Novel process for refining feedstock

Abstract

The present invention relates to a novel and efficient process for refining or purifying a raw material.

Description

Technical Field

[0001] The present invention relates to an efficient, cost-effective and novel process for refining or purifying a feedstock containing components that are generally considered difficult to refine or purify into useful components in, for example, the fuel industry or as starting materials for any type of fuel or fine chemicals. An example of a feedstock to which the present invention relates relates to palm oil mill effluent (POME) oil and its refining. This feedstock has proven difficult to process directly in, for example, bleaching due to the types of impurities present therein. During post-bleaching filtration, the removal of impurities (metals and phosphorus compounds) and filterability characteristics are generally very poor. The present invention overcomes these difficulties. Background Art

[0002] As mentioned above, raw materials such as palm oil mill effluent (POME) oil are difficult raw materials to process directly in bleaching due to the type of impurities present in POME oil. During the filtration after bleaching, the removal of impurities (metals and phosphorus compounds) and the filterability characteristics are very poor. Currently, crude POME oil cannot be pretreated by any method that allows feeding it to a PTU (pretreatment unit), except for evaporation (distillation to obtain POME-FAD / palm oil mill effluent-fatty acid distillate), which is very expensive and makes this type of raw material less attractive from a commercial point of view.

[0003] Acid degumming and different types of variations, which can also be used to purify POME oils, have been used for decades in the edible vegetable oil industry to remove residual phospholipids (80-200 ppm as phosphorus) and metal content from water-degummed oils using aqueous citric acid and process water.

[0004] The main disadvantages of acid degumming are the high oil losses during centrifugation, due to the fact that a given entrained oil is carried into the aqueous phase due to the emulsification effect or separation efficiency, and the heavy aqueous phase produced, which requires expensive wastewater treatment. In addition, a washing stage is usually used to further improve the removal of residual metals and P, in which 2-3% of process water is added to the oil, followed by separation in a second centrifugal separator, which is also required to improve the removal of phosphorus. In addition, the acid degumming process is sensitive to the amount of solids in the raw material, and it can only process raw materials with a low amount of solids. In addition, a very low quality (very high COD value) wastewater is produced, the treatment of which is problematic and expensive. Summary of the invention

[0005] The present invention overcomes the above-mentioned shortcomings and provides a cost-effective large-scale method for refining or purifying some raw materials to low, single-digit ppm levels of metal and phosphorus impurities. In essence, this requires low oil loss. The method can also recycle the production water back into the method, thereby minimizing wastewater treatment and water consumption. In addition, it has been found that due to the method, the filterability in the bleaching of the pre-treated product of the gained is improved (reduction in filtration resistance). This greatly improves the large-scale industrial processing of raw materials mentioned herein.

[0006] Accordingly, the present invention provides methods or products that exhibit one or more of the following:

[0007] - Improved removal of one or more nitrogen-containing, phosphorus-containing and metal-containing compounds from the feedstock,

[0008] - Reduced filtration resistance during raw material processing,

[0009] - minimizing the consumption of process water by recycling it back into the process,

[0010] - Reduce wastewater, which has both economic and environmental benefits,

[0011] - Reduction of oil losses, ie improvement of the yield of purified raw material obtained by reducing its losses during processing.

[0012] In one aspect, the invention relates to a process or method for refining or purifying a raw material or feedstock.

[0013] The method according to the present invention may include any combination of the following steps:

[0014] i) providing raw materials,

[0015] ii) optionally heating the provided feedstock,

[0016] iii) treating the provided feedstock with an acid, wherein the acid is capable of forming a precipitate, or a salt, or a chelate with impurities present in the feedstock,

[0017] iv) treating the feedstock treated with acid in iii) with process water, wherein the water content of the feedstock treated with acid in iv) is adjusted to a range of about 1 wt % to about 6 wt %, preferably about 1.5 wt % to about 4 wt %, more preferably about 2 wt % to about 3 wt % or about 5 wt %,

[0018] v) evaporating water from the acid-treated feedstock in iv) under vacuum,

[0019] vi) optionally, recovering and recycling the evaporated water from step v) to reuse it at least partly as process water in step iv) and / or step iii),

[0020] vii) contacting the chelated or precipitated metals and / or phospholipids from the acid treated feedstock with a filter aid and / or adsorbent,

[0021] viii) removing the chelate or precipitate and the filter aid and / or adsorbent by filtration with or without a pre-coat to obtain an acid treated filter feed,

[0022] ix) Bleaching the acid treated filtered feed from step viii.

[0023] In one aspect, the process according to the invention provides an acid treated filtered bleach stock obtained by said process.

[0024] In another aspect, the present invention may comprise a step vi) of recycling the evaporated water to reuse it at least partially as process water in step iv) and / or step iii). In other words, it may be necessary to recycle the evaporated water into the process. The inventors of the present invention have found that recycled process water provides results as good as using new water in the process. It has been surprisingly found that using recycled water from water evaporation in acid filtration to remove impurities (from the feedstock) is as effective as using new process water.

[0025] In one aspect, the feedstock may comprise or consist of palm oil mill effluent (POME) oil.

[0026] In another aspect, the acid is citric acid, phosphoric acid, or sulfuric acid.

[0027] In another aspect, the acid is citric acid.

[0028] In one aspect, the concentration of the acid added in step iii) (i.e., the acid for processing the provided raw material) can be in any appropriate range, such as, for example, about 10% to about 95%, such as, for example, about 20% to about 80%, such as, for example, about 30% to about 70%, such as, for example, about 40% to about 60%, or about 50%. It should be noted that the percentage in this regard can be wt% (weight percentage) or vol% (volume percentage). Non-limiting example can be that the acid can be citric acid with a concentration of about 30wt% to about 50wt%. Another non-limiting example can be that the acid is phosphoric acid with a concentration of about 75wt% to about 80wt%. In another aspect, the acid used can be considered to be concentrated, such as, for example, the concentrated sulfuric acid with a concentration of about 96wt%.

[0029] In one aspect, the acid added for treating the provided feedstock can be diluted with added water, which can be process water recycled from the process, or alternatively can be new water. The final concentration of the acid in step iii) can be in any range of about 1% to about 90%, such as, for example, about 10% to about 80%, such as, for example, about 20% to about 70%, etc. In another aspect, the dilution is such that the final concentration of the acid in step iii) can be in the range of about 1 wt% to about 6 wt%, preferably about 1.5 wt% to about 4 wt%, more preferably about 2 wt% to about 3 wt%, or about 5 wt%,

[0030] In one aspect, the acid-treated feedstock obtained from step iii) may be treated with process water, wherein the water content of the acid-treated feedstock in iv) is adjusted to within a range of about 1 wt % to about 6 wt %, preferably about 1.5 wt % to about 4 wt %, more preferably about 2 wt % to about 3 wt %, or about 5 wt %, or within a range of about 1 wt % to about 3 wt %,

[0031] In a preferred aspect, at least a portion of the process water is recycled back into the process.

[0032] According to the present invention, the feedstock may be heated prior to addition of the acid or contact with the acid.

[0033] In one aspect, the starting materials are heated prior to addition of or contacting with the acid and then reacted at the same temperature without further heating.

[0034] According to the invention, the acid can form a chelate, a salt or any kind of precipitate or substance which forms a separate phase from the remaining raw material.

[0035] The acid is dosed in an amount of at least one stoichiometric equivalent of the impurities present in the feedstock (which may be, for example, metallic impurities).

[0036] The invention also relates to a refined or purified starting material obtainable by the process according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The method according to the invention is shown in the form of a flow chart. DETAILED DESCRIPTION

[0038] Definition / Abbreviation

[0039] According to the present invention, the words or terms "feedstock" or "raw material" that can be used interchangeably throughout the specification are intended to represent any type of feedstock from any type of source, such as, for example, plant, animal or microbial sources, or can be a fossil-based feedstock or a combination of fossil-based feedstock and plant, animal and / or microbial sources. Such feedstock can also be any type of waste material or a by-product produced by any of the above processing. In one embodiment, the feedstock comprises at least one of animal fat, animal oil, vegetable fat, vegetable oil, fish fat, fish oil, microbial oil, waste fat, waste oil, residual fat, residual oil, sludge derived from vegetable oil production, or any combination thereof. In one embodiment, the feedstock comprises at least one of acidulated soapstock, poultry fat, dry rendered poultry fat, brown grease, waste edible fat, trapped grease, DAF (dissolved air flotation) grease, sewage sludge, mixed grease trap waste, used cooking oil, tall oil, tall oil fraction, crude tall oil, tall oil pitch, palm oil effluent sludge, palm oil mill effluent (POME) oil, crude palm oil, palm oil, palm kernel oil, palm fatty acid distillate, babassu oil, carinata oil, coconut esters, muscat butter oil, sesame oil, corn oil, cottonseed oil, soybean oil, bay seed oil, jatropha oil, palm kernel oil, camelina oil, archaeal oil, bacterial oil, fungal oil, protozoan oil, algae oil, algae oil, mustard oil, oil from halophiles, soybean oil, industrial corn oil, rapeseed oil, colza oil, canola oil oil), sunflower oil, olive oil, linseed oil, mustard oil, peanut oil, castor oil, coconut oil, lard, tallow, whale oil, spent bleaching earth oil, lignocellulose based feeds or any mixture thereof.

[0040] In particular, the feedstock according to the present invention may comprise palm oil mill effluent (POME) oil, any type of brown grease (BG), such as for example waste cooking grease, trapped grease, DAF (dissolved air flotation) grease, sewage sludge and mixed grease trap waste, or any mixture thereof.

[0041] The word or term "acid" is intended to mean any type of acid or a substance chemically classified as an acid. Acids can be organic acids or inorganic acids. Acids can also be monoacids, diacids, triacids, or tetraacids having one or more acid functional groups. Some non-limiting examples can be, for example, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, ethylenediaminetetraacetic acid (EDTA), phosphoric acid, sulfuric acid, etc., at any appropriate concentration.

[0042] The word or term "process water" is intended to mean water introduced into the process in the acid treatment step iii) and / or the water treatment step iv). The process water may be new water or recycled water from the evaporation step v) or a mixture thereof.

[0043] The word or term "filter aid", also abbreviated as "FA", is intended to mean any agent consisting of solid particles (such as diatomaceous earth), which improves the filtration efficiency (such as by increasing the permeability of the filter cake) and is added to the suspension to be filtered and / or placed on the filter as a layer through which the liquid must pass. Non-limiting examples of filter aids can be, for example, diatomaceous earth (DE) or expanded perlite, etc. Other examples of filter aids can be any suitable mineral-based material, plant-based material (such as, for example, cellulose-based material), polymer-based material (such as, for example, spun or woven polymer) or material based on any type of composite material or any mixture of filter aids. Therefore, a filter aid is a product that has the main function of removing solids present in the raw material during its processing, even solids of very small size, and makes the filterability of the filtration sufficiently effective, and can be considered as an agent or compound that mechanically removes solids, etc. from the raw material. As is apparent throughout the description, the filtration can be performed with or without a pre-coat and can vary depending on the type of raw material.

[0044] In one embodiment, the filter aid is non-adsorptive and / or is not capable of adsorbing one or more components, for example, from the feedstock at any stage of the process according to the invention.

[0045] In other embodiments, the filter aid is not a silica-based compound.

[0046] In other embodiments, the filter aid may be, for example, based on diatomaceous earth, may be a plant-based filter aid, such as, for example, a cellulose-based filter aid, a polymer-based filter aid, or may be based on any type of composite material.

[0047] The word or term "adsorbent" is intended to mean a reagent capable of at least partially adsorbing one or more components from a raw material during any stage of the method according to the invention. Non-limiting examples of adsorbents include, such as, for example, activated carbon, silica-based compounds, such as, for example, silica gels of various types and forms, such as, for example, silica hydrogels. The role of the adsorbent is to remove phosphorus-containing compounds and metals from the oil phase, i.e., compounds or reagents that can be soluble in the oil phase. In other words, the adsorbent can be a solid substance for collecting solute molecules from a liquid or gas. The adsorbent is capable of exerting an adsorption effect, which means that the adsorbent is capable of extracting the compound by attaching the compound to the adsorbent, such as, for example, activated carbon or silica gel. Therefore, the adsorbent can be a porous solid that binds liquid or gas molecules to their surface and thus collects solute molecules from a liquid or gas.

[0048] The word or term "silica hydrogel" is intended to mean any synthetic amorphous micronized silica hydrogel having phospholipid and cationic metal adsorption properties.

[0049] The word or term "body feed" or "body feed filtration" is intended to mean the continuous addition of a controlled amount of filter aid during operation to maintain the filter cake permeable. If added as a slurry, this may be referred to as a slurry feed.

[0050] The word or term "precoat filtration" or "precoat filter" is intended to mean a filter which may be a rigid, semi-flexible or flexible screen on which a filter aid or medium is deposited. During the filtration process, the filter medium and the filtered solids form a filter bed which acts as an additional filter element to collect finer contaminants. The "bed" medium can be filtered both by adsorption and by mechanical means. The filter vessel is filled with the suspension under pressure and it passes through the filter bed, leaving the solids in the filter bed.

[0051] According to the present invention, the term "contacting" is intended to mean that two or more components are brought together in solid and / or liquid / fluid form. In one aspect, "contacting" is intended to mean mixing the acid-treated feedstock with the filter aid and / or adsorbent. Thus, for example, the filter aid and / or adsorbent can be in powder form or granular form, or as a slurry, or as a solution.

[0052] Detailed description of the invention

[0053] As mentioned herein, the process according to the present invention enables the use of feedstocks or raw materials that are considered in the art to be economically less attractive or difficult to purify or refine for any further use.

[0054] In particular, the present invention relates to a method comprising the following steps:

[0055] i) providing raw materials,

[0056] ii) optionally heating the provided feedstock,

[0057] iii) treating the provided raw material with an acid, wherein the acid is capable of forming a precipitate, a salt, or a chelate with, for example, metals and / or phospholipids present as impurities in the raw material,

[0058] iv) treating the feedstock treated with acid in iii) with process water, wherein the water content of the feedstock treated with acid in iv) is in the range of about 1 wt % to about 6 wt %, preferably about 1.5 wt % to about 4 wt %, more preferably about 2 wt % to about 3 wt %,

[0059] v) evaporating water from the acid-treated feedstock in iv) under vacuum,

[0060] vi) optionally, recovering and recycling the evaporated water from step v) to reuse it at least partly as process water in step iv) and / or step iii),

[0061] vii) contacting the chelated or precipitated metals and / or phospholipids from the acid treated feedstock with a filter aid and / or adsorbent,

[0062] viii) removing the chelate or precipitate and the filter aid and / or adsorbent by filtration with or without a pre-coat to obtain an acid treated filter feed,

[0063] ix) bleaching the acid-treated filtered feed from step vii),

[0064] Thus, an acid-treated filtered bleached stock is obtained.

[0065] In other aspects, the present invention relates to a method for refining or purifying a feedstock, the method comprising the steps of:

[0066] i) providing raw materials,

[0067] ii) heating the provided raw materials to 70-90° C.,

[0068] iii) treating the provided raw material with an acid, wherein the acid is capable of forming a precipitate, a salt, or a chelate with impurities such as metals and / or phospholipids present in the raw material,

[0069] iv) treating the acid-treated feedstock in iii) with process water, wherein the acid-treated feedstock has a water content in the range of about 1 wt % to about 6 wt %,

[0070] v) evaporating water from the acid-treated feedstock in iv) under vacuum,

[0071] vi) optionally, recovering and recycling the evaporated water from step v) to reuse it at least partly as process water in step iv) and / or step iii),

[0072] vii) contacting the chelated or precipitated metals and / or phospholipids from the acid treated feedstock with a filter aid and / or adsorbent such as, for example, silica hydrogel,

[0073] viii) removing the chelate or precipitate and the filter aid and / or adsorbent by filtration with or without a pre-coat to obtain an acid treated filter feed, and

[0074] ix) bleaching the acid-treated filtered feed from step viii),

[0075] Thus, an acid-treated filtered bleached stock is obtained.

[0076] In one aspect, the invention relates to a method comprising the steps of:

[0077] a) provide raw materials,

[0078] b) treating the feedstock with an acid, wherein process water is added to the feedstock and acid mixture,

[0079] c) removing the added process water to obtain an acid-treated feedstock,

[0080] d) a method of recycling the removed process water and recycling said process water back into step b),

[0081] e) mixing the acid-treated feedstock from step c) with a filter aid and / or an adsorbent,

[0082] f) Removal of the filter aid and / or adsorbent by filtration, with or without a pre-coat, to obtain an acid treated and filtered feed.

[0083] The process according to the invention may be followed by a bleaching step, which may be carried out after step f).

[0084] According to one aspect, the acid-treated feedstock is dried by removing process water as described herein and, for example, in step c) or, for example, in step v). In another aspect, the dried acid-treated feedstock may be mixed or contacted with a filter aid and / or an adsorbent.

[0085] In one aspect, the feedstock can in principle have any type of source. In one embodiment, the feedstock can comprise or consist of palm oil mill effluent (POME) oil, any type of brown grease (BG), such as, for example, waste edible grease, trapped grease, DAF (dissolved air flotation) grease, sewage sludge and mixed grease trap waste, or any mixture thereof.

[0086] In particular embodiments, the feedstock may comprise or consist of POME oil.

[0087] In another aspect, the feedstock may comprise or consist of waste edible oils and fats.

[0088] In other aspects, the feedstock can comprise or consist of captured grease.

[0089] According to the present invention, the acid in the method can be any type of acid that can form a chelate, or a salt, or a complex, or any type of precipitate with one or more impurities present in the raw material. Non-limiting examples can be (for example) citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, ethylenediaminetetraacetic acid (EDTA), phosphoric acid, etc., or any mixture thereof.

[0090] In particular aspects, the acid can be, for example, citric acid.

[0091] Acid can be used directly, i.e. not diluted with any type of solvent at all, or can be present in an aqueous solution. The concentration of the acid can be, for example, from about 5wt% to about 100wt%, such as, for example, 10wt% to about 90wt%, such as, for example, 20wt% to about 80wt%, such as, for example, 30wt% to about 70wt%, such as, for example, 40wt% to about 60wt%, or such as, for example, 30wt% to about 50wt% concentration.

[0092] If the acid concentration is too low, this may result in the metal cation reacting with the H from the acid. + Low contact between.

[0093] In particular aspects, the concentration of the acid can be, for example, from about 30 wt % to about 50 wt %.

[0094] According to the present invention, the provided raw material can be heated before contacting with the acid. In step ii), the raw material can be heated to a temperature in the range of about 50°C to about 110°C, such as, for example, about 60°C to about 100°C, or such as, for example, about 70°C to about 90°C.

[0095] In one embodiment, in step ii), the feedstock is heated to a temperature of, for example, about 70°C to about 90°C.

[0096] In another aspect, the feedstock may be heated to an elevated temperature prior to the addition of the acid, and subsequently, during the contacting of the feedstock with the acid in step iii), further heating may be avoided. Thus, the contacting of the feedstock with the acid is carried out at the same temperature as described in step ii).

[0097] In one aspect of the invention, the amount of acid exceeds the raw material or metal impurities present in the raw material in i), such as, for example, a stoichiometric ratio of metal / acid of at least about 30%, such as at least about 40%, such as at least about 50%, etc. In other words, the acid is present in a ratio of at least 1:1 (relative to the molar ratio or molar equivalent of the impurities present in the raw material), such as, for example, about 2:1, such as, for example, about 3:1, such as, for example, about 4:1, such as, for example, about 5:1 or more, etc. Alternatively, the molar ratio or molar equivalent can be in any range of, for example, about 3:7 to about 9:1, such as, for example, about 2:3, or about 1:1, or about 3:2, or about 7:3, or about 4:1.

[0098] The pH of the aqueous phase of the feedstock / acid / water mixture may be in the range of about 1 to about 4, such as, for example, about 2 to about 3, and the like.

[0099] According to the invention, suitable contact between the feedstock and the acid is provided by any suitable technique. Non-limiting examples may be, for example, the use of any type of mixing, stirring or agitation, which may be, for example, high shear mixing.

[0100] The reaction time between the acid and the starting material in step iii) may be at least about 5 minutes, such as for example about at least 10 minutes, such as for example about at least 15 minutes.

[0101] According to the present invention, process water can be added to the method. In one aspect, process water can be added in step iv). Based on the weight of the raw material, the amount of process water added can be in any range of about 1 wt% to about 6 wt%, such as, for example, about 1.5 wt% to about 4 wt%, or, for example, about 2 wt% to about 3 wt%.

[0102] In one aspect, process water may be added after the acid treatment step iii) is completed.

[0103] In another aspect, process water may be added as part of the acid treatment step iii).

[0104] In other aspects, the process water may be partially added as part of the acid treatment step iii) and the remainder of the process water may be added after the acid treatment step iii) is completed.

[0105] The treatment of the acid / feedstock mixture with process water in step iv) (which may also be referred to as a hydration step) may be performed, for example, using any type of mixing, stirring or agitation, which may be, for example, high shear mixing.

[0106] Process step iv) may have a duration of, for example, at least 10 minutes or more, or at least 20 minutes or more, at least 30 minutes or more, or at least 45 minutes or more, such as for example about at least 60 minutes or more.

[0107] In a specific embodiment, process step iv) can have a duration of, for example, at least about 45 minutes or longer, such as, for example, at least about 60 minutes or longer.

[0108] According to the invention, after the hydration step iv) is completed, the process may comprise a drying step, or a step comprising evaporation of the process water, or any type of combination of drying and evaporation. The purpose of this process step is to remove or reduce the amount of water in the feedstock.

[0109] The drying or evaporation step v) may be carried out under reduced pressure. The reduced pressure may be in the range of about 70 mbar to about 100 mbar.

[0110] The temperature during step v) may range, for example, from about 70°C to about 120°C, or such as for example from about 80°C to about 110°C, or such as for example from 90°C to about 110°C.

[0111] In a preferred embodiment, the temperature during step v) may be, for example, from 90°C to about 110°C.

[0112] The drying or evaporation step v) may also be carried out until the amount of water after step v) is from about 200 ppm to about 1200 ppm, such as for example from about 400 ppm to about 700 ppm, such as for example from about 500 ppm to about 600 ppm, such as for example from about 700 ppm to 1000 ppm, based on the total weight of the dry feedstock produced in step v).

[0113] In specific aspects, after the evaporated process water is collected in step v), the process water is recycled back into the process. In one aspect, at least about 60%, at least about 70%, at least about 80%, or at least about 90% of the evaporated water is recovered and recycled into the process and subsequently reintroduced into the process in step iv).

[0114] According to the invention, the process may comprise contacting the acid / feedstock mixture resulting from the drying step v) with a filter aid and / or an adsorbent. The purpose of this operation is to remove or at least partially eliminate chelated or precipitated metals (as salts) and / or phospholipids or other impurities from the acid-treated feedstock. This process step is illustrated in step vii).

[0115] The filter aid according to the present invention can in principle be any filter aid known in the art. Therefore, according to the present invention, the filter aid can be any type of mineral-based filter aid. Non-limiting examples can be (for example) diatomaceous earth, expanded perlite, etc. In a specific embodiment, the filter aid can be (for example) diatomaceous earth, bleaching earth, silica gel or any combination thereof. The filter aid can be activated in any way, such as, for example, acid activation or surface activation by any appropriate means. The filter aid can also be any type of plant-based filter aid, such as, for example, any type of cellulose-based material as a filter aid. The filter aid can also be any type of polymer-based material, such as, for example, a textile or non-textile material. The filter aid can also be any type of composite material. According to the present invention, the filter aid can be any type of combination of mineral-based, plant-based, polymer-based or composite-based filter aids.

[0116] The filter aid may be present in any suitable amount relative to the weight of the feedstock / acid mixture, such as, for example, 0.1 wt% to about 2 wt%, such as, for example, about 0.5 wt% to about 1.0 wt%, such as, for example, about 0.5 wt% to about 0.6 wt%, such as, for example, about 0.3 wt% to about 0.5 wt%, or such as, for example, about 0.5 wt% to about 0.7 wt%. It should be noted that a combination of filter aids may be used, such as, for example, but not limited to, a mixture of diatomaceous earth and silica hydrogel.

[0117] The filter aid and / or adsorbent may be mixed with the feed mixture produced in step v) at an elevated temperature, such as, for example, about 80°C to about 90°C.

[0118] The contact time between the filter aid and / or adsorbent and the feed mixture can be a period of time, such as, for example, at least 10 minutes, or at least 20 minutes, at least 30 minutes, or at least 45 minutes, such as, for example, about at least 60 minutes. In specific aspects, the contact time can be, for example, about 20 minutes. The contacting itself can include any type of mixing, stirring or agitation.

[0119] The filter aid and / or adsorbent may be mixed with the resulting feed mixture from step v) at a pressure anywhere in the range of about 800 to about 1020 mbar.

[0120] According to the present invention, after contacting the filter aid and / or adsorbent (which may be, for example, but not limited to, silica hydrogel or diatomaceous earth) with the feed mixture, a separation step is then performed to remove the filter aid, adsorbent, and impurities present in the feed. This process step may be described in step viii). The separation step may be performed with the aid of a pre-coating filter device. Alternatively, the separation step may be used without a pre-coating filter device.

[0121] In one aspect according to the invention, in step vii), for contacting the chelated or precipitated metals and / or phospholipids from the acid-treated feedstock in step v), it may be with the aid of a filter aid and / or an adsorbent. Thus, in other aspects of the invention, the filter aid may be used alone, i.e. not in combination with an adsorbent. In other aspects of the invention, the adsorbent may be used alone, i.e. not in combination with a filter aid. Specifically and in a non-limiting sense, Trisyl alone may be used for the purpose of the method according to the invention.

[0122] In another aspect, a combination of Trisyl and diatomaceous earth (DE) can be used for the purposes of the present invention.

[0123] In another aspect, a combination of Trisyl and bleaching earth (BE) can be used for the purposes of the present invention.

[0124] The pre-coat itself may be, for example, a filter aid such as, for example, diatomaceous earth.

[0125] The removing step viii) may be performed at an elevated temperature, such as, for example, at any temperature ranging from about 80°C to about 100°C.

[0126] After separation step viii), an acid treated filter feed is obtained.

[0127] In one aspect of the present invention, the method may comprise a bleaching step. This step is as described in step ix) of the method. Thus, the acid treated filtered material obtained from step viii) is subjected to a bleaching step.

[0128] Bleaching can include any known bleaching components or methods known in the art. In one aspect, bleaching includes adding an acid, such as, for example, citric acid. Bleaching can also include adding bleaching earth. In a specific embodiment, the bleaching step includes first adding an acid and then adding a bleaching agent, such as, for example, bleaching earth.

[0129] In addition to the advantages of the present invention, the oil loss is less than 0.7 wt % compared to typical oil losses in acid degumming (in the range of 3-10 wt %). In one aspect, the oil loss is from about 20% to about 70% relative to the weight of the filter aid, such as, for example, from 30% to about 50% relative to the weight of the filter aid. The theoretical oil loss can be calculated using the following formula:

[0130] For example, if 0.6% filter aid (FA) and 0.4% silica are used (fresh silica contains 60% water, used silica contains 10% water), if the filter cake contains 40% oil

[0131] Oil loss = 6kg FA / ton POME oil / (100-40)*100+4kg silica×0.5 / ton POME oil / (100-40)*100-6kg FA / ton POME oil-4kg silica×0.5=5.33kg / ton=0.53% POME oil loss

[0132] The invention also relates to one or more products obtainable by the process according to the invention.

[0133] In one aspect, the present invention relates to an acid treated filtered and bleached POME oil obtainable by the process according to the present invention, wherein the acid treated filtered and bleached POME oil may be characterized by having:

[0134] The amount of nitrogen-containing compounds (N) is about 72.3 ppm or less,

[0135] Phosphorus compounds (P) below about 2.7 ppm,

[0136] About 4.6ppm or less of metals,

[0137] And it is also characterized by having about 328GPas / kg 2 The following filtration resistance.

[0138] Example

[0139] The present invention is further illustrated in the following non-limiting examples.

[0140] In the following examples, "N" refers to nitrogen-containing compounds, "P" refers to phosphorus-containing compounds. "CA" refers to citric acid. "BE" refers to bleaching earth. "DE" refers to diatomaceous earth. "Metal" refers to the amount of metal compound present in the feedstock or produced as a salt / chelate / precipitate formed during the process of the present invention. "POME" refers to palm oil mill effluent oil. "FA" refers to filter aid.

[0141] Reference bleaching example:

[0142] Example 1

[0143] Crude POME 1 (N = 44.0 ppm, P = 37.5 ppm, metals = 248.5 ppm) was bleached (CA = 3000 ppm, added water = 0%, BE = 1%).

[0144] Bleached POME 1N=21.7ppm, P=1.7ppm, metal=0.7ppm, filtration resistance 1444GPas / kg2.

[0145] Example 2

[0146] Crude POME 2 (N = 189.3 ppm, P = 19.5 ppm, metals = 189.0 ppm) was bleached (CA = 3000 ppm, added water = 0%, BE = 1%).

[0147] Bleached POME 2N=86.0ppm, P=7.6ppm, metal=52.1ppm, filtration resistance 1243GPas / kg2.

[0148] Example 3

[0149] Crude POME 3 (N = 97.3 ppm, P = 24.8 ppm, metals = 347.7 ppm) was bleached (CA = 3000 ppm, added water = 0%, BE = 1%).

[0150] Bleached POME 3N=52.2ppm, P=2.6ppm, metal=4.5ppm, filtration resistance 2530GPas / kg2.

[0151] Example 4

[0152] Crude POME 4 (N = 105.2 ppm, P = 23.1 ppm, metals = 346.1 ppm) was bleached (CA = 3000 ppm, added water = 0%, BE = 1%).

[0153] Bleached POME 4N=59.6ppm, P=3.1ppm, metal=4.4ppm, filtration resistance 3650GPas / kg2.

[0154] Example 5

[0155] The captured grease (N=383ppm, P=25ppm, metal=810ppm) was bleached (CA=1000ppm, added water=0.4%, BE=1%). The bleached captured grease N=289ppm, P=10.8ppm, metal=465ppm, and the filtration resistance was 13076GPas / kg2.

[0156] Example 6

[0157] The captured grease (N=383ppm, P=25ppm, metal=810ppm) was bleached (CA=4000ppm, added water=0.4%, BE=2%). The bleached captured grease N=233ppm, P=8.2ppm, metal=79.7ppm, and the filtration resistance was 30000GPas / kg2.

[0158] Example 7

[0159] Waste edible oil (N = 173.4ppm, P = 27.3ppm, metal = 151.5ppm) was bleached (CA = 1000ppm, added water = 0.5%, BE = 1%). The bleached waste edible oil N = 128ppm, P = 14.1ppm, metal = 82.9ppm, filtration resistance 7378GPas / kg2.

[0160] POME acid degumming + bleaching example:

[0161] Example 8

[0162] Crude POME 1 (N=44.0 ppm, P=37.5 ppm, Metals=248.5 ppm) was acid degummed (CA=3000 ppm, water added=2.5%). The acid treated POME 1 was centrifuged to obtain an acid treated centrifuge product (N=39.2, P=11.4, Metals=6.5 ppm). The water / heavy phase resulted in pH=3 and COD (Chemical Oxygen Demand)=183000 mg / l.

[0163] The acid degummed product was further bleached (CA=500ppm, added water=0.5%, BE=1%) to obtain the final acid degummed+bleached product (N=19.8ppm, P=1.6ppm, metal=4.5ppm, filtration resistance 321GPas / kg2).

[0164] POME acid filtration + bleaching example

[0165] Example 9

[0166] Crude POME 1 (N = 44.0 ppm, P = 37.5 ppm, metal = 248.5 ppm) was acid treated (CA = 3000 ppm, added water = 2.5%). Water was removed by evaporation and the dried oil filter aid (DE) was filtered to obtain an acid treated filtration product (N = 37.2, P = 10.7, metal = 8.3 ppm, filtration resistance 180 GPas / kg2). The acid treated filtration product was further bleached (CA = 500 ppm, added water = 0.5%, BE = 1%) to obtain a final acid treated filtration + bleached product (N = 20.6 ppm, P = 1.6 ppm, metal = 0.8 ppm, filtration resistance 287 GPas / kg2).

[0167] Example 10

[0168] The crude POME 2 (N = 189.3 ppm, P = 19.5 ppm, metal = 189.1 ppm) was acid treated (CA = 3000 ppm, water added = 3.1%). Water was removed by evaporation and the dried oil filter aid (DE) was filtered to obtain an acid treated filtration product (N = 125.0 ppm, P = 4.3 ppm, metal = 10.3 ppm, filtration resistance 270 GPas / kg2). The acid treated filtration product was further bleached (CA = 500 ppm, water added = 0.5%, BE = 1%) to obtain a final acid treated filtration + bleaching product (N = 86.4 ppm, P = 1.9 ppm, metal = 4.7 ppm, filtration resistance 377 GPas / kg2).

[0169] Embodiment 11

[0170] The crude POME3 (N=97.3, P=24.8, metal=347.7 ppm) was acid treated (CA=3000 ppm, water added=2.6%). Water was removed by evaporation and the dried oil filter aid (DE) was filtered to obtain an acid treated product (N=84.1, P=9.6, metal=5.9 ppm, filtration resistance 180 GPas / kg2). The acid treated filtered product was further bleached (CA=500 ppm, water added=0.5%, BE=1%) to obtain a final acid treated filtered + bleached product (N=58, P=2.4, metal=1.9 ppm, filtration resistance 359 GPas / kg2).

[0171] Example 12

[0172] Crude POME 4 (N=105.2, P=23.1, metal=346.1 ppm) was acid treated (CA=3000 ppm, added water=1.9%). Water was removed by evaporation and the dried oil filter aid (DE) was filtered to obtain an acid treated filtration product (N=94.7, P=8.4, metal=8.3 ppm, filtration resistance 4 GPas / kg2). The acid treated filtration product was further bleached (CA=500 ppm, added water=0.5%, BE=1%) to obtain a final acid treated filtration+bleached product (N=70, P=2.3, metal=1.7 ppm, filtration resistance 311 GPas / kg2).

[0173] Example 13

[0174] The same crude POME 4 (N = 105.2 ppm, P = 23.1 ppm, metal = 346.1 ppm) was acid treated (CA = 1800 ppm, added water = 2%). Water was removed by evaporation, and the dried oil was mixed with filter aid (DE) / Trisyl at a ratio of 0.4% Trisyl / 0.6 filter aid and filtered (Misc ID831) to obtain an acid treated filtered product (N = 96.6, P = 5.5, metal = 10.1 ppm, filter resistance 259 GPas / kg2). The acid treated filtered product was further bleached (CA = 500 ppm, added water = 0.5%, BE = 1%) to obtain a final acid treated + bleached product (N = 68.6, P = 1.9, metal = 3.5 ppm, filter resistance 301 GPas / kg2).

[0175] Capture of Grease and Waste Edible Grease Acid Filtration + Bleaching Example

[0176] Embodiment 14

[0177] The captured grease (N=383ppm, P=25ppm, metal=810ppm) was acid treated (CA=7500ppm, water added=2.7%). Water was removed by evaporation, and the dried oil was mixed with filter aid (DE) / Trisyl at a ratio of 0.4% Trisyl / 0.6 filter aid and filtered to obtain an acid-treated filtered product (N=305, P=8.8, metal=19.9ppm). The acid-treated filtered product was further bleached (CA=1000ppm, water added=0.8%, BE=1%) to obtain the final acid-treated filtered + bleached product (N=239, P=5.9, metal=9.4ppm, filtration resistance 387GPas / kg2).

[0178] Embodiment 15

[0179] Waste edible oil (N = 173.4ppm, P = 27.3ppm, metal = 151.5ppm) was treated with acid (CA = 1080ppm, water added = 3.0%). Water was removed by evaporation, and the dried oil was mixed with filter aid / Trisyl in a ratio of 0.4% Trisyl / 0.6 filter aid (DE) and filtered to obtain an acid-treated filtered product (N = 155, P = 10.4, metal = 44.7ppm). The acid-treated filtered product was further bleached (CA = 1000ppm, water added = 0.5%, BE = 1%) to obtain the final acid-treated filtered + bleached product (N = 113, P = 5.5, metal = 3.7ppm, filtration resistance 931GPas / kg2).

[0180] The POME oil results for the above examples are summarized in the following table.

[0181] Table 1

[0182]

[0183] Table 2

[0184]

[0185]

[0186] Table 3

[0187]

[0188] Table 4

[0189]

[0190]

[0191] In the reference bleaching, all four POME samples were treated with 3000 ppm citric acid and 1 wt% bleaching earth without the addition of water.

[0192] In acid degumming, the four POME samples were treated with 3000 ppm citric acid and 2.5 wt% added water, followed by samples treated with 500 ppm citric acid, 1 wt% bleaching earth and 0.5 wt% added water.

[0193] In the acid filtration, 4 POME samples were treated with 3000 ppm citric acid and 2.5 wt% added water, followed by evaporation of the water and filter aid filtration with 1 wt% filter aid, and 1 POME sample was treated with 1800 ppm citric acid and 2.5 wt% added water, followed by evaporation of the water and 0.6% filter aid and 0.4% adsorbent (Trisyl), and then the sample was treated with 500 ppm citric acid, 1 wt% bleaching earth, and 0.5 wt% added water.

[0194] Compared to the reference bleaching, the removal of nitrogen, silicon, phosphorus and metals for all POME samples by acid filtration followed by bleaching was at the same level or better, while the filtration time was significantly reduced.

[0195] In Table 4, the removal of nitrogen, silicon, phosphorus and metals in crude POME sample 4 after acid filtration and subsequent bleaching was at the same level as the reference bleaching, but the filterability resistance values ​​after acid filtration were significantly lower, at 301-311 GPas kg -2 3650GPas kg -2 .

[0196] The best results were achieved with the method described in Example 12, where the crude POME 4 was first treated with a lower acid amount (CA = 1800 ppm, added water = 2 wt%). The water was removed by evaporation and the dried oil was mixed with filter aid (DE) / adsorbent (Trisyl) in a ratio of 0.6 filter aid (DE) / 0.4% adsorbent (Trisyl) and filtered to obtain an acid treated filtration product (N = 96.6, P = 5.5, metal = 10.1 ppm, filtration resistance 259 GPas / kg 2 The acid treated filtration product was further bleached (CA = 500 ppm, added water = 0.5%, BE = 1%) to obtain the final acid treated + bleached product (N = 68.6, P = 1.9, metal = 3.5 ppm, filtration resistance 301 GPas / kg2). It can be seen that even with less citric acid, the method in Example 12 removed more metals than the reference bleaching, and the removal of P was higher than when only the filter aid was used, which shows the important role of the adsorbent (Trisyl) in reducing the residual P in the POME oil. In addition, the filtration resistance was the lowest value, resulting in a reduction in filtration time from 31 minutes to 6 minutes, a reduction of more than 80%.

[0197] Tables 1-4 show that using the same amount of added water and the same amount of bleaching earth, acid degumming followed by bleaching and acid filtration followed by bleaching are equally effective in removing nitrogen, silicon and phosphorus. However, acid filtration followed by bleaching is more effective in removing metals.

[0198] From Tables 1 to 4, it can be seen that based on the impurities and acid filtration conditions, the purification results after acid filtration are at the same level as the reference bleaching, or even better, but the filterability resistance after acid filtration is significantly lower, 301-311 GPas kg -2 3650GPaskg -2 , which in the best case results in a reduction of filtration time of more than 80%, from 31 to 6 minutes.

[0199] The amount of citric acid adjusted during the acid treatment and the combined use of filter aids and adsorbents (silica hydrogel Trisyl) in the acid filtration allowed to minimize the residual amounts of P and metals in the POME oil.

[0200] Recirculation of process water

[0201] Example 16

[0202] The acid treated (CA 1800 ppm and H2O 2%) POME 4 was centrifuged to give a centrifuge product (N = 109.2 ppm, P = 9.1 ppm, metals = 9.0 ppm). The water / heavy phase from the centrifugation had a pH = 3.0.

[0203] The evaporated water from Example 10 was collected and used as process water using the same crude POME 4 (N=105.2, P=23.1, Metals=346.1 ppm) acid filtered using the same conditions (CA 1800 ppm and H2O 2%, same as the reused water collected from Example 9) to obtain the centrifuged product (N=107.5 ppm, P=9.2 ppm, Metals=16.9 ppm). The heavy / aqueous phase pH=3.6.

[0204] Using recycled process water from water evaporation before the filter aid / silica hydrogel step had the same P removal compared to using new process water, the metal content was slightly elevated, and the pH of the water from the centrifugation was in the same order of magnitude, indicating that impurity removal using recycled water from water evaporation in acid filtration is as effective as using new process water, and the aqueous phase pH is maintained at the same order of magnitude.

Claims

1. A method for refining or purifying a raw material, characterized in that The method comprises the following steps: i) providing raw materials, ii) optionally heating the provided feedstock, iii) treating the provided raw material with an acid, wherein the acid is capable of forming a precipitate, or a salt or a chelate with impurities such as metals and / or phospholipids present in the raw material, thereby obtaining an acid-treated raw material, iv) treating the acid-treated feedstock in iii) with process water, v) evaporating water from the acid-treated feedstock in iv), vi) optionally, recovering and recycling the evaporated water from step v) to at least partly reuse it as process water in step iv) and / or step iii), vii) contacting the chelated or precipitated metals and / or phospholipids from the acid treated feedstock in step v) with a filter aid and / or adsorbent, viii) removing the chelate or precipitate and the filter aid and / or adsorbent by filtration with or without a pre-coat to obtain an acid treated filtered stock, and ix) bleaching the acid treated filtered stock from step viii.

2. The method as claimed in claim 1, wherein the feedstock comprises palm oil mill effluent (POME) oil, brown grease, waste cooking grease, trapped grease, DAF (dissolved air flotation) grease, sewage sludge or mixed grease trap waste.

3. The process according to any one of the preceding claims, wherein the feedstock is heated in step i) to a temperature in the range of about 50°C to about 110°C, such as for example from about 60°C to about 100°C, or such as for example from about 70°C to about 90°C, prior to adding the acid in step iii).

4. The process according to any one of the preceding claims, wherein the acid treatment of the feedstock in step iii) is carried out at a temperature according to claim 3.

5. The method according to any one of the preceding claims, wherein the acid is, for example, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, ethylenediaminetetraacetic acid (EDTA), phosphoric acid, etc., or any mixture thereof.

6. A method according to any one of the preceding claims, wherein the acid is a citric acid solution in an aqueous solution at a concentration of about 20 wt% to about 60 wt%, such as for example 30 wt% to about 50 wt%.

7. A process according to any one of the preceding claims, wherein the amount of acid in i) is in a ratio to the amount of metal impurities present in the feedstock in any range of about 3:7 to about 9:1, such as, for example, about 2:3, about 1:1, about 3:2, about 7:3 or about 4:

1.

8. A process according to any one of the preceding claims, wherein the acid treatment in step iii) comprises providing suitable contact between the feedstock and the acid, such as for example using any type of mixing, stirring or agitation, which may be for example high shear mixing.

9. The method according to any one of the preceding claims, wherein the reaction time in step iii) is at least about 5 minutes, such as for example about at least 10 minutes, such as for example about at least 15 minutes.

10. The method according to any one of the preceding claims, wherein the pH in step iii) is in the range of about 1 to about 4, such as for example about 2 to about 3, etc.

11. The process according to any of the preceding claims, wherein water is added to the process after the addition of the acid and after the reaction time specified in claim 9 and / or partly together with the addition of the acid to the starting materials in step iii).

12. The method according to any one of the preceding claims, wherein the water content of the acid-treated feedstock in step iv) is adjusted to a range of about 1 wt % to about 6 wt %, preferably about 1.5 wt % to about 4 wt %, more preferably about 2 wt % to about 3 wt %, relative to the total weight of the feedstock.

13. A method according to any one of the preceding claims, wherein the process water added in step iv) is contacted with the feed mixture, for example by any type of mixing, stirring or agitation, which may be for example high shear mixing.

14. The method according to any one of the preceding claims, wherein the hydration time in step iv) is at least 10 minutes, or at least 20 minutes, at least 30 minutes, or at least 45 minutes, such as for example about at least 60 minutes.

15. The process according to any one of the preceding claims, wherein the drying step / evaporation step v) is carried out under vacuum, such as for example in the range of about 70 mbar to about 100 mbar, and in a temperature range of for example about 70°C to about 120°C or such as for example about 80°C to about 110°C.

16. The process of any one of the preceding claims, wherein at least about 60%, at least about 70%, at least about 80%, or at least about 90% of the evaporated water is recovered and recycled into the process.

17. The process according to any one of the preceding claims, wherein the amount of water remaining after step v) is from about 200 ppm to about 1200 ppm, such as for example from about 400 ppm to about 700 ppm, such as for example from about 500 ppm to about 600 ppm, such as for example from about 700 ppm to 1000 ppm, based on the total weight of the dry raw material.

18. The method according to any of the preceding claims, wherein the filter aid is, for example, a mineral-based filter aid, such as, for example, a silica-based or diatomaceous earth-based filter aid; a plant-based filter aid, such as, for example, a cellulose-based filter aid; a polymer-based filter aid; or can be a filter aid based on any type of composite material.

19. The method according to any one of the preceding claims, wherein the adsorbent is activated carbon; a silica-based compound, such as, for example, silica gels of various types and morphologies, such as, for example, silica hydrogels, or mixtures thereof.

20. The process according to any one of the preceding claims, wherein the dried and acid treated feedstock is mixed with a filter aid and / or adsorbent in step vii) under stirring at elevated temperature such as, for example, about 80°C to about 90°C and at a pressure of 800-1020 mbar for a period of about 20 minutes, wherein the filter aid is, for example, diatomaceous earth (0.5-1.0 wt%) as the main feed and / or silica gel (0.5-0.6 wt% silica gel, or a blend in a ratio of 0.3-0.5 wt% silica gel and 0.7-0.5 wt% filter aid) as the main feed.

21. The process according to any one of the preceding claims, wherein the chelated or precipitated metals and / or phospholipids from the acid treated feedstock in v) are contacted with a filter aid and / or an adsorbent, wherein the adsorbent is a silica hydrogel.

22. The method according to any one of the preceding claims, wherein the removal / separation in step viii) is performed by filtration, for example using a pre-coated filter device, at elevated temperature, such as for example about 80°C to about 90°C.

23. A process according to any one of the preceding claims, wherein the bleaching in step ix) comprises adding a citric acid solution and then adding bleaching earth to the mixture.

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