mPa and temperatures of approximately 70-degrees Celsius, with an extraction agent throughput of between 4 and 20 kg/kg of starting materials. 
         [0011]    U.S. Application Publication No. 2011/0133120 teaches a method of plant oil extraction, which provides for a hermetically first tank coupled to a first valve, the first tank for storing a solvent comprising butane, an extraction zone comprising an extraction chamber coupled between the first valve and a second valve, the extraction chamber having a filter proximate to the second valve; the extraction chamber having a volume between one-fourth and one-sixth of the volume of the first tank. A filter separates flowing butane solvent and plant oil from organic plant material in the extraction chamber. A second tank has an exit valve for removing plant oil located on a bottom portion of the second tank, and an exit valve located near a top portion of the second tank. However, this design provides for the use of filter only at the bottom of the extraction zone. 
         [0012]    U.S. Application Publication No. 2011/0100894 teaches a plant oil extraction device that has a main body member with a hollow interior that receives a plant. A filter member is removably mounted on the main body and has a groove therein that receives glass frit. Thus, when a solvent is placed in the hollow interior with the plant, the glass frit filters the plant particulate, allowing plant oil and solvent to flow into a receiving vessel. Once the oil is collected, the filter member may be removed from the main body such that the glass frit can be cleaned of all plant particulate and be reused. 
         [0013]    A commercially available example of an extraction distillation unit is a Tamisium Extractor manufacture by TmiE of Cleburne, Tex. This extractor utilizes several different single solvents, and sometimes co-solvents, a primary solvent and a carrier solvent; in total three distinct types of extractions. 
         [0014]    While the designs discussed above may work satisfactorily in different environments, there is a need for an easy-to-operate inexpensive apparatus for plant oil extraction that can be used in a non-industrial setting by a cosmetics laboratory, small shop, or consumer, without the need to mix solvents during an extraction process. During tests, it was also noted that the extraction process is made more efficient if the liquid material used to extract oil is maintained at a cooler temperature. 
       SUMMARY OF THE INVENTION 
       [0015]    This invention provides a continuous-flow extraction system and method for extracting oil from oil-bearing plant parts, or biomass, with liquid-phase hydrocarbon solvent in a continuous process providing more than one extraction vessel, such that one or more extraction vessels can be cleared of exhausted biomass and reloaded with biomass while another one or more extraction vessels are undergoing the extraction process. Optionally provided are a de-waxer for use when needed; a primary jacketed separator vessel for flashing hydrocarbon solvent to a vapor phase and precipitating and collecting liquid plant extract; at least one secondary jacketed separator vessel for purification and refinement of vapor-phase hydrocarbon solvent and providing for re-liquefaction of the solvent for the purpose of re-circulating and reusing the solvent; the heating, cooling, and pumping necessary to carry out the various steps. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]    Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein: 
           [0017]      FIG. 1  is a schematic view of the extraction system according to the present invention, showing the operating principles of a batch-processing embodiment of the invention; 
           [0018]      FIG. 2  is an exploded view of the major components of the extraction system according to the present invention, showing the operating principles of a batch-processing embodiment of the invention; 
           [0019]      FIG. 3  is a schematic flowchart of the extraction system of the present invention, showing the operating principles of a batch-processing embodiment of the invention; 
           [0020]      FIG. 4  is an assembled and an exploded view of an extraction vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0021]      FIG. 5  is an assembled and an exploded view of a jacketed extraction vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0022]      FIG. 6  is an exploded and an assembled view of an embodiment of a jacketed de-waxing vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0023]      FIG. 7  is an assembled and an exploded view of the de-waxer baffle array of a jacketed de-waxing vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0024]      FIG. 8  is a perspective view of the metal plate components of the de-waxer baffle array of a jacketed extraction vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0025]      FIG. 9  is an exploded and an assembled view of another embodiment of a jacketed de-waxing vessel according to the continuous-flow extraction system and method embodiment of the invention; 
           [0026]      FIG. 10  is a schematic view of an embodiment of the continuous-flow extraction system and method embodiment of the invention; 
           [0027]      FIG. 11  is a schematic view of another embodiment of the continuous-flow extraction system and method embodiment of the invention; 
           [0028]      FIG. 12  is a schematic view of a nominal first phase of operation of the continuous-flow extraction system and method embodiment of the invention; 
           [0029]      FIG. 13  is a schematic view of a nominal second phase of operation of the continuous-flow extraction system and method embodiment of the invention; 
           [0030]      FIG. 14  is a schematic view of a nominal third phase of operation of the continuous-flow extraction system and method embodiment of the invention; and 
           [0031]      FIG. 15  is a schematic view of the monitoring and control system of the continuous-flow extraction system and method embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Turning now to the drawings in more detail, numeral  10  designates the system of plant oil extraction according to this invention. The system  10  comprises an extraction assembly  12 , a separator assembly  14 , an expansion filter assembly  16 , a solvent recovery assembly  18 , and an upright support assembly  19 , which supports the extraction assembly  12  and the expansion filter assembly  16 . If desired, the support assembly  19  can also support the separator assembly  14 . 
         [0033]    The extraction assembly  12  comprises a tubular hollow extraction vessel  20  having an open top  22  and an open bottom  24 . A peripheral flange  23  extends outwardly from the open top  22 . A similar peripheral flange  25  extends outwardly from the open bottom  24 . 
         [0034]    A top cup  26  normally detachably engages with the open top  22 . The top cup has an open bottom  28  that matches the size and configuration of the top open end  22  of the extraction vessel  20 . The top cup  26  is provided with a peripheral flange  27  that matches the top peripheral flange  23  of the extraction vessel  20 . A two-piece top clamp member  30  having clamp members  30   a  and  30   b  secures the peripheral flanges  23  and  27  with the help of bolt  31  and nut/washer assembly  33 . 
         [0035]    A perforated gasket  36  is sandwiched between the bottom of the top cup  26  and the top open end  22  of the extraction vessel  20 . The perforated gasket  36  allows the gas to atomize before saturating the biomass or plant material in the extraction vessel  20 . The gasket  36  also prevents the biomass from moving upwardly into the top cup  26 . 
         [0036]    The top cup  26  has a closed top plate  29 , which carries a connector assembly  40 . The connector assembly  40  comprises an operationally connected, an extractor connector conduit  42 ; a gas inlet valve  43  fitted in the extractor connector conduit  42 ; and a pressure gauge  45  connected to the gas inlet valve  43 . The top of the extractor connector conduit  42  is provided with a quick-connect male connector member  46 . The inlet valve  43  can be a ball valve. 
         [0037]    A bottom cup  50  is detachably secured to the bottom end  24  of the extraction vessel  20 . The bottom cup  50  is provided with a matching peripheral flange  51  extending about an open upper edge of the bottom cup  50 . The flange  51  of the bottom cup  50  is securable to the bottom peripheral flange  25  of the extraction vessel  20 . A hinge clamp assembly  52  having clamp members  52   a  and  52   b  secures the flanges  25  and  51  with the bolt  53  and nut/washer assembly  54 . In one aspect of the invention, the top cup  26  has longitudinal dimensions at least slightly greater, and preferably twice as great, as the longitudinal dimensions of the bottom cup  50 , which allows for more head space for the gas of the solvent to move into the extraction vessel  20 . 
         [0038]    A bottom perforated gasket  56  and a fine screen  57  are sandwiched between the bottom cup  50  and the bottom end  24  of the extraction vessel  20  in order to fine filter the extracted oil. In a preferred embodiment, the perforated gaskets  36  and  56  can be made of non-reactive metal, such as stainless steel, and the screen  57  can be a silk screen. 
         [0039]    The bottom cup  50  is provided with a bottom plate  58 , which closes the bottom of the bottom cup  50 . A liquid outlet conduit  60  of the extraction vessel  20  is fitted in the bottom plate  58 . An extractor outlet valve  61 , which can be a ball valve, is operationally coupled to the liquid outlet conduit  60 . A quick-connect connector member  62  is secured to the lower end of the liquid outlet conduit  60 . 
         [0040]    The separator assembly  14  is mounted below the extraction assembly  20  in fluid communication therewith. The separator assembly  14  comprises a hollow separator or collector vessel  70  enclosed in a separator vessel jacket  72 . An annular space is formed between exterior of the separator vessel  70  and interior the separator vessel jacket  72 . The annular space can be between 0.5-1.0 inch around the circumference of the separator vessel  70  and the separator vessel jacket. Heated water is circulated in the annular space to heat the separator vessel and speed the conversion of solvent from liquid to gas along the flow line. 
         [0041]    The separator vessel has an open top  71  and a closed bottom  73 . A separator vessel cap  74  is detachably engageable with the open top  71  of the separator vessel  70 . The separator vessel cap  74  sealingly closes the open top  71 . The separator vessel cap  74  carries a separator connector conduit  75 , which is configured for sealing engagement with the connector member  62  of the bottom cup  50 . 
         [0042]    A thermal probe member  76  is coupled to the separator vessel cap  74 , extending into the interior of the separator vessel  70 . A gas outlet conduit  77  is mounted on the separator vessel cap  74  in fluid communication with the separator vessel  70 . The gas outlet conduit  77  is provided with a pressure gauge  78  and a gas outlet valve  79 . The gas outlet conduit  77  carries a male quick-disconnect member  80 . The gas outlet conduit  77  is operationally connected to the solvent recovery assembly  18  via a return line  100 . 
         [0043]    The separator vessel cap  74  is secured to the separator vessel  70  using a tri-clamp  81 , which is similar to the clamps  30  and  52  described above. The clamp  81  ensures tight sealing engagement between the periphery of the separator vessel cap  74  and the separator vessel  70 . A resilient gasket  82  is sandwiched between the separator vessel cap  74  and the open top of the separator vessel  70  to further ensure a fluid-tight seal therebetween. 
         [0044]    The expansion filter assembly  16  comprises a hollow cylindrical expansion filter vessel  84  enclosed in a filter thermal jacket  86 , which similarly to the separator vessel jacket  72 , is spaced from the wall of the expansion filter vessel  84  by a distance of 0.5-1.0 inches to allow warm water circulation in the created annular space. An open top  88  of the expansion filter vessel  84  is configured for detachable engagement with a cover plate  89 , which carries a filter  90 . A tri-clamp  92  secures the cover plate  89  to the open top  88 . A flexible gasket  94  ensures a fluid-tight engagement. The filter  90  can be a sintered metal filter. The filter  90  is placed on the outlet side of the expansion filter member to further filter out any impurities or solid material, which may be carried by a flow of gas into a recirculation pump  108 , as will be described in more detail hereinafter. 
         [0045]    A collection cup  91  is detachably secured to the bottom of the expansion filter vessel  84  with the help of a tri-clamp  93 . A perforated filter gasket  95  is fitted between the bottom of the expansion filter vessel  84  and the collection cup  91 . 
         [0046]    A connector conduit  96  connects the expansion filter vessel  84  with the separator vessel  70 . A pressure gauge  98  is provided on the connector conduit  96  for measuring gas pressure in the connector conduit  96 . An elongated tube  102  is removably inserted in the expansion filter vessel  84  to allow the gas to travel to the bottom of the expansion filter vessel. A quick-connect fixture  104  is secured on an upper end of the tube  102  for easy connection to gas supply. 
         [0047]    A gas booster pump  108  is operationally connected to the connector conduit  96 . The gaseous material exiting the expansion filter member  86  is forced to move to the extractor assembly  12  with the assistance of the gas booster pump  108 . A gas bottle or gas tank  159  is mounted between the gas booster pump  108  and the extraction assembly  12 . 
         [0048]    The support assembly  19  comprises an upright stand  120  having a frame-like structure. A pair of base members  122  and  124  is secured in a spaced-apart parallel relationship by a cross bar  126 . The base members  122 ,  124  are designed to rest on a horizontal surface in a work shop, laboratory, or similar space. Upright supports  128  and  130  extend upwardly from the base members  122 ,  124 , respectively, at right angles to the axes of the horizontal base members  122 ,  124  being secure thereto by bolts  129 ,  131 . A plurality of leveling feet  132  is provided on the bottom of the base members  122 ,  124  to help maintain the upright support stand  19  on the floor. 
         [0049]    Spaced-apart parallel cross members  136 ,  138  extend between the upright members  128  and  130 , further ensuring stability of the support assembly  19 . The cross member  138  carries a Y-shaped upper yoke  140 , which extends horizontally from the cross member  138  transversely to a longitudinal axis of the cross member  138 . The yoke  140  is configured to engage the extraction vessel  20  between the clamps  30  and  52 , suspending the extraction vessel  20  on the support stand  120 . 
         [0050]    A pair of bottom support bars  142 ,  142  is secured in a spaced-apart parallel relationship to each other and attached to the cross member  136 . The bottom support bars  142 ,  144  extend transversely to a longitudinal axis of the cross member  136 . The bottom plate  58  of the bottom cup  50  rests on the bottom support bars  142 ,  144  when the extraction assembly is mounted on the stand  120 . As can be seen in  FIG. 1 , the extractor assembly  14  is suspended from the bottom support bars  142 ,  144 . 
         [0051]    The support assembly  19  also supports a temperature monitor unit  150  for the thermal probe  76  of the separator vessel  20 . The temperature monitor unit  138  forms a part of the separator assembly  13 . The temperature monitor unit  138  is provided with a temperature indicator  152 , which allows visual determination of the thermal conditions inside the separator vessel  70 . 
         [0052]    The solvent recovery assembly  18  comprises a source of solvent (a gas tank  159 ) and a gas recovery/control unit  160 , as well as associated connected hoses, or lines. On the inlet side, the gas recovery/control unit  160  is connected to the gas return line  162 ; on the outlet side, to the gas tank  159  via a gas conduit  164 . The gas recovery/control unit  160  contains a recovery pump having a pressure indicator  166 . A condenser is provided in the gas recovery/control unit for condensing gas evacuated from the separator vessel  70 . The condenser has a monitor  168  on the face of the gas recovery/control unit  160 . 
         [0053]    The gas tank  159  contains a hydrocarbon solvent, such as propane or butane. The gas tank  159  is operationally connected, on the outlet side, to the manually operated gas inlet valve  43  of the extraction assembly  12  via a liquid gas line  170 . Liquid gas (such as, for instance, propane) exits the gas tank  159  to act as a solvent for the oil extraction process and re-enters the gas tank  159  as recovered condensed gas. 
         [0054]    The temperature of the solvent in the system is regulated by a heat exchanger or computer-based temperature control assembly  200 , which regulates delivery and release of the solvent into the extraction assembly  12 . The temperature control assembly  200  comprises a cooling device  202  operationally connected to an injector coil member  204 , a control valve  206 , and a temperature sensor  208  operationally connected to a computer unit  216 . The cooling device  202  may be mounted exteriorly to a building, where the apparatus  10  is located if the building is not zoned for hazardous operation. The injection coil member  204  is jacketed in a thermal jacket  210 , allowing the user to run the chilled liquid around the outside of a hollow inner tube. 
         [0055]    A delivery line  212  runs between the cooling device  202  and the injection coil member  204 . The control valve  206  regulates the flow of cooling agent from the cooling device  202  to the injection coil member  204 . The gas from the gas tank  159  is cooled when it runs through the injection coil member  204  before entering the liquid gas line  170 . The temperature sensor  208  is operationally connected to the computer unit  216 , delivering information to the computer unit on the temperature of the solvent entering the extraction vessel  20 . 
         [0056]    The computer processes the data from the sensor and regulates the operation of the cooling device  202 , activating it when necessary to bring the temperature of the solvent to within the desired range of between  25 -degrees Fahrenheit and  30 -degrees Fahrenheit. As a result, the user can regulate the delivery of the pre-determined temperature hydrocarbon solvent into the extraction vessel  20 . 
         [0057]    Liquid solvent from the gas tank  159  is drawn through the chilled inner tube of the injection coil member  204  by creating a lower pressure area. The overall temperature of the liquid solvent is lowered, allowing it to be more efficient in the extraction process. The cooling medium is recirculated back to the cooling device  202  via a coolant return line  218  connecting the injection coil member  204  and the cooling device  202 . 
         [0058]    It is envisioned that the solvent temperature of between 25-degrees Fahrenheit and 30-degrees Fahrenheit is beneficial for optimizing the extraction process in the extraction vessel  20  in many applications. The temperature regulating assembly facilitates recovery of more liquid within a shorter period of time. More oil can be extracted, while lower temperature of the extraction process ultimately saves energy. 
         [0059]    In  FIG. 3 , solid lines designate gas lines and phantom lines designate water lines. In operation, the user removes the high-pressure clamp  30  connecting the top cup  26  to the extraction vessel  20 . The user then loads the organic plant material into the extraction vessel  20  and reattaches the top cup  26  to the extractor vessel  20  with the high-pressure clamp  30 . The user then manually opens the gas inlet valve  43  and extractor outlet valve  61 . The user also attaches the vacuum hose  162  to the gas inlet valve  43 . 
         [0060]    A predetermined amount of water from a water reservoir  180  is delivered via a water hose  182  into a water heater/cooler  184 . Heated water is then transferred to the jacket  72  of the separator vessel  70  and to the jacket  86  of the expansion filter vessel  84 . 
         [0061]    Next, the user turns on the recycling pump inside the gas recovery/control unit  160  and allows the gas recovery/control unit  160  to pull a vacuum on the extractor vessel  20  and the separator vessel  70 . Once vacuum has been reached, as evident from monitoring the pressure indicator  166 , the valves  43  and  16  are closed. The hose  170  can now be disconnected from the recycling pump and connected to the liquid port on the gas tank  159 . 
         [0062]    The liquid port on the gas tank  159  is opened, and the gas inlet valve  43  is also slowly opened. This will allow the solvent (such as, for instance, propane) from gas tank  159  to enter the extraction vessel  20 . The temperature control assembly  200  regulates the temperature of the solvent entering the extraction vessel  20 . Solvent permeates the plant material or biomass that was deposited into the extraction vessel  20 , and removes the desired constituents. The soak time and pressure will vary depending on the solvent used. The solvent remains fluid under pressure contained within the extraction vessel  20  between the valves  43  and  61 . When the valve  61  is opened, the pressure forces the liquid solvent through the silk screen  57  and the perforated gasket  56  into the separator vessel  70 . The pressure gauges should reflect pressure equalizing shortly after the valve  61  is manually opened. 
         [0063]    The extract pools at the bottom of the separator vessel  70 , and the solvent begins converting into vapor. Applying heat to the water inside the jacket  72  speeds the vaporization process. The valve  63  on the outlet side of the separator assembly  14  is then manually opened, which releases pressurized solvent into the expansion filter via the connecting gas line  65 . 
         [0064]    The top connector conduit  96  on the expansion filter vessel  84  receives solvent from the separator vessel  70 . The vaporized gas descends to the bottom of the expansion filter vessel  84 , where it is forced through a molecular sieve  95  before being drawn out by the recovery pump  108 . The recovery pump  108  ensures that 99% of the gas is recovered, minimizing exposure to flammable solvents. 
         [0065]    Pressure on the outlet side of the expansion filter is monitored by the valve  98 . Applying heat to the expansion filter  84  via the filter thermal jacket  86  speeds the process. 
         [0066]    The solvent vapor exits the expansion filter vessel  84  and is drawn into the inlet side of the recovery pump via a gas line  67 . Before entering the recovery pump  108 , the vapor passes through a desiccant filter  95  and spot glass  91  connected to the recovery pump inlet. In the system of the present invention, the expansion filter vessel  84  uses a molecular sieve to filter the vaporized gas solvent. The extraction vessel  20  uses pressure to filter the liquid solvent using a silk filter. The separator vessel  70  converts the liquid solvent to pressurized gas, leaving the extract in liquid form. 
         [0067]    The scrubbed solvent vapor is drawn into the recovery pump  108  in pulses and stabilizes in the internal compressor. The solvent is then released from the discharge side of the recovery pump  108  back into the gas tank  159 . 
         [0068]    The gas recovery/control unit  96  recovers that gas and pumps it back into the gas tank or recovery cylinder  159 . The thermal probe  76  in the separator vessel  70  is attached to the thermostat  150 , allowing the user to monitor the temperature in the separator vessel  70  during this process. Once all gas has been removed from the separator vessel  70 , the user closes the extractor outlet valve  61 . The separator vessel  70  is disconnected from the extractor assembly  12  using the quick-disconnect connector below the extractor vessel  20 . 
         [0069]    Once the separator vessel  70  is detached from the extractor vessel  20 , the user can remove the high-pressure clamp that is connecting the separator cap  74  to the separator vessel. The extracted oil can now be removed from the separator vessel. The process can then be repeated by loading a new batch of plant material into the extraction vessel  20 , forcing the solvent through the plant material and separating the extracted oil from the plant material. 
         [0070]    In one aspect of the invention, both the separator vessel  70  and the extraction vessel  20  hold equal amounts of volume. The volume may be between 5-liters to 10-liters. The separator vessel  70  has a fixed thermal water jacket  90  that allows hot or cold water to be circulated around the separator, when required. In an alternative embodiment, the water heater is replaced with an electric heater. Propane gas can be substituted with other hydrocarbon solvent if desired. A variety of natural organic raw materials can be processed using the apparatus and method of this invention. 
         [0071]    The enhanced continuous-flow extraction system and method, the object of this continuation-in-part application, provides for a continuously operated extraction process by providing more than one extraction vessel and providing the ability to dismount, evacuate, refill, and re-mount at least one extraction vessel while at least one other extraction vessel is undergoing the extraction process. In a preferred embodiment, three such extraction vessels are provided. One vessel can be undergoing the extraction process, one vessel can be filled and waiting to be activated next, and one vessel can be dismounted and being cleaned and refilled. 
         [0072]    This disclosure of the continuous-flow extraction system and method  300  may start, arbitrarily, with a supply of hydrocarbon solvent, such as propane or butane, under pressure, chilled, and in a liquid phase, for most efficient extraction. This supply corresponds to the gas tank  159  disclosed above. 
         [0073]    Referring now to  FIG. 4 , an extraction vessel  319  embodiment of the extraction assembly  12  is shown. The extraction vessel  319  has an extractor body  311  encompassing an extraction assembly  12  chamber, as described above. The top opening of the jacketed extractor body  311  is sealed with an extractor top assembly  314  corresponding to the top cup  26  disclosed above. In a preferred embodiment, this top assembly provides an extractor view port  315 , allowing for visual confirmation and evaluation of the liquified hydrocarbon solvent being injected into the extraction vessel  319 . An extractor bottom assembly  316  seals the bottom opening of the extractor body  311  and houses an extractor filter unit  317 , which in turn incorporates or performs the functions of the bottom perforated gasket  56  and fine screen  57  disclosed above. The extractor filter unit  317  allows the extracted oil and liquified hydrocarbon solvent to pass out the bottom of the bottom assembly while keeping the raffinate, which is the eventually exhausted biomass and any solid residue, inside the extractor body  311 . 
         [0074]    Referring now to  FIG. 5 , a jacketed extraction vessel  310  embodiment of the extraction assembly  12  is shown. The jacketed extraction vessel  310  has a jacketed extractor body  311  providing a temperature-modulating-fluid jacket around an extraction assembly  12  chamber, as described above. An extractor jacket upper port  312  and an extractor jacket lower port  313  provide an inlet and an outlet for the connection of lines to and from a temperature-modulating-fluid circulator, such that the temperature-modulating fluid can be circulated through the jacketed extractor body  311  of the jacketed extraction vessel  310 . In use, the jacketed extraction vessel  310  will be cooled in order to keep the hydrocarbon solvent in a liquid phase for more efficient extraction. The target temperature will vary with different solvents under different pressures, but will be lower than the boiling point of the pure solvent under the applicable pressure. The top opening of the jacketed extractor body  311  is sealed with an extractor top assembly  314  corresponding to the top cup  26  disclosed above. In a preferred embodiment, this top assembly provides an extractor view port  315 , allowing for visual confirmation and evaluation of the liquified hydrocarbon solvent being injected into the jacketed extraction vessel  310 . An extractor bottom assembly  316  seals the bottom opening of the jacketed extractor body  311  and houses an extractor filter unit  317 , which in turn incorporates or performs the functions of the bottom perforated gasket  56  and fine screen  57  disclosed above. The extractor filter unit  317  allows the extracted oil and liquified hydrocarbon solvent to pass out the bottom of the bottom assembly while keeping the raffinate, which is the eventually exhausted biomass and any solid residue, inside the jacketed extractor body  311 . 
         [0075]    As disclosed further below, the continuous-flow extraction system and method  300  provides at least two of these extraction vessels  319  or jacketed extraction vessels  310  so that at least one can be undergoing the extraction process while at least one other can be emptied and reloaded with fresh biomass. The extraction vessels  319  and jacketed extraction vessels  310  therefore are designed to be accessible and easy to open and close, either while remaining mounted in place or being unmounted for reloading and re-mounted for extraction. 
         [0076]    Referring now to  FIG. 6 , a jacketed de-waxing vessel  320  is provided for the purpose of removing unwanted wax or fats or lipids components of the extract flowing from the extractor bottom assembly  316  of the jacketed extraction vessel  310 . The jacketed de-waxing vessel  320  provides a jacketed de-waxer body  321  providing a temperature-modulating-fluid jacket around a central chamber. A de-waxer jacket upper port  324  and a de-waxer jacket lower port  325  provide an inlet and an outlet for the connection of lines to and from a temperature-modulating-fluid circulator, such that temperature-modulating fluid can be circulated through the jacketed de-waxer body  321  of the jacketed de-waxing vessel  320 . In use, the jacketed de-waxing vessel  320  will be cooled to a temperature in the range of 5-20 degrees Fahrenheit or −15 to −7 degrees Celsius, inclusive, in order to promote the coagulation of fats and lipids inside the vessel. The jacketed de-waxing vessel  320  provides a de-waxer top assembly  322  and a de-waxer bottom assembly  323  to seal the top and bottom openings of the jacketed de-waxer body  321 , and to allow entry of extract into the de-waxer top assembly  322 , and exit through the de-waxer bottom assembly  323 . 
         [0077]    Referring additionally to  FIG. 7  &amp;  FIG. 8 , an embodiment of the invention provides a de-waxer baffle array  326  inside the jacketed de-waxer body  321 . The de-waxer baffle array  326  is made from several metal plates  327 , 328 , each having a cut-out or opening located toward the outer edge of the plate such that a distinct open side and closed side are defined, as illustrated. The metal plates  327 ,  328  are arrayed in a stack, with separation between the plates, and are held in position by mounting bars  329 , as illustrated. In the stack, the metal plates  327 ,  328 , are arranged such that between any two plates, the open side of one is located opposite the open side of the other, placing the openings in a staggered arrangement such that extract spilling from the open side of an upper plate will make contact with the closed side of a lower plate, ensuring that the extract makes contact with each and all of the plates as it cascades down through the jacketed de-waxing vessel  320 . At the proper cool temperatures, fats and lipids will coagulate and become stuck to the baffles. Optionally, additional other known mediums or filters can be packed into the jacketed de-waxing vessel  320  between the metal plate baffles. For example, stainless steel shot or mesh can be added. 
         [0078]    Referring now to  FIG. 9 , another embodiment of the invention provides stainless-steel diffuser medium  318  inside the jacketed de-waxer body  321 . 
         [0079]    Referring now to  FIG. 10 , an embodiment of the continuous-flow extraction system and method  300  provides more than one extraction vessel  319 . In the illustrated embodiment, three extraction vessels  401 ,  402 ,  403  are provided. Each jacketed extraction vessel  401 ,  402 ,  403  is supplied with the liquid-phase hydrocarbon solvent, optionally through a liquid-solvent manifold  520 , and expels the raw extract, optionally into a raw-extract manifold  530 . The connections of each individual jacketed extraction vessel  401 ,  402 ,  403  to the liquid-solvent source and the raw-extract output provide valves that can stop the flow of liquid solvent and raw extract independently, allowing for cleaning, refilling, and dismounting of each vessel individually. 
         [0080]    Referring to  FIG. 11 , another embodiment of the continuous-flow extraction system and method  300  provides more than one jacketed extraction vessel  310 . In the illustrated embodiment, three jacketed extraction vessels  401 ,  402 ,  403  are provided. Each jacketed extraction vessel is supplied with chilled cooling fluid circulating through an extraction chiller  560 . The cooling fluid is supplied to the jacketed extraction vessels  401 ,  402 ,  403  through tubing or piping that provides valves. These valves which can stop the flow to each vessel independently, so that a vessel being opened or removed for cleaning and refilling will not have a flow of cooling fluid during that time. Each jacketed extraction vessel  401 ,  402 ,  403  is supplied with the liquid-phase hydrocarbon solvent through a liquid-solvent manifold  520 , and expels the raw extract into a raw-extract manifold  530 . The connections of each individual jacketed extraction vessel  401 ,  402 ,  403  to the liquid-solvent manifold  520  and the raw-extract manifold  530  provide valves that can stop the flow of liquid solvent and raw extract independently, allowing for cleaning, refilling, and dismounting of each vessel individually. In embodiments where the extraction vessels are unmounted and remounted frequently, the couplings to and from the extraction chiller  560 , the solvent manifold  520 , and the extract manifold  530  should be configured to be quickly, easily, and securely coupled and uncoupled. 
         [0081]    Referring now to both  FIG. 10  &amp;  FIG. 11 , which illustrate embodiments without jacketed extractors or jacketed secondary separators, and embodiments with jacketed extractors and jacketed secondary separators, the overall extraction process of the invention is essentially the same whether using unjacketed or jacketed vessels. The invention is described and illustrated here with reference to the more complex, jacketed embodiments, so that all aspects of the invention are disclosed. The description of the jacketed embodiments should be understood to apply to the unjacketed embodiments, with disregard of the jacket-specific language. Similarly, the invention is described and illustrated with reference to manifolds  520 ,  530 ,  540  for a clearer presentation of the interconnection and flow of the continuous-flow extraction system and method. However, it is understood in the art that other methods are known for making one-to-many and many-to-one connections, and this invention is meant to encompass all of those known methods. 
         [0082]    The liquid-phase hydrocarbon solvent is supplied from a liquid-phase-solvent holding tank  360 , which corresponds to the gas tank  159  disclosed above. The liquid-phase solvent is necessarily at a cold temperature and is under some pressure generated by the vapor-pressure pump  510  in another part of the system. Optionally, the liquid-phase solvent exiting the tank can be provided a supplemental cooling by routing through a heat-exchange or cooling segment using cooling fluid circulated through a solvent chiller  550 , as illustrated. 
         [0083]    In use, liquid-phase hydrocarbon solvent is routed through one or more of the jacketed extraction vessels  401 ,  402 ,  403  filled with plant material, or similar biomass from which an extract is to be obtained. The extractor filter unit  317  in the extractor bottom assembly  316  contains the eventually-exhausted biomass or raffinate within the jacketed extraction vessel  310 , while allowing a raw extract with still-liquified solvent to exit into the raw-extract manifold  530  and subsequently through the system. 
         [0084]    The raw extract obtained from the jacketed extraction vessels  401 ,  402 ,  403  and routed through the raw-extract manifold  530  includes the hydrocarbon solvent still in liquid phase, and may contain unwanted components. The raw extract can optionally be routed through the jacketed de-waxing vessel  320 . Depending upon the specific biomass being processed, the specific hydrocarbon solvent being used, and the specific end product desired, there may not be a need to send the raw extract through the jacketed de-waxing vessel  320 . In such a case, using three-way valves and bypassing the jacketed de-waxing vessel  320  is possible. For many applications, it is likely that de-waxing is desired, and the raw extract from the raw-extract manifold  530  will be routed through the jacketed de-waxing vessel  320 . As disclosed above, the jacketed de-waxing vessel  320  is cooled to the desired temperature, with the cooling fluid circulating through a de-waxing chiller  570 . 
         [0085]    The raw extract, optionally de-waxed, then is routed to a primary jacketed separator vessel  330 . This primary jacketed separator vessel performs the combined functions of the separator assembly  14 , comprising a hollow separator vessel  70  enclosed in a separator vessel jacket  72 , plus some of the functions of the expansion filter vessel  84 , as disclosed above. The primary jacketed separator vessel  330  shares essentially the same design as the jacketed extraction vessel  310 , with the exception of having a jacketed precipitate collector  340  in place of a bottom assembly. The primary jacketed separator vessel  330  is also likely to be larger, for most applications, than an individual jacketed extraction vessel  310 , because the primary jacketed separator vessel  330  accommodates a liquid phase to vapor phase flash transition, accommodates the precipitation of extract, and is heated. The primary jacketed separator vessel  330  can optionally provide a view port, as illustrated, allowing visual confirmation and evaluation of the separation process. 
         [0086]    Heat to the primary jacketed separator vessel  330  and to the secondary jacketed separator vessels  350 , disclosed below, is provided by heated fluid circulated by a separator heater  590 . The target temperature in the separator vessels is related to the flash point of the specific hydrocarbon solvent being used, the amount of negative pressure applied, and any adjustments necessitated by the influence of other components in the raw extract, such as contaminants. 
         [0087]    The raw extract entering the primary jacketed separator vessel  330  is at a cool temperature, and the hydrocarbon solvent is in a liquid phase. The primary jacketed separator vessel  330  is heated to a higher temperature by the separator heater  590 . Also, a negative pressure is being applied to the primary jacketed separator vessel  330  by the action of the vapor-pressure pump  510  elsewhere downstream in the system, as described below. Upon entering the primary jacketed separator vessel  330 , with its raised temperature and lower pressure, the liquified hydrocarbon solvent flashes from a liquid to a vapor and the extract precipitates. The solvent vapor is drawn out of the top, and the extract precipitate falls to the bottom of the primary jacketed separator vessel  330 , where it enters a jacketed precipitate collector  340  attached to and serving as a bottom assembly for the primary jacketed separator vessel  330 . 
         [0088]    The jacketed precipitate collector  340  is independently heated by a precipitate-collector heater  580 , so that a different temperature, optimized for the specific compounds in the extract, can be provided. A drain valve in the jacketed precipitate collector  340  provides for the continuous draining of the precipitated extract into a precipitated-extract tank  400 , which can accommodate and take off a continuous flow of the precipitated extract. In this continuous-flow extraction system and method  300 , the precipitated extract is produced continuously, with no need to interrupt the overall extraction process. 
         [0089]    The continuous-flow extraction system and method  300  also reconstitutes, reclaims, and reuses the hydrocarbon solvent. In the primary jacketed separator vessel  330  described above, the liquid-phase solvent flashes to vapor, leaving the extract to precipitate and remain in liquid phase. This now-vaporized solvent might carry some non-precipitated components either extracted from the biomass or formed during the extraction process. These other non-precipitated components are, at this point, contaminants in the hydrocarbon solvent, lowering the solvent&#39;s effectiveness in a subsequent extraction cycle. These contaminants are removed by a secondary jacketed separator vessel  350 . In a preferred embodiment, as illustrated, there are more than one, and in this case two, secondary jacketed separator vessels  411 ,  412 , which allows one secondary jacketed separator vessel  350  to be taken out of service for cleaning, which might be necessary if, for instance, particularly sticky and stubborn contaminants were encountered. Most contaminants should flow out of the drain valve in the secondary jacketed separator vessel  350 , and from there can be properly discarded or, if the contaminant has any independent value, be collected and further processed. 
         [0090]    The secondary jacketed separator vessel  350  performs some of the functions of the expansion filter vessel  84 , as disclosed above, but performs apart from, and downstream of, the primary jacketed separator vessel  330 . The secondary jacketed separator vessel  350  shares essentially the same design as the jacketed extraction vessel  310 , but does not necessarily need an extractor filter unit  317 , because the separator vessels only ever accommodate vapors and liquids. The secondary jacketed separator vessel  350  has a jacketed body with upper and lower ports, and has a top and a bottom assembly. The top assembly optionally provides a view port, as illustrated, allowing visual confirmation and evaluation of the separation process. 
         [0091]    In use, possibly contaminate-bearing vapor-phase hydrocarbon solvent is evacuated from the primary jacketed separator vessel  330  under the negative pressure provided by the vapor-pressure pump  510  further downstream in the system. This vapor is drawn into a secondary jacketed separator vessel  350 , which is heated by fluid circulating through the separator heater  590 , at an appropriate temperature for the specific conditions, as described above for the primary jacketed separator vessel  330 , which also draws heat from the separator heater  590 . The secondary jacketed separator vessel  350  further purifies the vapor-phase hydrocarbon solvent, as described for the expansion filter vessel above. The resulting purified vapor-phase solvent then enters a vapor-solvent manifold  540 , from which the vapor-phase solvent is drawn by a vapor-pressure pump  510 , which in turn pushes the vapor-phase solvent through a heat-exchange or cooling segment using cooling fluid circulated through a solvent chiller  550 . The combination of the increased pressure provided by the vapor-pressure pump  510  and the cooling provided by the solvent chiller  550  transforms the hydrocarbon solvent back into a liquid phase. The target is a combined temperature and pressure that brings the specific solvent being used below its vapor-liquid phase change point. 
         [0092]    The now-liquid-phase solvent is then routed to a liquid-phase-solvent holding tank  360 , which corresponds to the gas tank  159  disclosed above. This solvent has been reconstituted and reclaimed from the previous iteration of the continuous-flow extraction process. At this point, the process has returned to the arbitrary starting point identified above. 
         [0093]    Referring now to  FIG. 12 , during a nominal first phase of the continuous-flow extraction system and method  300 , plant material or biomass contained in a nominal first jacketed extraction vessel  401  undergoes the extraction process, with liquid-phase hydrocarbon solvent passing through the extraction vessel and extracting the desired compound or compounds. A nominal second jacketed extraction vessel  402  has been loaded with fresh biomass, and is ready for the start of the extraction process either before or concurrent with the end of the extraction process in the first jacketed extraction vessel  401 . A nominal third jacketed extraction vessel  403  has been removed or has been opened in place for removal of any exhausted biomass, for any necessary cleaning, and for the reloading of fresh biomass. 
         [0094]    Referring now to  FIG. 13 , during a nominal second phase of the continuous-flow extraction system and method  300 , plant material or biomass contained in a nominal second jacketed extraction vessel  402  undergoes the extraction process, with liquid-phase hydrocarbon solvent passing through the extraction vessel and extracting the desired compound or compounds. A nominal third jacketed extraction vessel  403  has been loaded with fresh biomass, and is ready for the start of the extraction process either before or concurrent with the end of the extraction process in the second jacketed extraction vessel  402 . A nominal first jacketed extraction vessel  401  has been removed or has been opened in place for removal of any exhausted biomass, for any necessary cleaning, and for the reloading of fresh biomass. 
         [0095]    Referring now to  FIG. 14 , during a nominal third phase of the continuous-flow extraction system and method  300 , plant material or biomass contained in a nominal third jacketed extraction vessel  403  undergoes the extraction process, with liquid-phase hydrocarbon solvent passing through the extraction vessel and extracting the desired compound or compounds. A nominal first jacketed extraction vessel  401  has been loaded with fresh biomass, and is ready for the start of the extraction process either before or concurrent with the end of the extraction process in the third jacketed extraction vessel  403 . A nominal second jacketed extraction vessel  402  has been removed or has been opened in place for removal of any exhausted biomass, for any necessary cleaning, and for the reloading of fresh biomass. 
         [0096]    Because all of the jacketed extraction vessels  310  are essentially identical, additional unmounted vessels can be kept in a ready state and be substituted in for an exhausted vessel in conditions, for instance, where the extraction process runs to exhaustion more quickly than the mounted vessels can be cleaned and reloaded. 
         [0097]    Although, because the exhausted biomass must be removed and replaced, the extraction process for any given single jacketed extraction vessel  310  is necessarily a batch process, the continuous-flow extraction system and method  300  provides for a rotating, staggered sequence of extraction using at least two different jacketed extraction vessels  310 , and thereby provides a continuous flow to the primary jacketed separator vessel  330 , and therefore a continuous flow of desired extract from the jacketed precipitate collector  340  into the precipitated-extract tank  400 . 
         [0098]    Referring now to  FIG. 15 , an embodiment of the continuous-flow extraction system and method  300  provides a system of monitoring and controlling the opening and closing of the several valves controlling the flow of cooling or heating fluid and controlling the flow of the extraction process through various vessels. A main controller  601  exercises overall control of the system, communicating with the subsidiary controllers and facilitating communication among the subsidiary controllers. An extraction-vessel controller  602  coordinates the activation and deactivation of individual jacketed extraction vessels  310 , and therefore coordinates the status of any particular vessel for removal or for opening in place for the purposes of unloading, cleaning, and reloading. The extraction-vessel controller  602  opens or closes the valve between the liquid-solvent manifold  520  and the top assembly of any given jacketed extraction vessel  310 , and in a coordinated fashion controls the flow of cooling fluid from the extraction chiller  560 . The de-waxing controller  603  controls whether raw extract from the raw-extract manifold  530  is routed through the jacketed de-waxing vessel  320  or routed directly to the primary jacketed separator vessel  330 . One way of implementing such routing is with two three-way valves, as illustrated. Optionally, where more than one secondary jacketed separator vessel  350  is provided in order to allow periodic downtime for any single vessel without interrupting the continuous flow, a secondary-separator controller  604  can be provided to control the routing of possibly contaminated vapor-phase solvent from the primary jacketed separator vessel  330  to a specific secondary jacketed separator vessel  350 , and the coordinated opening or closing of valves regulating the heating fluid circulated through the separator heater  590 . 
         [0099]    Many further changes and modifications can be made in the present invention without departing from the spirit thereof. I therefore pray that my rights to the present invention be limited only by the scope of the appended claims.