Patent Publication Number: US-11389749-B2

Title: System for filtering organic compounds

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 16/368,419, filed on Mar. 28, 2019 and entitled SYSTEM AND METHODS FOR FILTERING ORGANIC COMPOUNDS. The complete disclosure of the above application is hereby incorporated by reference for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to diatomaceous earth as a filtration medium and more specifically, the present invention relates to diatomaceous earth filters used to extract beneficial organic compounds from plant materials by filtering out the non-desirable compounds such as organic pigments, plant fats, lipids, and other plant cells that are not considered medicinally or industrially valuable. 
     Diatomaceous earth has been used for many years in a number of applications utilizing its absorptive properties and its filtration properties, among other applications. Diatomaceous earth ore is a naturally occurring ore that is fairly easily crushed or crumbled into a fine powder. 
     Diatomaceous earth consists primarily of the skeletal remains of diatoms, which is a type of algae, and includes primarily silica, along with some minor amounts of sodium, magnesium, and iron. The percentages of the various elements may vary depending on the source or collection point of the diatomaceous earth, but generally the silica (in an amorphous form) constitutes over 85% by weight of the diatomaceous earth. 
     Diatomaceous earth has been used for many years as a filter due to its high porosity and because its porosity can be adjusted by modifying the particle size of the final diatomaceous earth product. 
     In conventional processes, some of the amorphous silica of the diatom frustules is converted to crystalline silica in the form of cristobalite. 
     BRIEF SUMMARY OF THE INVENTION 
     Solvents such as a liquid non-polar solvent can be used to extract organic compounds from plant-based materials such as various forms of hemp or cannabis. Various types of liquid non-polar solvents that can be used with the present invention include butane, hexane, pentane, heptane, ethanol, MCT oil, cold pressed hemp oil, olive oil, benzene, toluene, diethyl ether, chloroform, 1,4 dioxane and most other non-polar liquids. Cannabinoids attach to non-polar substances. The processes and apparatus mentioned herein will work with any cannabinoids derived from hemp or cannabis including, but not limited to: THCA, delta 9 THC, CBN, CBD, CBG, THCV CBC, CBDA, CBDV, as well as any other unnamed, but present, cannabinoid found in hemp or cannabis as long as it is suspended in anything liquid and non-polar. 
     The desirable components of such an extraction process primarily included cannabinoids or terpenes that can be collected and provided to consumers to aid with numerous medical conditions. Along with the desirable cannabinoids and terpenes there can be a plurality of undesirable compounds that are extracted from the plant matter. These undesirable compounds can include, but are not limited to pigments such as chlorophylls, anthocyanins and carotenoids as well as plant waxes, lipids, or other plant cells that are not considered active ingredients in hemp or cannabinoid products. 
     The present invention is a system and method for removing these undesirable compounds so that the desirable cannabinoids, terpenes, and any other beneficial organic compounds can be easily and effectively captured. 
     The equipment used in the invention includes glass Buchner funnels and flasks, and vacuum pumps for suction. But other filtration apparatuses could be used, especially at industrial scale. That is, one could put together similar filtration apparatuses using stainless steel and scale it to any size. Diatomaceous earth is placed in the funnel, solution is poured into the funnel and vacuum suction pulls the solution through the diatomaceous earth and down into the flask, removing pigments and other compounds. Filtration is repeated until solution is pigment free. 
     The method of filtration as according to an embodiment of the present invention includes setting up and prepping filters, ideally a plurality of filters are connected to each pump to maximize efficiency of the system. A maximum efficiency state is considered to exist when the maximum number of filters are attached to each pump without detrimentally effecting the suction performance of each pump. The optimal ratio of filters to pumps will vary from embodiment to embodiment. 
     Before pouring solution into filters, proper dilution of the solution to be filtered is necessary. Ideally the pre-filtration solution should be less than 0.01 g of hemp or cannabis oil per mL to minimize potential yield loss. 
     Diatomaceous earth is placed into filters. It should be noted that on a first pass less diatomaceous earth is used than in subsequent passes. 
     After proper dilution, turn on vacuum pumps and pack down diatomaceous earth in the filter. Evenly packed diatomaceous earth is optimal because it minimizes the solution&#39;s ability to find a path of least resistance. The solution is then poured into a filter containing the diatomaceous earth and pulled through via vacuum suction. When the solution is almost fully pulled through, meaning a small amount is still in filter, a liquid non-polar solvent rinse is added. The liquid non-polar solvent helps to dissolve and pull through any yield stuck in the diatomaceous earth. The rinse process is repeated until the resultant solution is clear. 
     Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention. To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of this application. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a flowchart showing a method for filtering organic compounds using diatomaceous earth as according to an embodiment of the present invention, and 
         FIG. 2  is a diagram showing the components of a system for filtering organic compounds using diatomaceous earth as according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     Referring now to  FIGS. 1 and 2 , the invention comprises a method and system of using diatomaceous earth for filtration. The purpose of the filtration is to remove undesirable compounds ( 200 ) from a liquid non-polar solvent solution that are not cannabinoids or terpenes. The cannabinoids and terpenes provide medical benefits and are desirable extraction products of the cannabis plant. The method of filtration described herein starts ( 100 ) with preparing the filter ( 101 ) that will extract undesirable organic compounds from a solution ( 202 ) such as pigments as well as plant waxes, lipids, or other plant cells that are not considered active ingredients in hemp or cannabinoid products ( 200 ). The pigments include chlorophyll, anthocyanin and carotenoid. These undesirable compounds have no medical benefit and are undesirable byproducts ( 200 ) from the process of extracting cannabinoids and terpenes from cannabis using a liquid non-polar solvent. Liquid non-polar solvents that can be used with the present invention include butane, hexane, pentane, heptane, ethanol, MCT oil, cold pressed hemp oil, olive oil, benzene, toluene, diethyl ether, chloroform, 1,4 dioxane and other non-polar liquids. 
     The filter preparation step ( 100 ) comprises preparing at least one filter by placing a filtering device, such as a paper, glass or quartz frit, woven metal, spun or woven rock, clay or cloth filter designed to trap particles roughly the size of diatomaceous earth particles and larger, into a filter container. The filter container can be a glass Buchner funnel or could be a larger funnel made of a different material ( 205 ). Alternatively, the filter could be a large-scale industrial apparatus such as a 1,000-ton stainless steel reactor half full of diatomaceous earth with a large 10,000-liter extraction pump that distributes the entire solution over the filtration material all at one time. Next in the filter preparation step is to attach a vacuum pump ( 207 ) and hose lines to the funnel ( 205 ) and a receptacle that will catch the filtered solution such as a glass flask ( 203 ). Then, diatomaceous earth ( 204 ) is added to the filter container ( 205 ). For the first iteration, a lesser amount of diatomaceous earth ( 204 ) is desirable whereas subsequent iterations can use greater amounts. It is preferable to evenly pack the diatomaceous earth ( 204 ) in the funnel ( 205 ) so that solution flowing through the diatomaceous earth ( 204 ) cannot find a path of least resistance and avoid proper filtration. One possible technique for packing the diatomaceous earth ( 204 ) is to activate the vacuum pump ( 207 ) to draw down the diatomaceous earth ( 204 ) into the funnel ( 205 ). 
     In an embodiment of the present invention, a plurality of filters ( 205 ) are connected to each pump ( 207 ) so that a maximum number of filters ( 205 ) are attached to each pump without detrimentally effecting the suction performance of each pump ( 207 ). The optimal ratio of filters ( 205 ) to pumps ( 207 ) will vary from embodiment to embodiment. 
     The next step in the process is to prepare the solution for filtration ( 102 ). Before filtering, it is necessary to properly dilute the solution ( 204 ). Ideally the solution ( 204 ) should be thin enough that it is less than 0.01 g/mL of a liquid non-polar solvent ( 206 ) to minimize potential yield loss. Dilution is performed by adding a liquid non-polar solvent to the solution. 
     Adding a liquid non-polar solvent also provides the benefit of minimizing the loss of cannabinoids and terpenes. An ideal solution dilution mixture is 0.009 g/mL of a liquid non-polar solvent ( 206 ). 
     It should be noted that the steps of preparing the filter ( 101 ) and preparing the solution ( 102 ) can be done in any order or simultaneously. It is not essential to embodiments of the present invention that they be performed in the sequential order as shown in  FIG. 1 . 
     Once the filter(s) and solution are prepared ( 101 ,  102 ), the vacuum pump ( 207 ) is engaged. In an embodiment of the present invention, at least one vacuum pump ( 207 ) is attached to at least one funnel ( 205 ) containing diatomaceous earth ( 204 ). In other embodiments of the present invention, a plurality of vacuum pumps ( 207 ) are attached to a plurality of funnels ( 205 ) with the ratio generally being one vacuum pump ( 207 ) for as many funnels ( 205 ) as possible without significantly degrading the efficiency or performance of the pump ( 207 ). The invention is scalable and can be expanded to meet whatever production capacity is required by adjusting the size of the vacuum, or the size of the filtration apparatus. 
     After the vacuum pump is engaged ( 103 ), the solution to be filtered is poured over the top of the packed diatomaceous earth ( 104 ) and allowed to flow through to the bottom of the funnel ( 205 ). This is the filtration step and it can be repeated with the liquid non-polar solvent rinse, described below, as many times as required. The first filtration step ( 104 ) is performed with a lesser amount of diatomaceous earth ( 204 ) because of the high wax content of the crude solution. The greater the wax content, the greater the loss of the desirable organic compounds ( 201 ). The desirable organic compounds ( 201 ) are the cannabinoids and terpenes. The exact amount of diatomaceous ( 204 ) earth used during filtration varies from embodiment to embodiment based on the scale of the filtering system. Larger apparatus and pumps will allow for greater amounts of diatomaceous earth ( 204 ) to be used. 
     The resultant solution from step ( 104 ) is collected in a receptacle such as a glass flask ( 105 ). This is the collection step that captures the filtered solution that should contain very little to no undesirable compounds ( 200 ). If the solution was properly prepared in step ( 102 ), then substantial amounts of desirable compounds ( 201 ) will be collected without the filter becoming clogged. 
     To extract additional amounts of desirable compounds ( 201 ), the diatomaceous earth ( 204 ) can be rinsed with a liquid non-polar solvent ( 106 ). The term “rinse” and “wash” can be used interchangeably to describe the process of adding additional amounts of a liquid non-polar solvent ( 206 ) to the diatomaceous earth ( 204 ) through which the solution that was filtered. 
     The rinsed solution is collected ( 107 ) and the rinse can be step ( 106 ) can be repeated as many times as necessary. Optimally, the rinse step ( 106 ) will be repeated until the solution exiting the filter is clear ( 108 ). 
     The diatomaceous earth or other filtration medium can be replaced ( 110 ) and the entire filtration process repeated ( 103 - 110 ) as many times as necessary. 
     Parameters that affect the efficiently of the filtration process include the suction power of the vacuum pump ( 207 ), the amount of the diatomaceous earth ( 204 ) placed in the filter ( 205 ), and the initial dilution of the crude solution. The crude solution is considered to be the solution that is to be filtered ( 202 ) prior to it being filtered. 
     In a preferred embodiment of the present invention, for every 1 unit of crude solution ( 202 ) approximately 1.6 to 3.8 units of diatomaceous earth ( 204 ) is used while 3.3 to 8 units of a liquid non-polar solvent such as butane, hexane, pentane, heptane, ethanol, MET oil, cold pressed hemp oil, olive oil, benzene, toluene, diethyl ether, chloroform, 1,4 dioxane and other hydrocarbon oils ( 206 ) is required. The primary factors that change the amount of diatomaceous earth ( 204 ) and a liquid non-polar solvent ( 206 ) required are the strain of the cannabis being filtered and the age of the crude solution ( 202 ). The number of rinse steps ( 108 ) required varies depending on the amount of desirable compound ( 201 ) yield per run. 
     In a preferred embodiment of the present invention, approximately 1.6 to 3.8 times more diatomaceous earth ( 204 ) than crude solution is used in every filter ( 205 ). A crude solution containing a ratio of a liquid non-polar solvent ( 206 ) to desirable compounds ( 201 ) is 0.001 g/mL to 0.009 g/mL. At this ratio, the diatomaceous earth ( 204 ) can effectively pull out high concentrations of undesirable compounds ( 200 ) from the crude solution ( 202 ) due to lower PPM measurements of the undesirable compound ( 200 ). The crude solution contains cannabinoids that contain, but are not limited to: THCA, delta 9 THC, CBN, CBD, CBG, THCV CBC, CBDA, CBDV, as well as any other unnamed, but present, cannabinoid found in hemp or cannabis as long as it is suspended in anything liquid and non-polar. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the symmetrical measuring tool, suitable methods and materials are described above. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. The symmetrical measuring tool may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive. Any headings utilized within the description are for convenience only and have no legal or limiting effect.