Patent Publication Number: US-10307690-B2

Title: Method for extracting essential oils

Description:
BACKGROUND 
     Technical Field 
     The present disclosure pertains to a system for extracting essential oils from plant material and, more particularly, to a closed extraction system that utilizes a vacuum to pull a solvent through the plant material. 
     Description of the Related Art 
     Many plants include oils and other minerals that have various uses and benefits apart from the fibrous plant material itself. Essential oils, once removed from the plant material, can be used in foods, medicines, and other products. Typical methods of extracting essential oils use highly pressurized systems to force a solvent through the plant material. These systems can be expensive and are very dangerous due to the high pressures. 
     BRIEF SUMMARY 
     In accordance with the present disclosure a system and method of extracting essential oils from plant material through the use of a vacuum closed system is provided. 
     In accordance with one aspect of the present disclosure, the system includes a solvent source, a material container structured to contain plant material, the material container in fluid communication with the solvent source, a recovery chamber in fluid communication with the material container, and a vacuum pump in fluid communication with the recovery chamber and structured to remove air from within the recovery chamber and pull solvent from the solvent source through plant material in the material container to extract oil from the plant material and move the extracted oil into the recovery chamber. 
     In accordance with another aspect of the present disclosure, a system for extracting essential oils from plant materials is provided. The system generally includes a solvent chamber, a material container or chamber in the form of a column, a filter, a recovery chamber, and a vacuum pump. The solvent chamber is structured to contain a solvent, such as alcohol or alcohol-based solvent. A fluid output of the solvent chamber is connected to a fluid input of the material column. The material column is structured to contain the plant material. An output of the material column is connected to an input of the filter, and an output of the filter is connected to an input of the recovery chamber. The vacuum pump is connected to the recovery chamber to create a vacuum in the recovery chamber. Ideally, the recovery chamber is structured to capture the extracted material. 
     The material in the material column and the solvent in the solvent chamber are cooled; either pre-cooled or by using a cooling liquid, such as liquid nitrogen. A valve at the output of the material column is used to control the movement of fluid through the system, such that when opened, the vacuum in the recovery chamber pulls fluids (cooling fluid or solvent from the solvent chamber) through the material in the material column and into the recovery chamber. 
     In accordance with another aspect of the present disclosure, the solvent source is a solvent chamber having a fluid output, the material column has a fluid input and a fluid output, the fluid input of the material column in fluid communication with the fluid output of the solvent chamber, the filter has a fluid input and a fluid output, the fluid input of the filter in fluid communication with the fluid output of the material column, and the recovery chamber has a fluid input in fluid communication with the fluid output of the filter. 
     In accordance with a further aspect of the present disclosure, a method of extracting essential oils from plant material is provided. The method generally includes the steps of introducing plant material into a material container, introducing a cooling liquid into the material container, providing a solvent for introduction into the material container, creating a vacuum in a recovery chamber that is in fluid communication with the material container, and pulling the solvent through the plant material to extract oil from the plant material and pulling the solvent and extracted oil into the recovery chamber with the vacuum from the recovery chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The foregoing and other features and advantages of the present disclosure will be more readily appreciated as the same become better understood from the following detailed description when taken in conjunction with the following drawings, wherein: 
         FIG. 1  is a system diagram of an implementation of an oil extraction system in accordance with one implementation of the present disclosure; 
         FIG. 2  is a side elevational view of a material column stand in accordance with the present disclosure; 
         FIG. 3  is a cross-sectional view of a solvent chamber in accordance with the present disclosure; 
         FIG. 4  is a cross-sectional view of a material column in accordance with the present disclosure; 
         FIG. 5  is a cross-sectional view of a filter in accordance with the present disclosure; 
         FIG. 6  is a cross-sectional view of a recovery chamber and vacuum pump in accordance with the present disclosure; 
         FIG. 7  is an isometric view of a plunger for use with the system formed in accordance with the present disclosure; and 
         FIG. 8  is an isometric view of a rod used in the plunger of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that implementations may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures or components or both associated with filters, vacuum pumps, as well as the process of purging solvents from extracted plant oils have not been shown or described in order to avoid unnecessarily obscuring descriptions of the implementations. 
     Unless the context requires otherwise, throughout the specification and claims that follow, the word “comprise” and variations thereof, such as “comprises” and “comprising” are to be construed in an open inclusive sense, that is, as “including, but not limited to.” The foregoing applies equally to the words “including” and “having.” 
     Reference throughout this description to “one implementation” or “an implementation” means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearance of the phrases “in one implementation” or “in an implementation” in various places throughout the specification are not necessarily all referring to the same implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementations. 
     With reference to  FIGS. 1-9 , shown therein is a system  100  to extract oils, such as essential oils, from plant material and plant-based materials. As described more fully below, the system  100  generally includes a solvent source, a material container in the form of a material column structured to contain plant material, the material column in fluid communication with the solvent source, a recovery chamber in fluid communication with the material container, and a vacuum source in fluid communication with the recovery chamber and structured to remove air from within the recovery chamber and pull solvent from the solvent source through plant material in the material column to extract oil from the plant material and move the extracted oil into the recovery chamber. 
     More particularly, with reference to  FIG. 1 , shown therein is a representative implementation of the system  100  that includes a solvent source in the form of a solvent chamber  102 , a material container in the form of a material column  106  coupled to the solvent chamber  102  with a supply line  104 , one or more filters  112  coupled to the column  106  with a first recovery line  110 , and at least one recovery chamber  116  coupled to the filter  112  with a second recovery line  114 . The system also utilizes a vacuum source in the form of a vacuum pump  120  coupled to the recovery chamber  116  via a vacuum line  118 . The solvent chamber  102  preferably has a fluid output, the material container or column  106  has a fluid input and a fluid output, and the fluid input of the material column  106  is in fluid communication with the fluid output of the solvent chamber  102 . The filter  112  has a fluid input and a fluid output, the fluid input of the filter  112  is in fluid communication with the fluid output of the material column  106 , and the recovery chamber  116  has a fluid input in fluid communication with the fluid output of the filter  112 . 
     In more detail, the solvent chamber  102  is connected to and in fluid communication with the material column  106  through the supply line  104 . A first end  103  of the supply line  104  is connected to a fluid output  105  of the solvent chamber  102 , and a second end  107  of the supply line  104  is connected to a fluid input  109  of the material column  106 . In some implementations, the first end of the supply line  104  connects to a fluid port formed in a top  101  of the solvent chamber  102 . 
     The material column  106  is connected to and in fluid communication with the filter  112  through a valve  108  via the first recovery line  110 . A second end or output  111  of the material column  106 , which is opposite of the first end  103  of the material column  106 , is connected to the valve  108 . A first end  113  of the first recovery line  110  is connected to a side of the valve  108  opposite of the side that is connected to the second end  111  of the material column  106  such that when the valve  108  is opened, a fluid (i.e., solvent and extracted material) can flow from the material column  106  to the first recovery line  110 . A second end  115  of the first recovery line  110  is connected to a fluid input  117  of the filter  112 . 
     The filter  112  is connected to and in fluid communication with the recovery chamber through the second recovery line  114 . A first end  119  of the second recovery line  114  is connected to a fluid output of the filter  112 , and a second end  121  of the second recovery line  114  is connected to a fluid input  123  of the recovery chamber  116 . 
     The recovery chamber  116  is also connected to and in fluid communication with the vacuum pump  120  via the vacuum line  118 . Although not shown, the vacuum pump  120  can include a vapor filter. A first end  125  of the vacuum line  118  connects to a fluid input port  127  of the vacuum pump  120  and a second end  129  of the vacuum line  118  connects to a fluid output port  131  of the recovery chamber  116 . In some implementations, the input and output ports  123 ,  131  of the recovery chamber  116  are configured and structured to be in a top  133  of the recovery chamber  116 . 
     A ball float or ball check valve (not shown) can be used in controlling the level of fluid in the recovery chamber  116  and prevent it from entering the vacuum pump. As the fluid rises in the chamber, the ball rises inside the housing and blocks the vacuum, thereby preventing any further fluid from being drawn into the recovery chamber  116 . A housing for the ball float has holes in a top thereof to allow the vacuum to pull through the system while holes in a bottom of the housing allow fluid in the recovery chamber  116  to raise the ball and ultimately plug the vacuum port when the recovery chamber  116  is full. 
     To understand the basic operation of the system  100  before going into greater detail on the components, the steps for using this system  100  and the resulting process will now be described. Generally, the above-described system  100  is designed to implement a method of extracting essential oils from plant material. The method generally includes the steps of introducing plant material into the material column  106 , introducing a cooling liquid into the material column  106 , providing a solvent for introduction into the material column  106 , creating a vacuum in the recovery chamber  116  that is in fluid communication with the material column  106 , and pulling the solvent through the plant material to extract oil from the plant material and pulling the solvent and extracted oil into the recovery chamber  116  with the vacuum from the recovery chamber  116 . Preferably, the plant material in the material container is cooled, either by pre-cooling in a deep freezer or other similar cooling system, or cooled within the system such as with liquid nitrogen, prior to pulling the solvent through the plant material. Additionally or in the alternative, the solvent can be cooled prior to being pulled through the plant material. This cooling of the solvent can be done by deep freezing the solvent or using a cooling liquid, such as liquid nitrogen that is introduced into the solvent container. A jacketed material container, such as a column, can be used with a cooling agent in the jacket to cool material in the container. Ethanol alcohol is recommended as a solvent because it is considered safe for human consumption; however, any solvent that remains liquid under normal atmospheric pressure and temperature may be appropriate. Isopropyl, hexane and naphtha are also commonly used solvents. 
     As an initial step, the material column  106  is positioned to accept plant material into an interior  135 . In some implementations, the material column  106  may be placed into a stand  180 , such as illustrated in  FIG. 2 . In various implementations, the material column  106  is structured such that the first end  103  of the material column  106  (in which an input port is connected to the supply line  104 ) is configured as a top of the material column  106 , and the second end  111  of the material column  106  (in which an output port is connected to the valve  108 ) is configured as a bottom of the material column  106 . The material column  106  may be initially placed in the stand  180  without a cap at the top  101  of the material column  106  to allow for material and cooling liquid to be added to the material column  106 . 
       FIG. 2  is a side elevational view of a material column stand  180  formed in accordance with the present disclosure. In this illustration, the material column  106  is connected to an upright post  181  on the stand  180  by a bracket  182 . This mounting configuration maintains an orientation of the material column  106 , such that the top  101  of the material column  106  (and the supply line) are positioned above the bottom  111  of the material column  106  (and the valve  108  and first recovery line  110 ). The bracket  182  may be movably mounted in the stand  180  to enable selective raising and lowering of the material column  106  by a user. 
     A filter pad  200  is placed between the valve  108  and the second end of the material column  106 . In some implementations, the filter pad  200  may be positioned inside and at the bottom of the material column  106 . In other implementations, the filter pad  200  may be positioned outside of the material column  106  but between the second end  111  of the material column  106  and the valve  108 . In some implementations, a valve assembly may include the filter pad  200  and the valve  108 . In at least one implementation, the filter pad  200  is a stainless steel filter pad. The filter pad  200  is readily commercially available and is well known to those skilled in the art and will, therefore, not be described in detail herein. It should be recognized that other filters may be used that restrict material from exiting the material column  106  and entering the first recovery line  110  while allowing fluid (e.g., solvent and essential oils removed from the material) to flow from the material column  106  to the first recovery line  110 . Once the filter pad  200  is in position, the valve  108  is connected to the second end  111  of the material column  106 . 
     A filling cone  139 , such as shown in  FIG. 4 , is connected to the top of the material column  106 . Material is then added to the material column  106 . It should be recognized that in some implementations, material may be added to the material column  106  without a filling cone  139 . A packing rod may be used to push the material from the top of the interior  135  of the material column  106  to the bottom of the interior  135  of the material column  106  near the valve  108 . The material should be loosely packed in the material column  106 . 
     The first recovery line  110  is connected between the valve  108  and the filter  112 , and the second recovery line  114  is connected between the filter  112  and the recovery chamber  116 . The vacuum line  118  is connected between the vacuum pump  120  and the recovery chamber  116 . 
     With the valve  108  closed, the vacuum pump  120  is turned on to create a vacuum in the recovery chamber  116 . As used herein, the term vacuum refers to a negative air pressure measured in Hg in the corresponding space with substantially all air removed. It should be recognized that a perfect vacuum in the recovery chamber  116  may not be possible nor is it required to practice implementations described herein. 
     Cooling liquid is poured into the material column  106  through the filling cone  139  at the top of the material column  106 . The amount of cooling liquid may vary depending on the size of the material column  106  and desired temperature. In one implementation, the initial amount of cooling liquid poured into the material column  106  is one liter. Some of the cooling liquid may seep into the material in the material column  106  and some may rest on top of the material. The valve  108  can then be opened so that the vacuum in the recovery chamber  116  pulls the cooling liquid into the material. The valve  108  may be closed once the cooling liquid is no longer resting on the top of the material, i.e., the cooling liquid has been completely pulled into the material column. Additional cooling liquid can be added to the material through the filing cone  139  at the top of the material column  106 , and the valve  108  opened to pull the additional cooling liquid into the material. 
     These steps can be repeated until the material is sufficiently cool. In one implementation, these steps are repeated a total of three times such that three liters of the cooling liquid, one liter per iteration, are added to the material column  106 . In some implementations, after the cooling liquid has been added to the material, the valve  108  can be opened until the first recovery line  110  at the bottom or second end  111  of the material column  106  begins to frost. This frosting typically indicates that the material in the material column  106  is of sufficiently cold temperature. 
     It should be noted that other mechanisms, such as thermometers, may also be used to check the temperature of the material. The temperature range can be from and including −10 degrees Fahrenheit to −20 degrees Fahrenheit. The valve  108  is then closed once the material in the material column  106  is of sufficiently cold temperature. In some implementations, the vacuum pump  120  may continuously run during this process to ensure that the vacuum within the recovery chamber  116  is maintained to pull the cooling liquid into the material. In some implementations, a cooling liquid line (not shown) may be connected to the material column  106  to supply the cooling liquid to cool the material. 
     If the filling cone  139  was used to fill the material column  106  with material, the filling cone is removed from the material column  106 . The second end  107  of the supply line  104  is connected to the input port at the first end  103  of the material column. 
     The solvent chamber  102  is filled with a proper amount of solvent. The level of solvent depends on the quantity of material in the material column  106 . In at least one implementation, the solvent is alcohol. In some implementations, the solvent chamber  102  may be about 19 liters. Cooling liquid, such as liquid nitrogen, is added to the solvent in the solvent chamber  102  until the solvent reaches a desired temperature, such as approximately −57 degrees Celsius. This mixture may be occasionally stirred as the cooling liquid is added to the solvent. In some implementations, pre-cooling the solvent may help speed up this cooling process. For example, alcohol may be kept in a freezer prior to adding it to the solvent chamber  102 . Once the solvent has been placed in the solvent chamber  102 , the first end  103  of the supply line  104  is connected to the fluid output or output port  105  of the solvent chamber  102 . 
     It should be recognized that sealed connections at each connection point of the solvent chamber  102 , the supply line  104 , the material column  106 , the valve  108 , the first recovery line  110 , the filter  112 , the second recovery line  114 , the recovery chamber  116 , the vacuum line  118 , and the vacuum pump  120  may help the efficiency of the system in extracting essential oils from the material in the material column  106  and collecting them in the recovery chamber  116 . Likewise, the filter  112  may improve the quality of the extracted material deposited in the recovery chamber. However, in some implementations, the filter  112  may not be used between the material column and the recovery chamber, but rather post-process filtering of the extracted material may be used to remove any unwanted leftover material in the extracted material. 
     In some situations, additional cooling liquid may be added to the solvent chamber  102  to keep the solvent at the desired temperature. In at least one implementation, a coolant chamber, coolant supply line, and valve (not illustrated) may be connected to and in fluid communication with the solvent chamber  102  so that coolant can be added to the solvent chamber  102  without disconnecting the supply line  104  from the solvent chamber  102 . Even in this implementation, the valve  108  should be closed prior to adding additional cooling liquid to the solvent chamber  102 . 
     Once the solvent chamber  102  is empty and the extracted oils are drained from the filter  112  into the recovery chamber  116 , the valve  108  can be closed and the vacuum pump  120  turned off. At this point, the supply line  104 , the first recovery line  110 , and the second recovery line  114  can be removed. 
     The resulting material in the recovery chamber is ready for purging. 
     Used material in the material column  106  can be removed from the chamber. In one implementation, the valve  108  and valve assembly can be removed from the material column  106 , and a push rod (described in more detail herein below) can be inserted through the top of the material column  106  to push the material out the bottom of the material column  106 . 
     In some implementations, the material column  106  and all connections between the solvent chamber  102 , the supply line  104 , the material column  106 , the valve  108 , the first recovery line  110 , the filter  112 , the second recovery line  114 , and the recovery chamber  116  may be cleaned, such as with cleaning brushes. Such cleaning may also include cleaning all gaskets at each connection. 
       FIG. 3  is a cross-sectional view of the solvent chamber  102  formed in accordance with the present disclosure. The solvent chamber  102  includes a solvent receptacle  202  having an interior  204  and a lid  206 . In some implementations, the lid  206  and the solvent receptacle  202  may be insulated to help maintain the cooled temperature of the solvent. 
     The solvent receptacle  202  includes the interior reservoir  204  structured to hold solvent, cooling liquid, or both. The lid  206  is configured such that a solvent line  208  passes through an aperture in the lid  206  such that a seal is created between an exterior of the solvent line  208  and the lid  206 . In some implementations, a longitudinal axis of the solvent line  208  may be transverse to a planar axis of the lid  206 . The first end  103  of the supply line  104  connects to a first end  210  of the solvent line  208  via couplers  212  and  214 . A second end  216  of the solvent line  208  terminates in the reservoir  204  to allow solvent  218  in the solvent receptacle or chamber  202  to enter the solvent line  208  and flow to the supply line  104 . 
     The lid  206  and the solvent receptacle  202  are configured to be removably connected to one another. In this way, the lid  206  can be removed from the solvent receptacle  202  so that solvent, cooling liquid, or both can be added to the solvent receptacle  202 . Once solvent  218  is added, the lid  206  can be connected to the solvent receptacle  202 . In various implementations, the interior  204  of the solvent chamber  102  is at or near normal atmospheric pressure. In this way, the pressure in the solvent chamber  102  is higher than the vacuum in the recovery chamber  116 , which allows for the movement of solvent from the higher pressure solvent chamber  102  through the material in the material column  106  and to the recovery chamber  116 . 
       FIG. 4  is a cross-sectional view of the material column  106  formed in accordance with the present disclosure. As described elsewhere, a filling cone  139  may be attached to the top of the material column  106  to assist a user in adding material  144  into a material receptacle  140  in the interior  135  of the material column  106 . Once the material  144  has been added to the material column  106 , the filling cone  139  is removed from the material column  106  and the material column  106  is connected to the remainder of the system as described above. In some implementations, the material receptacle  140  may be surrounded by insulation  142  to help maintain the cooled temperature of the material. 
     A top cap  235  is connected to the material receptacle  140  by a clamp  238 . In some implementations, a gasket  240  may be positioned between the top cap  235  and a top of the material receptacle  140  to help seal the material column  106 . The top cap  235  of the material column  106  includes a coupler  234 , which connects to a coupler  236  at the second end  107  of the supply line  104 . 
     A bottom cap  251  is connected to the material receptacle  140  by a clamp  250 . In various implementations, a gasket  248  may be positioned between the bottom cap  251  and a bottom of the material receptacle  140  to help seal the material column  106 . In some implementations a filter pad  246  is positioned within the material receptacle  140  at the bottom of the material receptacle  140 . In other implementations, the filter pad  246  is positioned outside the material receptacle  140  and between the bottom of the material receptacle  140  and the bottom cap  251 . The bottom cap  251  of the material column  106  connects to the valve  108 . The valve  108  connects to the first end of the first recovery line  110  via couplers  252  and  254 . In some implementations the bottom cap  251 , the valve  108 , and the coupler  252  may be part of a valve assembly, which, in some implementations, may also include the filter pad  246 . 
       FIG. 5  is a cross-sectional view of the filter  112 , formed in accordance with the present disclosure. Filter  112  includes filter material  160  and couplers  158  and  162 . In some implementations, the filter material  160  may be a charcoal filter. The second end  115  of the first recovery line  110  connects to the filter  112  via two couplers  156  and  158 . The first end  119  of the second recovery line  114  connects to the filter  112  via the two couplers  162  and  164 . It should be recognized that other types or configurations of the filter  112  may be used. In addition, the filter  112  may take the form of multiple filter assemblies, or filters coupled in series. 
       FIG. 6  is a cross-sectional view of the recovery chamber  116  and vacuum pump  120 , formed in accordance with the present disclosure. The recovery chamber  116  includes a recovery lid  171  that has a vacuum gauge  170  so that a user can observe the current pressure in the recovery chamber  116 . It should be recognized that the vacuum gauge  170  may be another type of pressure sensor and may be positioned inside the recovery chamber  116  or connected to the recovery chamber  116  in other configurations. The second end  121  of the second recovery line  114  connects to the recovery chamber  116  via the couplers  166  and  168 . In some implementations, a first end  175  of a final recovery line  173  is attached to coupler  168  and a second end  177  of the final recovery line  173  terminates in the recovery chamber  116 . 
     The first end  125  of the vacuum line  118  connects to the vacuum pump  120  via two couplers  176  and  178 , and the second end  129  of the vacuum line  118  connects to the recovery chamber  116  via two couplers  172  and  174 . In this way, the vacuum pump  120  pulls air out of the recovery chamber  116  via the vacuum line  118 . Solvent  218  is then pulled from the solvent chamber  102  through the material and into the recovery chamber  116  via the second recovery line  114  and the final recovery line  173 . The recovered material then settles on a bottom of the recovery chamber  116 . 
     Although the couplers illustrated in  FIGS. 1-6  are male/female connections and arranged in specific configurations, implementations are not so limited and other arrangements or types of couplers may be used so long as they are configured to properly mate together and provide a sealed connection. 
       FIGS. 7-8  illustrate a plunger  300  and corresponding rod  302  for use in using the system  100  described above. The plunger  300  is used as an aid in filling the material column  106  as well as in cleaning the column  106 . When the column  106  is initially filled, it is at times useful to compress the material  144  before processing begins. When the process is complete, the plunger  300  is used to press spent material from the column  106 . 
     In the representative implementation shown in  FIGS. 7 and 8 , the plunger  300  includes a rod  302 , preferably an ACME threaded rod, having an unthreaded top  304  with a hexagonal cross-sectional configuration that extends from a first end  308  of a first smooth shaft section  306 . A threaded central section  312  has a first end  314  that extends from an opposing second end  310  of the first smooth shaft section  306  and a second end  316 . Extending from the second end  316  is a second smooth shaft section  318  that has its first end  320  extending from the second end  316  of the threaded central section  312  and a second end  322  that intersects with a first end  326  of a terminal threaded section  324  that has a terminal second end  328 . 
     Ideally an outside diameter of the first and second smooth shaft sections  306 ,  318  is less than an outside diameter of the threaded central section  312  and the terminal threaded section  324 . The threaded sections  312 ,  324  of the rod  302  are designed to thread faster than normal threads and is used generally when longer distance travel is needed with fewer turns required. In one implementation, an Acme thread at a 29 degree angle is suitable. 
     The hex-shaped section  304  at the top of the rod  302  has the hex shape milled into the rod. It is intended for use with a drill to speed the travel of the plunger  300  in the cleaning process. A hexagonal nut  330  is threaded onto the rod  302  and welded in position below the hex. It is sized and shaped for use with a wrench when it is desirable to just compress the material  144  in the material column  106  and not eject it. 
     A spool cap  332  having an Acme hexagonal nut  334  welded thereto is sized and shaped to be clamped to a spool of the material column in a fixed position, and the plunger  300  travels or rotates through the cap  332  to compress material or to clean material from the material receptacle  140  or “spool.” A “spool” is a manufacturing term for the receptacle, in this case the material column, and manufacturing companies manufacture them in standard sizes. As shown in  FIG. 7 , the cap  332  is a standard spool cap that is welded to the nut  334 . The cap  332  is clamped to the material column or spool with a tri-clamp to hold it in place for cleaning, “plunging,” or pressing. 
     The first and second smooth shaft sections  306 ,  318  of the rod  302  that have the threads removed are sized and shaped to allow the plunger  300  to spin freely at the top and bottom of the column  106  to prevent the plunger  300  from impacting the top or bottom of the interior of the material column  106 . This prevents injury to the operator as well. 
     Located on the terminal threaded section  324  are first and second hexagonal nuts  336 ,  338 , respectively, with a thrust bearing  340  adjacent the first nut  336  and a washer  342  between the thrust bearing  340  and the second nut  338 . 
     The thrust bearing  340  is in the position adjacent and below the locked first nut  336  to allow the washer  342  to turn freely when under the pressure of forcing material to compress or when ejecting material from the spool (material receptacle  140 ). The Acme threaded nuts  336 ,  338  with the holes drilled in them are used for locking the thrust bearing  340  and the plunger washer  342  in their position without tightening or loosening. A roll pin  344  is driven through openings in both nuts to bear against the terminal threaded section  324  and hold the assembly in place on the rod  302 . The roll pin  344  is sized and shaped to be driven out of the nuts  336 ,  338  if the need arises to disassemble the plunger  300 . 
     In use, the plunger is used as an aid in filling the material column as well as cleaning the column. 
     When the column is initially filled, it is at times useful to compress the product before processing begins. The plunger is then attached to the top of the filled column  106  and turned down with a wrench applied to the nut  330  welded to the rod  302  close to the top in order to compress the material  144  in the column  106  for a higher density and more solid pack for the processing. The plunger  300  is removed, and the process is continued. 
     When the processing is complete, the plunger  300  is re-attached to the top of the material column  106  and a drill motor is attached to the hexagonal top  304  of the plunger shaft and used to press the spent material from the column  106 . 
     It will be readily appreciated from the foregoing that the plunger assembly  300  eliminates the need to compress the material in the column  106  with a rod and hammer and prevents possible damage to the finished surface on the interior of the column  106 . The plunger assembly  300  is also used to force the spent material out of the bottom of the column  106 , eliminating possible damage to the column  106  and reducing the cleaning time by a substantial amount. 
     What follows next are a series of questions and responses regarding optimal usage of the system  100  and the process.
     Q What is the recommended temperature for maximum yield and quality?   A. Yield results and third party potency tests show that the ideal temperature is in the range of −10 to −20 degrees. Warmer temperatures result in extraction of unwanted plant material that will be filtered out but greatly reduces filter life. Temperatures below −40 degrees Fahrenheit have shown as much as a 75% drop in yield with zero effect on potency.   Q. How much nitrogen should I use to cool unfrozen material?   A. It is recommended to start with approximately 1 cup per pound of material for unfrozen material. Once nitrogen vapor is no longer visible, check for desired temperature.   Q. How long does the extraction process take?   A. It depends on the quantity of material you will be running. Once the system is set up, it takes approximately 2 to 3 minutes per gallon of alcohol.   Q. How much alcohol is required?   A. Generally 1 gallon per ½ pound of material is sufficient. Different plant material may require more or less, and we recommend using enough alcohol that it appears clear in the first filter upon completion.   Q. How much alcohol will be lost during the process?   A. After the alcohol becomes clear as seen through the filter container, it is recommended to remove the suction tube and allow the machine to continue running until there is nothing dripping into the first filter. This may take up to 60 minutes. Generally the material will retain approximately ½ cup per pound of material. Empty the material column and allow remaining alcohol to drain into a container for further use.   Q. How much oil will a run typically yield?   A. The yield greatly depends on the type and quality of material that will be running. On average one should expect between 3 and 4 grams per oz. of good dry material.   Q. Should the material be wet or dry?   A. Test results show dry material provides up to 50% more yield. Drying the starting plant material as much as possible allows the plant compounds to release more easily and also saves on filter life. If it is desired to store dry material, it is recommended to keep it sealed and frozen to retain freshness   Q. How tight should I pack the material column?   A. Gentle packing is recommended, which means press your material down and gently pack but do not use extreme force. The material must become fully saturated, ensuring full extraction, but once saturated, the flow through the material guarantees maximum yield. If material is packed too tightly, flow is restricted, resulting in the possibility of material retaining some desired compounds. If material is too loosely packed, material may not reach full saturation, leaving behind desired compounds.   Q. What color should the oil be?   A. There are many different plant types that contain many different compounds and quantities of each. Different compounds pose different colors. There is no “normal” color or consistency for an oil. Essential oils come in many different forms. Many oil processors try to use selective processing to achieve golden or clear color, stating that they are eliminating unwanted elements. The operator must ask what part of these plants they are eliminating as unwanted and what parts they are trying to process.   

     The various implementations described above can be combined to provide further implementations. For example, it is to be understood that the washer  342  and the stainless steel tri-clamp cap  332 , as well as the overall length of the Acme rod  302 , will vary to fit the intended column  106  size. 
     These and other changes can be made to the implementations in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific implementations disclosed in the specification and the claims, but should be construed to include all possible implementations along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.