Method for improving low-value waste fats, oils, and grease

Abstract

The present invention provides a method comprising the steps of: contacting a composition with a caustic solution to produce a caustic-treated composition; combining the caustic-treated composition with silica particles to produce a slurry; and removing the silica particles from the slurry to produce a treated composition, wherein the composition comprises one or more of animal fat, animal oil, vegetable fat, vegetable oil, vegetable fat, vegetable oil, grease, and waste cooking oil, and the composition comprises at least about 10 wppm of total metal, at least about 8 wppm of phosphorus, at least about 10 wppm of chlorine, at least about 10 wppm of sulfur, at least about 20 wppm of nitrogen, and at least about 5 wt% of free fatty acids; having an acid value of about 10 mg KOH / g to about 150 mg KOH / g, and the silica particles have a particle size of about 10 microns to about 50 microns and a BET surface area of ​​about 200 m2 / g to about 1000 m2 / g.

Description

Technology Field

[0001] Cross-reference of related applications

[0002] The present application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 665,991 filed on May 2, 2018, the contents of which are incorporated herein by reference in their entirety.

[0003] Technology field

[0004] The present invention generally relates to the processing of compositions that can be used as biorenewable feedstocks for hydroprocessing. More specifically, but not limited to, the present invention provides a method for improving low-value waste fat, oil, and grease compositions to produce a treated composition having reduced amounts of precipitates, sulfur, nitrogen, chlorine, polymers, phosphorus, and total metals.

[0005] In one embodiment, the present invention provides a method comprising the steps of: contacting a composition with a caustic solution to produce a caustic-treated composition; combining the caustic-treated composition with silica particles to produce a slurry; and removing the silica particles from the slurry to produce a treated composition. The composition comprises animal fat, animal oil, plant fat, plant oil, vegetable fat, vegetable oil, grease, waste cooking oil, or any combination of two or more of these. Additionally, the composition comprises at least about 10 wppm of total metal, at least about 8 wppm of phosphorus, at least about 10 wppm of chlorine, at least about 10 wppm of sulfur, at least about 20 wppm of nitrogen, and at least about 5 wt% of free fatty acids, and has an acid value of about 10 to about 150 mg KOH / g. The above silica particles have an average particle size of about 10 microns to about 50 microns and about 200 m2 / g to about 1000 m 2 It has a Brunauer-Emmett-Teller surface area of ​​ / g ("BET surface area"). Brief explanation of the drawing

[0006] Figure 1 illustrates the percentage reduction of phosphorus as a function of the total acid number ("TAN") of an unprocessed fat, oil, and grease (FOG) feed according to the method of the present invention. Figure 2 illustrates the percentage reduction of metal as a function of TAN of the raw FOG feed according to the method of the present invention. Specific details for implementing the invention

[0007] Various embodiments are described below. It should be noted that specific embodiments are not intended to be a complete description or limitation of the broader aspects discussed herein. An aspect described in connection with a specific embodiment is not necessarily limited to that embodiment and may be practiced in combination with any other embodiment(s).

[0008] In this document, "about" will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. Where there is a use of a term that is not clear to those skilled in the art, considering the context in which it is used, "about" means up to ±10% of the specific term, for example, "about 10 wt%" will mean "9 wt% to 11 wt%". Where "about" precedes a specific term, it should be understood that the term should be interpreted as disclosing "about" the term as well as the term in the absence of modification by "about", for example, "about 10 wt%" discloses "10 wt%" as well as "9 wt% to 11 wt%".

[0009] In the context of describing components (particularly in the context of the following claims), terms and similar references indicating the singular shall be interpreted as including both the singular and plural forms, unless otherwise indicated herein or clearly contradictory by the context. Enumeration of numerical ranges in this specification is intended to serve merely as a shortened method of individually referring to each individual value within the range, unless otherwise indicated herein, and each individual value is included in this specification as individually referred to herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or clearly contradictory by the context. Any and all examples or exemplary language provided herein (e.g., “e.g.,”) are intended merely to make embodiments clearer and do not limit the claims, unless otherwise stated. No language in this specification shall be interpreted as indicating an unclaimed component as essential.

[0010] Decarboxylation (DCO) is understood to refer not only to the hydrogenation of organic molecules in which a carboxyl group is removed to produce CO2, but also to decarbonylation that causes the formation of CO.

[0011] Pyrolysis refers to the thermochemical decomposition of carbonaceous materials containing or lacking diatomic oxygen or diatomic hydrogen present in a thermochemical reaction process. The optional use of a catalyst in pyrolysis is generally referred to as catalytic decomposition, which is encompassed within the term pyrolysis and should not be confused with hydrocracking.

[0012] Hydrotreating (HT) involves the removal of elements of IUPAC Groups 13, 15, 16, and / or 17 of the periodic table from organic compounds. Hydrotreating may also involve hydrodemetallization (HDM) reactions. Thus, hydrotreating involves the removal of heteroatoms, such as oxygen, nitrogen, sulfur, and any combination of two or more of these, through hydroprocessing. For example, hydrodeoxygenation (HDO) is understood to mean the removal of oxygen by a catalytic hydroprocessing reaction that produces water as a byproduct; similarly, hydrodesulfurization (HDS) and hydrodenitrification (HDN) describe the individual removal of the aforementioned elements through hydroprocessing.

[0013] Hydrogenation involves adding hydrogen to organic molecules without breaking the molecules down into their subunits. Adding hydrogen to carbon-carbon or carbon-oxygen double bonds to create single bonds is two non-limiting examples of hydrogenation. Partial hydrogenation and selective hydrogenation are terms used to refer to hydrogenation reactions that cause partial saturation of unsaturated feedstocks. For example, vegetable oils containing a high percentage of polyunsaturated fatty acids (e.g., linoleic acid) can undergo partial hydrogenation to yield a hydrogenated product, where the polyunsaturated fatty acids are converted into monounsaturated fatty acids (e.g., oleic acid) without increasing the percentage of unwanted saturated fatty acids (e.g., stearic acid). Hydrogenation is distinguished from hydrogenation, hydrogenation isomerization, and hydrogenation cracking, and hydrogenation can occur during these different reactions.

[0014] Hydrocracking (HC) is understood to mean the cleavage of carbon-carbon bonds of a molecule to form at least two molecules in the presence of hydrogen. This reaction generally involves the subsequent hydrogenation of the resulting double bond.

[0015] Hydroisomerization (HI) is defined as the rearrangement of the carbon-carbon bond framework in the presence of hydrogen to form isomers. Hydrocracking is a competing reaction to most HI-catalyzed reactions, and the HC reaction pathway as a secondary reaction is understood to be included in the use of the term HI. Hydrodewax (HDW) is a specific form of hydrocracking and hydroisomerization designed to improve the low-temperature properties of hydrocarbon fluids.

[0016] "Hydrocarbonaceous" is defined as being primarily composed of organic molecules containing carbon and hydrogen (i.e., hydrocarbons), but also includes those composed of other organic molecules, for example, atoms selected from IUPAC Groups 13 through 17 of the periodic table (e.g., boron, nitrogen, oxygen, phosphorus, sulfur, and / or halogens).

[0017] This technology

[0018] Replacing fossil fuels with biofuels reduces greenhouse gas emissions, which is determined by the feedstocks used in biofuel production. Unlike most vegetable oils, low-value waste fats, oils, and greases ("FOG") are non-edible byproducts and waste streams discharged from food processing industries and water treatment plants. For example, in the production of renewable diesel, lipid feedstocks (containing varying free fatty acid ("FFA") contents) are converted into isoparaffinic hydrocarbons in a hydroprocessing reactor. A hydroprocessing reactor is typically a high-pressure vessel filled with an extrusion catalyst impregnated with a hydride metal (e.g., Ni, Mo, Co, W, Pd, and Pt).

[0019] However, FOG composition feeds generally contain several inherent contaminants that have a negative impact on their conversion to biofuel, e.g., phosphorus, IUPAC Group 1 to 12 metals (as phospholipids and soaps), organic chlorine, nitrogen and sulfur compounds and polymers, as well as any combination of two or more of these (collectively referred to herein as “FOG contaminants”). During hydroprocessing, FOG contaminants can cause catalyst deactivation, plugging of the catalyst layer, and / or corrosion of the reactor. For example, phosphorus and IUPAC Group 1 to 12 metals are known to be toxins to hydroprocessing catalysts; chlorine compounds can generate hydrochloric acid through hydrodechlorination, which can cause stress corrosion cracking in stainless steel; and polymers can precipitate within the catalyst layer, causing deactivation and plugging. Additionally, organic N and S compounds compete with oxygen-containing substances for the catalytic hydrodeoxygenation sites, and thus their removal is advantageous for the HDO process. Proteins present in the FOG composition contain both N and S. Some lipid components are also known to contain nitrogen and sulfur atoms in their molecular structure.

[0020] Bleaching clay (e.g., Pyophoto, TONSIL®) is known to be effective in removing color bodies containing nitrogen compounds (e.g., chlorophyll) and other polar species. However, at relatively high FFA concentrations in the FOG composition feed (i.e., about 8 wt percent ("wt%") or higher in the FOG composition), metals such as Mg, Fe, and Ca leach from the clay and are absorbed into the washed oil, further contaminating the FOG. Although FFA can be removed from the FOG composition by reaction with caustic solutions such as sodium hydroxide or potassium hydroxide and centrifugation / filtration ("soap out"), the removal of FFA as soap stock degrades the biofuel yield from the FOG. Therefore, there is a need for processes and systems to improve the FOG composition stream by removing metals, S, N, Cl, and polymers while maintaining the FFA content of the feed without requiring the use of bleaching clay.

[0021] The present invention provides a method for improving a FOG composition comprising metals, sulfur, nitrogen, phosphorus, and polymers, such that the resulting treated composition has less metal, sulfur, nitrogen, phosphorus, chlorine, and polymers. In contrast to comparative methods for removing these components from a FOG composition, the present invention can reduce metals, sulfur, nitrogen, phosphorus, chlorine, and polymers while maintaining the weight percentage of FFAs in the composition.

[0022] Accordingly, in one embodiment, the present invention provides a method comprising the steps of: contacting a composition with a caustic solution to produce a caustic-treated composition; combining the caustic-treated composition with silica particles to produce a slurry; and removing the silica particles from the slurry to produce a treated composition. The composition comprises animal fat, animal oil, plant fat, plant oil, vegetable fat, vegetable oil, grease, waste cooking oil, or any combination of two or more of these. Additionally, the composition comprises at least about 10 wppm of total metal, at least about 10 wppm of phosphorus, at least about 10 wppm of chlorine, at least about 10 wppm of sulfur, at least about 20 wppm of nitrogen, and at least about 5 wt% of free fatty acids, and has an acid value of about 10 mg KOH / g to about 150 mg KOH / g. The above silica particles have an average particle size of about 10 microns to about 50 microns and about 200 m 2 / g to about 1000 m 2 It has a Brunauer-Emmett-Teller surface area of ​​ / g ("BET surface area").

[0023] In any embodiment of the present invention, the treated composition may be combined with silica particles ("a second set of silica particles," wherein such silica particles may have any embodiment of the silica particles described herein) to produce a second slurry; and the second set of silica particles may be removed from the second slurry to produce a second treated composition. In any embodiment of the present invention, the second treated composition may be combined with silica particles ("a third set of silica particles," wherein such silica particles may have any embodiment of the silica particles described herein) to produce a third slurry; and subsequently, the third set of silica particles may be removed from the third slurry to produce a third treated composition. In any embodiment of the present invention, similar steps may be used to provide a fourth treated composition, a fifth treated composition, and the like. For ease of reference in the discussion of the above technology, "treated composition" collectively refers to the treated composition, the second treated composition, and the like, provided that each treated composition may independently have any embodiment described herein.

[0024] As discussed above, the composition comprises animal fat, animal oil, plant fat, plant oil, vegetable fat, vegetable oil, grease, waste cooking oil, or any combination of two or more of these. Plant and / or vegetable oils may include, but are not limited to, babassu oil, carinata oil, soybean oil, non-edible corn oil, canola oil, coconut oil, rapeseed oil, tall oil, tall oil fatty acids, palm oil, palm oil fatty acid distillate, palm sludge oil, jatropha oil, palm kernel oil, sunflower oil, castor oil, camelina oil, archaeal oil, and any mixture of two or more of these. These may be classified into unrefined, degummed, and RBD (refined, bleached, and deodorized) grades depending on the level of pretreatment and residual phosphorus and metal content. However, any of these grades may be used in the present invention. The animal fats and / or oils used above may include, but are not limited to, inedible tallow, edible tallow, industrial tallow, floating tallow, lard, poultry fat (e.g., chicken fat), poultry oil, fish fat, fish oil, and mixtures thereof. The grease may include, but is not limited to, yellow grease, brown grease, waste cooking oil, waste vegetable oil, restaurant grease, municipal trap grease such as water treatment facilities, and waste oil derived from industrial packaging food operations, and mixtures of any two or more of these.For example, in any embodiment of the present invention, the composition may include yellow grease, brown grease, floating grease, poultry fat, non-edible corn oil, waste cooking oil, non-edible tallow, floating tallow, palm sludge oil, or any two or more of these mixtures.

[0025] The above composition may contain at least 8 wppm of total metal when measured by inductively coupled plasma (ICP) spectroscopy, e.g., ICP-AES (atomic emission spectroscopy) and ICP-OES (optical emission spectroscopy), e.g., AOCS Recommended Practice Ca 17-01. These metals may include, but are not limited to, As, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Pb, Sr, Zn, or any combination of two or more of these. For example, in any embodiment of the present invention, the total metal may include Ca, Fe, K, Mg, and Na. The amount of total metal present in the composition may include about 10 wppm to about 1000 wppm of total metal. Accordingly, the total amount of metal in the above composition is about 10 wppm, about 15 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, about 105 wppm, about 110 wppm, about 115 wppm, about 120 wppm, about 125 wppm, about 130 wppm, about 135 wppm, about 140 wppm, about 145 wppm, about 150 wppm, approx. 155 wppm, approx. 160 wppm, approx. 165 wppm, approx. 170 wppm, approx. 175 wppm, approx. 180 wppm, approx. 185 wppm, approx. 190 wppm, approx. 195 wppm, approx. 200 wppm, approx. 225 wppm, approx. 250 wppm, approx. 275 wppm, approx. 300 wppm,Approximately 325 wppm, approximately 350 wppm, approximately 375 wppm, approximately 400 wppm, approximately 425 wppm, approximately 450 wppm, approximately 475 wppm, approximately 500 wppm, approximately 550 wppm, approximately 600 wppm, approximately 650 wppm, approximately 700 wppm, approximately 750 wppm, approximately 800 wppm, approximately 850 wppm, approximately 900 wppm, approximately 1000 wppm, or may be any range including any two of these values ​​and / or between any two of these values; The total amount of metal in the composition is 10 wppm, 15 wppm, 20 wppm, 25 wppm, 30 wppm, 35 wppm, 40 wppm, 45 wppm, 50 wppm, 55 wppm, 60 wppm, 65 wppm, 70 wppm, 75 wppm, 80 wppm, 85 wppm. wppm, 90 wppm, 95 wppm, 100 wppm, 105 wppm, 110 wppm, 115 wppm, 120 wppm, 125 wppm, 130 wppm, 135 wppm, 140 wppm, 145 wppm, 150 wppm, 155 wppm, 160 165 wppm, 170 wppm, 175 wppm, 180 wppm, 185 wppm, 190 wppm, 195 wppm, 200 wppm, 225 wppm, 250 wppm, 275 wppm, 300 wppm, 325 wppm, 350 wppm, 375 wppm, 400 wppm, 425 wppm, 450 wppm, 475 wppm, 500 wppm, 550 wppm, 600 wppm, 650 wppm, 700 wppm, 750 wppm, 800 wppm, 850 wppm, 900 wppm, 1000 wppm, or any range including and / or between any two of these values. There is. For example, an appropriate amount of total metal in the above composition is about 10 wppm to about 1000 wppm, 10 wppm to 1000 wppm,It may be about 10 wppm to about 800 wppm, 10 wppm to 800 wppm, about 10 wppm to about 600 ppm, 10 wppm to 600 ppm, about 10 ppm to about 400 wppm, 10 ppm to 400 wppm, about 10 wppm to about 200 wppm, 10 wppm to 200 wppm, about 10 wppm to about 100 wppm, 10 wppm to 100 wppm, about 10 wppm to about 50 wppm, or 10 wppm to 50 wppm.

[0026] The above composition may contain at least about 8 wppm of phosphorus as measured as the phosphorus element. The amount of phosphorus in the above composition is about 8 wppm, about 10 wppm, about 15 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, about 110 wppm, about 120 wppm, about 130 wppm, about 150 wppm, about 170 wppm, about 190 wppm, about 200 wppm, about 300 wppm, about 400 wppm, about 500 wppm, about 600 wppm, about 700 wppm, about 800 wppm, or any range including and / or between any two of these values, or any range greater than any one of these values.

[0027] The above composition may contain at least about 10 wppm of chlorine measured as a chlorine element (Cl atom). The amount of chlorine is about 10 wppm, about 11 wppm, about 12 wppm, about 13 wppm, about 14 wppm, about 15 wppm, about 16 wppm, about 17 wppm, about 18 wppm, about 19 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, or any range including and / or between any two of these values, or any of these values It can be an arbitrary range larger than one.

[0028] The above composition may contain at least about 10 wppm of sulfur, measured as elemental sulfur when measured, for example, by AOAC method 923.01. The amount of sulfur is at least about 10 wppm, about 15 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, about 110 wppm, about 120 wppm, about 130 wppm, about 150 wppm, about 170 wppm, about 190 wppm, about 200 wppm, or any range including and / or between any two of these values, or any of these values It may include any range greater than one, but is not limited to this.

[0029] The above composition may contain at least about 10 wppm of nitrogen, measured as the elemental nitrogen when measured, for example, by ASTM D4629-17. The amount of nitrogen is at least about 10 wppm, about 15 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, about 110 wppm, about 120 wppm, about 130 wppm, about 150 wppm, about 170 wppm, about 190 wppm, about 200 wppm, about 250 wppm, about 300 wppm, about 350 wppm, about 400 wppm, about 450 wppm, about 500 wppm, about 550 wppm, about 600 wppm, about 650 wppm, about 700 wppm, about 750 wppm, about 800 wppm, about 850 wppm, about 900 wppm, about 950 wppm, about 1000 wppm, about 1100 wppm, or any two of these values, or any range between any two of these values, or any range greater than any one of these values, but not limited thereto.

[0030] The above composition contains at least about 5 weight percent of FFA based on the total weight of the composition when measured by standard analytical techniques such as AOCS Ca 5a-40. The amount of FFA may be about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, about 20 wt%, about 21 wt%, about 22 wt%, about 23 wt%, about 24 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 70 wt%, about 75 wt%, or any two of these values, or any range between any two of these values. For example, in any embodiment of the present invention, the amount of FFA in the composition may be about 5 weight% to about 15 weight%. In any embodiment of the present invention, the amount of FFA in the composition may be about 5 weight% to about 10 weight%.

[0031] The above composition may have an acid value of about 10 mg KOH / g to about 150 mg KOH / g. Suitable acid value amounts may include, but are not limited to, about 10 mg KOH / g to about 150 mg KOH / g, about 10 mg KOH / g to about 100 mg KOH / g, about 10 mg KOH / g to about 50 mg KOH / g, about 10 mg KOH / g to about 25 mg KOH / g, about 10 mg KOH / g to about 20 mg KOH / g, about 10 mg KOH / g to about 15 mg KOH / g, and any range including any two of these values ​​or between any two of these values, and any range greater than any one of these values. For example, in any embodiment of the present invention, the acid value of the composition may be about 10 mg KOH / g to about 30 mg KOH / g. In another embodiment, the acid value of the composition may be about 10 mg KOH / g to about 20 mg KOH / g.

[0032] The above composition may further comprise a polymer. Such polymer may be a dissolved polymer, a solubilized polymer, a granular polymer, or a mixture of any two or more of these. The granular polymer may have a weight-average diameter of about 0.01 μm to about 1 millimeter (mm); thus, the granular polymer may have a weight-average diameter of about 0.01 μm, about 0.1 μm, about 1 μm, about 5 μm, about 10 μm, about 25 μm, about 50 μm, about 75 μm, about 80 μm, about 100 μm, about 200 μm, about 300 μm, about 500 μm, about 750 μm, about 1 mm, or any range including and / or between any two of these values. The granular polymer may have a weight-average diameter of less than about 0.01 μm. The polymer may be a synthetic or natural polymer. A partial list of synthetic polymers is provided in Table 1.

[0033]

[0034] In any embodiment of the present invention, the synthetic polymer is an acrylonitrile butadiene styrene thermoplastic resin, polyacrylate rubber, ethylene-acrylate rubber, polyester urethane, bromoisobutylene isoprene rubber, polybutadiene rubber, chloroisobutylene isoprene rubber, polychloroprene, chlorosulfonated polyethylene, epichlorohydrin, ethylene propylene rubber, ethylene propylene diene monomer, polyether urethane, tetrafluoroethylene / propylene rubber, perfluorocarbon elastomer, fluoroelastomer, fluorosilicone, fluorocarbon rubber, high-density polyethylene, hydrogenated nitrile butadiene, polyisoprene, isobutylene isoprene rubber, low-density polyethylene, polyethylene terephthalate, ethylene vinyl acetate, acrylonitrile butadiene, polyethylene, polyisobutene, polypropylene, polystyrene, polyvinyl The polymer may comprise chloride, polyvinylidene chloride, polyurethane, styrene butadiene, styrene ethylene butylene styrene copolymer, polysiloxane, vinyl methyl silicone, acrylonitrile butadiene carboxy monomer, styrene butadiene carboxy monomer, thermoplastic polyether-ester, styrene butadiene block copolymer, styrene butadiene carboxy block copolymer, polyester, polyamide, polyacetal, polylactic acid, or any mixture of two or more of these. For example, in any embodiment of the present invention, the polymer may comprise polyethylene, chlorosulfonated polyethylene, low-density polyethylene, high-density polyethylene, polyethylene terephthalate, polylactic acid, or any combination of two or more of these, but is not limited thereto. The natural polymer may comprise proteins, oligopeptides, polysaccharides, and lignin.

[0035] The amount of polymer in the above composition is about 0.05 wppm, about 0.1 wppm, about 0.5 wppm, about 0.1 wppm, about 5 wppm, about 10 wppm, about 15 wppm, about 20 wppm, about 25 wppm, about 30 wppm, about 35 wppm, about 40 wppm, about 45 wppm, about 50 wppm, about 55 wppm, about 60 wppm, about 65 wppm, about 70 wppm, about 75 wppm, about 80 wppm, about 85 wppm, about 90 wppm, about 95 wppm, about 100 wppm, about 105 wppm, about 110 wppm, about 115 wppm, about 120 wppm, about 125 wppm, approx. 130 wppm, approx. 135 wppm, approx. 140 wppm, approx. 145 wppm, approx. 150 wppm, approx. 155 wppm, approx. 160 wppm, approx. 165 wppm, approx. 170 wppm, approx. 175 wppm, approx. 180 wppm, approx. 185 wppm, approx. 190 wppm, approx. 195 wppm, approx. 200 wppm, approx. 225 wppm, approx. 250 wppm, approx. 275 wppm, approx. 300 wppm, approx. 325 wppm, approx. 350 wppm, approx. 375 wppm, approx. 400 wppm, approx. 425 wppm, approx. 450 wppm, approx. 475 wppm, approx. 500 wppm, approx. 550 wppm, approx. 600 wppm, approx. 650 wppm, approx. 700 wppm, approx. 750 wppm, approx. 800 wppm, approx. 850 wppm, approx. 900 wppm, approx. 1000 wppm, approx. 1500 wppm, approx. 2000 wppm, approx. 2500 wppm, approx. 3000 wppm, approx. 3500 wppm, approx. 4000 wppm, approx. 4500 wppm, approx. 5000 wppm, approx. 5000 wppm, approx. 5500 wppm, approx. 6000 wppm, approx. 6500 wppm, approx. 7000 wppm, approx. 7500 wppm, approx. 8000 wppm, approx. 8500 wppm, approx. Approximately 9000 wppm,It may be about 9,500 wppm, about 10,000 wppm, about 10,500 wppm, about 11,000 wppm, and any range including / or between any two of these values, and any range greater than any one of these values. In any embodiment of the present invention, the composition may not include a detectable polymer. Throughout the present invention, "detectable" means detection on a commercially available detection device known in the art.

[0036] The above composition may contain about 15 mg or more of precipitate per 100 mL of composition. The precipitate is measured according to the method described in AOCS Ca 3d-02, provided that the method be performed at 65°C instead of 20°C.

[0037] The above composition may or may not undergo pretreatment before contacting the composition with the caustic solution. Such pretreatment may include, but is not limited to, FFA stripping, bleaching, deodorization, washing, glycerol degradation, degumming, alkalinity reduction, or any combination of two or more of these. Glycerol degradation generally involves reducing the amount of FFA by a reaction between the composition and glycerol, as described in U.S. Patent No. 7,087,771 incorporated herein by reference. The products of this reaction may include monoglycerides, diglycerides, triglycerides, or a mixture of two or more of these. For example, a typical reaction for converting FFA to monoglycerides may be as described below:

[0038] R-COOH + CH2(OH)CH(OH)CH2OH ↔ R-COOCH2CH(OH)CH2OH + H2O

[0039] Accordingly, glycerol decomposition can reduce the FFA content to about 15 wt% or less, for example, in the range of about 5 wt% to about 15 wt% (about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, or any range including any two of these values ​​and / or between any two of these values). For example, in any embodiment of the present technology, the FFA content may be reduced to about 10 wt% or less before contacting the composition with the caustic solution by pretreating the composition (e.g., through glycerol decomposition); As another example, in any embodiment of the present technology, the FFA content may be reduced to a range of about 5% by weight to about 10% by weight before contacting the composition with the caustic solution by glycerol decomposition pretreatment of the composition.

[0040] One type of degumming is acid degumming, which includes the step of contacting the composition with a concentrated aqueous acid before contacting the composition with the caustic solution. An exemplary acid degumming process is described in U.S. Patent No. 9,404,064, incorporated herein by reference. Exemplary acids may include phosphoric acid, citric acid, and maleic acid. Acid degumming may reduce phosphorus as well as metals such as calcium and magnesium. Similarly, alkalinity reduction is generally performed by adding an acid (referring to any acid, e.g., citric acid) to a composition having high alkalinity. The acid has the effect of neutralizing soap and / or chelating metal ions. Process equipment used for acid degumming and / or alkalinity reduction may include high-shear mixers, recirculation mixers, decanter centrifuges, and / or disk stack centrifuges.

[0041] Accordingly, alkalinity reduction can reduce the concentration of metals, in particular Fe, Ca, K, and Na, in the composition before contacting the composition with a caustic solution. In any embodiment of the present invention, alkalinity reduction comprises the steps of: heating the composition by contacting it with steam to provide a steam-heated composition; combining the steam-heated composition with an acid (e.g., citric acid) to provide an acid-contacted composition; combining the acid-contacted composition with water and then stirring to provide a mixture comprising uniformly dispersed droplets; and then separating the sludge phase, aqueous phase, and oil phase in a three-phase centrifuge, wherein the oil phase is a pretreated composition having a reduced total metal content and reduced alkalinity (compared to the composition). The steam-heated composition may be at a temperature of about 150°F to about 200°F. The amount of acid (e.g., citric acid) combined with the steam-heated composition may be about 0.2 wt% to about 10.0 wt% (based on the mass of the composition). The amount of water combined with the acid-contacted composition may be about 0.2 wt% to about 10.0 wt% (based on the mass of the composition). Stirring may include the use of a stirrer, a recirculation loop, any other mixing means, or any combination of two or more of these. The total time of stirring (e.g., total mixing time) may be about 2 minutes to about 90 minutes. The pretreated composition may contain a reduced amount of metal based on the total amount of metal in the composition prior to alkalinity reduction. The alkalinity reduction may provide a total metal content that is about 40% to about 99% lower than that of the composition prior to alkalinity reduction.

[0042] In any embodiment of the present invention, the process may or may not include bleaching using bleaching clay. Bleaching generally comprises the step of contacting the degummed composition with adsorbent clay and filtering the clay through a pressure leaf filter. Bleaching clay (e.g., Pyophoto, TONSIL®) is known to be effective in removing color bodies containing nitrogen compounds (e.g., chlorophyll) and other polar species. However, at relatively high FFA concentrations typical of the raw FOG compositions of the present invention, metals such as Fe, Mg, and Ca leach from the clay and are absorbed into the washed composition, further contaminating the composition.

[0043] A method of the present invention comprises the step of contacting a composition described in any embodiment of the present invention with a caustic solution to produce a caustic-treated composition. For example, in any embodiment of the present invention, the caustic solution may comprise an aqueous hydroxide solution, an aqueous bicarbonate solution, an aqueous disulfide solution, an aqueous alkoxide solution (e.g., an aqueous methoxide solution), a basic resin dissolved and / or suspended in an aqueous solution, a methoxide solution, or a combination of two or more of these. In any embodiment of the present invention, the caustic solution may comprise sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium bicarbonate, potassium bicarbonate, ammonium bisulfide, sodium methoxide, potassium methoxide, or any combination of two or more of these. For example, in any embodiment of the present invention, the caustic solution may be an aqueous hydroxide solution of about 10% by weight to about 50% by weight.

[0044] In any embodiment of the present invention, the step of contacting the composition with the caustic solution may first provide a first mixture, wherein the step of producing the caustic-treated composition may include the step of separating the caustic-treated composition from the first mixture. This separation step may include the use of a disk stack centrifuge, a decanter centrifuge, and / or a three-phase centrifuge. Other methods, systems, and apparatuses for separating the caustic-treated composition from the first mixture may be included. These include methods, systems, and apparatuses such as a settling tank, which are known to those skilled in the art. The caustic-treated composition may contain reduced amounts of phosphorus and total metal based on the amounts of phosphorus and total metal in the composition prior to contact with the caustic solution. The net reduction of phosphorus and metal may each be independently about 60% to about 96% of the amounts in the composition prior to contact with the caustic solution.

[0045] The step of separating the caustic-treated composition from the first mixture may also include the step of generating an aqueous waste. The aqueous waste may have a pH of less than about 7.0. A pH value suitable for the composition may include, but is not limited to, about 6.5, about 6.0, about 5.5, about 5.0, about 4.5, about 4.0, about 3.5, about 3.0, about 2.5, about 2.0, or any range including any two of these values ​​and / or between any two of these values, or any range smaller than any one of these values. For example, in any embodiment of the present invention, the aqueous waste may have a pH of 3.5 to about 6.0, about 4.0 to about 5.0, and any range including any two of these values ​​and / or between any two of these values, and any range smaller than any one of these values.

[0046] After contacting the above composition with the above caustic solution, the resulting caustic-treated composition is combined with silica particles to form a slurry. The silica particles may have an average particle size of about 10 microns (μm) to about 50 microns as determined by laser diffraction analysis. The average particle size of the silica particles through laser diffraction analysis may be about 10 microns, about 11 microns, about 12 microns, about 13 microns, about 14 microns, about 15 microns, about 16 microns, about 17 microns, about 18 microns, about 19 microns, about 20 microns, about 21 microns, about 22 microns, about 23 microns, about 24 microns, about 25 microns, about 26 microns, about 27 microns, about 28 microns, about 29 microns, about 30 microns, about 35 microns, about 40 microns, about 45 microns, about 50 microns, and any two of these values, or any range between any two of these values, and any range smaller than any one of these values, but is not limited thereto.

[0047] As mentioned above, the silica particles are approximately 200 m 2 / g to about 1000 m 2 It has a BET surface area of ​​ / g. The said BET surface area can be measured by various methods, including the method described in ASTM-D3663-03 (2008) (which is incorporated herein by reference in its entirety for any and all purposes). The BET surface area of ​​the silica particles is approximately 200 m² 2 / g, approx. 210 m 2 / g, approx. 220 m 2 / g, approx. 230 m 2 / g, approx. 240 m 2 / g, approximately 250 m 2 / g, approx. 260 m 2 / g, approx. 270 m 2 / g, approx. 280 m2 / g, approx. 290 m 2 / g, approximately 300 m 2 / g, approx. 320 m 2 / g, approx. 340 m 2 / g, approx. 360 m 2 / g, approx. 380 m 2 / g, approximately 400 m 2 / g, approximately 450 m 2 / g, approximately 500 m 2 / g, approx. 550 m 2 / g, approximately 600 m 2 / g, approximately 650 m 2 / g, approximately 700 m 2 / g, approx. 750 m 2 / g, approximately 800 m 2 / g, approximately 850 m 2 / g, approximately 900 m 2 / g, approx. 950 m 2 / g, approximately 1000 m 2 / g, or may include any two of these values ​​and / or any range between any two of these values, but is not limited thereto.

[0048] The above silica particles may include amorphous silica particles, wherein the amorphous silica particles may be synthetic amorphous silica, natural amorphous silica, or a combination thereof.

[0049] The silica particles may have an aqueous solution pH of about 2.0 to about 6.0 when present in an aqueous dispersion at 15% by weight. Suitable aqueous solution pH values ​​for the silica particles may include, but are not limited to, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, or any range including any two of these values ​​and / or between any two of these values. For example, in any embodiment of the present invention, the silica particles may have an aqueous pH of about 2.0 to about 3.5, about 2.0 to about 3.0, about 2.5 to about 3.0, and any range including any two of these values ​​and / or between any two of these values, and any range smaller than any one of these values.

[0050] The silica particles may also have a compacted bulk density of about 100 g / L to about 1000 g / L according to standard bulk density measurement techniques such as ASTM D6393-08 Test E. The compacted density of the silica particles may include, but is not limited to, about 100 g / L, about 200 g / L, about 300 g / L, about 400 g / L, about 500 g / L, about 600 g / L, about 700 g / L, about 800 g / L, about 900 g / L, about 1000 g / L, and any range including / or between any two of these values, and any range smaller than any one of these values. For example, in any embodiment of the present invention, the silica particles may have a compacted bulk density of about 500 g / L.

[0051] The silica particles may be combined with the caustic-treated composition in an amount of about 0.1% (weight of silica particles relative to the weight of the caustic-treated composition) to about 0.8%. The weight of silica particles relative to the weight of the caustic-treated composition may be about 0.1% (w / w), about 0.15% (w / w), about 0.2% (w / w), about 0.25% (w / w), about 0.3% (w / w), about 0.35% (w / w), about 0.4% (w / w), about 0.45% (w / w), about 0.5% (w / w), about 0.55% (w / w), about 0.6% (w / w), about 0.65% (w / w), about 0.7% (w / w), about 0.75% (w / w), about 0.8% (w / w), or any two of these values, or any range between any two of these values. For example, in any embodiment of the present invention, the weight of silica particles relative to the weight of the caustic-treated composition may be about 0.1% (w / w) to about 0.8% (w / w), about 0.2% (w / w) to about 0.6% (w / w), and about 0.3% (w / w) to about 0.4% (w / w).

[0052] The silica particles may be combined with the caustic-treated composition at a temperature of about 150°F to about 200°F. Combination with the silica particles may be performed at a temperature of about 150°F, about 155°F, about 160°F, about 165°F, about 170°F, about 175°F, about 180°F, about 185°F, about 190°F, about 195°F, about 200°F, or any two of these values, or any range between any two of these values, but not limited thereto. For example, in any embodiment of the present invention, the temperature may be in the range of about 160°F to about 190°F; and in any embodiment of the present invention, the temperature may be in the range of about 175°F to about 185°F.

[0053] To remove moisture, an absolute pressure of about 100 Torr to about 500 Torr may be applied to a slurry obtained by combining the caustic-treated composition with the silica particles. The absolute pressure may include, but is not limited to, about 100 Torr, about 150 Torr, about 200 Torr, about 250 Torr, about 300 Torr, about 350 Torr, about 400 Torr, about 450 Torr, about 500 Torr, or any two of these values, or any range between any two of these values.

[0054] The slurry obtained by combining the above caustic-treated composition with the silica particles may have a residence time of about 10 minutes to about 90 minutes. Suitable residence times may include, but are not limited to, about 10 minutes, about 11 minutes, about 12 minutes, about 13 minutes, about 14 minutes, about 15 minutes, about 16 minutes, about 17 minutes, about 18 minutes, about 19 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 50 minutes, about 55 minutes, about 60 minutes, about 65 minutes, about 70 minutes, about 75 minutes, about 80 minutes, about 85 minutes, about 90 minutes, or any range including any two of these values ​​and / or between any two of these values. For example, in any embodiment of the present invention, the residence time may be about 20 minutes to about 50 minutes. The combination of the caustic-treated composition and silica particles described in any embodiment of the present invention can be carried out in a continuous flow operation tank.

[0055] The method of the present invention may further include the step of combining the slurry with diatomaceous earth (DE). The DE may be combined with the slurry such that the weight ratio of DE to silica particles (DE:silica) is in the range of about 0.1:1 to about 1.5:1; thus, the weight ratio of DE:silica for any embodiment of the present invention may be about 0.1:1, about 0.2:1, about 0.3:1, about 0.4:1, about 0.5:1, about 0.6:1, about 0.7:1, about 0.8:1, about 0.9:1, about 1:1, about 1.1:1, about 1.2:1, about 1.3:1, about 1.4:1, about 1.5:1, or any range including any two of these values ​​or between any two of these values.

[0056] After the slurry is obtained by combining the caustic-treated composition with silica particles as described in any embodiment of the present invention, the method of the present invention comprises the step of removing the silica particles from the slurry to produce the treated composition. The removal of the silica particles from the slurry may comprise the step of filtering the slurry with one or more filters. For example, in any embodiment of the present invention, the one or more filters may include pressure filtration (e.g., vertical- and / or horizontal-leaf filters), filter presses, cartridge filters, compression filters, membrane plate presses, disc filters, drum filters, or any combination of two or more of these. The one or more filters may include filters pre-coated with DE, cellulose, perlite, or any combination of two or more of these. For example, in any embodiment of the present invention, the one or more filters may include pressure leaf filters pre-coated with DE.

[0057] The above-described treated composition may contain reduced amounts of phosphorus, total metals, sulfur, nitrogen, and chlorine while maintaining the amount of FFA present in the composition described in any embodiment of the present invention. The above-described treated composition may contain at least about 5 wt% to about 10 wt%. The amount of FFA in the above-described treated composition may include, but is not limited to, at least about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, and any two of these values, or any range between any two of these values, and any range greater than any one of these values.

[0058] The above-described treated composition may have an acid value of about 10 mg KOH / g to about 150 mg KOH / g. Suitable acid value amounts may include, but are not limited to, about 10 mg KOH / g to about 150 mg KOH / g, about 10 mg KOH / g to about 100 mg KOH / g, about 10 mg KOH / g to about 50 mg KOH / g, about 10 mg KOH / g to about 25 mg KOH / g, about 10 mg KOH / g to about 20 mg KOH / g, about 10 mg KOH / g to about 15 mg KOH / g, and any two of these values, or any range between any two of these values, and any range greater than any one of these values. For example, in any embodiment of the present invention, the acid value of the above-described treated composition may be about 10 mg KOH / g to about 30 mg KOH / g; In any embodiment of the present invention, the acid value of the treated composition may be about 10 mg KOH / g to about 20 mg KOH / g. Representative acid values ​​for the above-mentioned treated composition may include, but are not limited to, about 10 mg KOH / g, about 11 mg KOH / g, about 12 mg KOH / g, about 13 mg KOH / g, about 14 mg KOH / g, about 15 mg KOH / g, about 16 mg KOH / g, about 17 mg KOH / g, about 18 mg KOH / g, about 19 mg KOH / g, about 20 mg KOH / g, about 21 mg KOH / g, about 22 mg KOH / g, about 23 mg KOH / g, about 24 mg KOH / g, about 25 mg KOH / g, about 26 mg KOH / g, about 27 mg KOH / g, about 28 mg KOH / g, about 29 mg KOH / g, about 30 mg KOH / g, or any two of these values, or any range between any two of these values.

[0059] The treated composition may contain less than about 10 wppm of total metal. The amount of total metal in the treated composition may be about 9 wppm, about 8 wppm, about 7 wppm, about 6 wppm, about 5 wppm, about 4 wppm, about 3 wppm, about 2 wppm, about 1 wppm, about 0.9 wppm, about 0.8 wppm, about 0.7 wppm, about 0.6 wppm, about 0.5 wppm, about 0.4 wppm, about 0.3 wppm, about 0.2 wppm, about 0.1 wppm, or any range including any two of these values ​​and / or between any two of these values, or any range smaller than any one of these values. For example, in any embodiment of the present invention, the amount of total metal in the treated composition may be less than about 5 wppm.

[0060] The above-described treated composition may contain less than about 5 wppm of phosphorus. The amount of phosphorus in the above-described treated composition may be about 4 wppm, about 3 wppm, about 2 wppm, about 1 wppm, about 0.9 wppm, about 0.8 wppm, about 0.7 wppm, about 0.6 wppm, about 0.5 wppm, about 0.4 wppm, about 0.3 wppm, about 0.2 wppm, about 0.1 wppm, or any two of these values, or any range between any two of these values, or any range smaller than any one of these values.

[0061] The above-described treated composition may contain less than about 10 wppm of chlorine. The amount of chlorine in the above-described treated composition may be about 9 wppm, about 8 wppm, about 7 wppm, about 6 wppm, about 5 wppm, about 4 wppm, about 3 wppm, about 2 wppm, about 1 wppm, about 0.9 wppm, about 0.8 wppm, about 0.7 wppm, about 0.6 wppm, about 0.5 wppm, about 0.4 wppm, about 0.3 wppm, about 0.2 wppm, about 0.1 wppm, or any two of these values, or any range between any two of these values, or any range smaller than any one of these values.

[0062] The above-described treated composition may contain less than about 5 wppm of sulfur. The amount of sulfur in the above-described treated composition may be about 4 wppm, about 3 wppm, about 2 wppm, about 1 wppm, about 0.9 wppm, about 0.8 wppm, about 0.7 wppm, about 0.6 wppm, about 0.5 wppm, about 0.4 wppm, about 0.3 wppm, about 0.2 wppm, about 0.1 wppm, or any two of these values, or any range between any two of these values, or any range smaller than any one of these values.

[0063] The above-described treated composition may contain less than about 100 wppm of nitrogen. The amount of nitrogen in the above-described treated composition may be about 95 wppm, about 90 wppm, about 85 wppm, about 80 wppm, about 75 wppm, about 70 wppm, about 65 wppm, about 60 wppm, about 50 wppm, about 45 wppm, about 40 wppm, about 35 wppm, about 30 wppm, about 25 wppm, about 20 wppm, about 15 wppm, about 10 wppm, about 5 wppm, about 1 wppm, or any two of these values, or any range between any two of these values, or any range smaller than any one of these values.

[0064] The above-described treated composition may contain less than about 15 mg of precipitate per 100 mL of the treated composition. Accordingly, the amount of precipitate per 100 mL of the treated composition may be about 15 mg, about 14 mg, about 13 mg, about 12 mg, about 11 mg, about 10 mg, about 9 mg, about 8 mg, about 7 mg, about 6 mg, about 5 mg, about 4 mg, about 3 mg, about 2 mg, about 1 mg, about 0.1 mg, about 0.01 mg, or any two of these values, or any range between any two of these values, or any range smaller than any one of these values.

[0065] The method of the present invention may further include the step of hydrogenating the above-mentioned processed composition. Hydrogenating as used herein describes, without limitation, various types of catalytic reactions occurring in the presence of hydrogen. Examples of the most common hydrogenating reactions may include, but are not limited to, hydrogenation, hydrodesulfurization (HDS), hydrodenitrification (HDN), hydrogenation treatment (HT), hydrocracking (HC), aromatic saturation or hydrodearomatization (HDA), hydrodeoxygenation (HDO), decarboxylation (DCO), hydroisomerization (HI), hydrodewaxing (HDW), hydrodemetallation (HDM), decarbonylation, methanation, and reforming. Depending on the type of catalyst, reactor structure, reactor conditions, and feedstock composition, a number of reactions may occur ranging from purely thermochemical reactions (i.e., not requiring a catalyst) to catalytic reactions.

[0066] The invention as generally described above will be more easily understood by referring to the following examples, which are provided as examples and are not intended to limit the invention.

[0067] Examples

[0068] Comparative Example 1. Citric acid-treated FOG (acid degumming)

[0069] Sulfur, nitrogen, and chlorine compounds were analyzed for an unprocessed FOG mixture containing waste cooking oil (UCO) and non-edible corn oil (ICO). Table 2 summarizes the amounts of sulfur, nitrogen, and chlorine in the unprocessed FOG.

[0070] The raw FOG stream was combined with an aqueous citric acid solution at a ratio of approximately 2% (acid weight / FOG weight) through a high-shear mixer. The stream from the high-shear mixer outlet flowed through a hold tank providing a residence time of approximately 15 minutes and was centrifuged through three disc stack centrifuges arranged in series. Condensate was used as the wash water for the centrifuges. The water was supplied to the third centrifuge, where the heavy phase flowed to the second centrifuge and from there to the first centrifuge, thereby flowing back to the raw FOG / light phase passing through the first, second, and third centrifuges. The water / heavy phase exiting the first centrifuge had a pH of approximately 3.2 to 3.4. Sulfur, nitrogen, and chlorine were analyzed for the light phase exiting the third centrifuge. Table 1 shows the resulting amounts of sulfur, nitrogen, and chlorine in the "treated FOG". As additionally presented in Table 1, this treatment method removed trace amounts of organic sulfur from raw FOG, while effectively not removing nitrogen and organic chlorine compounds.

[0071]

[0072] Comparative Example 2. Aqueous / citric acid treated (acid degumming) and filtered FOG having high levels of sulfur and nitrogen.

[0073] A mixture of low-value unprocessed FOG feedstock was prepared using the mixture ingredients and amounts presented in Table 3.

[0074]

[0075] Table 4 provides the physical properties and contaminant concentrations for the unprocessed FOG mixture of Comparative Example 2.

[0076]

[0077] The raw FOG mixture was filtered through a 10-micron bag filter and subjected to two washing cycles using deionized water by continuously contacting the two liquids through a mixing valve. A batch settling tank was used to separate the light phase (washed oil) from the heavy phase (contaminated water). Subsequently, the water-washed FOG was treated with a 10% citric acid solution (in water). The contaminant concentrations of the treated FOG (final light phase) are presented in Table 5.

[0078]

[0079] Tables 4 and 5 show that while phosphorus and metals were reduced by aqueous / citric acid treatment, no intrinsic reduction of nitrogen and sulfur occurred.

[0080] Example 1. Process for improving FOG according to the present technology

[0081] ICP analysis was applied to a raw FOG stream containing waste cooking oil and high-grade bleached tallow (Table 6). The raw FOG stream was mixed with an aqueous citric acid solution at a ratio of approximately 2% (weight of acid / weight of FOG) and centrifuged through a series of three disc stack centrifuges. Condensate was used as the wash water for the centrifuges. The water was supplied to the third centrifuge, and the heavy phase therein was supplied to the second centrifuge, from where it was supplied to the first centrifuge, thereby counter-flowing with the FOG / light phase flowing through the first, second, and third centrifuges. A caustic solution (25% NaOH in water) was mixed with the heavy phase supplied to the second centrifuge. The flow rate of the caustic solution was adjusted so that the heavy phase from the third centrifuge had a pH of 4 to 4.5.

[0082] The hard phase of the third centrifuge was pumped into a continuous flow stirred slurry tank. Amorphous silica particles and diatomite (DE) were continuously metered into the slurry tank at a ratio of 0.31% each (based on w / w FOG). The tank provided a residence time of 30 minutes for the slurry at a temperature of approximately 181 to 184°F. The slurry was processed through a pressure leaf filter pre-coated with DE. The filtered FOG was sampled downstream of the tank and subjected to elemental analysis via ICP, as well as analysis for sulfur, nitrogen, and chlorine.

[0083]

[0084] Table 7 summarizes the amounts of sulfur, nitrogen, and chlorine in raw FOG, and the acid value / FFA %.

[0085]

[0086] Table 6 shows the improved removal of phosphorus and metals achieved through the process of the present technology compared to degumming (and Comparative Examples 1 and 2), indicating that phosphorus was reduced from 13 wppm to 4 wppm and all ICP metals and non-metals were reduced from 21.2 wppm to 9.4 wppm.

[0087] Table 7 shows reductions in organic sulfur, nitrogen, and chlorine ranging from 82%, 67%, and 52%, respectively. In contrast, as shown in Comparative Examples 1 and 2, these components were not effectively reduced by FOG degumming alone. Furthermore, the method of the present invention maintained FFA % despite treatment with a caustic solution, which suggests that there was no detectable loss of FFA as sodium soap.

[0088] Example 2. Removal of polymer from polymer-contaminated FOG according to the present technology

[0089] For the various non-edible tallow and yellow grease loads constituting the raw FOG, the polymer content was measured according to the AOCS technique Ca 16-75 for dissolved polyethylene (PE). The raw FOG composition was filtered through a standard wire mesh filter. PE results varied from below detection to a maximum of 11,000 ppm (1.1 wt%). The mixed FOG composition feed was treated with citric acid and centrifuged according to the conditions of Example 1. The hard phase from the third centrifuge was periodically sampled over several days of operation, and the polymer was tested according to the AOCS method for dissolved PE. The PE results for the various samples ranged from 50 to 80 ppm, suggesting that the degumming step alone was insufficient to remove the dissolved polymer.

[0090] The centrifuged FOG was further processed according to the silica-treatment step of Example 1. The silica-treated FOG discharged from the leaf filter was sampled simultaneously with the collection of the sample from the centrifuge. The silica-treated sample contained no detectable PE, and the FOG sample obtained after performing only degumming showed 50 to 80 ppm PE (average 70 ppm).

[0091] Example 3. Influence of acid value on FOG improvement performance

[0092] The method of the present invention was evaluated over time for various low-value FOG composition feed formulations. Performance was measured as the percentage reduction in phosphorus and metals as a function of the acid value of the raw feed. Surprisingly, as observed in Figures 1 and 2, FOG acid value values ​​of less than 20 mg KOH / g (10% FFA) (indicated by empty circles in Figures 1 and 2) showed a maximum reduction of 95% in phosphorus and total metals after treatment according to the method of the present invention (Example 1). However, for values ​​greater than 20 mg KOH / g (indicated by filled circles in Figures 1 and 2), a decrease in performance with increasing acid value was observed.

[0093] Example 4. Pretreatment of High Alkaline FOG

[0094] The raw FOG feedstock, characterized by high alkalinity, was processed through a pretreatment step to reduce alkalinity and remove excess metal. In this continuous pretreatment process, a brown grease stream was mixed with saturated steam at a ratio of 5% by mass of the brown grease and heated to approximately 80°C. Immediately after steam injection, a commercially available 50% aqueous citric acid solution was added at a ratio of 1% by weight by mass of the brown grease. The acid treatment was intended to neutralize the soap and chelate the metal ions. The mixture was homogenized using a mixing vessel with an average residence time of 30 to 60 minutes to ensure complete dispersion and contact of the citric acid. The acidified water and oil mixture was pumped from the mixing tank to a three-phase centrifuge, which removed insoluble salts and impurities as sludge. The three-phase centrifuge provided continuous removal of solids and precipitates through the implementation of a scroll element that mechanically extracts solids from the two liquid phases via an Augering action. The three-phase centrifuge was fine-tuned so that a portion of the light oil phase was removed along with the heavy phase, ensuring the near-complete removal of the heavy phase. Water-soluble salts, metals, and other water-soluble impurities were removed as part of the heavy water phase. The light oil phase was recovered with a yield of over 95% based on the bottom fraction. The total alkalinity of the oil and the reduction of impurities throughout the pretreatment process are summarized in Table 8.

[0095]

[0096] Although specific embodiments have been illustrated and described, it should be understood that modifications and variations can be made to such embodiments in accordance with the art without departing from the broader aspects of the art as defined in the claims below.

[0097] The exemplary embodiments described herein may be appropriately implemented without limitation or without any components or elements not specifically disclosed herein. Accordingly, terms such as "comprising," "including," and "containing" should be interpreted broadly without limitation. Additionally, terms and expressions used herein are used for descriptive rather than restrictive purposes, and the use of such terms and expressions is not intended to exclude any equivalents of the features presented and described or any part thereof, and it is understood that various modifications are possible within the scope of the claimed technology. Additionally, the phrase "consisting essentially of" is understood to include additional components that do not substantially affect the specificly mentioned components and the fundamental and novel characteristics of the claimed technology. The phrase "consisting of" excludes any components not specified.

[0098] The present disclosure is not limited to the specific embodiments described herein. As will be obvious to those skilled in the art, numerous variations and modifications may be made without departing from the spirit and scope thereof. In addition to those listed herein, functionally equivalent methods and compositions falling within the scope of the present disclosure will be apparent to those skilled in the art from the foregoing description. Such variations and modifications are intended to be included within the scope of the appended claims. The present disclosure should be limited only by the terms of the appended claims, along with the full scope of equivalents corresponding to the appended claims. It should be understood that the present disclosure is not limited to specific methods, reagents, compounds, or compositions, and that these may, of course, be varied. Furthermore, the terms used herein are intended solely for the purpose of describing specific embodiments and are not intended to be limiting.

[0099] Furthermore, where a feature or aspect of the present disclosure is described in relation to the Markush Group, those skilled in the art will recognize that the present disclosure is also described in relation to any individual member or subgroup of the members of the Markush Group.

[0100] As understood by those skilled in the art, for any and all purposes, particularly in terms of providing a described description, all scopes disclosed herein also include any and all possible sub-scopes and combinations of sub-scopes. Any enumerated scope may be readily recognized as sufficiently describing and enabling the same scope to be subdivided at least the same half, 1 / 3, 1 / 4, 1 / 5, 1 / 10, etc. As a non-limiting example, each scope discussed herein may readily be subdivided into a lower 1 / 3, a middle 1 / 3, an upper 1 / 3, etc. As understood by those skilled in the art, all language such as “maximum ~,” “at least,” “greater than ~,” “less than ~,” etc. includes the mentioned number and refers to a scope that may subsequently be subdivided into sub-scopes as discussed above. Finally, as understood by those skilled in the art, a certain scope includes each individual member.

[0101] All publications, patent applications, granted patents, and other documents mentioned in this specification are incorporated herein by reference, just as each individual publication, patent application, granted patent, and other document is specifically and individually indicated as being incorporated by reference in its entirety. Definitions contained within the context in which they are incorporated by reference are excluded if they conflict with definitions in this disclosure.

[0102] The present technology may include, but is not limited to, the features and combinations of features mentioned in the paragraphs below, and the following paragraphs should not be construed as limiting the scope of the claims attached herein or as requiring all such features to be included in such claims.

[0103] A. As a method,

[0104] A step of contacting a composition with a caustic solution to produce a caustic-treated composition;

[0105] A step of forming a slurry by combining the above caustic-treated composition with silica particles; and

[0106] The method includes the step of removing the silica particles from the slurry to produce a treated composition;

[0107] Here,

[0108] The above composition comprises the following:

[0109] One or more of animal fats, animal oils, vegetable fats, vegetable oils, vegetable fats, vegetable oils, grease, and waste cooking oil;

[0110] At least about 10 wppm of total metal;

[0111] At least about 8 wppm of phosphorus;

[0112] At least about 10 wppm of chlorine;

[0113] At least about 10 wppm of sulfur;

[0114] At least about 20 wppm of nitrogen;

[0115] At least about 5 weight percent of free fatty acids;

[0116] Having an acid value of about 10 mg KOH / g to about 150 mg KOH / g;

[0117] The above silica particles have an average particle size of about 10 microns to about 50 microns and about 200 m 2 / g to about 1000 m 2 A method having a BET surface area of ​​ / g.

[0118] B. In paragraph A, the composition comprises animal fat, animal oil, vegetable fat, vegetable oil, vegetable fat, vegetable oil, grease, or any two or more of these.

[0119] C. A method according to paragraph A or paragraph B, wherein the composition comprises yellow grease, brown grease, floating grease, poultry fat, non-edible corn oil, waste cooking oil, non-edible beef tallow, floating beef tallow, palm sludge oil, or any two or more of these.

[0120] D. A method in which, in any one of paragraphs A to C, the total metal comprises one or more members selected from the group consisting of As, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn.

[0121] E. A method according to any one of paragraphs A to D, wherein the composition further comprises a polymer of about 0.05 wppm to about 11,000 wppm.

[0122] F. A method in which, in any one of paragraphs A to E, the composition has an acid value of about 10 mg KOH / g to about 50 mg KOH / g.

[0123] G. A method in which, in any one of paragraphs A to F, the composition has an acid value of about 10 mg KOH / g to about 30 mg KOH / g.

[0124] H. A method according to any one of paragraphs A to G, wherein the composition comprises about 5% by weight to about 15% by weight of free fatty acids.

[0125] I. A method according to any one of paragraphs A to H, wherein, before contacting the composition with the caustic solution, the composition undergoes a glycerol decomposition process to provide about 5% by weight to about 15% by weight of free fatty acids in the composition.

[0126] J. A method in any one of paragraphs A to I, wherein the method further comprises an acid degumming step before contacting the composition with a caustic solution.

[0127] K. In any one of paragraphs A to J, the method further comprises an alkalinity reduction step before contacting the composition with a caustic solution.

[0128] L. A method in any one of paragraphs A to K, wherein the method does not include the step of contacting the composition with bleaching clay.

[0129] M. A method in which, in any one of paragraphs A to L, the caustic solution comprises an aqueous ammonium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous sodium hydroxide solution, or any combination of two or more of these.

[0130] N. A method in which, in any one of paragraphs A to M, the silica particles comprise amorphous silica particles.

[0131] O. A method in which, in any one of paragraphs A to N, the silica particles are combined with the caustic-treated composition in an amount of about 0.1% (w / w) to about 0.8% (w / w) based on the weight of the silica particles relative to the weight of the caustic-treated composition.

[0132] P. A method in which, in any one of paragraphs A to O, the silica particles have an aqueous solution pH of about 2.0 to about 6.0.

[0133] Q. A method in which, in any one of paragraphs A to P, the combination with silica particles is performed at a temperature of about 150°F to about 200°F, and an absolute pressure of about 100 Torr to about 500 Torr is applied to the slurry.

[0134] R. A method in which, in any one of paragraphs A to Q, the combination with silica particles is performed in a continuous flow working tank.

[0135] S. A method in which, in any one of paragraphs A to R, the combination with silica particles comprises a residence time of about 10 minutes to about 90 minutes.

[0136] T. A method wherein, in any one of paragraphs A to S, the method further comprises the step of combining the slurry with diatomite (DE), and the weight ratio of DE to silica particles is about 0.1:1 to about 1.5:1.

[0137] U. A method comprising, in any one of paragraphs A to T, a step of filtering the slurry with one or more filters for removal.

[0138] V. A method in which, in paragraph U, one or more filters comprise a pressure leaf filter, and the pressure leaf filter is optionally pre-coated with at least one of DE, cellulose, and perlite.

[0139] W. In any one of paragraphs A to V, the treated composition comprises:

[0140] At least about 5 weight% to about 10 weight% of free fatty acids;

[0141] Total metal less than about 10 wppm;

[0142] Phosphorus of less than about 5 wppm;

[0143] Chlorine less than about 5 wppm;

[0144] Sulfur of less than about 5 wppm;

[0145] Total metal less than about 100 wppm;

[0146] A method having an acid value of 10 mg KOH / g to about 20 mg KOH / g.

[0147] X. A method in any one of paragraphs A to W, wherein the method further comprises the step of hydrogenating the processed composition.

[0148] Other embodiments are set forth in the following claims.

Claims

Claim 1 The method comprises: an acid-degumming step of the composition; a step of, after acid-degumming, contacting the composition with a caustic solution to produce a first mixture comprising a caustic-treated composition; a step of separating the caustic-treated composition from the first mixture using a disk stack centrifuge; a step of combining the caustic-treated composition with silica particles to produce a slurry, wherein the combination with the silica particles is performed at a temperature of about 150°F to about 200°F, wherein an absolute pressure of about 100 Torr to about 500 Torr is applied to the slurry, and the slurry has a residence time of about 10 minutes to about 90 minutes; and a step of removing the silica particles from the slurry to produce a treated composition; wherein the composition comprises one or more of animal fat, animal oil, plant fat, vegetable oil, vegetable fat, vegetable oil, grease, and waste cooking oil; at least about 10 wppm of total metal; and at least about 8 wppm of phosphorus. It comprises at least about 10 wppm of chlorine; at least about 10 wppm of sulfur; at least about 20 wppm of nitrogen; and at least about 5 wt% of free fatty acids; having an acid value of about 10 mg KOH / g to about 150 mg KOH / g; said treated composition comprises reduced amounts of phosphorus, total metals, sulfur, nitrogen, and chlorine while maintaining the amount of free fatty acids present in said composition; and said silica particles have an average particle size of about 10 microns to about 50 microns and about 200 m 2 / g to about 1000 m 2 A method having a BET surface area of ​​ / g; wherein the caustic solution comprises an aqueous ammonium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous sodium hydroxide solution, or any combination of two or more of these. Claim 2 A method according to claim 1, wherein the composition comprises animal fat, animal oil, vegetable fat, vegetable oil, vegetable fat, vegetable oil, grease, or any two or more of these. Claim 3 The method of claim 1, wherein the composition comprises yellow grease, brown grease, floating grease, poultry fat, non-edible corn oil, waste cooking oil, non-edible beef tallow, floating beef tallow, palm sludge oil, or any two or more of these. Claim 4 A method according to claim 1, wherein the total metal comprises one or more members selected from the group consisting of As, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr and Zn. Claim 5 The method of claim 1, wherein the composition further comprises about 0 wppm to about 11,000 wppm of polymer. Claim 6 A method according to claim 1, wherein the composition has an acid value of about 10 mg KOH / g to about 50 mg KOH / g. Claim 7 A method according to claim 1, wherein the composition has an acid value of about 10 mg KOH / g to about 30 mg KOH / g. Claim 8 A method according to claim 1, wherein the composition comprises about 5% by weight to about 15% by weight of free fatty acids. Claim 9 A method according to claim 1, wherein the composition undergoes a glycerol decomposition process before contacting the composition with a caustic solution to provide about 5% by weight to about 15% by weight of free fatty acids in the composition. Claim 10 A method according to claim 1, further comprising an alkalinity reduction step before contacting the composition with a caustic solution. Claim 11 A method according to claim 1 that does not include the step of contacting the composition with bleaching clay. Claim 12 A method according to claim 1, wherein the silica particles comprise amorphous silica particles. Claim 13 A method according to claim 1, wherein the silica particles are combined with a caustic-treated composition in an amount of about 0.1% (w / w) to about 0.8% (w / w) based on the weight of the silica particles relative to the weight of the caustic-treated composition. Claim 14 A method according to claim 1, wherein the silica particles have an aqueous solution pH of about 2.0 to about 6.

0. Claim 15 A method according to claim 1 in which the combination with silica particles is performed in a continuous flow working tank. Claim 16 A method according to claim 1, further comprising the step of combining a slurry with diatomite (DE), wherein the weight ratio of DE to silica particles is about 0.1:1 to about 1.5:

1. Claim 17 A method according to claim 1, wherein the removal step comprises a step of filtering the slurry with one or more filters. Claim 18 A method according to claim 17, wherein one or more filters comprise a pressure leaf filter, wherein the pressure leaf filter is optionally pre-coated with at least one of DE, cellulose, and perlite. Claim 19 A method according to claim 1, further comprising the step of hydrogenating the processed composition. Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete

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