Hydrodeoxygenation of phenolic lipids and renewable hydrocarbon fuels derived therefrom

Abstract

The present invention relates to renewable hydrocarbons, and more particularly to biomass-based diesel fuels produced by a process involving hydrodeoxygenation (HDO) of phenolic lipids. The process may generally include combining phenolic lipids with a hydrocarbon diluent to provide a hydrocarbon-diluted phenolic lipid, and then subjecting the hydrocarbon-diluted phenolic lipids to hydrodeoxygenation in a reactor to provide a reactor effluent containing hydrodeoxygenated phenolic lipids. The hydrodeoxygenated phenolic lipids are separated from the reactor effluent.

Description

[Technical Field]

[0001] The present invention relates to renewable hydrocarbons, more particularly renewable hydrocarbon fuels, and most particularly biomass-based diesel fuels. [Background technology]

[0002] This application claims priority to U.S. Provisional Application No. 63 / 377,573, filed September 29, 2022, which is incorporated herein by reference in its entirety.

[0003] Hydroprocessing of fatty acids / glycerides to produce renewable diesel (RD) fuels has been described in the prior art, e.g., U.S. Pat. Nos. 8,026,401 and 7,968,757. RD feedstocks described in the prior art include most conventional lipids, such as animal fats and vegetable oils. As described in the cited prior art and many other relevant references, RD is produced in two conversion steps. In the first step, a hydrodeoxygenation (HDO) reaction converts fatty acid / glyceride molecules to n-paraffins within the diesel boiling range (150-380°C). The glycerol backbone of fatty acid glycerides (i.e., triglycerides or diglycerides) is converted to propane during HDO. This reaction generates water, CO, and CO as major by-products. To convert the C16+ n-paraffin "wax" and improve cloud point and other cold flow properties, the normal n-paraffins in the HDO product are converted to primarily methyl-branched paraffins in a second step called "catalytic dewaxing" or "hydroisomerization" (HI).

[0004] Due to its isoparaffinic composition (n-paraffins and isoparaffins with little naphthenic or aromatic compounds), RD has a very high cetane number, typically above 84. This makes RD an excellent fuel for compression ignition engines.

[0005] However, fatty acid-derived RDs have certain drawbacks. 3 The RD density value is approximately 880 kg / m for petroleum diesel (typically 3 ) and biodiesel (approx. 850 kg / m 3 ) Generally, denser hydrocarbon compositions are desirable for renewable diesel because higher mass density equates to higher energy density.

[0006] Co-hydroprocessing of conventional lipids with petroleum fractions has been described in the prior art. For example, co-hydroprocessing of 10% and 20% rapeseed oil with straight-run diesel / light gas oil was described by Jerzy Walendziewski and coworkers (Fuel Processing Technology 90, 2009, 686-691). In a more recent study, P. Dhar and coworkers reported the co-processing of 5-15% palm oil and jatropha oil with straight-run gas oil (Hydrocarbon Processing, January 2018; 25-28). These studies broadly describe the conversion chemistry of lipids with primarily C16 and C18 fatty acids to n-paraffins in the C15-C18 range, highlighting that the low temperature properties of the processed diesel (i.e., cloud point, cold filter plugging point (CFPP), pour point) deteriorate with increasing lipid content of the feed. Additionally, petroleum refineries targeted for co-hydrotreating are typically not set up to address carbonate corrosion (caused by the water and CO2 by-products discussed previously herein). As noted by Rasmus Egeberg and coworkers (Petroleum Technology Quarterly, 2nd Quarter, 2010, pp. 1–11; and Top Catal (2009) 52:229–240) and Jane Yao et al. (U.S. Patent No. 8,932,453), co-hydrotreating conventional lipids with petroleum fractions has also been shown to affect the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrodearomatization (HDA) activity of the catalysts. In particular, CO by-products have been shown to inhibit the HDS, HDN, and HDA reactions, particularly the catalytic activity of cobalt-molybdenum (CoMo) hydrotreating catalysts commonly used in petroleum refining.Inhibition of nickel-molybdenum (NiMo) catalysts by CO is less pronounced and can result in coprocessing operations requiring higher reactor temperatures to achieve specified product sulfur levels, potentially resulting in shorter catalyst cycle lengths.

[0007] Due to their paraffinic nature, fatty acid HDO products have high cloud points (typically between 20 and 22 °C); for use as neat fuels, a high degree of isomerization is required to lower the cloud point by 20 to 40 °C. The primary HDO product of typical fatty acid lipids is n-octadecane (C18 n-paraffin), which has a melting point of 28 °C. In comparison, n-dodecylcyclohexane (C18 alkylcyclohexane) has a melting point of 9 °C. Alkyl aromatic compounds have even lower melting points, with n-dodecylbenzene (C18 alkylbenzene) reported to have a melting point of -7 °C.

[0008] Another drawback of RD processes based on fatty acid glyceride feed relates to equipment expense and capital costs: separation and recovery of the propane co-product adds multiple process units and equipment to the plant that are not directly related to the production of RD.

[0009] A further drawback of the process relates to the oxygen content of the feedstock. With more than 11 wt% oxygen in the fatty acid feedstock, a significant amount of hydrogen is used to remove the oxygen as a water effluent. Furthermore, fatty acid deoxygenation always results in the formation of carbon oxides (CO and CO) in addition to water, and measures are required to separate these non-condensable gas-phase by-products from the recycled hydrogen.

[0010] One type of biomass-based liquid feedstock that may address some of the above shortcomings is phenolic bio-oil. As those skilled in the art will recognize, phenols can be hydrodeoxygenated to produce n-paraffins with similar carbon numbers (e.g., n-hexane, 655 kg / m 3 ) or isoparaffin (e.g., 2-methylpentane, 653 kg / m 3) have a higher energy density than aromatic compounds (e.g., benzene, 876 kg / m 3 ) and naphthenic compounds (e.g., cyclohexane, 779 kg / m 3 The production of phenolic bio-oil from lignocellulosic biomass has been disclosed in the prior art. However, the prior art also highlights challenges associated with processing such phenolic bio-oil, including incomplete deoxygenation and relatively short catalyst deactivation times.

[0011] Therefore, there remains an unmet need for renewable diesel with higher energy density and lower capital cost processes.

[0012] The present inventors have identified a type of lipid that meets the above-mentioned requirements.This type of lipid is called phenolic lipid.This phenolic lipid is structurally similar to traditional non-phenolic fatty acid lipid, but has the above-mentioned advantages provided by phenolic functionality.The similarities and differences between traditional fatty acid lipid and phenolic lipid can be seen in the exemplary molecular structures I and II of stearic acid and anacardic acid, respectively. [ka]

[0013] Structure II represents a lipid with fused phenolic groups attached to the second and third carbons from the carboxylic acid carbon of the fatty acid molecule, as shown above.

[0014] Thus, phenolic lipids have a carboxylic acid group at the ortho position of the phenol and an alkyl / alkenyl chain at the meta position. Phenolic lipids also include structures such as catechol (1,2-dihydroxybenzene) instead of phenol (hydroxybenzene).

[0015] The prior art has disclosed that the carboxylic acid group can be removed by thermal treatment (including pyrolysis, mechanical treatment, and distillation) to provide thermally decarboxylated phenolic lipids.The removal of this carboxylic acid group provides the additional advantage of reducing or eliminating the yield of CO by-products during HDO.This effect can be particularly beneficial for co-processing with petroleum feedstock, thereby reducing the inhibition of HDS activity by CO and allowing for more renewable feedstocks to be included.

[0016] Conventional lipids are prone to oxidation. Autoxidation occurs with atmospheric oxygen through a radical-initiated process involving unsaturated fatty acids. The primary products formed are hydroperoxides, which then decompose in a complex series of reactions to form multiple secondary products. These secondary products can include alcohols and carbonyl compounds, as well as polymers / oligomers. U.S. Pat. No. 2,482,760 describes a method for separating oleic acid from polyunsaturated fatty acids (having similar boiling points) by thermally polymerizing them. U.S. Pat. No. 2,664,429 discloses an alternative method for thermally polymerizing fatty acids. Thermal polymerization of unsaturated fatty acid esters has also been described in the prior art (e.g., Paschke, RF, Wheeler, DH, The Journal of the American Oil Chemists' Society, June 1949, pp. 278-283). The oxidative stability of fats and oils is measured using the active oxygen method (AOCS Cd 12-57) or the Rancimat method (AOCS Cd 12b-92).

[0017] The prior art teaches that alkylphenols are effective antioxidants. Hindered phenols, such as butyrated hydroxy toluene (BHT), are versatile antioxidants for a variety of products, including fuels and oils. Similar compounds (e.g., hydroquinone) are also used commercially as shortstopping agents to inhibit polymerization reactions (see, e.g., Index of Commercial Antioxidants and Antiozonants, The Goodyear Tire & Rubber Company, 1999). Summary of the Invention

[0018] In one aspect of the present technology, a process involving hydrodeoxygenation (HDO) of phenolic lipids is used to produce lipids with a density (at 15.6°C) of 780 kg / m 3 or greater and produces a renewable diesel fuel with a cloud point of 18° C. or less. In embodiments, the phenolic lipids are decarboxylated prior to HDO conversion.

[0019] In different aspects of the present technology, the phenolic lipid HDO process utilizes green hydrogen from water electrolysis. In some embodiments, the phenolic lipids are pre-hydrogenated. In other embodiments, the pre-hydrogenated phenolic lipids are used as a carrier for green hydrogen. In further embodiments, the pre-hydrogenated phenolic lipids are subjected to an HDO process to produce renewable diesel. In additional embodiments, the pre-hydrogenated phenolic lipids are blended with conventional non-phenolic fatty acid lipids prior to HDO conversion to renewable diesel. In some embodiments, the RD from HDO conversion is hydroisomerized to further reduce the cloud point. In other embodiments, the RD from HDO conversion is hydrocracked to produce renewable jet fuel or sustainable aviation fuel (SAF) and renewable gasoline.

[0020] In embodiments, phenolic lipids are used to provide antioxidant and polymerization inhibitor properties to traditional fatty acid-based lipids. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 shows exemplary reaction pathways for converting phenolic lipids into hydrocarbon fuel components. [Figure 2] FIG. 1 is a process flow diagram illustrating one embodiment of a method for producing renewable diesel from phenolic lipids. [Figure 3] FIG. 1 is a process flow diagram illustrating one embodiment of a method for converting phenolic lipids in a batch reactor. [Figure 4] 1 is a chromatogram showing product peaks from a gas chromatography-mass spectrometry (GCMS) instrument relating to Example 2. [Figure 5] 1 is a graph showing the results of the oxidation stability test associated with Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0022] Decarboxylation of phenolic lipids: Phenolic lipids (PL) are readily decarboxylated by thermal treatment to provide decarboxylated phenolic lipids (DPL). Figure 1 shows an example conversion pathway in which a representative PL compound, anacardic acid, is decarboxylated to the corresponding DPL, cardanol. Conversion of PL to DPL may be achieved using any number of conditions and apparatus, heating PL to temperatures between 250 and 550°F, generally in the absence of air (to avoid oxidation). Decarboxylation systems and apparatus include a stirred reactor with a heating jacket for heating with steam or hot oil. Alternatively, a vessel with steam injection may be employed. Alternatively, reactive distillation may be employed. As those skilled in the art will recognize, many variations exist and may be employed to optimize decarboxylation.

[0023] Hydrogenation of phenolic lipids: DPL undergoes hydrogenation due to the saturation of the carbon-carbon double bond and benzene ring of the alkyl group. In the case of cardanol, the alkyl group is a 15-carbon chain with one, two, or three carbon-carbon double bonds. As shown in Figure 1, the hydrogenated phenolic lipid (HPL) may be an alkylcyclohexanone or alkylcyclohexanol, depending on the degree of functional group reduction. Hydrogenation is often carried out at temperatures ranging from 250 to 500°F and under relatively high pressures (100 to 2,000 psig). Preferred catalysts include palladium on alumina or reduced nickel on alumina support or as a sponge metal catalyst (e.g., Raney catalyst). DPL may be hydrogenated in both batch and continuous reactors using fixed-bed or slurry catalyst reactor systems.

[0024] Hydrodeoxygenation of phenolic lipids: HPL compounds undergo HDO to produce hydrocarbons according to Equations 3a and 3b in Figure 1. Hydrodeoxygenation of phenolic lipids preferably uses a molybdenum sulfide or tungsten sulfide catalyst with hydrocracking activity. Examples of promoters for the HDO catalyst include nickel and cobalt. In the present invention, reactor conditions are selected so that PL can be converted to RD in a single step (Equations 1, 2a, 2b, 3a, and 3b combined). The HDO temperature in the present invention is 500-700°F under a H partial pressure of 100-2,500 psia. In an embodiment, DPL is used as the HDO feed. In an embodiment, the hydrodeoxygenation of PL / DPL to RD is carried out in a single reactor, and the RD has an oxygen content of less than 0.1 wt%, an aromatics content of less than 4%, and a bromine index of greater than 70.

[0025] First embodiment of the present technology Referring to the process embodiment shown in FIG. 2, a biological feedstock 101 containing phenolic lipids is introduced into a surge drum 10. The phenolic lipids can be plant, bacterial, fungal, or a combination thereof. In an exemplary embodiment, the phenolic lipids are cashew nut shell liquid (CNSL). CNSL is a nut component of the cashew fruit. CNSL is a dark reddish-brown liquid contained in the soft honeycomb shell of the nut and is released when the shell is broken. CNSL is a typical by-product of the cashew industry. In some embodiments, the phenolic lipids include anacardic acid, cardol, cardanol, and 2-methylcardol.

[0026] In other embodiments, the biological feedstock 101 comprises decarboxylated phenolic lipids. In embodiments, the feedstock 101 may be decarboxylated CNSL (also referred to as second boiled CNSL or technical CNSL). In embodiments, the decarboxylated phenolic lipids are at least 50% by weight cardanol.

[0027] In some embodiments, the feedstock 101 is pretreated according to lipid pretreatment methods described in the prior art, for example, U.S. Patent Nos. 11,118,133 and 9,404,064, which are incorporated herein by reference. The purpose of the pretreatment is to remove phosphorus, silicon, and metal contaminants from the feedstock 101. The need for pretreatment is more significant when the phenolic lipids are not decarboxylated, as phenolic lipids typically have higher concentrations of the contaminants listed above.

[0028] In embodiments where the phenolic lipids are not decarboxylated, measures may need to be taken in the surge drum 10 to ensure a homogenous biological feedstock is maintained. Such measures include mechanical agitation or a recirculation pump, which are well known to those skilled in the art. Additional measures may include stabilizing additives such as polymerization inhibitors, surfactants, peroxide scavengers, and antioxidants.

[0029] Surge drum 10 provides pump suction 102 for pressurization and transfer as pressurized feed 103. Pressurized feed 103 is optionally combined with a hydrocarbon diluent, such as hydrocarbon product recycle stream 113, as shown in FIG. 2. Hydrocarbon-diluted feed 103A is combined with pressurized hydrogen 133 to provide heat exchanger feed inlet 104. Heat exchanger feed inlet 104 is heated through feed-effluent exchanger 30 to provide heat exchanger feed effluent 105. Heat exchanger feed effluent 105 is further heated in heater 46 to provide heated reactor feed 106.

[0030] The heater 46 is preferably a shell-and-tube exchanger, with the reactor feed flowing through the tubes, with the heat transfer fluid flowing through the shell side. The heated reactor feed 106 has a temperature between 500 and 700°F. In embodiments, the heated reactor feed has a temperature of 520°F, 540°F, 560°F, 580°F, 600°F, 620°F, 640°F, 660°F, 680°F, or a value between any two of these temperatures. For example, in a preferred embodiment, the heated reactor feed is between 560 and 660°F. While a shell-and-tube heat exchanger is described for this embodiment of the process, those skilled in the art will recognize that other types of heat exchangers or heating methods may also be used. For example, in a preferred embodiment, the hydrocarbon product recycle stream 113 is heated in a fired heater to a temperature that, when combined with the pressurized feedstock 103, reaches the temperature of the heated reactor feed described herein, thereby avoiding heating of the phenolic lipid components in the heat exchanger.

[0031] Returning to FIG. 2, the heated reactor feed 106 enters a hydrodeoxygenation (HDO) reactor 20 containing a fixed bed catalyst. The HDO reactor 20 is maintained at a pressure between 500 and 2,700 psig. In embodiments, the reactor is maintained at 600 psig, 800 psig, 1,000 psig, 1,200 psig, 1,400 psig, 1,600 psig, 1,800 psig, 2,000 psig, 2,200 psig, 2,400 psig, 2,600 psig, or a value between any two of these pressures. In a preferred embodiment, the HDO reactor 20 is maintained between 1,600 and 2,400 psig.

[0032] The pressurized feedstock 103 is fed for 0.3 to 6.0 h. -1 The pressurized hydrogen 133 is introduced into the reactor at a liquid hourly space velocity (LHSV) between 2,000 SCF / Bbl and 10,000 SCF / Bbl of feedstock 103 per volume of catalyst per hour. In a preferred embodiment, the reactor is operated at an LHSV between 0.5 and 5.0 h -1 and gas-to-oil ratios between 4,000 and 8,000 SCF / Bbl.

[0033] HDO reactor 20 contains at least one bed of a sulfided catalyst containing molybdenum or tungsten. Preferred catalysts further contain a nickel or cobalt promoter. Such catalysts include sulfided nickel-molybdenum (NiMo), nickel-tungsten (NiW), or cobalt-molybdenum (CoMo) on an alumina or silica-alumina support. Those skilled in the art will appreciate that any catalyst or combination of catalysts may be used in the present invention, so long as the catalyst system functions in accordance with the invention described herein.

[0034] Although organic sulfur is absent or present at very low (<40 wppm) concentrations in most biological feedstocks, to maintain the functionality of the active metal sulfides of the catalyst, the composite feedstock 103 may be supplemented with sulfur compounds that decompose to hydrogen sulfide when heated and / or contacted with the catalyst. Two preferred sulfur compounds are dimethyl disulfide and carbon disulfide. The preferred concentration of these sulfur compounds in the pressurized feedstock 103 is from about 100 to about 2,000 wppm sulfur.

[0035] HDO reactor 20 operates at a weighted average bed temperature (WABT) between 550 and about 650° F. WABT is commonly used in fixed-bed, adiabatic reactors to represent the "average" or "equivalent isothermal temperature" of the reactor, which accounts for the non-linear temperature profile between the inlet and outlet of the reactor according to the following equation:

number

[0036] where i represents the bed number and Wc i is the weight fraction of total catalyst in bed i. In the embodiment of Figure 2, HDO reactor 20 includes two beds, bed 22A and bed 22B. If bed 22A and bed 22B have the same weight of catalyst, an inlet temperature of 560°F, and an outlet temperature of 640°F (due to the adiabatic temperature rise from the exothermic reaction in the HDO reactor), then bed 22A and bed 22B each have WABT1 = WABT2 = [550°F + 2(640°F)] / 3 = 610°F, and total WABT = 0.5(610°F) + 0.5(610°F) = 610°F. In Figure 1, quench hydrogen gas 107, preferably a slip stream from compressed hydrogen 133, is introduced between the two reactors to reduce the inlet temperature of bed 22B. HDO reactor 20 is operated at a WABT value between 580°F and 640°F. In embodiments, the WABT is 580°F, 590°F, 600°F, 610°F, 620°F, 630°F, 640°F, or maintained within a range between any two of these temperatures. In a preferred embodiment, the WABT is maintained between 590°F and 630°F. Surprisingly, it has been found that such a temperature range achieves a desired balance between moderate saturation to maintain a low cloud point relative to fully saturated hydrocarbons and high phenol oxygen removal.

[0037] The reactor effluent 108 is cooled through feed-effluent exchanger 30 to provide partially cooled reactor effluent 109, which is further cooled in reactor effluent cooler 32. The cooled reactor effluent 110 has a temperature of about 250 to about 400°F and contains liquid and vapor phase HDO products in addition to unconverted hydrogen gas. A gas / vapor phase 115 is separated from the liquid hydrocarbon phase 114 in separator 34. High-pressure separator 34 operates at reactor outlet pressure (negative pressure drop through the piping and exchangers). The gas / vapor phase 115 contains hydrogen and a water vapor by-product of the HDO reaction. The gas / vapor phase 115 is cooled in condenser 36 to provide a two-phase fluid, which is separated in low-temperature separator drum 38. In an embodiment, wash water 118 is introduced upstream of condenser 36 to wash solid deposits that may form on the condensation surfaces. This removes condensed water 117 from the gas phase 130, which is primarily hydrogen. The gas phase 130 is mostly recycled through the hydrogen compressor 44. To maintain the purity of the pressurized hydrogen 133 at a hydrogen purity target between 80-99 mol%, a portion of the recycle gas 130 is purged as bleed gas 130A when make-up hydrogen 131 is provided to replace chemical hydrogen consumption (as well as solubility and other losses) and maintain the gas-to-oil ratio described above. In embodiments where the phenolic lipids are not decarboxylated, more gas (containing CO and CO contaminants) needs to be purged as bleed gas 130A because decarboxylation occurs in the HDO reactor. If the phenolic lipids in the biological feedstock 101 are substantially decarboxylated (e.g., when the second boiling CNSL is phenolic lipids), a much lower percentage of the recycle gas, typically less than 2% of the total pressurized hydrogen 133, needs to be purged as bleed gas 130A. In some embodiments using decarboxylated phenolic lipids, the bleed gas 130A is between 0% and 1% of the total pressurized hydrogen 133 during normal operating conditions.

[0038] Returning to separator 34, the liquid hydrocarbon phase 114 is optionally transferred to a stripper (not shown) where dissolved gas phase by-products, such as H2S and water, are removed to provide hydrocarbons suitable for use as a diesel fuel or diesel fuel blendstock in compression ignition engines. The hydrocarbon fuel composition comprises primarily alkylcyclohexanes and methylalkylcyclohexanes, where the alkyl groups are C9 to C21 straight chain hydrocarbons. The hydrocarbon composition contains less than 0.1 wt% oxygen and up to 4 wt% aromatics. The hydrocarbon composition has a density (at 15.5°C) of at least 780 kg / m 3 The cloud point is 18°C ​​or less, preferably 16°C or less, and the bromine index is 70 or more.

[0039] In embodiments, the liquid hydrocarbon phase 114 is directed to another hydrotreating reactor (not shown) where the hydrocarbons undergo hydrocracking and isomerization reactions. In some embodiments, the hydrocracking / isomerization product is fractionated to provide low cloud point diesel with a cloud point value of -5°C or less and / or jet fuel with a freezing point of -40°C or less.

[0040] Second embodiment of the present technology As can be seen from Equations 2(a) / 2(b) and 3(a) / 3(b) in Figure 1, the hydrogenation / hydrodeoxygenation of phenolic lipids to hydrocarbon fuel compositions of the present invention can advantageously be carried out without the production of propane, CO / CO2, and other non-condensable gas-phase by-products. Therefore, the above reaction can be carried out without the need for gas purification and recycling, for example, in a batch reactor system. Also as can be seen from Equations 2(a) / 2(b) and 3(a) / 3(b), the conversion reaction of cardanol, a representative phenolic lipid molecule, to hydrocarbon fuel consumes 7 moles of hydrogen (14.1 g) per mole of n-pentadecylcyclohexane product (294.6 g). When hydrogen is provided by intermittent renewable electricity (via water electrolysis), this technology, as described below, provides an efficient method for "storing" and "transporting" renewable electricity for use as a transportation fuel.

[0041] Referring to FIG. 3 , the water electrolysis unit 50 includes an anode and a cathode separated by a membrane (not shown), as described in the prior art. The water electrolysis unit or electrolyzer is supplied with water 201 and DC electricity 202, and converts the water molecules into hydrogen 204 (from the cathode) and oxygen 203 (on the anode). Typically, 10-20 kg of H2 is generated per MW of power. In an embodiment, the electricity 202 is provided by a photovoltaic power generation station. In another embodiment, the electricity 202 is provided by a wind turbine and inverter. The electrolyzer 50 includes a compressor (not shown) that increases the pressure of the hydrogen from near atmospheric pressure to above 100 psig. In an embodiment, the hydrogen 204 is supplied at a pressure between 100 and 2000 psig. In an embodiment, the compressor is a multi-stage compressor. Because the electricity 202 is available intermittently (e.g., during the day in a photovoltaic power generation station embodiment), the hydrogen 204 is not continuously available. When available, feed valve 52 is opened to batch reactor 60, which is precharged with phenolic lipid feedstock through conduit 205. Hydrogen is dispersed into the precharged feed through hydrogen sparger 204A.

[0042] The batch reactor 60 is a pressure vessel designed to carry out the hydrogenation reaction in a slurry mode, preferably using the same type of catalyst as described above for the continuous fixed-bed HDO reactor embodiment. The preferred catalyst for the batch slurry reaction is of smaller size, typically 1.3 mm or less in equivalent particle size. The reactor is preferably equipped with an agitation system 62 for suspending the catalyst and dispersing hydrogen in the pre-charged feedstock. The batch reactor 60 also includes provisions for heating and cooling via a heat transfer fluid circulating through heating / cooling coils 206. In some embodiments, heating is achieved through a reactor jacket (not shown) and cooling is achieved through cooling coils. Other reactor systems may be used for the batch reactor 60, as would be readily understood by one skilled in the art and disclosed in prior art documents relating to hydrogenation units. These include bus loop reactors and hollow shaft gas-supply agitated reactors. In a bus loop reactor, the recirculation pump and external heat exchanger are equipped with nozzles for intimate mixing of the gas / liquid / catalyst without the use of a mechanical agitator. In a hollow shaft gas-fed stirred reactor, hydrogen is dispersed into the reactor through the agitator itself.

[0043] In an embodiment, the feed precharged into batch reactor 60 is decarboxylated CNSL. Catalyst may be added to the precharged reactor as a slurry in oil or water through conduit 215. In a preferred embodiment, the catalyst is a presulfided NiMo catalyst in a C10-C20 hydrocarbon. The concentration of catalyst in the precharged feedstock is between 1 and 20 wt. %, preferably between 2 and 10 wt. %.

[0044] The reactor is equipped with provisions for temperature display / control 54 (e.g., via heat transfer fluid 206) and pressure display / control 56 (via hydrogen supply valve 52 and backpressure control valve 72). The reactor is therefore maintained at a pressure between 500 and 2,000 psig and a temperature between 500 and 650°F. In a preferred embodiment, the reactor is operated at a pressure between 500 and 1000 psi and a temperature between 580 and 640°F.

[0045] As the phenolic lipids undergo hydrogenation and hydrodeoxygenation, hydrogen is consumed and additional hydrogen is supplied through hydrogen supply valve 52 to maintain pressure. Meanwhile, water vapor in reactor headspace vapor 208 condenses in condenser 68, causing water by-product to accumulate in condenser drum 70.

[0046] Condensed water 214 accumulates in the condenser drum 70 during the batch reaction cycle. In an embodiment, water 214 is used to provide a portion of the water supplied to the electrolyzer 50.

[0047] The reaction is complete when little or no more hydrogen is consumed (no change in reactor pressure). At that point, the agitation system 62 is turned off, allowing the catalyst to settle to the bottom of the reactor heel. The clarified liquid product layer is then discharged through conduit 209 by opening valve 67 and directed to a polishing filter (not shown) to remove any suspended catalyst and catalyst fines. The filtered hydrocarbon product comprises primarily alkylcyclohexanes and methylalkylcyclohexanes, where the alkyl groups are C9 to C21 linear hydrocarbons. The hydrocarbon composition contains less than 0.1 wt. % oxygen and up to 4 wt. % aromatics. The hydrocarbon composition has a density (at 15.5°C) of at least 780 kg / m 3 The cloud point is 18°C ​​or less, preferably 16°C or less, and the bromine index is 70 or more.

[0048] After product discharge, a new charge of decarboxylated phenolic lipid feed may be charged to reactor 60 in preparation for the next utilization of electrolysis device 50 (e.g., the next morning's power generation for a photovoltaic solar power station). Depending on the feed contaminants, periodic complete discharge of spent catalyst slurry 207 through discharge valve 69 may be required for regeneration or disposal.

[0049] The hydrocarbon products can be used as carbon-neutral diesel or diesel fuel blendstock (the phenolic carbon and hydrogen are formed naturally through photosynthesis, and the hydrodeoxygenation reaction is performed with renewable electricity). This exemplary embodiment also provides a solution to the challenge of baseload electrical energy storage.

[0050] Third embodiment of the present technology In this exemplary embodiment, conventional lipid feedstock is blended with 0.5-10 wt% phenolic lipids prior to hydrodeoxygenation.

[0051] In an embodiment, blending occurs during the transfer of the feedstock to the blended feedstock storage tank. The phenolic lipid improves the oxidative stability of conventional lipids. As a result, the phenolic lipid minimizes secondary reactions resulting from the formation of hydroperoxides, improving workability (e.g., reducing corrosion due to the formation and evaporation of lighter carboxylic acids, and reducing fouling due to thermal polymerization). Because volatile carboxylic acids, such as formic acid and acetic acid, are by-products of fatty acid oxidation, the tops of tanks containing conventional fatty acid-based lipids are prone to corrosion, contaminating the tank contents with iron and other corrosion products. This embodiment of the disclosed technology reduces such corrosion and contamination of conventional lipid feedstocks.

[0052] A traditional test method for quantifying the oxidative stability of lipids is the Rancimat method (the basis for the measurement of the oxidative stability index according to AOCS Cd 1b-92). In this test method, lipids are heated to temperatures ranging from 80 to 160 °C and subjected to accelerated oxidation via an air sparge. Air leaving the sample passes through a deionized water container, where conductivity is continuously measured. Volatile organic acid by-products formed during oxidation dissolve in water, resulting in an increase in conductivity, indicating the onset of oxidation. The time required for oxidation to be observed is known as the induction time, which typically ranges from 1 to 20 hours, depending on the type of lipid and the test temperature. The shorter the induction time, the more susceptible the lipid is to oxidation.

[0053] In one embodiment, the blended feedstock comprises about 1% by weight of phenolic lipids and 99% by weight of conventional lipids. In another embodiment, the phenolic lipids are second-boiling CNSL, and the conventional lipid feedstock includes, but is not limited to, animal fats, animal oils, microbial oils, plant fats, plant oils, vegetable fats, vegetable oils, greases, or mixtures of any two or more thereof. Plant oils and / or vegetable oils include, but are not limited to, corn oil, non-edible corn oil, babassu oil, carinata oil, soybean oil, canola oil, palm oil, rapeseed oil, tall oil, tall oil fatty acids, palm oil, palm oil fatty acid distillates, jatropha oil, palm kernel oil, sunflower oil, castor oil, camelina oil, seaweed oil, oils derived from halophilic bacteria, and mixtures of any two or more thereof. These may be classified as crude grade, degummed grade, and refined, bleached, and deodorized (RBD) grade depending on the level of pretreatment and the residual phosphorus and metal content. However, any of these grades may be used in the present technology. The animal fats and / or oils used above include, but are not limited to, inedible tallow, edible tallow, industrial tallow, flotation tallow, lard, poultry fat, poultry oil, fish fat, fish oil, and mixtures of any two or more thereof. The grease may include, but is not limited to, yellow grease, brown grease, waste vegetable oil, restaurant grease, municipal trap grease such as water treatment plants, used oil from industrial packaged food operations, and mixtures of any two or more thereof. Depending on the level of pretreatment, such biorenewable lipid feedstocks may contain between about 1 wppm and about 100 wppm phosphorus, and between about 1 wppm and about 100 wppm total metals (primarily sodium, potassium, magnesium, calcium, iron, and copper). Conventional lipids may also contain up to 20% by weight free fatty acids.The conventional lipids can be about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 30%, about 32%, about 34%, about 36%, about 38%, about 40%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, or any two of these values ​​and / or any range therebetween.

[0054] The phenolic lipid blended feedstocks provide better oxidative stability compared to conventional feedstocks as measured by the AOCS Cd 12b-92 Rancimat method. In certain embodiments, the blended feedstocks of the present invention have an induction time of greater than 10 hours at a test temperature of 110°C according to AOCS Cd 12b-92. In embodiments, the blended feedstocks have an induction time of greater than 12 hours at a test temperature of 110°C according to AOCS Cd 12b-92.

[0055] The blended feedstock containing phenolic lipids may be stored in carbon steel storage tanks for further processing and hydrodeoxygenation as described above for the first embodiment.

[0056] Fourth embodiment of the present technology The decarboxylated phenolic lipids are introduced into a petroleum hydrotreater at a content of about 1 to about 20 wt%. In another embodiment, the hydrotreater is a diesel hydrotreater where straight-run diesel from a crude distillation unit is desulfurized. In preferred embodiments, the decarboxylated phenolic lipids are second-boiling CNSL containing less than 3 wppm phosphorus, less than 2 wppm phosphorus, or less than 1 wppm phosphorus. In these embodiments, the corresponding total metals in the second-boiling CNSL are less than 3 wppm, less than 2 wppm, or less than 1 wppm. The diesel hydrotreater contains one or more beds of CoMo catalyst and / or NiMo catalyst and operates at a WABT value in the range of 630 to 750°F and a pressure between 100 and 2,400 psig (typically 200 to 1,000 psig). The straight-run diesel has a sulfur content of up to 0.6 wt%, typically in the range of 0.1 to 0.5 wt%. In embodiments, the straight-run diesel feed is partially or completely replaced with light gas oil or cracked stock, such as light vacuum gas oil or light cycle oil, having sulfur levels as high as 1.3 wt.% or in the range of 0.6-1.3 wt.%. The diesel hydrotreater is operated to provide hydrotreated diesel containing 15 wppm or less of sulfur, preferably 10 wppm or less of sulfur. In embodiments, the hydrotreated diesel has a sulfur content of 5-10 wppm and a biomass carbon content of 1-20 wt.% as measured by standard test method ASTM D6866. Hydrodeoxygenation of biomass components is achieved while avoiding the formation of CO and CO by-products, thereby avoiding inhibition of HDS and HDN activity and the formation of carbonic acid in the water by-product.

[0057] example Example 1 Two identical pilot plant reactors were charged with two beds of catalyst in an identical manner. The top bed contained 8 cc of low-activity Mo catalyst, and the bottom bed contained 20 cc of high-activity NiMo catalyst. Each catalyst bed was diluted 1:1 by volume with inert glass beads of 70-100 mesh size.

[0058] The two catalysts were in the oxide form at the time of injection and were reduced to the active sulfide form during start-up. The sulfiding procedure included a low temperature hold at approximately 400°F and a high temperature hold at 650°F (after H2S breakthrough was observed).

[0059] Commercially available canola oil was used to confirm the catalytic activity of each reactor before switching to the phenolic lipid feedstock. Both reactors were operated at LHSV1h -1 , operated at a solvent-to-oil ratio of 3:1 (using SOLTROL 220 as the solvent), a hydrogen pressure of 1800 psi, and a similar stoichiometric excess of hydrogen (actual hydrogen-to-phenol-lipid ratio of approximately 8,600 SCF / Bbl).

[0060] Two different phenolic lipid feedstocks were used: (1) crude cashew nut shell liquid (CNSL) and (2) second-boiled CNSL (decarboxylated and distilled CNSL). Prior to blending with canola oil, the crude CNSL underwent a pretreatment process. The pretreatment process included citric acid washing and centrifugation, as commonly described in the prior art (e.g., U.S. Pat. No. 9,404,604). Both feedstocks were diluted with canola oil to achieve 10 wt. % CNSL in the mixed lipids.

[0061] The second boil CNSL at 10% by weight in canola had less than 1 ppm phosphorus and metals (combined) and only 25 ppm organic nitrogen. In contrast, the pretreated crude CNSL at 10% by weight in canola contained 30 ppm potassium, 5 ppm sodium, and 167 ppm organic nitrogen, and had substantially higher concentrations of these contaminants.

[0062] The reactor was operated isothermally at various temperature conditions, as summarized in Table 1. The hydrocarbon phase from the steady-state HDO product was analyzed for residual oxygen, cloud point, aromatics content, and bromine index. Oxygen analysis was performed using Fast Neutron Activation Analysis (FNAA) with a detection limit of 0.02 wt%.

[0063] [Table 1]

[0064] As can be seen from Table 1, HDO of feedstocks containing both crude CNSL and second-boil (decarboxylated) CNSL using this technology produced hydrocarbons without detectable oxygen at all reactor temperatures tested. The bromine index indicated that the saturation content of phenolic lipid-based hydrocarbons increased with temperature, along with a clear increase in the cloud point of the hydrocarbons. A similar correlation has not been reported for HDO hydrocarbons derived from conventional non-phenolic fatty acid lipids. Therefore, the optimal HDO conditions for producing phenolic lipid-based hydrocarbon fuels with lower cloud points than non-phenolic fatty acid lipid-based hydrocarbons appear to be WABTs between 600 and 620°F.

[0065] Example 2 A sample product of the hydrodeoxygenation of the second boiling CNSL from Example 1 was analyzed by gas chromatography (GC) with a mass spectrometer detector to identify the reaction products. The analysis was performed on an approximately 10-fold dilution of the sample in heptane.

[0066] The GC equipment and operating conditions are shown below. Agilent 7890 GC and 5977B GC Column: J&W HP-5ms GC column, 30 m, 0.25 mm, 0.25 μm, Agilent 19091S-433 Column flow rate: 1 mL / min Inlet: Split, split ratio 20:1, 250℃ Oven: 45°C, heating rate 15°C / min up to 325°C, hold for 5 minutes). ·Injection volume: 1μL

[0067] The chromatogram generated in this experiment is shown in Figure 4, with product peaks numbered 1 through 19. Peaks associated with SOLTROL solvent and canola oil HDO conversion (i.e., octadecane, heptadecane, hexadecane, and pentadecane) are not numbered.

[0068] Table 2 shows the identification of each product species by highest probability match with the National Institute of Standards and Technology (NIST) mass spectrometry database library. As can be seen in Table 2, the major product (peak 7) is identified as n-pentadecyclohexane. Pentadecylbenzene (peak 9) is identified as a minor product. Both of these are related to the hydrodeoxygenation of cardanol. C20-C22 paraffins (eicosane, heneicosane, and docosane) may include products of canola oil HDO. C24+ hydrocarbons (peaks 16-19) among the reaction products are related to the hydrodeoxygenation of sterols (which may be present as minor unsaponifiables in lipids).

[0069] [Table 2]

[0070] Example 3 Blends of fats, oils, and greases (FOG), including used cooking oil, were subjected to oxidative stability testing with and without CNSL. Distilled CNSL was added to the FOG at concentrations of 1% and 2% by weight of the blend feedstock. These two samples, along with a sample of the same FOG without CNSL, were subjected to oxidative stability testing per AOCS Test Method Cd 12b-92. Testing was performed at 110°C.

[0071] The results are shown in Figure 5. As can be seen in Figure 5, the oxidative stability increased with induction time from 6.7 hours (without CNSL) to 10.7 hours (with 2% CNSL).

[0072] While the present invention has been described in relation to its preferred embodiments, it will be apparent to those skilled in the art that various modifications can be made to the preferred embodiments described herein without departing from the spirit and scope of the invention. However, all such modifications and variations apparent to those skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A lipid having a C3 to C18 carbon chain containing a carbon-carbon double bond, having a fused phenolic group attached to the second and third carbons from the carboxylic acid carbon of a fatty acid molecule according to structure II, wherein the phenolic lipid is used as a feedstock for hydrodeoxygenation for renewable diesel, and the lipid is optionally decarboxylated prior to the hydrodeoxygenation step. 【Chemistry 1】

2. 1. A method for producing renewable diesel fuel, the method comprising: a. combining a phenolic lipid with a hydrocarbon diluent to provide a hydrocarbon-diluted phenolic lipid; b. hydrodeoxygenating the hydrocarbon-diluted phenolic lipids in a reactor to provide a reactor effluent comprising hydrodeoxygenated phenolic lipids; and c. Separating the hydrodeoxygenated phenolic lipids from the reactor effluent; Including, d. The hydrodeoxygenated phenolic lipid is a hydrocarbon having an oxygen content of less than 0.1% by weight; A method for producing renewable diesel fuel.

3. 3. The method of claim 2, wherein the reactor contains a molybdenum sulfide catalyst and operates at a temperature between 600 and 650°F in the presence of hydrogen under a pressure in the range of 500 to 2700 psig.

4. 3. The method of claim 2, wherein the phenolic lipid is cashew nut shell liquid (CNSL).

5. 3. The method of claim 2, wherein the phenolic lipid is blended with a non-phenolic lipid.

6. 3. The method of claim 2, wherein the phenolic lipid is diluted with a paraffinic hydrocarbon.

7. 7. The method of claim 6, wherein the volume ratio of the phenolic lipid to the paraffinic hydrocarbon is between 1:1 and 1:

4.

8. 3. The method of claim 2, wherein the phenolic lipid is partially hydrogenated.

9. 3. The method of claim 2, wherein the molybdenum sulfide catalyst comprises a nickel promoter or a cobalt promoter.

10. 3. The method of claim 2, wherein the hydrodeoxygenated phenolic lipid has a Bromine Index greater than 70.

11. 3. The method of claim 2, wherein the hydrodeoxygenated phenolic lipid is a hydrocarbon within the diesel boiling range (150-380°C).

12. 12. The method of claim 11, wherein the hydrocarbons have less than 4% by weight of mono-aromatic hydrocarbons and no detectable polyaromatic hydrocarbons.

13. 11. The method of claim 10, wherein the hydrocarbon comprises a C21 hydrocarbon.

14. 11. The method of claim 10, wherein the hydrocarbon comprises an alkylcyclohexane.

15. 11. The method of claim 10, wherein the hydrocarbon is used as a fuel or fuel component for a compression ignition engine.

16. 11. The process of claim 10, wherein the hydrocarbons are not isomerized.

17. 16. The method of claim 15, wherein the hydrocarbon has a cloud point of 16°C or less.

18. A renewable diesel (RD) fuel, the renewable diesel fuel comprising: a. n-alkylcyclohexane compounds, b. less than 0.1 wt. % oxygen; c. A Bromine Index of 70 or greater; d. A monoaromatic compound content in the range of 1% to 4% by weight Including, e. Contains no detectable di-, tri-, or polyaromatic compounds; f. The n-alkylcyclohexane compound is a product of hydrodeoxygenation of cashew nut shell liquid. Renewable diesel fuel.

19. 1. A method for storing electricity, the method comprising: a. directing said electricity to an electrolyzer for splitting a water stream into hydrogen and oxygen streams; b. supplying the hydrogen to a batch reactor containing phenolic lipids; c. subjecting the phenolic lipids to hydrodeoxygenation in the batch reactor; d. Discharging the hydrodeoxygenated phenolic lipid from the batch reactor; Including, e. The hydrodeoxygenated phenolic lipid is a hydrocarbon having an oxygen content of less than 0.1% by weight; A method for storing electricity.

20. 3. The method of claim 2, wherein the phenolic lipids are decarboxylated prior to hydrodeoxygenation.

21. 1. A blended feedstock for hydrodeoxygenation comprising phenolic lipids and conventional lipids, a. The phenolic lipids are second boiled cashew nut shell liquid; b. the conventional lipids contain at least 5% by weight of free fatty acids; c. the blended feedstock has greater oxidative stability than the conventional lipid; Blended Feedstocks.

22. 22. The method of claim 21, wherein the blended feedstock has a Rancimat induction time of greater than 10 hours measured at a test temperature of 110°C.

23. 1. A method for producing low sulfur diesel containing biomass, the method comprising: a. providing a composite feed comprising petroleum diesel (straight run, light gas oil, light cycle oil, or light vacuum gas oil) having 0.1 to 1.3 wt. % sulfur and a phenolic lipid; b. hydrotreating the composite feed in a hydrotreater comprising a CoMo catalyst and / or a NiMo catalyst; and c. recovering a hydrotreated diesel fuel having less than 15 wppm sulfur; Including, d. The composite feed comprises up to 20% by weight of decarboxylated phenolic lipids, wherein the decarboxylated phenolic lipids are second boiled cashew nut shell liquid. A method for producing low sulfur diesel containing biomass.

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