Method for purifying lipids

Abstract

The present invention provides a method of purifying a lipid feedstock, the method comprising: i) providing a lipid feedstock (a); ii) adjusting the net element charge of the lipid feedstock (a) to a total net element charge Qt of at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, by mixing the lipid feedstock (a) with a charge balancing component comprising or consisting of a metal compound, when the net element charge Q1 of the lipid feedstock (a) is less than 0 mmol / kg; and iii) optionally adjusting the free fatty acid (FFA) concentration of the lipid feedstock (a) to 2 wt% or more of the total weight of the resulting lipid feedstock, such as 2.5 to 40 wt%, preferably at least 3 wt%, such as 3 to 30 wt%, more preferably at least 4 wt%, such as 4 to 20 wt%, even more preferably 4 to 10 wt%; and iv) removing solid impurities, and optionally an excess of water, from the lipid feedstock (a) to obtain a conditioned lipid feedstock (b) having a total net element charge Qt within the values defined in step ii); v) heating the conditioned lipid feedstock (b), preferably in the presence of water, at a temperature of 180 to 325 DEG C to obtain a heat-treated lipid feedstock (c); vi) further treating the heat-treated lipid feedstock (c) optionally with an acid and / or adsorbent material, preferably under decolorization conditions, to obtain a further treated lipid feedstock (d); and vii) recovering the heat treated lipid feedstock (c) and / or the further treated lipid feedstock (d) by phase separation to obtain a purified lipid feedstock (e). The invention also provides a process for providing a renewable hydrocarbon, the process comprising x) purifying a lipid feedstock by the provided process to obtain a purified lipid material, and y) subjecting the purified lipid material to a hydrotreating to obtain at least one renewable hydrocarbon.

Description

Methods for purifying lipids Technical Field

[0001] This invention relates to the purification of lipid materials, particularly those containing high levels of phosphorus and metal impurities. Specifically, this invention relates to the purification of lipid materials to make them suitable for catalytic processing. Background Technology

[0002] It is well known that lipid materials (such as oils and fats) may contain impurities that need to be removed before catalytic processing because they are detrimental to the quality of the final product and can lead to reactor clogging, catalyst deactivation, and equipment fouling. However, current methods may not be entirely suitable for the most difficult-to-process oils and fats because, despite adequate removal of at least some impurities, these methods still face or even create challenges in downstream unit operations, such as filtering the purified product. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide a method to overcome the above problems. This object is achieved by a method characterized by the features described in the independent claim. Preferred embodiments of the invention are disclosed in the dependent claims.

[0004] This invention is based on the unexpected discovery that a method combining two operations can successfully purify lipid feedstocks: adjusting the total net charge and optionally the free fatty acid content of the lipid feedstock to ideal levels, and removing solid impurities from the lipid feedstock prior to further purification steps (such as heat treatment followed by decolorization). This achieves efficient impurity removal by facilitating downstream phase separation operations following further purification steps. This further allows for the efficient production of renewable hydrocarbons from the lipid feedstock. Attached Figure Description

[0005] The invention will now be described in more detail with reference to the accompanying drawings and preferred embodiments, wherein...

[0006] Figure 1 shows a first exemplary process flow of the method of the present invention; Figure 2 shows a second exemplary process flow of the method of the present invention; Figure 3 shows a third exemplary process flow of the method of the present invention; Figure 4 shows a fourth exemplary process flow of the method of the present invention; Figure 5 shows a fifth exemplary process flow of the method of the present invention; Figure 6 shows a sixth exemplary process flow of the method of the present invention. Detailed Implementation

[0007] This invention provides a method for purifying lipid raw materials, the method comprising:

[0008] i) providing a lipid source (a); ii) when the net initial charge Q1 of the lipid source (a) is less than 0 mmol / kg, adjusting the net initial charge of the lipid source (a) to at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, to a total net initial charge Qt; and iii) optionally adjusting the free fatty acid (FFA) concentration of the lipid source (a) to more than 2 wt% of the total weight of the resulting lipid source, such as 2.5 to 40 wt%, preferably at least 3 wt%, such as 3 to 30 wt%, more preferably at least 4 wt%, such as 4 to 20 wt%, even more preferably 4 to 10 wt%. wt%; and iv) removing solid impurities and optionally excess water from lipid feedstock (a); to obtain a conditioning lipid feedstock (b) having a total net elementary charge Qt within the value defined in step ii); v) heating the conditioning lipid feedstock (b) at a temperature of 180°C to 325°C, preferably in the presence of water, to obtain a heat-treated lipid feedstock (c); vi) preferably further treating the heat-treated lipid feedstock (c) with acid and / or adsorbent material under decolorization conditions to obtain a further treated lipid feedstock (d); and vii) recovering the heat-treated lipid feedstock (c) and / or the further treated lipid feedstock (d) by phase separation to obtain a purified lipid feedstock (e).

[0009] The present invention also provides a method for providing renewable hydrocarbons, the method comprising: x) purifying a lipid feedstock by a method contemplated herein to obtain a purified lipid material; and y) subjecting the purified lipid material to hydrogenation to obtain at least one renewable hydrocarbon.

[0010] In this specification, weight percentages (wt%) are calculated based on the total weight of the materials under discussion (typically blends or mixtures). Any amount defined as ppm (parts per million) is based on weight (i.e., mg / kg).

[0011] The term "molar ratio" refers to the ratio of substance a to substance b, where the amounts of substance a and substance b are determined in moles. The concentration of the raw material, expressed in mg / kg, is converted to mol / kg (n=m / M) using appropriate methods (such as inductively coupled plasma (ICP), ICP coupled with atomic emission spectrometry (ICP-AES), tandem inductively coupled plasma mass spectrometry (ICP-MS / MS), or inductively coupled plasma optical emission spectrometry (ICP-OES)). Weight is calculated based on the amount of the substance in question present in its elemental form.

[0012] In the context of renewable feedstocks, renewable feedstocks, or renewable fuels or fuel components, the term "renewable" refers to one or more organic compounds derived from any renewable source (as opposed to fossil sources). Therefore, a renewable compound or composition is wholly or partially available, obtained, derived, derived from, or derived from plants, animals, and / or microorganisms (including compounds or compositions available, obtained, derived, derived from, or derived from fungi and / or algae), whether in their original, recycled, or regenerated form. As used herein, a renewable compound or composition may contain gene-manipulating compounds or compositions. Renewable feedstocks, components, compounds, or compositions may also be referred to as bio-feedstocks, components, compounds, or compositions, or bio-derived feedstocks, components, compounds, or compositions. As used herein, the term "fossil" refers to a compound or composition that is available, obtained, derivable, derived from, or derived from naturally occurring non-renewable compositions such as crude oil, petroleum / gas, shale oil / gas, natural gas, or coal sediments and combinations thereof, including any hydrocarbon-rich sediments that can be utilized from surface and / or subsurface sources. Therefore, renewable hydrocarbons are based on renewable sources and are thus not derived from or derived from any fossil-based material.

[0013] The 14C isotope content can serve as evidence of the renewable or biological origin of raw materials or products. Carbon atoms in renewable materials contain a greater number of unstable radioactive carbon (14C) atoms than those in fossil-derived materials. Therefore, biologically derived carbon compounds can be distinguished from fossil-derived carbon compounds by analyzing the ratio of 12C to 14C isotopes. Thus, a specific ratio of this isotope can be used to identify and quantify renewable carbon compounds and to differentiate those compounds from non-renewable carbon compounds (i.e., fossil carbon compounds). The isotope ratio remains unchanged during chemical reactions. An example of a suitable method for analyzing the content of carbon from biological sources is ASTM D6866 (2020). An example of how ASTM D6866 can be applied to determine the renewable content in fuels is provided in an article by Dijs et al. published in Radiocarbon, Vol. 48, No. 3, 2006, pp. 315–323. For the purposes of this invention, a renewable material is considered to have a renewable source if it contains 90% or more modern carbon (pMC) (such as about 100% modern carbon, as measured by ASTM D6866).

[0014] As used herein, “hydrocarbon” refers to a compound consisting of carbon and hydrogen. Examples of hydrocarbons include alkanes (including n-alkanes and isoalkanes), cycloalkanes, aromatics, and alkenes (alkenes). “Oxygenated hydrocarbon” in this document refers to hydrocarbons containing covalently bonded oxygen. Examples of oxygenated hydrocarbons include triglycerides, diglycerides and monoglycerides, fatty acids, and alkyl esters of fatty acids (e.g., methyl or ethyl esters of fatty acids).

[0015] As used herein, "alkanes" refers to acyclic alkanes, i.e., acyclic, open-chain saturated hydrocarbons that are either straight-chain (n-alkanes) or branched (iso-alkanes). In other words, alkanes in this document refer to n-alkanes and / or iso-alkanes.

[0016] In the context of this disclosure, "olefin" refers to an unsaturated, straight-chain, branched, or cyclic hydrocarbon (excluding aromatic compounds). In other words, an olefin refers to a hydrocarbon having at least one unsaturated bond (excluding unsaturated bonds in aromatic rings).

[0017] “Cycloalkanes” in this document refer to cycloalkanes or cycloolefins containing at least one cyclic structure, with or without side chains, and also include compounds having one or more olefinic bonds in the cyclic structure and / or in the side chains, but exclude compounds containing any one or more aromatic ring structures.

[0018] In this paper, "aromatic hydrocarbons" refers to hydrocarbons containing at least one aromatic ring structure (i.e., a ring structure with delocalized π bonds that satisfy the Hückel (4n + 2) rule).

[0019] The term "fuel" refers to two fuels that can be used as is and / or as fuel components, and that meet the standard requirements for their respective uses. For example, within the EU, the standard for gasoline is EN 228 (2017), the standard for paraffinic diesel is EN 15940 (2019), and the standard for aviation turbine fuels containing synthetic hydrocarbons is D7566 (2020).

[0020] lipid raw materials

[0021] The term "lipid feedstock" refers to a lipid material intended for conversion into renewable hydrocarbons or other valuable renewable products (including fuels) through hydrotreating, but which contains excessively high concentrations of impurities, making it unsuitable for in-situ feeding into the hydrotreating process. The lipid feedstock considered herein typically comprises at least 5 mg / kg, such as 5 to 5000 mg / kg, dissolved phosphorus impurities as measured in elemental phosphorus and one or more elemental metals, and at least 10 mg / kg, such as 10 to 10000 mg / kg, dissolved metal impurities. Preferably, the lipid feedstock considered herein comprises at least 15 mg / kg, such as 15 to 2000 mg / kg, dissolved phosphorus impurities as measured in elemental phosphorus and one or more elemental metals, and at least 20 mg / kg, such as 20 to 3000 mg / kg, dissolved metal impurities. The net initial charge of the lipid feedstock considered herein can be positive or negative based on the presence of phosphorus and one or more metals in the lipid feedstock. However, this method is particularly advantageous for lipid feedstocks with a negative net initial charge Q1, i.e., the negative charge from phosphorus impurities outweighs the positive charge from metal impurities. The method of the present invention is particularly applicable to lipid feedstocks having a net initial charge Q1 of less than 0 mmol / kg, such as -60 to -0.5 mmol / kg, and especially less than -0.5 mmol / kg, such as -30 to -1 mmol / kg.

[0022] Therefore, in embodiments, the present invention provides a method for purifying a lipid raw material, the method comprising: i) providing a lipid raw material (a) having a net initial charge Q1 of less than 0 mmol / kg, such as -60 to -0.5 mmol / kg, particularly less than -0.5 mmol / kg, such as -30 to -1 mmol / kg; ii) adjusting the net initial charge of the lipid raw material (a) to at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, by mixing the lipid raw material (a) with a charge-balancing component comprising a metal compound or composed of a metal compound, such as a total net initial charge Qt; iii) optionally adjusting the concentration of free fatty acids (FFA) in the lipid raw material (a) to 2% of the total weight of the resulting lipid raw material. iv) removing solid impurities and optionally excess water from lipid feedstock (a) to obtain a conditioned lipid feedstock (b) having a total net elementary charge Qt within the value defined in step ii); v) heating the conditioned lipid feedstock (b) at a temperature of 180°C to 325°C, preferably in the presence of water, to obtain a heat-treated lipid feedstock (c); vi) optionally treating the heat-treated lipid feedstock (c) with acid and / or an adsorbent material to obtain a further treated lipid feedstock; and vii) recovering the heat-treated lipid feedstock and / or the further treated lipid feedstock (c) by phase separation to obtain a purified lipid feedstock (e).

[0023] In an alternative embodiment, the present invention provides a method for purifying a lipid raw material, the method comprising: i) providing a lipid raw material (a) having a net elementary charge Q1 of at least 0 mmol / kg, such as 0 to 80 mmol / kg, particularly more than 1 mmol / kg, such as 1 to 60 mmol / kg; iv) removing solid impurities and optionally excess water from the lipid raw material (a); to obtain a conditioning lipid raw material (b) within the value defined in step i); v) heating the conditioning lipid raw material (b) at a temperature of 180°C to 325°C, preferably in the presence of water, to obtain a heat-treated lipid raw material (c); vi) optionally treating the heat-treated lipid raw material (c) with an acid and / or an adsorbent material to obtain a further treated lipid raw material (d); and vii) recovering the heat-treated lipid raw material and / or the further treated lipid raw material (d) by phase separation to obtain a purified lipid raw material (e).

[0024] As used in this article, the term "dissolved impurities" refers to impurities that remain in the liquid phase after filtration through a 0.45 μm filter. Impurities in solid form removed by such filtration are not considered dissolved impurities in this context.

[0025] Phosphorus impurities can exist in lipid feedstocks in various chemical forms of phosphorus-containing compounds, such as phospholipids, oil-soluble or water-soluble or insoluble phosphorus compounds, or inorganic phosphates, diphosphates, and phosphites. Typical phosphorus-containing compounds may further include glycerophospholipids, sphingolipids, phosphatidic acid complexes, phosphatidylethanolamine, nucleoside phosphates, apatite, or bone meal (calcium phosphate), etc.

[0026] Metallic impurities can similarly exist in lipid feedstocks in various chemical forms of various inorganic or organic metal-containing compounds, in water-soluble, oil-soluble, or insoluble forms.

[0027] The lipid feedstock may contain both dissolved and undissolved impurities (including dissolved phosphorus and / or metal impurities as well as undissolved phosphorus and / or metal impurities). The amount of insoluble impurities is not considered part of the dissolved impurities, but is taken into account as solid impurities and treated accordingly, i.e., removed along with other solid impurities (in step iv). Therefore, to determine the dissolved phosphorus and metal impurities, the feedstock sample is filtered to remove any solid particles, and then the amounts of various metals and phosphorus as elemental metals and elemental phosphorus are measured.

[0028] The method of this invention can be used to purify any lipid raw material, such as vegetable oil, vegetable fat, animal fat, animal oil, fish fat, fish oil, waste fat, waste oil, residual fat, residual oil, fatty acid distillate, acidified soapstock, moldy oil, rapeseed oil, low erucic acid rapeseed oil, rapeseed oil, babassu kernel oil, carinata oil, coconut oil, musk oil, sesame oil, corn oil, poppy seed oil, cottonseed oil, soybean oil, laurel seed oil, jatropha fruit oil, palm kernel oil, linseed oil, tall oil, tall oil fraction, crude tall oil, tall oil resin, sunflower oil, corn oil, industrial / distilled corn oil, soybean oil, hemp seed oil, olive oil, flaxseed oil, cottonseed oil, etc. Seed oil, mustard oil, mustard seed oil, peanut oil, castor oil, coconut oil, palm oil, crude palm oil, palm seed oil, palm fatty acid distillate, sludge derived from vegetable oil production, palm oil plant wastewater, peanut oil, castor oil, coconut oil, archaea oil, bacterial oil, fungal oil, protozoan oil, algae oil, seaweed oil, oil from halophilic bacteria, poultry fat, dry-refined poultry fat, brown grease, waste edible oil, lard, pork fat, beef tallow, whale blubber, recycled edible fat, acidified oil, whale oil, waste decolorized clay oil, lignocellulose-based raw materials, materials produced through genetic engineering, and biomaterials produced by microorganisms, or any combination or mixture thereof. The method of this invention is particularly suitable for lipid materials containing large amounts of phosphorus and / or lipophilic phosphorus, metals, and solid impurities.

[0029] Lipid feedstocks can be in unprocessed form (e.g., animal fat) or processed form (e.g., waste cooking oil).

[0030] Typical lipid feedstocks include waste oil and recycled oil, typically in combination. These lipid materials typically initially contain high levels of phosphorus, usually in the form of phosphorus compounds, metals, and solid impurities.

[0031] Examples of lipid materials that benefit from the purification method of the present invention include soapstock oil (SAO), low-quality animal fat (LQAF) grades (such as selected white fat (CWG) and poultry fat (APF)), unused edible oil (UCO), and palm oil mill wastewater (POME) and mixtures thereof.

[0032] Soapstock acid oil (SAO) is a byproduct obtained in the vegetable oil refining industry through the acidification of soapstock. Typically, SAO contains significant amounts of phosphorus and metallic impurities, such as at least 30 mg / kg (e.g., 50 to 700 mg / kg) of phosphorus, at least 10 mg / kg (e.g., 10 to 3000 mg / kg) of metals, and at least 0.1 wt% (e.g., 0.1 to 3 wt%) of solids. Typically, SAO has a net charge of -13 mmol / kg, such as -60 to -10 mmol / kg. Typically, SAO contains at least 10 wt% of the total weight of the composition, such as 15 to 80 wt% of free fatty acids (FFA).

[0033] Low-quality animal fat (LQAF) is typically an inedible lipid derived from animals. Typically, LQAF contains significant amounts of phosphorus and metallic impurities, such as at least 50 mg / kg (e.g., 100 to 700 mg / kg) of phosphorus, at least 50 mg / kg (e.g., 50 to 1200 mg / kg) of metals, and at least 0.01 wt% (e.g., 0.01 to 2.0 wt%) of solids. Typically, LQAF has a net charge of -30 mmol / kg, such as -50 to -5 mmol / kg. Typically, LQAF contains at least 2 wt% of FFA, such as 2 to 10 wt%, of the total weight of the composition.

[0034] Examples of LQAF (Selected White Fats (CWG)) are inedible, low-quality animal fats obtained from hogs through refining processes in the North American raw material market. Typically, CWG contains significant amounts of phosphorus and metallic impurities, such as at least 300 mg / kg (e.g., 300 to 700 mg / kg) of phosphorus, at least 600 mg / kg (e.g., 600 to 1200 mg / kg) of metals, and at least 0.4 wt% (e.g., 0.4 to 2.0 wt%) of solids. Typically, CWG has a net charge of -10 mmol / kg, such as -30 to -5 mmol / kg. Typically, CWG contains at least 2 wt% of FFA, such as 2 to 10 wt%, of the total weight of the composition.

[0035] Another example of LQAF (Avian Fat (AFP)) is fat obtained from poultry through refining and processing. Typically, AFP contains significant amounts of phosphorus and metallic impurities, such as at least 50 mg / kg (e.g., 100 to 700 mg / kg) of phosphorus, at least 10 mg / kg (e.g., 50 to 500 mg / kg) of metals, and at least 0.01 wt% (e.g., 0.1 to 1.0 wt%) of solids. Typically, AFP has a net charge of -30 mmol / kg, such as -50 to -15 mmol / kg. Typically, AFP contains at least 5 wt% of FFA, such as 2 to 15 wt%, of the total weight of the composition.

[0036] Waste cooking oil (UCO) is oil and fat that has been used for cooking or frying. Typically, UCO contains significant amounts of phosphorus and metallic impurities, such as at least 2 mg / kg (e.g., 5 to 300 mg / kg) of phosphorus, at least 10 mg / kg (e.g., 20 to 2000 mg / kg) of metals, and at least 0.01 wt% (e.g., 0.01 to 1.0 wt%) of solids. Typically, UCO has a net charge of at least 0 mmol / kg, such as 0 to 10 mmol / kg. Typically, UCO contains 3 wt% of the total weight of the composition, such as 0.5 to 15 wt% of free fatty acids (FFA).

[0037] Palm oil mill wastewater (POME) is an oily waste separated from wastewater generated during palm oil processing. Typically, POME contains significant amounts of phosphorus and metallic impurities, such as at least 5 mg / kg (e.g., 5 to 150 mg / kg) of phosphorus, at least 10 mg / kg (e.g., 10 to 4000 mg / kg) of metals, and at least 0.01 wt% (e.g., 0.1 to 2.0 wt%) of solids. Typically, POME has a net charge of 10 mmol / kg, such as 0 to 70 mmol / kg. Typically, POME contains at least 50 wt% of the total weight of the composition, such as 10 to 85 wt% of free fatty acids (FFA).

[0038] The amounts of phosphorus and metallic impurities can be determined, for example, according to the ASTM D5185-18 standard test method or as described in the experimental section of this document, preferably as described herein.

[0039] Adjusting net elemental charge - Step ii)

[0040] The molar ratio of dissolved phosphorus impurities to dissolved metal impurities in lipid feedstocks is reflected in the net elementary charge of lipid feedstocks based on the phosphorus and one or more metals contained in the lipid feedstock.

[0041] The term "net elemental charge of the raw material" refers to the net elemental charge of phosphorus and one or more metals contained in the raw material, and the term "net elemental charge of the raw material" is used for the sake of brevity. Similarly, when the net elemental charge of the raw material is given as a numerical value, the unit is mmol elemental charge / kg of the raw material under discussion, and mmol / kg may also be used for the sake of brevity.

[0042] The total net charge of the lipid feedstock is determined by the net charge Q1 based on phosphorus and at least one metal, obtained by equation (I).

[0043] Q1 = (CPQP) + i(CMiQMi) (I)

[0044] Wherein, CP is the concentration of dissolved phosphorus in the raw material, in mmol / kg raw material, QP is the elementary charge of dissolved phosphorus in the raw material, CMi is the concentration of dissolved metal i in the raw material, in mmol / kg raw material, QMi is the elementary charge of dissolved metal i in the raw material, and i is the number of dissolved metals considered, and i is from 1 to n.

[0045] The total net elementary charge Qt is the sum of the net elementary charges of each lipid precursor and any optional charge balance component different from the lipid precursor, i.e.

[0046] Qt = Q1 + Q2 + Q3 + ... + QC

[0047] In this equation, phosphorus has an elementary charge of -3e, as assumed herein to be present in the form of phosphate. Sodium has an elementary charge of +1e, potassium has an elementary charge of +1e, magnesium has an elementary charge of +2e, calcium has an elementary charge of +2e, and iron has an elementary charge of +3e, depending on the compounds present. In cases where other dissolved metals are present in the feed in significant amounts (amounts greater than 0.1 ppm by weight), these metals and their elementary charges are also included in the calculation of the net elementary charge. The same significant amount limit (0.1 ppm) can also be used for sodium, potassium, magnesium, calcium, and iron. Metals include Na, K, Mg, Ca, Fe, Al, Cr, Pb, Mn, Zn, W, Ni, and Cu, or any combination thereof. The elementary charge of a metal is the valence typically possessed by the metal when forming metal salts, such as metal phosphates. This determination can also be performed using another method skilled in the art. Only the concentrations of dissolved phosphorus and one or more metals (not solid impurities) are used in the net elementary charge calculation. According to the method of the present invention, solids are removed from the raw material to be processed by heat treatment, and are therefore not considered for determining net elemental charge Q1 and / or total net elemental charge Qt.

[0048] When the net initial charge Q1 of the lipid feedstock (a) is less than 0 mmol / kg, the net initial charge of the lipid feedstock is adjusted to at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, by mixing the lipid feedstock with a charge-balancing component comprising a metal compound (such as a metal hydroxide, an inorganic metal salt, an organometallic salt, or any mixture thereof) and / or a first additional lipid composition comprising one or more metal compounds, to achieve a total net initial charge Qt of 1 to 3 mmol / kg. This adjustment is accomplished by mixing with one or more charge-balancing components to achieve charge balance. In the case of using the first additional lipid composition, the lipid feedstock having a high phosphorus content (i.e., a negative net initial charge) needs to be mixed with the first additional lipid composition having a suitably high metal content, such that the metal charge is slightly greater than the P charge in the resulting mixture.

[0049] The adjustment in step ii) is performed before the heat treatment step v). This adjustment can be performed before or after the removal of solid impurities in step iv), and when performing step iii), it can be performed before, simultaneously with, or after the optional adjustment of the free fatty acid (FFA) concentration in step iii). The net initial charge Qt before the heat treatment in step v) is required to be greater than 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, so that there is an excess of metal rather than an excess of phosphorus in the feedstock to be treated. The total net initial charge Qt of the feedstock to be treated is preferably slightly positive (meaning a metal excess) to ensure that dissolved phosphorus is converted to insoluble phosphorus compounds as much as possible during the heat treatment step. After the treatment of the present invention, a slight excess of metal in the feedstock can be addressed by removing the metal with a sufficient dose of acid in a subsequent purification step (if necessary). When the metal is in slightly excess compared to phosphorus (i.e., with a slightly positive total net charge), a good filtration flux is obtained in the subsequent decolorization step compared to the case of a negative total net charge.

[0050] The amount of charge-balancing component added will depend on the quality of the lipid feedstock (a), i.e. the amount of dissolved phosphorus present in the lipid feedstock and the molar ratio of dissolved phosphorus impurities to dissolved metal impurities in the lipid feedstock (i.e., the net elementary charge Q1 of the lipid feedstock (a)).

[0051] The charge-balancing component can be used as is, or particularly as an aqueous solution when it is a metal hydroxide, inorganic metal salt, and / or organometal salt. Aqueous solutions facilitate easier addition, mixing, and dispensing of the reagent to the lipid feedstock during processing. In aqueous solutions, the charge-balancing component can comprise 5 to 50 wt% of the total weight of the aqueous solution, such as about 6 wt%, about 10 wt%, or about 50 wt%. Even with relative dilution, the total volume of the aqueous solution remains low. In thermal treatments (HT), the low water content allows for lower-pressure HT reactor setups, which reduces costs and minimizes the hydrolysis of triglycerides into free fatty acids. Further advantages involve the separation of wastewater and aqueous phases generated upon disposal of solid waste.

[0052] Examples of suitable metal compounds for use as charge-balancing components include, but are not limited to, soaps, one or more alkali metal hydroxides, and / or one or more inorganic and organic alkali metal salts. Alkali metal hydroxides, such as NaOH or KOH, are preferred. The use of alkali metal hydroxides (especially NaOH) is particularly preferred.

[0053] Examples of suitable first additional lipid components for use as charge-balancing components include, but are not limited to, palm oil mill wastewater (POME), brown oil (BG), crude tall oil (CTO), and any mixture thereof.

[0054] When the adjustment of net charge in step ii) is completed before step iv), particularly by adding a metal hydroxide (such as an alkali metal hydroxide), the FFA concentration of the lipid feedstock in step iii) is advantageously adjusted to more than 2 wt% of the total weight of the resulting lipid feedstock to prevent the removal of the added (alkali) metal during solid removal step iv), since the addition of the (alkali) metal hydroxide may induce the formation of solids containing the (alkali) metal, thereby reversing the total net charge Qt of the lipid feedstock back to an undesirable level. When both the adjustment of net charge of the lipid feedstock in step ii) and the adjustment of FFA concentration of the lipid feedstock in step iii) are performed, they can be performed in any order equivalent to each other or even in a single step, particularly when a single lipid composition is used as a second additional lipid composition containing a suitable high content of one or more free fatty acids from step iii) and as a first additional lipid composition from step ii). In one embodiment, the FFA concentration of the lipid feedstock is adjusted in step ii) before the adjustment of net charge of the lipid feedstock in step iii). In an alternative embodiment, adjusting the net charge of the lipid feedstock in step ii) is performed before adjusting the FFA concentration of the lipid feedstock in step iii). In another alternative embodiment, adjusting the net charge of the lipid feedstock and adjusting the FFA concentration of the lipid feedstock are performed simultaneously.

[0055] Adjusting the concentration of free fatty acids

[0056] Optionally, the free fatty acid (FFA) concentration of the lipid feedstock can be adjusted to a predetermined level in step iii) before subjecting the lipid feedstock to solid impurity removal in step iv). Step iii) is particularly desirable when the adjustment of net charge in step ii) is completed before solid removal in step iv). Ideally, but preferably, the free fatty acid (FFA) composition of the lipid feedstock (a) is adjusted to more than 2 wt% of the total weight of the resulting lipid feedstock, such as 2 to 40 wt%. As shown in Example 3, this enhances the filtration performance of the lipid feedstock in removing solid impurities when step iv) is performed by filtration. Adjusting the FFA concentration also allows for the addition of one or more charge-balancing components (particularly metal hydroxides) early in the process without causing process fluctuations. This further enables the flexibility to use challenging lipid feedstocks and purify them to the low impurity levels required in downstream refining processes.

[0057] Preferably, the FFA concentration of the lipid feedstock is adjusted to at least 3 wt% of the total weight of the resulting lipid feedstock, such as 3 to 30 wt%, preferably to at least 4 wt% of the total weight of the lipid feedstock, such as 4 to 20 wt%, and more preferably to 4 to 10 wt% of the total weight of the resulting lipid feedstock. At concentrations of 2 wt% and below, filter clogging and loss of charge-balancing components can be observed. While there appears to be no upper limit to the FFA concentration of the lipid feedstock in terms of observing the desired effects, adjusting the FFA concentration far above the minimum required limit is economically impractical.

[0058] Adjusting the FFA concentration can be achieved by mixing the lipid feedstock with a lipid component containing or composed of one or more free fatty acids, such as with one or more free fatty acids and / or with a second additional lipid composition containing an appropriate high content of one or more free fatty acids. Examples of suitable free fatty acids include, but are not limited to, C. 13 To C 21Free fatty acids, such as palmitic acid, stearic acid, oleic acid, and linoleic acid. Examples of a second additional lipid composition containing a suitably high amount of one or more free fatty acids include, but are not limited to: soapstock acid oil (SAO), palm oil mill wastewater (POME), brown oil (BG), fatty acid distillate (FAD), and mixtures thereof. The free fatty acid concentration of the lipid composition containing a suitably high amount of one or more free fatty acids includes at least 30 wt% of the total weight of the lipid composition, such as 30 to 100 wt% free fatty acids, preferably at least 50 wt% of the total weight of the lipid composition, such as 50 to 80 wt% free fatty acids. Advantageously, POME is used as both the first additional lipid composition and the second additional lipid composition.

[0059] In this implementation, the desired FFA concentration is achieved by combining it with one or more free fatty acids.

[0060] The concentration of FFA can be defined according to ISO 660:2020, and it should be noted that potentiometric titration is preferred.

[0061] Removal of solid impurities

[0062] In step iv), the lipid feedstock is subjected to the removal of solid impurities from lipid feedstock (a), and optionally, the removal of excess water. Solid impurities removed in step iv) include, for example, salt, protein residues, bone meal, fiber, carbohydrates, and / or sand. Steps iv) and ii) can be performed in any order relative to each other. In one embodiment, the removal of solid impurities in step iv) can be completed before adjusting the net charge of the lipid feedstock in step ii). In an alternative embodiment, the adjustment of the net charge of the lipid feedstock in step ii) is completed before the removal of solid impurities in step iv). If the removal of solid impurities is completed after adjusting the net charge, step iii) is advantageously performed before the removal of solid impurities.

[0063] The removal of solid impurities can be accomplished by any suitable phase separation method applicable to the removal of solid impurities from lipid materials, including but not limited to sedimentation, centrifugation, filtration, and any combination of these methods, preferably centrifugation and / or filtration.

[0064] Particularly preferred methods for removing solid impurities involve filtering lipid feedstocks with a filter aid, known as filter aid filtration (FAF). Examples of suitable filter aid materials include, but are not limited to, any material comprising or composed of mineral, silicon, and / or cellulose-based materials, such as diatomaceous earth, diatomaceous mud, perlite, bentonite, palygorskite, kaolin, kaolinite, silica of various crystalline or amorphous configurations, sepiolite, magnesium silicate, silicon, alumina-based materials, zinc oxide-based materials, neutral decolorizing clay, activated carbon, activated charcoal, cellulose fibers, or any combination thereof. The filter aid material can be activated using methods known in the art.

[0065] Advantageously, the lipid feedstock is dried before filtration with the filter aid to prevent metals from leaching out of the filter aid material.

[0066] Alternatively, the lipid feedstock can be centrifuged in step iv). This is beneficial because both excess water and solid impurities can be removed from the lipid feedstock.

[0067] After removal of solid impurities, the lipid feedstock advantageously contains less than 0.5 wt% of insoluble impurities, such as 0 to 0.2 wt%, of the total weight of the lipid feedstock. Typically, reducing the amount of insoluble impurities in the lipid feedstock to below 0.1 wt% makes the lipid feedstock suitable for successful downstream processing, which enables smooth downstream phase separation operations after additional purification steps, such as filtration in a subsequent decolorization step.

[0068] The amount of insoluble impurities can be determined according to ISO 663:2017.

[0069] Heat treatment, step v)

[0070] After completing steps ii) to iv) as described above, in step v), the conditioned lipid feedstock thus obtained is subjected to heat treatment at a temperature of at least 180°C, such as 180°C to 325°C, preferably at least 200°C, such as 200°C to 325°C, preferably at least 220°C, such as 220°C to 325°C, more preferably at least 270°C, such as 270°C to 300°C, and most preferably at least 280°C, such as 280°C to 290°C. This heat treatment promotes the separation of impurities such as phosphorus as solid precipitates. Temperatures above 180°C promote the formation of solid waste from the lipid material. At temperatures above 325°C, thermal decomposition of the components can begin to be observed.

[0071] The heat treatment in step v) can be carried out at a pressure of 100 to 5100 kPa(a), preferably 150 to 2100 kPa(a), more preferably 200 to 600 kPa(a), and most preferably 300 to 500 kPa(a). Those skilled in the art will be able to adjust the time to suit the intended purpose and understand that increasing the pressure minimizes the loss of lipid material in the heat treatment step.

[0072] The residence time in heat treatment step v) can range from a few minutes to a few hours, depending on the temperature. Those skilled in the art will be able to adjust the time to suit the intended purpose, understanding that a shorter residence time is sufficient at higher temperatures. In one embodiment, the residence time is from 5 to 120 minutes.

[0073] The total net charge Qt of the conditioning lipid feedstock treated under heat treatment conditions must be within the range required in step ii), i.e., at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg. If any pretreatment step after step ii) and before step v) changes the total net charge Qt, then the total net charge Qt must be further adjusted before the start of heat treatment step v). However, it is desirable that only one adjustment be made to step ii), and any changes in the total net charge Qt during intermediate steps should be accounted for at this stage by over-adjusting the net charge as needed, but within the range defined therein.

[0074] Advantageously, the mixture processed in heat treatment step v) contains at least a small amount of water. This mixture advantageously contains less than 10 wt%, preferably less than 5 wt%, such as 0.05 wt% to 2 wt%, preferably less than 1.5 wt%, such as 0.2 wt% to 1.5 wt%, more preferably less than 0.5 wt% of water by weight of the total mixture. Typically, the amount of water dissolved in the lipid feedstock is sufficient, and no additional water is added. Maintaining a low water content helps avoid emulsification and allows for lower processing pressures, particularly when the water content is maintained at less than 1 wt%, or preferably less than 0.5 wt%, of the total weight of the mixture.

[0075] The heat treatment in step v) can be carried out in any suitable reactor, where the indicated conditions can be achieved. Examples of suitable reactors include mixing reactors and / or tubular reactors. Additionally, the heat treatment in step v) can be performed in one or more batches and / or in a continuous mode.

[0076] Generally, it is advantageous to enhance the contact and transfer between the charge-balancing component and the lipid feedstock during heat treatment. Therefore, in a preferred embodiment, mixing is provided.

[0077] Following the heat treatment in step v), a heat-treated lipid feedstock (c) is obtained. The heat-treated lipid feedstock (c) can then be directly subjected to recovery via phase separation in step vii) and / or can be further purified in step vi) by treatment with acid and / or adsorbent material.

[0078] Further processing, step vi)

[0079] In step vi), particularly under decolorization conditions, the heat-treated lipid feedstock (c) is optionally further purified by treating it with acid and / or an adsorbent material to obtain a further-treated lipid feedstock (d). Further purification of the heat-treated lipid feedstock (c) is particularly advantageous for lipid feedstock (a) with a high content of phosphorus and / or metal impurities.

[0080] Further treatment with acid and / or adsorbent materials aims to minimize the content of impurities in the treated material, such as pigments (e.g., carotenoids and chlorophyll), metals, and / or phosphorus. This involves contacting, and particularly mixing, the material to be treated with the acid and / or adsorbent material. Further treatment in step vi) can be carried out in the presence of an acid (such as citric acid and / or phosphoric acid and / or an acidic or acid-activated adsorbent). Furthermore, further treatment in step vi) is typically carried out in the presence of a small amount of water. Advantageously, in step vi), decolorizing earth or other adsorbents (such as silica) can be added to the heat-treated lipid feedstock (c) to adsorb impurities (such as residual metals and / or phosphorus).

[0081] Further processing is preferably carried out under decolorization conditions. The decolorization conditions can be selected by a technician. Typically, the temperature in further processing step vi) can be, for example, in the range of 80°C to 120°C. Additionally, the pressure is typically close to atmospheric pressure, such as 60 kPa(a) to 600 kPa(a), preferably 80 kPa(a) to 200 kPa(a).

[0082] Before further processing in step vi) and after heat treatment in step v), the heat-treated lipid feedstock (c) can be subjected to solids removal, and waste containing impurities can be discarded. Solid impurities formed during heat treatment can be phase-separated based on the lipid material forming its own phase (i.e., the oil phase), wherein any impurities containing aqueous waste and / or solid waste can be removed from the oil phase by conventional separation unit processes. Therefore, the term "phase separation," as used herein and hereinafter, refers to both liquid-liquid phase separation and liquid-solid phase separation. Suitable phase separation methods include, but are not limited to, filtration, centrifugation, sedimentation, and any combination thereof.

[0083] Prior to further processing in step vi), the heat-treated purified lipid material may be additionally or alternatively subjected to drying, particularly evaporation under conditions capable of removing water vapor from the heat-treated purified lipid material. However, the evaporation conditions are controlled so that low-boiling-point components, such as the low-boiling-point fatty acids of the lipid material, are not lost. According to embodiments including evaporation, evaporation can be carried out at a temperature of 50°C to 130°C and a pressure of 1 to 100 kPa(a). For example, a combination of a temperature of 105°C and a pressure of 8 kPa(a) can be applied to evaporation.

[0084] Preferably, the heat-treated raw material is subjected directly to step vi) without intermediate recycling.

[0085] Recycling, step vii)

[0086] Following the heat treatment in step v) and / or the optional further treatment in step vi), the heat-treated lipid feedstock (c) and / or the further-treated lipid feedstock (d) are subjected to phase separation (preferably filtration) to remove solids and coagulated and / or precipitated impurities, thereby providing purified lipid feedstock (e). With phase separation achieved by filtration, the aforementioned steps allow for smooth operation.

[0087] Solid impurities formed in heat treatment step v) and / or further treatment step vi), as well as solid adsorbent material from step vi), can be phase separated based on the lipid material forming its own phase (i.e., the oil phase), wherein any impurities containing aqueous waste and / or solid waste can be removed from the oil phase by conventional separation unit processes. Therefore, the term "phase separation," as used herein and hereinafter, refers to both liquid-liquid phase separation and liquid-solid phase separation. Suitable phase separation methods include, but are not limited to, filtration, centrifugation, sedimentation, and any combination thereof.

[0088] Phase separation is preferably accomplished by filtration. Filtration can be performed by any means deemed suitable for this purpose by those skilled in the art.

[0089] Before or after phase separation, the heat-treated lipid feedstock (c) and / or further-treated lipid feedstock (d) can be subjected to drying, particularly evaporation, under conditions that allow water vapor to be removed from the lipid feedstock. However, the evaporation conditions are controlled so that low-boiling-point components, such as low-boiling-point fatty acids of the lipid material, are not lost. Typically, evaporation can be carried out at temperatures from 50°C to 130°C and pressures from 1 to 100 kPa(a). For example, a combination of a temperature of 105°C and a pressure of 8 kPa(a) can be applied to evaporation.

[0090] The purified lipid feedstock thus obtained typically contains residual phosphorus and metals, both below 30 mg / kg, preferably below 2.0 mg / kg, and more typically close to 1.0 mg / kg. Compared to lipid feedstock (a), the reduction in phosphorus impurities is typically greater than 90% and the reduction in metal impurities is greater than 95%, excluding any dilution of lipid feedstock (a) due to the addition of one or more charge-balancing components and / or adjustment of FFA with one or more lipid components. Actual purification results depend on the quality of the initial feedstock.

[0091] Figure 1 shows a first exemplary process flow diagram of the method of the present invention. The process flow illustrated in Figure 1 is particularly suitable for lipid feedstocks with a total net charge Q1 of less than 0 mmol / kg and a free fatty acid concentration of 2 wt% or less (especially less than 3 wt%).

[0092] Referring to Figure 1, the feed of lipid feedstock 1 is subjected to a step of adjusting the net initial charge of the lipid feedstock 10 with charge balancing component 2 to obtain a charge-balanced lipid feedstock 11 as discussed herein with respect to step ii). The charge-balanced lipid feedstock 11 is then subjected to a step of adjusting the free fatty acid concentration of the charge-balanced lipid feedstock 11 20 with FFA component 3 to obtain an FFA-adjusted and charge-balanced lipid feedstock 12 as discussed herein with respect to step iii). The FFA-adjusted and charge-balanced lipid feedstock 12 is then subjected to a step of removing solid impurities 30, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a conditioning lipid feedstock 13 with a total net initial charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. The conditioning lipid feedstock 13 is then preferably subjected to a step of heating 40 in the presence of water at a temperature of 180°C to 325°C, as discussed herein with respect to step v), to obtain a heat-treated lipid feedstock 41. The heat-treated lipid feedstock can then optionally be subjected to a further treatment 70 step with acid and / or adsorbent material 71, such as under decolorizing conditions, to further purify the heat-treated lipid feedstock 41 as discussed herein with respect to step vi), thereby obtaining a further treated lipid feedstock 43. Optionally, prior to the further treatment 70, the heat-treated lipid feedstock 41 can be subjected to a phase separation 60 step to remove the solid material 69 contained in the heat-treated lipid feedstock 41, thereby obtaining a solids-depleted heat-treated lipid feedstock 42, which is then subjected to further treatment 70 to obtain a further treated lipid feedstock 43. The heat-treated lipid feedstock 41 and / or the further treated lipid feedstock 43 are subjected to a phase separation (preferably filtration) 50 step to obtain a purified lipid feedstock 51.

[0093] Figure 2 illustrates a second exemplary process flow of the method of the present invention. The process flow illustrated in Figure 2 is particularly suitable for lipid feedstocks with a total net charge Q1 of less than 0 mmol / kg and a free fatty acid concentration of 2 wt% or less (especially less than 3 wt%).

[0094] Referring to Figure 2, the feedstock of lipid feedstock 1 is subjected to a step of adjusting the free fatty acid concentration of lipid feedstock 1 by lipid component 3 to obtain an FFA-adjusted lipid feedstock 14 as discussed herein with respect to step iii). The FFA-adjusted lipid feedstock 14 is then subjected to a step of adjusting the net charge of the FFA-adjusted lipid feedstock 14 by charge balancing component 2 to obtain an FFA-adjusted and charge-balanced lipid feedstock 12 as discussed herein with respect to step ii). The FFA-adjusted and charge-balanced lipid feedstock 12 is then subjected to a step of removing solid impurities 39, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a conditioning lipid feedstock 13 with a total net charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. Then, preferably in the presence of water, at a temperature of 180°C to 325°C, as discussed herein with respect to step v), the conditioning lipid raw material 13 is subjected to a heating 40 step to obtain a heat-treated lipid raw material 41. The heat-treated lipid raw material can then optionally be subjected to a further treatment 70 step with acid and / or adsorbent material 71, such as under decolorizing conditions, to further purify the heat-treated lipid raw material 41 as discussed herein with respect to step vi), thereby obtaining a further-treated lipid raw material 43. Optionally, prior to the further treatment 70, the heat-treated lipid raw material 41 can be subjected to a phase separation 60 step to remove solid material 69 contained in the heat-treated lipid raw material 41, thereby obtaining a solids-depleted heat-treated lipid raw material 42, which is then subjected to a further treatment 70 to obtain a further-treated lipid raw material 43. The heat-treated lipid raw material 41 and / or the further-treated lipid raw material 43 are subjected to a phase separation (preferably filtration) 50 step to obtain a purified lipid raw material 51.

[0095] Figure 3 illustrates a third exemplary process flow of the method of the present invention. The process flow illustrated in Figure 3 is particularly suitable for lipid feedstocks with a total net charge Q1 of less than 0 mmol / kg and a free fatty acid concentration of 2 wt% or less (especially less than 3 wt%).

[0096] Referring to Figure 3, the feed of lipid feedstock 1 is subjected to a step of adjusting the free fatty acid concentration and net charge of lipid feedstock 1 by a second lipid feedstock 4 representing the FFA component and charge-balancing component as discussed herein with respect to steps ii) and iii), to obtain an FFA-adjusted and charge-balanced lipid feedstock 14. The FFA-adjusted and charge-balanced lipid feedstock 14 is then subjected to a step of removing solid impurities 39, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a conditioning lipid feedstock 13 with a total net charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. The conditioning lipid feedstock 13 is then preferably subjected to a heating step 40 in the presence of water at a temperature of 180°C to 325°C, as discussed herein with respect to step v), to obtain a heat-treated lipid feedstock 41. The heat-treated lipid feedstock can then optionally be subjected to a further treatment 70 step with acid and / or adsorbent material 71, such as under decolorizing conditions, to further purify the heat-treated lipid feedstock 41 as discussed herein with respect to step vi), thereby obtaining a further treated lipid feedstock 43. Optionally, prior to the further treatment 70, the heat-treated lipid feedstock 41 can be subjected to a phase separation 60 step to remove the solid material 69 contained in the heat-treated lipid feedstock 41, thereby obtaining a solids-depleted heat-treated lipid feedstock 42, which is then subjected to further treatment 70 to obtain a further treated lipid feedstock 43. The heat-treated lipid feedstock 41 and / or the further treated lipid feedstock 43 are subjected to a phase separation (preferably filtration) 50 step to obtain a purified lipid feedstock 51.

[0097] Figure 4 illustrates a fourth exemplary process flow of the method of the present invention. The process flow illustrated in Figure 4 is particularly suitable for lipid feedstocks with a net initial charge Q1 of less than 0 mmol / kg and a free fatty acid concentration of more than 2 wt%.

[0098] Referring to Figure 4, the feedstock of lipid feedstock 1 is subjected to a step of adjusting the net charge of the lipid feedstock by charge balancing component 2 to obtain a charge-balanced feedstock 12 as discussed herein with respect to step ii). The charge-balanced lipid feedstock 12 is then subjected to a step of removing solid impurities 39, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a conditioning lipid feedstock 13 with a total net charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. The conditioning lipid feedstock 13 is then preferably subjected to a heating step 40 in the presence of water at a temperature of 180°C to 325°C, as discussed herein with respect to step v), to obtain a heat-treated lipid feedstock 41. Optionally, the heat-treated feedstock may be subjected to a further treatment step 70, wherein the heat-treated lipid feedstock 41 is further purified using acid and / or adsorbent material 71, such as under decolorizing conditions, as discussed herein with respect to step vi), to obtain a further treated lipid feedstock 43. Optionally, prior to further treatment 70, the heat-treated lipid feedstock 41 may be subjected to a phase separation step 60 to remove solid material 69 contained in the heat-treated lipid feedstock 41, thereby obtaining a solids-depleted heat-treated lipid feedstock 42, which is then subjected to further treatment 70 to obtain a further treated lipid feedstock 43. The heat-treated lipid feedstock 41 and / or the further treated lipid feedstock 43 may be subjected to a phase separation (preferably filtration) step 50 to obtain a purified lipid feedstock 51.

[0099] Figure 5 illustrates a fifth exemplary process flow diagram of the method of the present invention. The process flow illustrated in Figure 5 is particularly suitable for lipid feedstocks with a net initial charge Q1 of less than 0 mmol / kg.

[0100] Referring to Figure 5, the feedstock of lipid raw material 1 is subjected to a step of removing solid impurities 30, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a lipid raw material 15 with reduced solids. The solid-depleted lipid raw material is then subjected to a step of adjusting the net charge of the solid-depleted lipid raw material 15 with charge balancing component 2 10, to obtain a conditioning lipid raw material 13 with a total net charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. The conditioning lipid raw material 13 is then preferably subjected to a heating 40 step of conditioning lipid raw material 13 in the presence of water at a temperature of 180°C to 325°C, as discussed herein with respect to step v), to obtain a heat-treated lipid raw material 41. Optionally, the heat-treated raw material may be subjected to a further treatment 70 step, wherein the heat-treated lipid raw material 41 is further purified using acid and / or adsorbent material 71, such as under decolorizing conditions, as discussed herein with respect to step vi), to obtain a further treated lipid raw material 43. Optionally, prior to further processing 70, the heat-treated lipid feedstock 41 may be subjected to a phase separation 60 step to remove solid material 69 contained in the heat-treated lipid feedstock 41, thereby obtaining a solid-depleted heat-treated lipid feedstock 42, which is then subjected to further processing 70 to obtain a further processed lipid feedstock 43. The heat-treated lipid feedstock 41 and / or the further processed lipid feedstock 43 may be subjected to a phase separation (preferably filtration) 50 step to obtain a purified lipid feedstock 51.

[0101] Figure 6 illustrates a sixth exemplary process flow of the method of the present invention. The process flow illustrated in Figure 6 is particularly suitable for lipid feedstocks with a net initial charge Q1 greater than 0 mmol / kg and a free fatty acid concentration greater than 2 wt%.

[0102] Referring to Figure 6, the feedstock of lipid feedstock 1 is subjected to a solid impurity removal step 30, preferably by filtration with a filter aid, as discussed herein with respect to step iv), to obtain a conditioning lipid feedstock 13 with a total net charge Qt greater than 0 mmol / kg, preferably 0.5 mmol / kg, such as 0.5 to 3 mmol / kg. The conditioning lipid feedstock 13 is then subjected to a heating step 40, preferably in the presence of water, at a temperature of 180°C to 325°C, as discussed herein with respect to step v), to obtain a heat-treated lipid feedstock 41. Optionally, the heat-treated feedstock may be subjected to a further treatment step 70, wherein the heat-treated lipid feedstock 41 is further purified using an acid and / or an adsorbent material 71, such as under decolorizing conditions, as discussed herein with respect to step vi), to obtain a further treated lipid feedstock 43. Optionally, prior to further processing 70, the heat-treated lipid feedstock 41 may be subjected to a phase separation 60 step to remove solid material 69 contained in the heat-treated lipid feedstock 41, thereby obtaining a solid-depleted heat-treated lipid feedstock 42, which is then subjected to further processing 70 to obtain a further processed lipid feedstock 43. The heat-treated lipid feedstock 41 and / or the further processed lipid feedstock 43 may be subjected to a phase separation (preferably filtration) 50 step to obtain a purified lipid feedstock 51.

[0103] Hydrogenation treatment of purified lipid raw materials

[0104] After purification of the lipid feedstock according to the purification methods discussed herein, the lipid feedstock can be used as is and / or subjected to further value-added treatments, such as hydrotreating, to obtain renewable hydrocarbons, such as one or more ready-to-use renewable fuels, one or more renewable fuel components, and / or other valuable renewable hydrocarbon products. Such catalytic upgrading processes include, but are not limited to: catalytic cracking, catalytic hydrocracking, thermocatalytic cracking, catalytic hydrotreating, fluidized bed catalytic cracking, catalytic ketylation, and catalytic esterification. These processes require the liquid feedstock to be sufficiently pure and free of impurities; otherwise, these impurities may hinder the catalytic process or deactivate or poison one or more catalysts present in the process.

[0105] Therefore, purified lipid feedstocks can be subjected to post-processing, including hydrogenation.

[0106] Therefore, this article provides an application for using purified lipid feedstock obtained from the purification methods described herein as feedstock for at least one catalytic hydrogenation process to obtain renewable hydrocarbons. Additionally, purified lipid feedstock obtained from the purification methods described above can be used as feedstock for the production of fatty acids and / or soaps.

[0107] Furthermore, this article provides a method for providing renewable hydrocarbons, the method comprising: x) purifying a lipid feedstock to obtain a purified lipid feedstock as described above, and y) subjecting the purified lipid feedstock to hydrogenation treatment (preferably catalytic hydrogenation treatment) to obtain at least one renewable hydrocarbon.

[0108] The lipid feedstock is a lipid feedstock as defined herein. Preferably, the lipid material may comprise streams known to have high phosphorus, metal, and / or solid impurity contents, such as SAO, AFP, and LQAF.

[0109] Hydrotreating (preferably catalytic hydrotreating) can be any upgrading process employing hydrogen, wherein lipid materials can be used as process feedstocks, optionally in conjunction with co-feeds. For example, hydrotreating can be an upgrading process to obtain liquid transport fuel components, solvents, industrial fluids (such as electrical fluids), fatty alcohols, cracking feedstocks (such as feedstocks for thermal cracking and / or catalytic cracking), and basic chemicals for various synthesis. Preferably, the hydrotreating is catalytic hydrotreating.

[0110] According to one implementation, fossil-derived co-feed is fed into a catalytic hydrogenation process.

[0111] Hydrogenation treatment can include altering molecular weight, removing heteroatoms, altering saturation, rearranging molecular structure, or any combination thereof. Hydrogenation treatment preferably includes: altering the molecular weight of the process feed or any intermediate stream or intermediate product from which it can be derived; removing heteroatoms from the process feed or any intermediate stream or intermediate product from which it can be derived; altering the saturation of the process feed or any intermediate stream or intermediate product from which it can be derived; rearranging the molecular structure of the process feed or any intermediate stream or intermediate product from which it can be derived; or any combination thereof.

[0112] In some preferred embodiments, hydrotreating includes hydrotreating, isomerizing and / or cracking the process feed or intermediate stream or intermediate product from or derived therefrom, preferably hydrodeoxygenation (HDO), hydroisomerization (HI) and / or hydrocracking (HC), optionally followed by fractionation.

[0113] In some preferred embodiments, catalytic hydrotreating includes converting lipid materials into one or more ready-to-use liquid transport fuels, one or more liquid transport fuel components, and / or one or more other valuable hydrocarbon product chemicals. The method includes subjecting the process feed to hydrotreating, including hydrodeoxygenation, hydroisomerization, and optionally hydrocracking; subsequently fractionating the hydrotreating effluent and recovering one or more ready-to-use liquid transport fuels, one or more liquid transport fuel components, and / or other valuable hydrocarbon products from the fraction.

[0114] According to one embodiment, catalytic hydrotreating includes one or more of hydrodeoxygenation, hydroisomerization, hydrocracking, hydrodenitrogenation, hydrodesulfurization, hydrodehalogenation, hydroaromatication, and double bond hydrogenation. High metal content in the feed often leads to deactivation of catalysts typically used in these processes. With this in mind, it is particularly advantageous that the content of the metal charge-balancing component added in step ii) can be kept relatively low.

[0115] Catalytic hydrogenation can be carried out under conditions selected from the following catalysts: any one of Pd, Pt, Ni, Co, Mo, Ru, Rh, W, or combinations thereof such as CoMo, NiMo, NiW, CoNiMo, NiMoW, or in combination with SAPO-11, SAPO-41, ZSM-22, ZSM-23, ZSM-12, ZSM-48, ZSM-5, β-type zeolites, magnesium alkali zeolites and mixtures thereof (such as Pt / SAPO-11 / Al2O3, Pt / ZSM-22 / Al2O3, Pt / ZSM-23 / Al2O3, Pt / SAPO-11 / SiO2), which are optionally supported on a support, wherein the support preferably comprises alumina and / or silica.

[0116] experiment

[0117] FFA content in feed: The FFA concentration in all samples was analyzed using gel permeation chromatography (GPC) according to ISO 660:2020. Samples were analyzed after dilution in tetrahydrofuran. Components in the samples (oligomers, fatty acids, monoglycerides, diglycerides, triglycerides, and other compounds such as hydrocarbons) were identified by their retention times.

[0118] Analysis of phosphorus and metal impurities: The concentrations of phosphorus and metals in all samples were analyzed by first digesting the samples with acid in a microwave oven to obtain a clear water / acid matrix (by visual assessment), then diluting it to a known level and analyzing it using ICP-MS / MS (tandem inductively coupled plasma mass spectrometry) with acid-based calibration. Metals detected by this method included Li, B, Na, Mg, Al, P, K, Ca, Ti, V, Ch, Mn, Fe, Co, Ni, Cu, Zn, As, Mb, Cd, Sn, and Ba.

[0119] Example 1: The effect of charge balance on purification and filtration.

[0120] Low-quality animal fat (LQAF) feedstock and two different waste cooking oil (UCO) samples were subjected to solids removal, heat treatment (with and without net charge adjustment), followed by filtration or decolorization (treatment with acid and adsorbent followed by filtration). All feedstock samples were obtained from commercial sources.

[0121] Solids removal: For UCO samples, centrifugation (4300 RPM, 80°C, 30 min) or filter aid filtration for LQAF was used to remove solids from the crude feed. Commercial diatomaceous earth filter aid (1 wt%) was added to the sample for filter aid filtration. Before filtration, the sample was treated with 1 kg / m³ of [a specific solution / method / approach]. 2 The same filter aid and refined, decolorized, and deodorized palm oil (RBDPO) were used to create a pre-coating on the filter screen. The sample was filtered using a pressure filtration system at 85°C and 2.5 bar.

[0122] The net elementary charge of the feed sample was adjusted by adding 10 wt% NaOH aqueous solution to achieve the positive total elementary charge (+1 or +5) shown in Table 1. Other charge values ​​(-7.3, -0.3, and +0.3) refer to the natural net elementary charge of the filter feed.

[0123] Heat treatment was carried out in a 1-liter pressure reactor with a heating program of 280°C for 30 minutes (LQAF) or 250°C for 60 minutes (UCO sample), an initial pressure of 300 kPa(a) (nitrogen), and a mixing rate of 500 rpm. The heat-treated raw material was further filtered or decolorized (treated with acid and adsorbent and then filtered).

[0124] After heat treatment, the heat-treated raw material is filtered by filtering it through 0.45 μm filter paper at 80°C.

[0125] Decolorization is achieved by adding citric acid, water, and a decolorizing earth adsorbent to the heat-treated feedstock. Typically, for UCO, 800 mg / kg citric acid (added as a 50 wt% aqueous solution) and 0.9 wt% water are added to the oil, followed by mixing at 8000 rpm for 2 min at 85°C. Then, 0.7 wt% decolorizing earth is added and a pressure of 800 mbar is applied, and mixing continues for 20 min. Next, the sample is dried by reducing the pressure to 80 mbar and raising the temperature to 105°C, and mixing continues for 10 min at the elevated temperature. Finally, the reaction mixture is filtered through a pre-coating of decolorizing earth at 105°C and a pressure of 350 kPa(a) (nitrogen). For LQAF, the procedure is the same, but 3300 mg / kg citric acid and 0.8 wt% water, along with 1.0 wt% decolorizing earth, are used.

[0126] The impurity levels of the feed and samples after solid removal, charge adjustment, and decolorization, as well as the number of decolorization filtrations, are shown in Table 1.

[0127] Table 1. P and major metal (Al, Ca, Fe, K, Mg, Na) levels in LQAF and UCO samples after solid removal, adjustment of elementary charge, heat treatment, and filtration or decolorization and decolorization filtration time.

[0128]

[0129] The results in Table 1 show that phase separation by filtration after heat treatment results in good removal of phosphorus impurities; however, decolorization is recommended for optimal metal removal.

[0130] When the raw materials entering the heating step are conditioned to have a positive net charge, the filtration performance of the heat-treated raw materials treated with acid and adsorbent in the decolorization process is significantly improved (the filtration time in the filtration step is shorter).

[0131] Table 2 shows the purification results of LQAF under different pretreatment protocols. The decolorization protocols were the same as those described previously in all cases.

[0132] Table 2. Comparison of different pretreatment schemes for LQAF purification.

[0133]

[0134] Table 2 shows that when LQAF raw materials have undergone net charge adjustment and heat treatment before decolorization, the purification effect after decolorization is significantly improved.

[0135] Example 3. Effect of FFA in the feed on filtration performance in solid removal step iv) after charge balancing with NaOH.

[0136] 1100 ppm of charge-balancing component NaOH (added as a 50 wt% aqueous solution, approximately 630 ppm Na) was added to feed samples containing different levels of FFA (after adjusting the FFA concentration). Before adding the charge-balancing component, the net charge of the feed samples was -13 mmol / kg. After adding NaOH, the mixture was first mixed at 8000 rpm for 2 min using a high-shear mixer, followed by mixing at 250 rpm for 5 min at 70°C using a magnetic stirrer. 0.5 wt% of filter aid (diatomaceous earth) was added to the sample, and the mixture was maintained at 105°C and 800 mbar for 20 min, then passed through a pre-coated layer of filter aid (1 kg / m³) at 105°C and 1 bar. 2Filtration was performed. The filtration time required to filter 150 g of sample was recorded. The filtration times for samples with different FFA contents are presented in Table 3. It was observed that when the feed FFA concentration was adjusted to 3 wt% FFA or higher, the filtration process ran smoothly, and the charge balance component was recovered in the filtrate (the original Na concentration of the blend was 40 ppm, and the added Na was approximately 630 ppm), and a conditioned feedstock (net elementary charge of approximately +10 mmol / kg) was obtained. However, the feedstock with 2 wt% FFA had a very poor filtration flux, and it was noted that most of the charge balance component was lost (manifested as low sodium content in the filtrate), resulting in an elementary charge of the feedstock of less than 0 mmol / kg (-3.5 mmol / kg).

[0137] These blends were subjected to heat treatment followed by decolorization after filtration with filter aid. Treatment of blends with a net charge greater than 0 mmol / kg yielded excellent impurity removal, while blends that lost charge balance components during filtration (blended blends with 2 wt% FFA) resulted in significantly lower removal rates of P and metals.

[0138] Table 3. .

Claims

1. A method for purifying a lipid raw material (a), the method comprising: i) providing the lipid source (a); ii) when the net initial charge Q1 of the lipid source (a) is less than 0 mmol / kg, adjusting the net initial charge of the lipid source (a) to at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, to a total net initial charge Qt; iii) optionally adjusting the free fatty acid (FFA) concentration of the lipid source (a) to more than 2 wt% of the total weight of the resulting lipid source, such as 2.5 to 40 wt%, preferably at least 3 wt%, such as 3 to 30 wt%, more preferably at least 4 wt%, such as 4 to 20 wt%, even more preferably 4 to 10 wt%. wt%; and iv) removing solid impurities and optionally excess water from the lipid raw material (a); to obtain a conditioning lipid raw material (b) having a total net elementary charge Qt within the value defined in step ii); v) heating the conditioning lipid raw material (b) at a temperature of 180°C to 325°C, preferably in the presence of water, to obtain a heat-treated lipid raw material (c); vi) preferably further treating the heat-treated lipid raw material (c) with acid and / or adsorbent material under decolorization conditions to obtain a further treated lipid raw material (d); and vii) recovering the heat-treated lipid raw material (c) and / or the further treated lipid raw material (d) by phase separation, preferably by filtration, to obtain a purified lipid raw material (e).

2. The method according to claim 1, wherein, The lipid feedstock comprises at least 5 mg / kg, such as 5 to 5000 mg / kg, preferably at least 15 mg / kg, such as 15 to 2000 mg / kg, of dissolved phosphorus impurities, measured in terms of elemental phosphorus and elemental metals, and at least 10 mg / kg, such as 10 to 10000 mg / kg, preferably at least 20 mg / kg, such as 20 to 3000 mg / kg, of dissolved metal impurities.

3. The method according to claim 1 or 2, wherein, The lipid raw materials are selected from the group consisting of: soapstock oil (SAO), low quality animal fat grade (LQAF), unused edible oil (UCO), palm oil mill wastewater (POME) and mixtures thereof.

4. The method according to any one of claims 1 to 3, wherein, The lipid feedstock has a net charge of less than 0 mmol / kg, such as -60 to -0.5 mmol / kg, particularly less than -0.5 mmol / kg, such as -30 to -1 mmol / kg.

5. The method according to claim 4, wherein, The method comprises the following steps: i) providing the lipid source (a) having a net initial charge of less than 0 mg, such as -60 to -0.5 mmol / kg, particularly less than -0.5 mmol / kg, such as -30 to -1 mmol / kg; ii) adjusting the total net initial charge Q1 of the lipid source (a) to at least 0 mmol / kg, such as 0 to 10 mmol / kg, preferably at least 0.5 mmol / kg, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg, by mixing the lipid source (a) with a charge-balancing component comprising or composed of a metal compound; iii) optionally adjusting the concentration of free fatty acids (FFA) of the lipid source (a) to more than 2 wt% of the total weight of the resulting lipid source, such as 2.5 to 40 wt%, preferably at least 3 wt%, such as 3 to 30 wt%, more preferably at least 4 wt%, such as 4 to 20 wt%, even more preferably at least 5 wt%, such as 5 to 10 wt%. wt%; and iv) removing solid impurities and optionally excess water from the lipid raw material (a); to obtain a conditioning lipid raw material (b) having a total net elementary charge Q1 within the value defined in step ii); v) heating the conditioning lipid raw material (b) at a temperature of 180°C to 325°C, preferably in the presence of water, to obtain a heat-treated lipid raw material (c); vi) preferably further treating the heat-treated lipid raw material (c) with acid and / or adsorbent material under decolorization conditions to obtain a further treated lipid raw material (d); and vii) recovering the heat-treated lipid raw material (c) and / or the further treated lipid raw material (d) by phase separation to obtain a purified lipid raw material (e).

6. The method according to any one of claims 1 to 5, wherein, In step iii), the FFA concentration is adjusted to a predetermined level, and then in step iv), the lipid feedstock is subjected to the removal of solid impurities.

7. The method according to any one of claims 1 to 6, wherein, By mixing the lipid raw material with one or more free fatty acids and / or with a second additional lipid composition containing a suitable high content of one or more free fatty acids, preferably with C 13 To C 21 Free fatty acids such as palmitic acid, stearic acid, oleic acid and linoleic acid and / or lipid compositions selected from soapstock oil (SAO), palm oil mill wastewater (POME), brown oil (BG) and fatty acid distillates (FAD) and mixtures thereof are used to adjust the FFA concentration.

8. The method according to claim 7, wherein, The second additional lipid composition is selected from soapstock acid oil (SAO), palm oil mill wastewater (POME), brown oil (BG), fatty acid distillate (FAD), and mixtures thereof.

9. The method according to any one of claims 1 to 8, wherein, The charge balance component is selected from the group consisting of metal hydroxides and / or metal salts, preferably from alkali metal hydroxides and / or alkali metal salts, and more preferably from NaOH or NaOH aqueous solution.

10. The method according to any one of claims 1 to 8, wherein, The charge-balancing component is the same as the second additional lipid composition.

11. The method according to any one of claims 1 to 10, wherein, The net charge of the conditioning lipid raw material (b) is at least 0.5 mmol / kg as determined in the specification, such as 0.5 to 5 mmol / kg, more preferably at least 1 mmol / kg, such as 1 to 3 mmol / kg.

12. The method according to any one of claims 1 to 11, wherein, In step iv), the removal of solid impurities is accomplished by sedimentation, centrifugation, and / or filtration with a filter aid.

13. The method according to any one of claims 1 to 11, wherein, In step iv), the removal of solid impurities is accomplished by filtration with a filter aid.

14. The method according to any one of claims 1 to 13, wherein, vi) Contact the heat-treated lipid raw material (c) with an acid and / or an adsorbent material, preferably under decolorization conditions, to obtain a further treated lipid raw material (d).

15. The method according to claim 14, wherein, Step iv) is performed at a temperature of 80°C to 120°C and a pressure of 60 kPa(a) to 600 kPa(a), preferably 80 kPa(a) to 200 kPa(a).

16. A method for producing renewable hydrocarbons, comprising x) purifying a lipid feedstock (a) according to any one of claims 1 to 15 to obtain a purified lipid feedstock (d); and y) subjecting the purified lipid feedstock (d) to hydrogenation to obtain at least one renewable hydrocarbon.

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