Process for removing chlorides from lipid feedstocks using regenerated catalysts

Abstract

In one embodiment, a method includes sequentially treating a plurality of lipid feedstocks comprising a set of lipid feedstocks each having a chloride content of at least about 2 ppm with a metal oxide catalyst on an oxide support under first treatment conditions to produce respective treatment streams of the set of lipid feedstocks having a chloride content of less than 1 ppm, the metal oxide catalyst is converted to a spent metal oxide catalyst, converting the spent metal oxide catalyst to a regenerated metal oxide catalyst, and under a second treatment condition, separating the regenerated metal oxide catalyst from the spent metal oxide catalyst, one or more other lipid feedstocks each having a chloride content of at least about 2 ppm are treated with a regenerated metal oxide catalyst to produce one or more respective treated streams each having a chloride content of less than 1 ppm.

Description

[0001] Priority Statement

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 462,300, filed April 27, 2023, entitled “Method for Removing Chloride from Lipid Feedstock Using a Regenerating Catalyst,” the contents of which are incorporated herein by reference in their entirety. Background Technology

[0003] There is a growing interest in alternative feedstocks that can partially replace crude oil in the production of hydrocarbons suitable as fuels or fuel components, such as transportation fuels or fuel-compatible hydrocarbons. Biofuels are typically made from feedstocks derived from renewable sources, including oils and fats obtained from plants, animals, algae, fish, and various waste streams, sidestreams, and sewage sludge. These feedstocks, particularly various waste streams and sidestreams, contain varying amounts of contaminants such as gums, organochlorine compounds, phospholipids and other phosphorus compounds, metals and metal compounds, and residual soaps, which are harmful to conversion catalysts, for example. Summary of the Invention

[0004] According to the illustrative implementation plan, the method includes:

[0005] Under the first processing conditions, multiple lipid feedstocks, comprising a group of lipid feedstocks each having a chloride content of at least about 2 ppm, are sequentially treated with a metal oxide catalyst on an oxide support to produce corresponding processing streams of the group of lipid feedstocks each having a chloride content of less than 1 ppm, until the chloride content of a given one of the corresponding processing streams of the group of lipid feedstocks is greater than 1 ppm and the metal oxide catalyst on the oxide support is converted to a used metal oxide catalyst on the oxide support.

[0006] The conversion of used metal oxide catalysts on oxide supports into regenerated metal oxide catalysts on oxide supports, and

[0007] Under the second treatment condition, one or more other lipid feedstocks, each having a chloride content of at least about 2 ppm, are treated with a regenerated metal oxide catalyst on an oxide support to produce one or more corresponding treatment streams, each having a chloride content of less than 1 ppm. Detailed Implementation

[0008] The various illustrative embodiments described herein relate to methods for removing chlorides and other impurities from lipid feedstocks using regenerated catalysts to provide purified lipid feedstocks that can be used for refining processes.

[0009] definition

[0010] The term "lipid" is known in the art and refers to fatty acids and their derivatives. Therefore, examples of lipids include fatty acids (saturated and unsaturated fatty acids); glycerides (glyceride / glycerolipid), also known as acylglycerols (e.g., monoglycerides (monoacylglycerols), diglycerides (diacylglycerols), triglycerides (triacylglycerols, TAGs, or neutral fats), phosphoglycerides (glycerophospholipids)); non-glycerides (sphingolipids, sterol lipids including cholesterol and steroid hormones, isopentenyl lipids including terpenes, fatty alcohols, waxes, and polyketides); and complex lipid derivatives (glyco-linked lipids or glycolipids, and protein-linked lipids).

[0011] The term "fatty acid" refers to a monocarboxylic acid having an aliphatic chain containing about 3 to about 39 carbon atoms, more specifically about 7 to about 23 carbon atoms. The aliphatic chain can be straight or branched, and can be saturated or unsaturated (e.g., containing one or more carbon-carbon double bonds).

[0012] The term "bio-oil" refers to a liquid product generated from biomass through a thermochemical process. Bio-oil may include bio-derived hydrocarbon fractions and oxygenated hydrocarbons, such as carboxylic acids, alcohols, aldehydes, and ketones.

[0013] As used herein, the term "renewable feedstock" refers to materials derived from renewable resources (such as plants) and not geologically derived. The term "renewable" is also synonymous with the terms "sustainable," "sustainably derived," or "from sustainable sources." The term "geologically derived" refers to materials derived from, for example, crude oil, natural gas, or coal. Geologically derived materials are not easily replenished or regenerated (e.g., as opposed to oils produced from plants or algae).

[0014] The term “fresh catalyst” or “fresh metal oxide catalyst on oxide support” as used herein refers to a catalyst that has not been previously used in a catalytic process.

[0015] As used herein, the term "used catalyst" or "used metal oxide catalyst on an oxide support" refers to a catalyst that exhibits lower chloride removal activity under the same or similar reaction conditions (e.g., temperature, pressure, inlet flow rate, etc.) than the catalyst initially exposed to the method. This can be attributed to a variety of reasons, among which several non-limiting examples of reasons leading to lower chloride removal activity include cationic or anionic substitution, catalyst surface acidification, metal component consumption, and / or chemical or compositional changes.

[0016] As used herein, the term "regenerated catalyst" or "regenerated metal oxide catalyst on an oxide support" refers to a used catalyst, as defined above, which has been modified to enhance its chloride removal activity to a level higher than when it was used. Regenerated catalysts typically exhibit chloride removal activity that is the same as or substantially similar to that of the fresh catalyst.

[0017] The term "hydroprocessing" generally encompasses all processes in which hydrocarbon feedstocks react with hydrogen in the presence of a catalyst and under hydroprocessing conditions (typically at high temperatures and pressures). Hydroprocessing includes processes such as hydrogenation, hydrodeoxygenation, hydrodesulfurization, hydrodenitrogenation, hydrodemetallization, hydrodearomatization, hydroisomerization, hydrodewaxing, hydrocracking, and mild hydrocracking.

[0018] As used herein, the term "transport fuel" refers to a fraction or mixture of hydrocarbons having a fuel-standardized distillation profile, such as diesel fuel (middle fraction from 160°C to 380°C according to EN 590), gasoline (from 40°C to 210°C according to EN 228), aviation fuel (jet fuel from 160°C to 300°C according to ASTM D-1655), kerosene, naphtha, etc. Liquid fuels are hydrocarbons having a fuel-standardized distillation profile, such as transport fuels.

[0019] The term "ppm" as used in this article refers to parts per million, which is a weight-related parameter. Parts per million means one microgram per gram; therefore, a concentration of 10 ppm means that 10 micrograms of a specific component are present in 1 gram of aggregate mixture.

[0020] The term "upgrade" refers to the process of changing raw materials to obtain more desirable properties.

[0021] The term "biofuel" here refers to liquid fuels obtained from renewable feedstocks, such as biologically derived feedstocks.

[0022] The level of organochlorinated contaminants can be determined by X-ray fluorescence spectrometry, such as ASTM D7536-09, a standard test method for determining chlorine in aromatic hydrocarbons by monochromatic wavelength dispersive X-ray fluorescence spectrometry.

[0023] As mentioned above, there is a growing interest in alternative feedstocks that can partially replace crude oil in the production of hydrocarbons suitable as fuels or fuel components, such as transportation fuels or fuel-compatible hydrocarbons. Biofuels are typically made from feedstocks derived from renewable sources. These feedstocks contain varying amounts of contaminants that are harmful to conversion catalysts.

[0024] Despite ongoing research and development in lipid feedstock processing and fuel manufacturing, there remains a need for improved methods to purify lipid feedstocks, providing purified feedstocks with little or no detectable chlorides, suitable for conversion into valuable chemicals, such as hydrocarbons suitable as fuels or fuel blend components. For example, fresh catalysts can efficiently remove chlorides from lipid feedstocks, producing oil products free of detectable chlorides. However, the chloride removal activity of catalysts for the continuous removal of chlorides from lipid feedstocks slowly decreases over time and through reaction / regeneration cycles due to the accumulation of metallic impurities, such as those not removed during coke combustion, on the catalyst over time. Therefore, there is a need to regenerate (i.e., reactivate) the chloride removal activity of metal oxide catalysts for further processing of other lipid feedstocks, thereby continuing to provide purified lipid feedstocks with virtually no or no detectable chlorides (i.e., chloride content less than 1 ppm, less than 0.5 ppm, or less than 0.1 ppm).

[0025] The illustrative embodiments described herein overcome these and other drawbacks, providing an improved method for purifying renewable feedstocks to provide purified renewable feedstocks that are virtually free of or free of detectable chlorides, which are subsequently suitable for conversion into valuable chemicals by reactivating the chloride removal activity of a used metal oxide catalyst during the processing of lipid feedstocks. In a non-limiting illustrative embodiment, the method includes:

[0026] Under the first processing conditions, multiple lipid feedstocks, comprising a group of lipid feedstocks each having a chloride content of at least about 2 ppm, are sequentially treated with a metal oxide catalyst on an oxide support to produce corresponding processing streams of the group of lipid feedstocks each having a chloride content of less than 1 ppm, until the chloride content of a given one of the corresponding processing streams of the group of lipid feedstocks is greater than 1 ppm and the metal oxide catalyst on the oxide support is converted to a used metal oxide catalyst on the oxide support.

[0027] The conversion of used metal oxide catalysts on oxide supports into regenerated metal oxide catalysts on oxide supports, and

[0028] Under the second treatment condition, one or more other lipid feedstocks, each having a chloride content of at least about 2 ppm, are treated with a regenerated metal oxide catalyst on an oxide support to produce one or more corresponding treatment streams, each having a chloride content of less than 1 ppm.

[0029] First processing step

[0030] lipid raw materials

[0031] In step (a) of the illustrative implementation, the lipid feedstock is derived from a renewable or biological source, and it is intended to include feedstocks other than those obtained from mineral oil, shale oil, or coal.

[0032] In illustrative embodiments, the lipid source used herein may comprise, for example, 0 to 90% by weight of free fatty acids, about 5 to 100% by weight of fatty acid glycerides (e.g., monoglycerides, diglycerides, triglycerides), and 0 to 20% by weight of one or more compounds selected from non-glycerol fatty acid esters, fatty amides, and fatty alcohols. In illustrative embodiments, as can be combined with the foregoing embodiments, the lipid source comprises more than about 50% by weight of free fatty acids and fatty acid glycerides, for example, about 70% by weight or more, for example, about 80% by weight or more and up to 100% by weight.

[0033] In illustrative embodiments, the lipid feedstock may include lipids (e.g., fats or oils) derived from, for example, any type of plant, animal, microbial (e.g., algae oil, algal biomass, algal culture), fish, and microbial processes. In one embodiment, the lipid feedstock used includes triglycerides.

[0034] Many different lipid feedstocks derived from plants can be used. In a non-limiting illustrative embodiment, plant-based lipid feedstocks may include, for example, rapeseed oil, soybean oil (including degummed soybean oil), rapeseed oil, cottonseed oil, grapeseed oil, mustard seed oil, corn oil, flaxseed oil, safflower oil, sunflower seed oil, pecan oil, walnut oil, oat oil, peanut oil, rice bran oil, camellia oil, castor oil, olive oil, palm oil, coconut oil, rice oil, algae oil, seaweed oil, and tallow tree oil.Other plant-based lipid raw materials can be obtained from, for example, argan, avocado, babassu palm, balanites, Borneo tallow nut, Brazil nut, calendula, camellia, caryocar, cashew nut, Chinese vegetarian tallow, cocoa, coffee, cohune palm, coriander, cucurbitaceae plants, euphorbia plants, illipe, jatropha, jojoba, kenaf, kusum, macadamia nuts, mango seed, and Abyssinian rapeseed. abyssinia, nutmeg, perilla, pili nut, pumpkin seed, rice bran, sachainche, seje, sesame, shea nut, teased, allanblackia, almond, chaulmoogra, cuphea, jatropa curgas, karanja seed, neem, papaya, tonka bean, tung tree, eucalyptus, cajuput, clausena anisata, davana, galbanum natural oleoresin, German chamomile Chamomile), Hexastylis, high-geraniolmonarda, Juniapa-hinojo sabalero, lupine, melissaofficinalis, milfoil, ninde, patchouli, tarragon, and wormwood.

[0035] Many different lipid feedstocks derived from animals can also be used. In a non-limiting illustrative embodiment, animal-based lipid feedstocks may include, for example, selected white fat, lard (pork fat), beef tallow (beef fat), fish oil, and poultry fat.

[0036] Many different lipid feedstocks derived from microorganisms (eukaryotes, eubacteria, and archaea) can also be used. In a non-limiting illustrative embodiment, microbial-based lipid feedstocks may include, for example, L-glycerol lipids from archaea and algae, and diatom oil. In some embodiments, lipid feedstocks derived from microorganisms may include bacteria, protozoa, algae, and fungi.

[0037] In some embodiments, lipid feedstocks from plant and animal sources may be used, such as yellow oils, white oils, and brown oils. In non-limiting illustrative embodiments, yellow, white, or brown oils may include frying oil from a deep fryer, and therefore may include fats of plant and animal origin. Specifically, lipid feedstocks may include used edible oils. Brown oils (also known as threshed oils) may include fats extracted from wastewater systems, and therefore may include fats of plant and animal origin. In some embodiments, the lipid feedstocks used in the embodiments may include abiotic lipid feedstocks. The lipid feedstocks of the present invention may also include black oil.

[0038] In a non-limiting illustrative embodiment, lipid feedstocks include feedstocks derived from low-value renewable waste, side streams, by-products, refining waste and residues, sewage sludge, and any combination thereof.

[0039] In a non-limiting illustrative embodiment, the lipid feedstock may be selected from acidified soap feedstock, physically refined fatty acid distillates from vegetable oils or animal fats, corn distillers grains with lees (DCO) from ethanol production, waste cooking oil, lard, brown oils, yellow oils, threshed oils, waste fats, low-grade oils, supercritical water liquefaction oils (SCWL oils), vegetable oils, animal fats, and any combination thereof.

[0040] In the illustrative embodiments, as may be combined with one or more of the preceding paragraphs, the lipid feedstock includes one or more of alkali metals, alkaline earth metals, and / or other metals (e.g., iron and manganese), which are often considered unsuitable for catalytic processing in refinery operations, even in low concentrations, because each metal is a potent catalyst poison. Alkali metals, alkaline earth metals, and other metals may typically include Na, K, Mg, Ca, Mn, Fe, or combinations thereof. The lipid feedstock may contain a total of at least about 1 ppm (e.g., about 1 to about 250 ppm, about 1 to about 100 ppm, about 1 to about 50 ppm, about 1 to about 25 ppm, about 2 to about 250 ppm, about 2 to about 100 ppm, or about 2 to about 25 ppm) of alkali metals, alkaline earth metals, Group VIIB and Group VIIIB metals, or combinations thereof (calculated as elemental metals). The total metal content can be determined using AOCS recommended operating method Ca 17-01.

[0041] In a non-limiting illustrative embodiment, the lipid feedstock may include low-value lipid feedstocks, such as various types of animal fats and waste oils, which typically have a relatively high concentration of free fatty acids. One method for assessing the free fatty acid concentration is to determine the total acid number (TAN) of the feedstock. The total acid number is the mass (in milligrams) of potassium hydroxide (KOH) required to neutralize one gram of the chemical being evaluated.

[0042] In the illustrative embodiment, as may be combined with one or more of the preceding paragraphs, the lipid feedstock may have a total acid value of at least about 5 mg KOH / g (e.g., about 5 to about 150 mg KOH / g, about 10 to about 150 mg KOH / g, about 10 to about 100 mg KOH / g, about 10 to about 50 mg KOH / g, about 10 to about 25 mg KOH / g, or about 10 to about 20 mg KOH / g). The total acid value may be determined using ASTM D664.

[0043] Lipid feedstocks typically contain varying amounts of impurities, such as phosphorus, silicon, chlorides, alkali metals, alkaline earth metals, and other metals. In illustrative embodiments, as may be combined with one or more of the preceding paragraphs, lipid feedstocks may contain varying amounts of chlorides, such as at least about 2 ppm, or at least about 4 ppm, or at least about 10 ppm (e.g., about 2 to about 100 ppm, about 2 to about 75 ppm, about 2 to about 50 ppm, about 10 to about 100 ppm, or about 10 to about 50 ppm), wherein any lower limit may be combined with any upper limit.

[0044] In a non-limiting embodiment, in addition to the lipid feedstock having a chloride content of at least about 2 ppm, other lipid feedstocks with a chloride content of less than 2 ppm may also be present during processing. In other embodiments, in addition to the lipid feedstock having a chloride content of at least about 2 ppm, other chloride-free lipid feedstocks may also be present during processing.

[0045] In the illustrative embodiments, the lipid feedstock may be pretreated. Suitable pretreatments include, but are not limited to, degumming, neutralization, bleaching, deodorization, or any combination thereof.

[0046] catalyst

[0047] The catalyst used in step (a) is a fresh metal oxide catalyst on an oxide support. Suitable metal oxides include, for example, Na, K, Mg, Ca, Sr, Cr, Mo, Mn, Fe, Co, Ni, Cu, Zn, Al, rare earth metals, or mixtures thereof. In an illustrative embodiment, the metal oxide may be present in an amount ranging from about 0.1% to about 10% by weight. In an illustrative embodiment, a suitable oxide support may be any suitable inorganic oxide support. Representative examples of such suitable oxide supports include, but are not limited to, alumina, silica, silica-alumina, titanium dioxide, zirconium oxide, or mixtures thereof. In one embodiment, the oxide support is one of alumina and silica-alumina, wherein the silica content of the silica-alumina support may be from about 2% to about 30% by weight. The alumina may be any alumina conventionally used in hydrotreating catalysts. Such alumina is typically porous amorphous alumina with an average pore size of about 50 to about 200 angstroms. In a non-limiting illustrative embodiment, the metal oxide catalyst comprises CaO, and the oxide support is alumina. However, this embodiment is merely exemplary, and any combination of the aforementioned metal oxides and oxide supports is considered herein.

[0048] Metal oxide catalysts can be any commonly used catalyst shape known in the art, such as spheres, particles, pellets, fragments, rings, extrusions, or powders.

[0049] Processing of lipid raw materials

[0050] Under processing conditions, lipid feedstocks are sequentially treated with a metal oxide catalyst on an oxide support to produce a processed stream comprising a liquid fraction containing bio-oil and the metal oxide catalyst. This processed stream has a lower content of free fatty acids and impurities compared to the corresponding starting lipid feedstock. The resulting bio-oil, after further processing as described below, is particularly suitable as a renewable feedstock for hydrotreating in biofuel production.

[0051] Unbound by theory, the treatment is believed to be carried out through thermochemical processes, including one or more of the following: cracking, decarboxylation, decarboxylation coupling, dehydration, and / or deoxygenation reactions.

[0052] In illustrative embodiments, suitable processing conditions for the lipid feedstock, as may be combined with one or more of the preceding paragraphs, may include one or more of the following: a temperature in the range of about 400°C to about 700°C (e.g., about 425°C to about 650°C or about 450°C to about 600°C); a pressure in the range of 0 to about 10 MPa (e.g., about 0.1 to about 5 MPa or about 0.1 to about 1 MPa); and a temperature range of about 0.1 to about 10 h. -1 (e.g., about 0.2 to about 5 h) -1 or approximately 0.3 to approximately 3 hours -1 The liquid hourly space velocity (LHSV) is within the range of ). Any of the lower limits can be combined with any of the upper limits.

[0053] Treatment of lipid feedstocks with metal oxide catalysts can be carried out in the presence of a carrier gas. Suitable carrier gases include, for example, hydrogen, nitrogen, carbon dioxide, H2O (water vapor), or C1-C4 hydrocarbons (e.g., methane, ethane, propane, or mixtures thereof). These gases can be incorporated into the reaction mixture of the lipid feedstock and the metal oxide catalyst and / or can be formed during the reaction. The carrier gas can be used to remove gaseous or volatile reaction products, such as carbon dioxide (CO2) and H2O (water vapor), from the product mixture.

[0054] Metal oxide catalysts can be used to treat lipid feedstocks in any suitable reactor or reactor configuration. Suitable reactors or reactor configurations include, for example, fixed-bed reactors, moving-bed reactors, slurry reactors, fluidized-bed reactors, boiling-bed reactors, conveyed-bed reactors, two-phase-bed reactors, riser-tube reactors, and batch reactors. The feed stream of the lipid feedstock can flow upward or downward through the catalyst bed in any form of liquid, steam, or mixed phase.

[0055] The process can be intermittent, semi-intermittent, or continuous; continuous processes are used appropriately.

[0056] Those skilled in the art will understand that the method includes first treating a first lipid feedstock with a chloride content of at least about 2 ppm with a fresh metal oxide catalyst on an oxide support under first processing conditions to produce a first processed stream containing a liquid fraction containing bio-oil, wherein the first processed stream has a lower chloride content than the initial first lipid feedstock, for example, a chloride content of less than 1 ppm, or less than about 0.5 ppm, or less than about 0.01 ppm, or less than about 0.001 ppm, or a chloride content of 0 ppm.

[0057] The method then continues by treating a second lipid feedstock with a chloride content of at least about 2 ppm under second processing conditions with the same metal oxide catalyst on the oxide support used to treat the first lipid feedstock, to produce a second processed stream containing a liquid fraction of bio-oil, the second processed stream having a lower chloride content compared to the initial second lipid feedstock, for example, a chloride content of less than 1 ppm, or less than about 0.5 ppm, or less than about 0.01 ppm, or less than about 0.001 ppm, or a chloride content of 0 ppm.

[0058] The method further continues by sequentially treating other lipid feedstocks with a chloride content of at least about 2 ppm using the same metal oxide catalyst on an oxide support under respective processing conditions to produce corresponding processing streams with chloride contents of less than 1 ppm, or less than about 0.5 ppm, or less than about 0.01 ppm, or less than about 0.001 ppm, or a chloride content of 0 ppm. Those skilled in the art will readily understand that the method can also sequentially treat other lipid feedstocks with a chloride content of less than 2 ppm as described above using the same metal oxide catalyst on an oxide support under respective processing conditions to produce corresponding processing streams.

[0059] The method continues until the chloride content of a given feedstock in the corresponding processing stream exceeds 1 ppm, and the metal oxide catalyst on the oxide support is converted to a used metal oxide catalyst on the oxide support. In other words, as described above, the ability of a metal oxide catalyst to remove impurities (e.g., chlorides) from a lipid feedstock slowly decreases over time and through reaction / regeneration cycles. Therefore, when the chloride removal activity of the metal oxide catalyst reaches a point where it cannot remove less than 1 ppm of chloride from a given lipid feedstock being processed, the metal oxide catalyst is partially deactivated. In the past, such deactivated catalysts no longer had sufficient activity to achieve the desired chloride removal efficiency and needed to be replaced with fresh catalyst, i.e., they had to be unloaded and disposed of before being loaded with fresh metal oxide catalyst. However, it has been found that the chloride removal activity of the catalyst can be increased to restore or regenerate its chloride removal activity without having to discard it and replace it with fresh catalyst. Furthermore, the dechlorination activity can be regenerated in-situ within the reactor without unloading the catalyst.

[0060] Each of the resulting processed streams contains a liquid fraction containing bio-oil, which may contain a total of less than 1 ppm (preferably less than about 0.5 ppm) of alkali metals, alkaline earth metals, metals of Groups VIIB and VIIIB of the periodic table (other metals) or combinations thereof (calculated as elemental metals).

[0061] Each of the resulting processed streams contains a liquid fraction containing bio-oil, and its TAN can be less than 5 mg KOH / g (e.g., less than 4 mg KOH / g, less than 3 mg KOH / g, less than 2 mg KOH / g, or less than 1 mg KOH / g).

[0062] The bio-oil obtained from the above processing steps, after further processing as described below, is particularly suitable as a renewable feedstock for hydrotreating in biofuel manufacturing.

[0063] Catalyst regeneration steps

[0064] After treating their respective lipid feedstocks with metal oxide catalysts and oxide supports to produce a resulting processing stream containing a liquid fraction of bio-oil and a used metal oxide catalyst on an oxide support, the used metal oxide catalyst on the oxide support is converted into a regenerated metal oxide catalyst on the oxide support, whose chloride removal activity is equal to or substantially equivalent to that of the fresh catalyst.

[0065] In one non-limiting illustrative embodiment, a spent metal oxide catalyst can be converted into a regenerated metal oxide catalyst by directly spraying a water-soluble metal salt solution onto the spent metal oxide catalyst. For example, a metal (e.g., calcium) can be added in the form of a water-soluble calcium salt solution (e.g., calcium acetate) and then sprayed directly onto the spent metal oxide catalyst. The water-soluble metal salt solution can be sprayed onto the spent metal oxide catalyst using any known suitable spraying equipment. Suitable metal salts, such as calcium salts, include those that are converted to any one of calcium carbonate, calcium oxide, or calcium hydroxide under reaction conditions. Representative examples of suitable calcium salts include, but are not limited to, calcium nitrate, calcium hydroxide, calcium acetate, or other calcium carboxylate. Those skilled in the art will readily understand that other metals, such as magnesium and barium, can also be considered instead of calcium and can be deposited in a similar manner.

[0066] In illustrative embodiments, used metal oxide catalysts can be converted into regenerated metal oxide catalysts without removing the used metal oxide catalysts from the reactor system. For example, in a non-limiting illustrative embodiment, a concentrated metal (e.g., calcium) salt solution can be sprayed onto the used metal oxide catalyst until the desired amount of metal is added, and then the sprayed metal oxide catalyst can be dried by first heating the reactor to a drying temperature suitable for removing water (e.g., about 120°C to about 200°C), followed by heating to a calcination temperature and a suitable reaction temperature (e.g., about 400°C to about 600°C). Metal salts such as calcium acetate decompose under the reaction conditions to generate the corresponding calcium carbonate or calcium oxide. The desired amount of metal added to the used metal oxide catalyst can be an amount sufficient to convert the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support. For example, the desired amount of metal added to the used metal oxide catalyst can be about 0.1 to about 10% by weight.

[0067] In illustrative embodiments, during the treatment of lipid feedstocks with a metal oxide catalyst on an oxide support, the used metal oxide catalyst can be converted into a regenerated metal oxide catalyst by incorporating a metal salt (e.g., calcium, magnesium, or barium salt) into the metal oxide catalyst accompanying the lipid feedstock. In one embodiment, the metal salt can be mixed with the lipid feedstock as an emulsion of an aqueous solution of the metal salt (e.g., calcium acetate) in an oil feedstock. In alternative embodiments, the salt in an oil-soluble form can be dissolved in oil. Representative examples of oil-soluble salts include acetylacetonate salts, which are known to be soluble in organic solvents. For example, calcium acetylacetonate is known to have high solubility in low molecular weight alcohols such as methanol and ethanol.

[0068] Therefore, in one embodiment, a solution of an oil-soluble metal salt in a low molecular weight alcohol can be injected into the lipid feedstock, for example, with a metal content of about 0.05 to about 5% by weight. In one embodiment, glycerol can be used as a solvent for the oil-soluble metal salt. In another alternative embodiment, the mixture in the feedstock contains small amounts of calcium or magnesium, which are known impurities in some low-value lipid feedstocks. The metal salt can be injected together with the lipid feedstock in a reactor layout such as a moving bed or fluidized bed reactor, where more of the catalyst stock is exposed to the fresh feed over time, unlike a fixed bed option where only a portion of the catalyst stock is close to the feed injection point.

[0069] Second processing step

[0070] After converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support (whose chloride removal activity is equal to or substantially equivalent to that of the fresh metal oxide catalyst), the method continues by sequentially treating at least one or more other lipid feedstocks with a chloride content of at least about 2 ppm with the regenerated metal oxide catalyst on the oxide support under the above-described treatment conditions to produce corresponding processing streams, each of which contains a liquid fraction containing bio-oil with a lower chloride content compared to the starting lipid feedstock, for example, the chloride content of the corresponding processing stream is less than 1 ppm, or less than about 0.5 ppm, or less than about 0.01 ppm, or less than about 0.001 ppm, or its chloride content is 0 ppm.

[0071] As described above, in addition to the lipid feedstock with a chloride content of at least about 2 ppm, other lipid feedstocks with a chloride content of less than 2 ppm may also be present in the processing steps. In other embodiments, in addition to the lipid feedstock with a chloride content of at least about 2 ppm, other chloride-free lipid feedstocks may also be present during the processing.

[0072] The method then continues by sequentially treating other lipid feedstocks under their respective processing conditions with the same regenerated metal oxide catalyst on an oxide support to produce corresponding processing streams with chloride contents of less than 1 ppm, or less than about 0.5 ppm, or less than about 0.01 ppm, or less than about 0.001 ppm, or 0 ppm. The method continues until the chloride content of one of the given processing streams again exceeds 1 ppm, and the metal oxide catalyst on the oxide support is converted to the used metal oxide catalyst on the oxide support as described above.

[0073] The obtained bio-oil, after further processing as described below, is particularly suitable as a renewable feedstock for hydrotreating in biofuel manufacturing.

[0074] Hydrogenation

[0075] Advantageously, the bio-oil produced by the method of the illustrative embodiments disclosed herein can be used directly as a refining feedstock. The obtained bio-oil can also be blended with one or more mineral oil feedstocks derived from crude oil, shale oil, or coal, and used as a refining feedstock as well.

[0076] If necessary, the bio-oil can undergo a catalytic hydrotreating step. At least one effluent obtained (hydrotreating product) can be fractionated in a fractionation step to provide a hydrocarbon fraction suitable as a renewable fuel or fuel component, which can be used as a transport fuel, fuel component, and other chemicals. The catalytic hydrotreating step can be performed in one step or in multiple steps.

[0077] The catalytic hydrotreating process can process one or more fractions of the bio-oil separately (e.g., distilled fractions), or it can process the bio-oil as a whole.

[0078] Catalytic hydrotreating may include at least one hydrodeoxygenation step. Catalytic hydrotreating may include a hydrodeoxygenation step, followed by one or more steps selected from hydroisomerization and hydrocracking.

[0079] Hydrotreating can be carried out using one or more hydrotreating catalysts, said catalysts comprising one or more metals selected from Group VIA and Group VIII metals. Particularly useful examples are Mo, W, Co, Ni, Pt, and Pd. The catalyst may also comprise one or more support materials, such as zeolites, alumina, alumina-silica, zirconium oxide, alumina-silica-zeolite, and activated carbon. Suitable are mixtures of CoO and MoO3 (CoMo) and / or mixtures of NiO and MoO3 (NiMo), and / or mixtures of Ni, Mo, and Co and / or NiW, as well as one or more support materials selected from zeolites, alumina, silica, zeolite-alumina, alumina-silica, alumina-silica-zeolite, and activated carbon. In addition, noble metals such as Pt and / or Pd dispersed on alumina may also be used.

[0080] Hydrotreating conditions may include a temperature of about 100°C to about 450°C (e.g., about 200°C to about 370°C, or about 230°C to about 350°C); a pressure of about 0.5 to about 30 MPa (e.g., about 3 to about 25 MPa, or about 3 to about 12 MPa); and a time of about 0.01 to about 10 h. -1 (e.g., about 0.1 to about 5h) -1 The liquid hourly space velocity (LHSV) is approximately 600 to approximately 4000 Nm³. Hydrogen processing rates can range from approximately 600 to approximately 4000 Nm³. 3 / m 3 Within the range (e.g., approximately 1300 to approximately 2200 Nm) 3 / m 3 ).

[0081] Hydrogenation occurs during the reaction stage. The reaction stage may include one or more reactors or reaction zones, each containing one or more catalyst beds of the same or different catalysts. While other types of catalyst beds / reactors can be used, fixed beds are preferred. Other types of catalyst beds include fluidized beds, boiling beds, slurry beds, and moving beds. Interstage cooling or heating may be employed between reactors, between reaction zones, or between catalyst beds within the same reactor.

[0082] At least one effluent from the hydrotreatment is discharged from the last reactor. In one embodiment, the effluent is directed to a separator, such as any suitable separator or flash unit. In the separator, water, a gaseous stream containing hydrogen, light hydrocarbons (e.g., C1 to C5 hydrocarbons), H2S, CO, and CO2 are typically separated from a liquid component containing >C5 hydrocarbons and some C1 to C5 hydrocarbons. Water and gas can also be separated by other methods well known to those skilled in the art.

[0083] According to ISO EN 3405, the liquid hydrocarbon stream obtained from the hydrotreating step includes fuel-grade hydrocarbons with a maximum boiling point of 380°C. Those skilled in the art can modify distillation conditions and temperature cut-off points as needed to obtain any suitable hydrocarbon product that boils appropriately within the transport fuel range.

[0084] The following illustrative examples are intended to be non-limiting.

[0085] In the examples below, chloride content is reported as ppm chloride (by feed weight or composition weight) and determined by X-ray fluorescence on an XOS Chlora R benchtop analyzer.

[0086] Example

[0087] 50 ml of calcium-doped alumina catalyst was loaded into a ¾” reactor, and runs 1-3 were performed as described below, wherein lipid oil feedstock was treated in the presence of steam at a 1:1 steam / oil feed weight ratio, at 900℉, ambient pressure, and a flow rate of approximately 30 to 40 g oil / h, via upflow over the calcium-doped alumina catalyst. In the first run, 6 kg of pretreated used edible oil (UCO) feed with a chloride content of 11 ppm was processed. In the second run, using the same batch of catalyst, 10 kg of chloride-free soybean oil feed was processed. No chloride was detected in the oil products from either the first or second run. In the third run, using the same batch of catalyst, 1 kg of untreated UCO feed with a chloride content of 4.6 ppm was processed. The oil product samples from the third run were found to contain varying concentrations of chloride, with a maximum concentration of 1.8 ppm.

[0088] At this point, the calcium-doped alumina catalyst was cooled, and a solution of 5 g of calcium acetate dissolved in 30 ml of water was poured onto the top of the catalyst bed still in the reactor. The calcium-doped alumina catalyst was then slowly heated to 900℉ in nitrogen and restarted. Next, in a fourth run, 10 kg of untreated UCO feed with a chloride content of 4.6 ppm was treated under the above conditions. After adding calcium to the calcium-doped alumina catalyst, no chloride was detected in the treated product.

[0089] According to one aspect of this disclosure, the method includes:

[0090] (a) Under first processing conditions, a plurality of lipid feedstocks comprising a group of lipid feedstocks each having a chloride content of at least about 2 ppm are sequentially treated with a metal oxide catalyst on an oxide support to produce corresponding processing streams of the group of lipid feedstocks having a chloride content of less than 1 ppm, until the chloride content of a given one of the corresponding processing streams of the group of lipid feedstocks is greater than 1 ppm and the metal oxide catalyst on the oxide support is converted to a used metal oxide catalyst on the oxide support.

[0091] (b) Converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support, and

[0092] (c) Under the second treatment conditions, one or more other lipid feedstocks, each having a chloride content of at least about 2 ppm, are treated with a regenerated metal oxide catalyst on an oxide support to produce one or more corresponding treatment streams each having a chloride content of less than 1 ppm.

[0093] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, a plurality of lipid feedstocks and one or more other lipid feedstocks independently comprise at least one fatty acid selected from acidified soap feedstocks, physically refined fatty acid distillates from vegetable oils or animal fats, corn distillers grains from ethanol production, waste cooking oils, lard, brown oils, yellow oils, threshed oils, waste fats, low-grade oils, supercritical water liquefied oils, vegetable oils, animal fats, and any combination thereof.

[0094] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, sequentially treating multiple lipid feedstocks with a metal oxide catalyst on an oxide support under first treatment conditions includes: (i) treating one or more first lipid feedstocks with a metal oxide catalyst under first treatment conditions to produce a first treatment stream with a chloride content of less than 1 ppm; (ii) treating one or more second lipid feedstocks with a metal oxide catalyst under first treatment conditions to produce a second treatment stream with a chloride content of less than 1 ppm; (iii) treating one or more third lipid feedstocks with a metal oxide catalyst under first treatment conditions to produce a third treatment stream with a chloride content of less than 1 ppm; and (iv) treating one or more fourth lipid feedstocks with a metal oxide catalyst under first treatment conditions to produce a fourth treatment stream with a chloride content of greater than 1 ppm.

[0095] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the first and second treatment conditions independently include one or more of the following: a temperature range of about 400°C to about 700°C, a pressure range of about 0.1 to about 10 MPa, and a liquid hourly space velocity range of about 0.1 to about 10 h⁻¹. -1 .

[0096] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the metal oxide catalyst comprises a metal selected from Na, K, Mg, Ca, Ba, Sr, Cr, Mo, Mn, Fe, Co, Ni, Cu, Zn, Al, rare earth metals and any combination thereof, and the oxide support is selected from alumina, silica, silica-alumina, titanium dioxide, zirconium oxide and any combination thereof.

[0097] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the metal oxide catalyst comprises a metal selected from Ca, Mg, Ba, and any combination thereof.

[0098] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the metal oxide catalyst comprises CaO, and the oxide support comprises alumina.

[0099] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, converting a used metal oxide catalyst on an oxide support into a regenerated metal oxide catalyst on an oxide support comprises contacting the used metal oxide catalyst with a solution containing a water-soluble metal salt.

[0100] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the metal of the water-soluble metal salt is one of calcium, magnesium, or barium.

[0101] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, contacting a used metal oxide catalyst with a solution of a water-soluble metal salt comprises spraying a solution containing one of calcium nitrate, calcium hydroxide, calcium acetate, or calcium carboxylate onto the used metal oxide catalyst, wherein the used metal oxide catalyst comprises CaO.

[0102] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, step (a) is carried out in a reactor system and performs the step of converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support without removing the used metal oxide catalyst from the reactor system.

[0103] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, converting a used metal oxide catalyst on an oxide support into a regenerated metal oxide catalyst on an oxide support comprises spraying a solution containing a water-soluble metal salt onto the used metal oxide catalyst on the oxide support and heating the reactor.

[0104] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the solution containing the water-soluble metal salt is a calcium acetate solution, and the used metal oxide catalyst includes CaO.

[0105] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the processes of steps (a) and (c) are performed under a carrier gas flow.

[0106] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the carrier gas is nitrogen, carbon dioxide, C1 to C4 hydrocarbons, water, or a mixture thereof.

[0107] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, a plurality of lipid raw materials and one or more other lipid raw materials independently exhibit at least one of the following properties:

[0108] (i) The total acid value, as determined by ASTM D664, is at least approximately 5 mg KOH / g, and

[0109] (ii) Chlorides of about 2 ppm to about 100 ppm.

[0110] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the method further includes one or more of the corresponding processing streams in step (a) and one or more of the corresponding processing streams in step (c) to obtain a gas fraction and a liquid fraction containing bio-oil.

[0111] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the method further includes a catalytic hydrotreating step of the bio-oil to provide a hydrotreated product.

[0112] In one or more other illustrative embodiments, as may be combined with the foregoing paragraphs, the catalytic hydrogenation process includes a hydrodeoxygenation step.

[0113] In one or more other illustrative embodiments, as may be combined with the preceding paragraphs, at least one of the corresponding processing streams in step (a) and one or more of the corresponding processing streams in step (c) have a chloride content equal to 0.

[0114] For the sake of brevity, the various features disclosed herein are described in the context of a single embodiment, but may also be provided individually or in any suitable sub-combination. All combinations of embodiments are specifically included in the illustrative embodiments disclosed herein as if each combination were disclosed individually and explicitly. Furthermore, all sub-combinations listed in embodiments describing such variations are also specifically included in the compositions of the invention and disclosed herein as if each such sub-combination were disclosed individually and explicitly herein.

[0115] While the above description contains many details, these details should not be construed as limiting the invention, but merely as examples of preferred embodiments. Those skilled in the art will contemplate many other embodiments within the scope and spirit of the invention as defined by the appended claims.

Claims

1. A method comprising: (a) Under first processing conditions, a plurality of lipid feedstocks comprising a group of lipid feedstocks each having a chloride content of at least about 2 ppm are sequentially processed with a metal oxide catalyst on an oxide support to produce corresponding processing streams of the group of lipid feedstocks having a chloride content of less than 1 ppm, until the chloride content of a given one of the corresponding processing streams of the group of lipid feedstocks is greater than 1 ppm and the metal oxide catalyst on the oxide support is converted to a used metal oxide catalyst on the oxide support. (b) Converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support; as well as (c) Under the second processing conditions, one or more other lipid feedstocks, each having a chloride content of at least about 2 ppm, are treated with the regenerated metal oxide catalyst on the oxide support to produce one or more corresponding processing streams each having a chloride content of less than 1 ppm.

2. The method of claim 1, wherein the plurality of lipid raw materials and the one or more other lipid raw materials independently comprise at least one fatty acid, said fatty acid being selected from acidified soap raw materials, physically refined fatty acid distillates from vegetable oils or animal fats, corn distillers grains from ethanol production, waste cooking oils, lard, brown oils, yellow oils, threshed oils, waste fats, low-grade oils, supercritical water liquefied oils, vegetable oils, animal fats, and any combination thereof.

3. The method of claim 1 or 2, wherein sequentially treating multiple lipid feedstocks with the metal oxide catalyst on the oxide support under the first treatment conditions comprises: (i) Treating one or more first lipid feedstocks with the metal oxide catalyst under the first processing conditions to produce a first processing stream with a chloride content of less than 1 ppm; (ii) Treat one or more second lipid feedstocks with the metal oxide catalyst under the first treatment conditions to produce a second treatment stream with a chloride content of less than 1 ppm; (iii) treating one or more third lipid feedstocks with the metal oxide catalyst under the first treatment conditions to produce a third treatment stream with a chloride content of less than 1 ppm; and (iv) treating one or more fourth lipid feedstocks with the metal oxide catalyst under the first treatment conditions to produce a fourth treatment stream with a chloride content of greater than 1 ppm.

4. The method according to any one of claims 1-3, wherein the first processing condition and the second processing condition independently comprise one or more of the following: a temperature range of about 400°C to about 700°C, a pressure range of about 0.1 to about 10 MPa, and a liquid hourly space velocity range of about 0.1 to about 10 h⁻¹. -1 .

5. The method according to any one of claims 1-4, wherein the metal oxide catalyst comprises a metal selected from Na, K, Mg, Ca, Ba, Sr, Cr, Mo, Mn, Fe, Co, Ni, Cu, Zn, Al, rare earth metals and any combination thereof, and the oxide support is selected from alumina, silicon dioxide, silicon dioxide-alumina, titanium dioxide, zirconium oxide and any combination thereof.

6. The method according to any one of claims 1-4, wherein the metal oxide catalyst comprises a metal selected from Ca, Mg, Ba and any combination thereof.

7. The method of any one of claims 1-4, wherein the metal oxide catalyst comprises CaO, and the oxide support comprises alumina.

8. The method of any one of claims 1-7, wherein converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support comprises contacting the used metal oxide catalyst with a solution containing a water-soluble metal salt.

9. The method of claim 8, wherein the metal of the water-soluble metal salt is one of calcium, magnesium or barium.

10. The method of claim 8, wherein contacting the used metal oxide catalyst with a solution of a water-soluble metal salt comprises spraying a solution containing one of calcium nitrate, calcium hydroxide, calcium acetate, or calcium carboxylate onto the used metal oxide catalyst, wherein the used metal oxide catalyst comprises CaO.

11. The method of any one of claims 1-10, wherein step (a) is carried out in a reactor system and the step of converting the used metal oxide catalyst on the oxide support into a regenerated metal oxide catalyst on the oxide support is performed without removing the used metal oxide catalyst from the reactor system.

12. The method of claim 11, wherein converting the used metal oxide catalyst on the oxide support into the regenerated metal oxide catalyst on the oxide support comprises spraying a solution containing a water-soluble metal salt onto the used metal oxide catalyst on the oxide support and heating the reactor.

13. The method of claim 12, wherein the solution containing the water-soluble metal salt is a calcium acetate solution, and the used metal oxide catalyst comprises CaO.

14. The method of any one of claims 1-13, wherein the processes in steps (a) and (c) are performed under a carrier gas flow.

15. The method of claim 14, wherein the carrier gas is nitrogen, carbon dioxide, C1 to C4 hydrocarbons, water, or a mixture thereof.

16. The method of any one of claims 1-15, wherein the plurality of lipid raw materials and the one or more other lipid raw materials independently exhibit at least one of the following properties: (i) The total acid value, as determined by ASTM D664, is at least about 5 mg KOH / g; and (ii) Chlorides of about 2 ppm to about 100 ppm.

17. The method of any one of claims 1-16, further comprising one or more of the respective processing streams in step (a) and step (c) to obtain a gas fraction and a liquid fraction containing bio-oil.

18. The method of claim 17, further comprising a step of catalytically hydrotreating the bio-oil to provide a hydrotreated product.

19. The method of claim 18, wherein the catalytic hydrogenation treatment includes a hydrodeoxygenation step.

20. The method of any one of claims 1-19, wherein at least one of the respective processing streams in step (a) and one or more of the respective processing streams in step (c) have a chloride content equal to 0.