EP2611884A2

EP2611884A2 - Treatment of hydrocarbon feed

Info

Publication number: EP2611884A2
Application number: EP11822320.5A
Authority: EP
Inventors: Shabbir Husain; Lin Li; Zhen Zhou; Alexander E. Kuperman; Zunqing He; Huping Luo
Original assignee: Chevron USA Inc
Current assignee: Chevron USA Inc
Priority date: 2010-08-31
Filing date: 2011-08-10
Publication date: 2013-07-10
Also published as: WO2012030492A2; EP2611884A4; WO2012030492A3; BR112013004568A2; BR112013004568B1

Abstract

Disclosed are embodiments relating to a process for treating a hydrocarbon feedstock. In one embodiment with a biologically derived oil as the feedstock, the biologically derived oil feed is deoxygenated by contacting the feed with a metal titanate catalyst having an MTiO₃ structure wherein M is a metal having a valence of 2+. In another embodiment with a high acid crude oil as the feedstock, the metal titanate catalyst is employed to reduce the total acid number of the hydrocarbon feed by contacting the feed with the metal titanate catalyst, resulting in a hydrocarbon product having a final total acid number lower than the initial total acid number of the feed. The process can be integrated into conventional refining operations in order to treat refinery feedstreams, whether it is a biofuel source, or a high acid crude.

Description

TREATMENT OF HYDROCARBON FEED

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of US Patent Application Serial No.

12/889715 with a filing date of September 24, 2010; and US Patent Application Serial No. 12/873113 with a filing date of August, 2010, the disclosures of which are incorporated herein by reference.

FIELD

The disclosure relates to a process for treating a hydrocarbon feed, including removing oxygen from a biologically derived oil for a hydrocarbon products suitable for use as transportation fuel, or reducing the total acid number of a hydrocarbon feed.

BACKGROUND

For hydrocarbon feedstock, a high acid crude oil ("HAC") can cause corrosion of equipment utilized in refining operations, resulting in higher operating expenses involved in maintaining equipment and refinery shutdowns due to equipment failure. The corrosion is generally attributed to the high concentration of naphthenic acids and other acidic species in the crude oil. Naphthenic acids are found in various crudes, such as, for example, crudes from California, Venezuela, North Sea, Western Africa, India, China and Russia. Chemical reactions to reduce total acid number (TAN) of crude oil have been investigated. Such TAN reduction technologies can be divided into the categories of hydrotreating, chemical neutralization, esterification, amidation and decarboxylation.

Another type of hydrocarbon feedstock is biodiesel, which is biologically derived oils and fats. Biodiesel has attracted increased attention due to its potential of providing a significant portion of transportation fuels. Biologically derived oils and fats are complex mixtures of triglycerides and free fatty acids. Transesterification, i.e. reacting triglycerides with methanol to produce fatty acid methyl-ester (FAME), is used to make biodiesel from biologically derived oils and fats. FAMEs generally have a high cetane number and are considered to burn cleanly, but they still contain problematic levels of oxygen. A major drawback of this type of biodiesel is that it generally has poor oxidative and thermal stability.

In order to improve the energy density and stability of this type of hydrocarbon feedstock 1, oxygen must be at least partially removed. Hydrotreating is one route to remove oxygen from triglycerides, but it has the disadvantage that it consumes large amounts of hydrogen since during hydrotreating, oxygen is reacted with hydrogen and removed through the formation of water. The heat release from hydrotreating reactions is also a significant challenge for reactor design. Decarboxylation is another route to remove oxygen from biofuels. Although the hydrocarbons produced through decarboxylation may contain less carbon than its fatty acid or ester counterpart and those from the hydrotreating route, decarboxylation does not consume hydrogen. Generally speaking, consuming the carbon contained in a biologically derived feedstock to remove oxygen is less costly than consuming hydrogen which must be produced through expensive processes.

There have been reports in the literature of bio fuel production through decarboxylation and decarbonylation of biologically derived oils using supported noble metal catalysts at relatively high temperatures, e.g., for example, greater than 350°C. For example, platinum (Pt) supported on carbon had been found to be an effective catalyst. However, carbon monoxide (CO) produced from the reaction can poison the Pt catalyst. Hence, high hydrogen partial pressure is needed to keep the catalyst surface clean and reduce catalyst deactivation.

There is a need for an improved method to treat hydrocarbon feedstock such as biologically derived oils to produce transportation fuels. The improved method can also be used to treat other hydrocarbon feedstock, such as, for example, a high acid crude, to render it less corrosive to processing equipment.

SUMMARY

In one embodiment, the invention relates to a process for removing oxygen from a hydrocarbon feedstock such as biologically derived oil feed comprising fatty acids and/or fatty acid esters, by contacting the feed with a catalyst comprising a metal titanate having an MT1O₃ structure wherein M is a metal having a valence of 2+ in the absence of added hydrogen gas, resulting in a hydrocarbon product having a final oxygen content less than the initial oxygen content.

In another embodiment, the invention relates to a process for reducing the total acid number in a liquid hydrocarbon feed by, contacting the feed having an initial total acid number of at least 0.5 with a catalyst comprising a metal titanate having an MT1O₃ structure, wherein M is a metal having a valence of 2+ at a temperature of between 200° C. and 400° C, thereby resulting in a treated hydrocarbon product having a final total acid number at least 10% lower than the initial total acid number. In yet another embodiment, the invention relates to a process for refining a low acid crude oil and a high acid crude oil, comprising separately introducing a relatively low acid crude oil feed and a relatively high acid crude oil feed to an atmospheric distillation column, wherein the relatively high acid crude oil feed is contacted with a catalyst comprising a metal titanate having an MT1O₃ structure, wherein M is a metal having a valence of 2+ prior to introduction to the atmospheric distillation column.

DESCRIPTION OF THE DRAWINGS

Figure 1 is a block flow diagram illustrating an embodiment for a unit utilizing a catalyst comprising a metal titanate having an MT1O₃ structure, for the treatment of a high

TAN hydrocarbon feedstock or for the removal of oxygen from a biofuel.

Figure 2 is a process flow diagram illustrating an embodiment for a process to refine a crude oil feed, illustrating various locations at which a total acid number reduction unit can be utilized to treat various streams within the process scheme.

Figure 3 is a process flow diagram illustrating another embodiment for a process scheme in which a relatively low acid crude and a high acid crude are fed to an atmospheric distillation column, and a total acid number reduction unit is utilized to treat the high acid crude.

Figure 4 is a graph illustrating deoxygenation effects in a reaction employing an employing of a catalyst having an MT1O₃ structure.

Figure 5 is a graph comparing the deoxygenation effects (in terms of C0₂ release) in reactions with and without employing a catalyst having an MT1O₃ structure.

DETAILED DESCRIPTION

The following terms will be used throughout the specification and will have the following meanings unless otherwise indicated.

"Hydrocarbon feed" refers to a feed that includes hydrocarbons. Hydrocarbon feed may include, but is not limited to, crude oil, synthetic crude, distillate products, straight run feed, atmospheric and vacuum bottoms, vacuum gas oil, biologically derived oils, or mixtures thereof.

"Naphthenic acid" (NA) refers to the carboxylic acid content of a sample of hydrocarbon feed including but not limited to alkyl substituted acyclics, fatty acids, aromatic acids, carbazoles and isoprenoid acids. Examples in certain crude oils include complex acid structures with two, three or four carboxylic groups (tetrameric acids as well as structures containing heteroatoms, e.g., sulfur, oxygen, and nitrogen).

"Total acid number" (TAN) refers to the amount of KOH in milligrams required to neutralize one gram sample of hydrocarbon feed. TAN is determined by ASTM Method D664.

The prefix "bio," as used herein, refers to an association with a renewable resource of biological origin, such resources generally being exclusive of fossil fuels.

A "biologically-derived oil" or "biofuel" as defined herein, refers to any triglyceride- containing oil that is at least partially derived from a biological source such as, but not limited to, biomass such as crops, vegetables, microalgae, and the like. Such oils may further comprise free fatty acids. Plant and animal oils and fats typically contain 0-30 wt% free fatty acids, which are formed during hydrolysis (e.g. enzymatic hydrolysis) of triglycerides. The amount of free fatty acids present in vegetable oils is typically 1-5 wt% and in animal fat, 10-25 wt%. The biological source is henceforth referred to as "biomass."

"Triglyceride," as defined herein, refers to class of molecules having the following general formula:

CH₂OCOR¹

CHOCOR²

I

CH₂OCOR³

where R¹, R², and R³ are molecular chains comprising carbon and hydrogen, and can be the same or different, and wherein one or more of the branches defined by R¹, R², and R³ can have unsaturated regions. "Triglyceride-based," as defined herein, is used to describe biofuel precursor material comprising triglyceride species in the majority (by weight), but possibly also comprising other oxygenate species such as free fatty acids.

A "carboxylic acid" or "fatty acid," as defined herein, is a class of organic acids having the general formula: R-COOH, where R is generally a saturated (alkyl)hydrocarbon chain or a mono- or polyunsaturated (alkenyl)hydrocarbon chain.

"Transesterification," or simply "esterification," refers to the reaction between a fatty acid or ester (e.g., a triglyceride) and an alcohol to yield an ester species.

"Transportation fuels," as defined herein, refer to hydrocarbon-based fuels suitable for consumption by vehicles including, but are not limited to, diesel, gasoline, jet fuel and the like. "Diesel fuel," as defined herein, is a material suitable for use in diesel engines and conforming to the current version at least one of the following specifications: ASTM D 975— "Standard Specification for Diesel Fuel Oils"; European Grade CEN 90; Japanese Fuel Standards JIS K 2204; The United States National Conference on Weights and Measures (NCWM) 1997 guidelines for premium diesel fuel; and The United States Engine

Manufacturers Association recommended guideline for premium diesel fuel (FQP-1A).

"Biodiesel," as used herein, refers to diesel fuel that is at least significantly derived from a biological source, and which is generally consistent with ASTM International Standard Test Method D-6751. Often, biodiesel is blended with conventional petroleum diesel. B20 is a blend of 20 percent biodiesel with 80 percent conventional diesel. B 100 denotes pure biodiesel.

"Carbon number" or "C_n," where "n" is an integer, describes a hydrocarbon or hydrocarbon-containing molecule or fragment (e.g., an alkyl or alkenyl group) wherein "n" denotes the number of carbon atoms in the fragment or molecule.

While "hydrocarbons" are substantially comprised of carbon and hydrogen, hydrocarbon-based materials can include molecules with heteroatoms, e.g., alcohols, carboxylic acids, and the like; the heteroatoms generally being atoms other than C or H, and typically atoms selected from the group consisting of O, N, S, P, and combinations thereof.

"Deoxygenation" refers to the removal of oxygen from organic molecules, such as fatty acid derivatives, alcohols, ketones, aldehydes or ethers.

"Decarboxylation" refers to the removal of carboxyl oxygen from acid molecules.

"Decarbonylation" refers to the removal of carbonyl oxygen from organic molecules with carbonyl functional groups other than acids.

The present disclosure provides embodiments for treating hydrocarbon feedstock. In one embodiment, a biologically derived oil feed is deoxygenated by contacting the oil feed with a metal titanate catalyst in the absence of added hydrogen gas. In another embodiment, the total acid number, also referred to as TAN, of a hydrocarbon feed is reduced by contacting the hydrocarbon feed with a metal titanate catalyst in a suitable reactor.

Hydrocarbon Feedstock: In one embodiment, the hydrocarbon feedstock is a bio oil and/or fat, originating from renewable sources, such as fats and oils from plants and/or animals and/or fish and compounds derived from them. The basic structural unit of a typical plant or vegetable or animal oil/fat useful as the feedstock is a triglyceride, which is a triester of glycerol with three fatty acid molecules, having the structure presented in the following formula I: CH₂OCOR¹

CHOCOR² CH₂OCOR³

In formula I, R¹, R², and R³ can be alkyl chains. Fatty acids found in natural triglycerides are almost solely fatty acids of even carbon number. Therefore R¹, R², and R³ generally are C₅-C₂₃ alkyl groups, typically C₁₁-C₁₉ alkyl groups and often C₁₅ or C₁₇ alkyl groups. R¹, R², and R³ may contain carbon-carbon double bonds. These alkyl chains can be saturated, unsaturated or polyunsaturated.

Suitable bio oils are plant and vegetable oils and fats, animal fats, fish oils, and mixtures thereof containing fatty acids and/or fatty acid esters. Nonlimiting examples of suitable materials are wood-based and other plant-based and vegetable-based fats and oils such as rapeseed oil, colza oil, canola oil, tall oil, sunflower oil, soybean oil, hempseed oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, algae oil, as well as fats contained in plants bred by means of gene manipulation, animal-based fats such as lard, bacon fat, tallow, train oil, and fats contained in milk, as well as recycled fats of the food industry and mixtures of the above. In one embodiment, the feedstock is a bio oil comprising pyrolysis oil. In another embodiment, the hydrocarbon feedstock is a bio oil comprising FAME. Bio oils and fats suitable as feed may comprise C₁₂-C₂₄ fatty acids, derivatives thereof such as anhydrides or esters of fatty acids as well as triglycerides of fatty acids or combinations thereof. Fatty acids or fatty acid derivatives, such as esters may be produced via hydrolysis of bio oils or by their fractionalization or transesterification reactions of triglycerides.

In another embodiment, the hydrocarbon feedstock is a traditional feed including but are not limited to, crude oil, synthetic crude oil, straight run feed, distillate products, atmospheric and vacuum bottoms, vacuum gas oil and biologically derived oils having an initial total acid number of at least 0.5. In some embodiments, the liquid hydrocarbon feed is a high acid crude, i.e. crude oil having a TAN of at least 0.5.

Catalysts for Treatment: Catalysts suitable for use in the embodiments described herein include metal titanates, also referred to herein interchangeably as titanates, which can be expressed as MT1O₃ wherein M is a metal having a valence of 2+. The metal M may also be capable of multiple valences. In one embodiment, the catalyst consists essentially of at least a metal titanate of the formula MT1O₃. In another embodiment, the catalyst contains a mixture of a metal titanate with at least a metal oxide, with both basic and acid properties. In one embodiment, the catalyst consists essentially of at least a metal titanate with at least a basic oxide. Examples of basic (metal) oxides include, but are not limited to calcium oxide, magnesium oxide, magnesium aluminum oxide, zinc oxide, lanthanum oxide, cerium oxide, barium oxide and mixtures thereof. In one embodiment, the molar ratio of metal titanate to metal oxide ranges from 1 : 10 to 10: 1. In a second embodiment, the molar ratio ranges from 1 :5 to 5 : 1. In a third embodiment, the ratio ranges from 1 :2 to 2: 1.

Examples of suitable metal titanates for use in the catalyst include, but are not limited to, magnesium titanate, copper titanate, nickel titanate, iron(II) titanium oxide, cobalt titanium oxide, manganese(II) titanium oxide, lead(II) titanate, calcium titanate, barium titanate, zinc titanate, and mixtures thereof.

Pure metal titanates have a perovskite crystalline structure. In one embodiment, the catalyst contains at least 80% by weight titanate. In another embodiment, the catalyst contains at least 1% by weight titanate based on the total weight of the catalyst; in another embodiment at least 5% wt. % titanate; in another embodiment at least 10% 5wt. % titanate, including any other desirable active components as well as optional support material. The actual amount of titanate needed will vary depending on whether or not a support is used, and how the catalyst is dispersed on the support.

In one embodiment, the catalyst has a BET surface area greater than 20 m²/g; in another embodiment the BET surface area is greater than 200 mVg; in yet another embodiment the BET surface area is greater than 400 m²/g.

In one embodiment, the catalyst is a supported catalyst. Suitable support materials include silica, alumina, silica-alumina, carbon, molecular sieves and mixtures thereof. In one embodiment, the catalyst is deposited on a carbon support having a BET surface area of between 500 m²/g and 1500 m²/g. In another embodiment, the catalyst is deposited on a support selected from silica, alumina, silica-alumina and mixtures thereof, and the support has a BET surface area of between 150 m²/g and 600 m²/g. In one embodiment, the support can be a monolithic support. Alternatively, the catalyst can be unsupported.

Treatment Method: In some embodiments, the treatment process includes contacting the hydrocarbon feed with a metal titanate catalyst within a suitable reactor. A single catalyst bed or multiple catalyst beds may be used for the treatment. In some embodiments, the feed is passed over a catalyst, e.g., a monolithic catalyst, in a fixed bed reactor operating in continuous mode. In another embodiment, the feed contacts the catalyst in a slurry bed reactor in continuous mode. Either an upflow or downflow type reactor can be used. The feed can also be contacted with the catalyst in a batch reactor. In one embodiment, the reaction is conducted in the absence of added hydrogen.

It is desirable to minimize cracking of the liquid hydrocarbon feed by running the process at mild conditions, such as a temperature at less than 500°C. The feed is contacted with the catalyst in one embodiment from 200°C to 500°C; in another embodiment from 200°C to 400°C; and in yet another embodiment, from 200°C to 350°C. In one embodiment, the pressure within the reactor is between 100 kPa and 1000 kPa (all pressures indicated herein are absolute); in another embodiment the pressure is between 30 psi (210 kPa) and 100 psi (690 kPa). The pressure can be below 100 kPa, although depending on the pressure in the surrounding equipment, it may be necessary to pump the stream exiting the reactor to a higher pressure.

In one embodiment, the LHSV is between 0.1 and 10 h^"1' in another embodiment, the LHSV is between 0.2 and 5.0 h^"1; in another embodiment, the LHSV is between 0.4 and 2.0 h^"1. LHSV refers to the volumetric liquid feed rate per total volume of catalyst and is expressed as the inverse of hours (h^_1).

In one embodiment, the treatment is carried out under inert condition, meaning with the addition of a light hydrocarbon gas, e.g., C1-C4 gas, or an inert gas such as nitrogen, helium, neon, and argon, etc., and with very little if any added hydrogen. In another embodiment, the treatment is without any added hydrogen. In yet another embodiment, very little hydrogen gas introduced to the reactor is such that the mole ratio of hydrogen to hydrocarbon feed is less than 0.1.

In one embodiment for the treatment of high TAN crude, the treatment process can be utilized to treat various streams within a crude refining operation, e.g., for the pre-treatment of high acid crudes prior to further processing thus avoiding corrosion of equipment used in refining operations. In another embodiment, the treatment unit can be selectively located prior to critical pieces of equipment for the treatment of high acid crude prior to being introduced to the equipment, e.g., heaters, distillation columns, and the like. The equipment for the high acid crude feeds can be isolated from the equipment for the low acid crude, and being placed in operation whenever there is a need to treat a high acid feedstock.

In one embodiment for the removal of oxygen from a biofuel, the deoxygenation treatment step may optionally be followed by various other steps, e.g., isomerisation, hydrofinishing, etc., depending on the biofuel being used as the hydrocarbon feedstock as well as the desired final product. Treated Product: In one embodiment, the process is for treating high acid crude oils before reaching FCC (fluid catalytic cracking) or hydroprocessing units located downstream. After treatment, the TAN can be reduced significantly, allowing high acid crude to be treated prior to downstream processing in refineries. The TAN can be reduced by various amounts. In one embodiment, the final TAN of the treated hydrocarbon product is at least 10% lower than the initial TAN of the liquid hydrocarbon feed; in a second embodiment, the final TAN is at least 50% lower than the initial TAN; in a third embodiment, the final TAN is at least 90% lower than the initial TAN. The actual reduction will depend on the particular feed and the desired TAN of the treated hydrocarbon product. In one embodiment wherein the feed is a high acid crude having a TAN of at least 10, the treated crude has a TAN of less than 5. In a second embodiment wherein the feed is a high acid crude feed having a TAN of at least 20, the TAN reduction is at least 50% resulting in a treated crude with a TAN of 10 or less.

In one embodiment for the treatment of a biologically derived oil as the feedstock, the treated product has a lower oxygen content than that of the feed. In some embodiments, the oxygen content of the treated product is at least 20% less than the initial oxygen content of the feed. In some embodiments, the final oxygen content is at least 50% less than the initial oxygen content of the feed.

Figures Illustrating Embodiments: Reference will be made to the figures to further illustrate embodiments of the invention. In one embodiment, illustrated in Figure 1 , a hydrocarbon feed 2 is fed to a fixed bed reactor 4 containing a bed of catalyst comprising a metal titanate having an MT1O₃ structure. The process can alternatively be conducted in a slurry bed reactor (not shown). Treated product stream 8 is removed from the reactor for further processing as desired. Depending on the hydrocarbon feedstock being treated, gas stream 6 containing various components including, but not limited to, carbon dioxide and water vapor, is removed from the reactor and passes through condenser 10 utilizing incoming cooling water 12. In other embodiments, the gas stream 6 may further comprise methane, carbon monoxide, and light hydrocarbons. Effluent cooling water 14 exits from the condenser. Condensed and mixed stream 16 is sent to three-phase separator 18. Gas stream 20 is removed from the separator and processed. Water 22 is removed from the separator. Light ends stream 24 is removed from the separator and can be combined with the treated product stream, e.g., low acid crude stream 8.

In one embodiment for the treatment of high TAN hydrocarbon feedstock, the metal titanate catalyst bed can optionally be subjected to the flow of a stripping gas stream 28, which can be, for example, refinery gas or associated gas, depending on the location and application of the total acid number reduction unit. The stripping gas can also be an inert gas, e.g. nitrogen, for example, for the treatment of a biofuel as the feedstock. A blower or compressor 30 can be used to feed optional low pressure stripping gas stream 28 to the reactor. This gas stream serves to strip carbon dioxide, water vapor and other light gases if any from the reactor 4. In one embodiment, the flow of gas is countercurrent to the flow of the hydrocarbon feed. In one embodiment, the flow of gas is between 50 and 200 scf/bbl (standard cubic feet of gas per barrel of hydrocarbon feed).

In one embodiment for the treatment of a high TAN crude in a refining operation as illustrated in Figure 2. Crude oil feed 32, which can be a high acid crude or a blend of multiple crudes, is initially routed through heat exchanger 34, desalter 36 and second heat exchanger 38 prior to separation in flash drum 42. Light fraction 44 is separated overhead, and heavy fraction 46 is passed to fired heater 48 prior to being introduced to atmospheric distillation column 50. Various fractions 52, 54, 56, 58, 60 and 62 are removed from distillation column 50. Vacuum column 68 is used to treat the atmospheric distillation residue 67, thus producing vacuum overhead stream 70, multiple cuts of vacuum gas oil stream 72 and vacuum residual stream 74.

The TAN reduction 40 unit can be located to treat any refinery stream, such as those locations indicated in Figure 2 by the letters A through G. For example, in one embodiment, a TAN reduction unit at location A is used to treat stream 46 prior to entering heater 48, thus protecting the heater from corrosion. Alternatively, in another embodiment, a TAN reduction unit 40 at location B can be used to treat the stream exiting heater 48. A TAN reduction unit can be located at location C in order to treat the atmospheric distillation residue from distillation column 50 prior to entering heater 66. Where isolation of the desalting and heating train cannot be accomplished, this reduces the overall quantity of crude that must be processed through the TAN reduction unit. A TAN reduction unit can be located at location D in order to treat the atmospheric gas oil fraction 62. A TAN reduction unit can be located at location E in order to treat the diesel fraction 60. A TAN reduction unit can be located at location F in order to treat kerosene fraction 58. A TAN reduction unit can be located at location G in order to treat vacuum gas oil fraction 72, which is a petroleum fraction where acids are known to concentrate. While each of these locations indicated by letters A through G represents separate possible embodiments, a TAN reduction unit can be located at multiple of these locations. Figure 3 illustrates one embodiment in which a relatively low acid crude oil feed 82 and a relatively high acid crude oil feed 102 are separately fed to a refining operation. Each feed is heated through a heat exchanger (84 and 104, respectively), passes a desalter (86 and 106), a second heat exchanger (88 and 108), a flash drum (90 and 110) and a heater (96 and 114) prior to each stream being introduced to atmospheric distillation column 120. Relatively high acid crude 102 passes through a total acid number reduction unit 40 prior to being introduced to the distillation column 20. Various fractions 122, 124, 126, 128, 130, 132 and 134 are taken off the distillation column. Atmospheric distillation residue 134 is sent to heater 136 and vacuum column 138 from which fractions 140, 142 and 144 are taken off. In this embodiment, the equipment for the high acid crude feeds can be isolated from the equipment for the low acid crude. This configuration minimizes the size of the reaction column and quantity of catalyst required in the total acid number reduction unit 40.

EXAMPLES: In the examples, catalyst surface area was determined by N₂ adsorption at its boiling temperature. BET surface area was calculated by the 5-point method at P/Po = 0.050, 0.088, 0.125, 0.163, and 0.200. Catalyst samples were first pre-treated at

400°C for 6 hours in the presence of flowing, dry N₂ so as to eliminate any adsorbed volatiles like water or organics. C0₂ concentration was measured using an inline infrared C0₂ analyzer available from Qubit Systems, Inc., Kingston, Ontario. Total acid number (TAN) was determined according to ASTM D664.

Example 1 : The feed was prepared by mixing crude oil derived naphthenic acids

(obtained from Merichem Company, Houston, Texas) with a naphthenic white oil (HR Tufflo 1200, obtained from Calumet Specialty Products Partners L.P., Indianapolis, Indiana). A CaO-CaTi03 (3: 1 mole ratio) catalyst mixture was prepared by a thermal spray method from inorganic precursors and calcined at 750° C. for 2 hours in air. A 50 ml round bottom flask equipped with a glass coated magnetic stirrer was used. The flask was heated using a heating mantle, and a condenser (using dry ice) was used to minimize evaporative losses. A nitrogen gas sweep (~ 50 ml/min) was used to carry any C0₂ and water vapor formed from the flask.

A number of catalyst / feed combinations listed in Table 1 were initially tested in a batch process using approximately 5 wt. % catalyst with respect to the high acid feed. The catalysts and feed were heated to 150° C. and held for two hours, followed by heating to 200° C. and holding for two hours, followed by heating to 300° C. and holding for two hours. Catalytic activity was measured at the end of the reaction with TAN measurements.

Table 1 Catalyst TAN of feed TAN of treated stream TAN reduction (%)

Control (no catalyst) 20 17.5 13

CaO-CaTi0₃ 20 9.3 54

CaO-CaTi0₃ 10 4.7 53

Example 2: The following catalysts were obtained from Sigma-Aldrich Corp. (St. Louis, Missouri): barium titanate (product number 467634, >= 99% purity), calcium titanate (product number 633801, 99.9% purity) and zinc titanate (product number 634409, 99.5% purity). These catalysts were tested in a continuous experimental set up using a packed tube reactor heated by a clamshell furnace. The experimental feed and nitrogen stripping gas were fed co-currently at the bottom of the reactor. The mixed gas and liquid stream exiting the reactor was separated in a knock-out (KO) pot. A back pressure regulator at the gas stream exit of the knock-out pot was used to regulate the reactor and KO pot pressure. The gas stream from the knock-out pot was passed through a desiccant (available from W. A.

Hammond DRIERITE Co. LTD, Xenia, Ohio) to remove water before passing through an infra-red C0₂ analyzer (available from Qubits Systems, Kingston, Ontario) to measure the presence of C0₂. Liquid samples were drained from the knock-out pot at the end of the run. The effect of temperature on TAN reduction is shown for a liquid hourly space velocity (LHSV) of 1.6 hr^"1 and a stripping gas (N₂) superficial gas velocity (SGV) of 33 cm/min in Table 2. Both TAN reduction and C0₂ evolution are strong functions of temperature, as can be seen.

Table 2

The effect of residence time on TAN reduction at a temperature of 350° C and stripping gas (N₂) superficial gas velocity of 33 cm/min is shown in Table 3. The results indicate a strong effect of LHSV on TAN reduction. Table 3

Albacora crude was used to test the response of the catalysts (ZnTi0₃ product number 634409, supplied by Sigma-Aldrich Corp.) on real crude feeds. Albacora is a Brazilian high acid crude with a TAN of 1.88 mg KOH. The experiments were run at ambient pressure and stripping gas (N₂) SGV of 25 cm/min with 1 mm diameter borosilicate glass beads used as a control to isolate the effects of temperature on TAN reduction. As shown in Table 4, the experimental data suggests that the titanate is very effective in reducing the TAN of Albacora crude versus the control case using borosilicate glass beads.

Table 4

Example 3: A batch reactor was loaded with 16 g stearic acid having 3.55 mmol 0₂/g (P&G Chemicals, Cincinnati, Ohio) and 4 g ZnTi0₃ (product number 634409, Sigma-Aldrich Corp., St. Louis, Missouri) catalyst. N₂ was used as a purge gas to remove C0₂ formed through decarboxylation reactions. C0₂ concentration was measured to monitor the progress of the reaction. Figure 4 shows the results. It can be seen that at 350° C. there was a marked C0₂ release. The rate of C0₂ release is equivalent to the deoxygenation rate when considered on a molar basis. The highest deoxygenation rate was 0.089 mmol 0₂/min, indicating accelerated decarboxylation reaction.

Example 4: To examine catalyst activity for deoxygenation of triglycerides, 10 g canola salad oil having 3.39 mmol 0₂/g (sold under the name "Superb" from Costco

Wholesale Corporation, Richmond, California) and 2.5g ZnTi0₃ (product number 634409, Sigma-Aldrich Corp., St. Louis, Missouri) catalyst were mixed and heated from room temperature to 350°C in a batch reactor, with N₂ as a purge gas to remove C0₂ formed during the reaction. The highest deoxygenation rate was 0.078 mmol 0₂/min. Test results with and without catalyst are shown in Figure 5. The results indicate that ZnTi0₃ can catalyze canola oil deoxygenation reactions.

The testing results shown above indicate that ZnTi03 has considerable catalytic activity for deoxygenation reactions of both fatty acid (stearic acid) and triglycerides (canola oil), as demonstrated by the rate of C0₂ release.

Claims

WHAT IS CLAIMED IS:

1. A process to treat a liquid hydrocarbon feed, comprising contacting the liquid hydrocarbon feed with a catalyst comprising a metal titanate having an ΜΤΊΟ₃ structure, wherein M is a metal having a valence of 2+ at a temperature of between 200° C. and 400° C, thereby resulting in a treated hydrocarbon product.

2. The process of claim 1, wherein the liquid hydrocarbon feed comprises a biologically derived oil, and wherein the treated hydrocarbon product has a final oxygen content less than the initial oxygen content of the feed.

3. The process of claim 3, wherein the product has a final oxygen content at least 20% less than the initial oxygen content of the feed.

4. The process of claim 4, wherein the product has a final oxygen content at least 50% less than the initial oxygen content of the feed.

5. The process of any of claims 2 -4, wherein the biologically derived oil is derived from a plant source, an animal source, or mixtures thereof.

6. The process of any of claims 2 -4, wherein the biologically derived oil comprises FAME.

7. The process of any of claims 2 -4, wherein the biologically derived oil comprises pyrolysis oil.

8. The process of claim 1, wherein the liquid hydrocarbon feed has an initial total acid number of at least 0.5, and wherein the treated hydrocarbon product has a final total acid number at least 10% lower than the initial total acid number.

9. The process of claim 1, wherein the liquid hydrocarbon feed has an initial acid number of at least 10, and wherein the final total acid number is at least 50% lower than the initial total acid number.

10. The process of claim 8, wherein the final total acid number is at least 50% lower than the initial total acid number.

11. The process of claim 9, wherein the final total acid number is at least 90% lower than the initial total acid number.

12. The process of claim 8, wherein the liquid hydrocarbon feed is selected from the group consisting of crude oil, synthetic crude, distillate products, straight run feed, atmospheric and vacuum bottoms, vacuum gas oil and biologically derived oils.

13. The process of any of claims 1-4 and 8-9, wherein the metal titanate has a perovskite structure.

14. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises at least 1% by weight metal titanate.

15. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises at least 5% by weight metal titanate.

16. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises at least 10% by weight metal titanate.

17. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises at least 80% by weight metal titanate.

18. The process of any of claims 1-4 and 8-9, wherein the catalyst consists essentially of a metal titanate having an MT1O₃ structure.

19. The process of any of claims 1-4 and 8-9, wherein the catalyst further comprises a support selected from the group consisting of silica, alumina, silica-alumina, carbon, molecular sieves and mixtures thereof.

20. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises a metal titanate selected from the group consisting of magnesium titanate, copper titanate, nickel titanate, iron(II) titanium oxide, cobalt titanium oxide, manganese(II) titanium oxide, lead(II) titanate, calcium titanate, barium titanate and zinc titanate.

21. The process of any of claims 1-4 and 8-9, wherein the catalyst comprises a metal titanate selected from the group consisting of calcium titanate, barium titanate and zinc titanate.

22. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst at a temperature of less than 500°C.

23. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst at a temperature of less than 400°C.

24. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst at a temperature of between 250°C. and 350°C.

25. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst at a pressure of between 100 kPa and 1000 kPa absolute.

26. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst at a LHSV of between 0.2 and 5 h^"1.

27. The process of any of claims 1-4 and 8-9, wherein the feed is contacted with the catalyst in any of a fixed bed reactor and a slurry bed reactor.

28. The process of any of claims 1-4 and 8-9, further comprising introducing a stripping gas stream capable of removing carbon dioxide or water vapor.

29. The process of claim 1 , wherein the feed is contacted with the catalyst without the addition of hydrogen gas.

30. The process of claim 1, wherein the catalyst further comprises a metal oxide.

31. The process of claim 9, wherein the catalyst consists essentially of a basic oxide and a metal titanate having an MT1O₃ structure, with M being a metal having a valence of 2+, wherein the molar ratio of the basic oxide to the metal titanate ranges from 1 : 10 to 10: 1.

32. The process of claimlO, wherein the basic oxide is selected from the group of calcium oxide, magnesium oxide, magnesium aluminum oxide, zinc oxide, lanthanum oxide, cerium oxide, barium oxide and mixtures thereof.

33. The process of claim 1, wherein the catalyst further comprises a support selected from the group consisting of silica, alumina, silica-alumina, carbon, molecular sieves and mixtures thereof.

34. The process of claim 1, wherein the hydrocarbon feed is contacted with the catalyst at a temperature of between 200° C. and 350° C.

35. The process of claim 1, wherein the catalyst comprises a metal titanate selected from the group consisting of magnesium titanate, copper titanate, nickel titanate, iron(II) titanium oxide, cobalt titanium oxide, manganese(II) titanium oxide, lead(II) titanate, calcium titanate, barium titanate and zinc titanate.

36. The process of claim 1, wherein the catalyst comprises a metal titanate selected from the group consisting of calcium titanate, barium titanate and zinc titanate.

37. The process of claim 1, wherein the catalyst consists essentially of a metal titanate selected from the group consisting of magnesium titanate, copper titanate, nickel titanate, iron(II) titanium oxide, cobalt titanium oxide, manganese(II) titanium oxide, lead(II) titanate, calcium titanate, barium titanate and zinc titanate.

38. The process of claim 1, wherein the hydrocarbon feed is contacted with the catalyst at a LHSV of between 0.1 and 10 h^"1.

39. The process of claim 1, wherein the hydrocarbon feed is contacted with the catalyst at a LHSV of between 0.4 and 2 h^"1.

40. The process of claim 1, further comprising introducing a stripping gas stream capable of degassing the reactor contents.

41. The process of claim 1 , wherein the hydrocarbon feed is contacted with the catalyst without the addition of hydrogen gas.

42. The process of claim 1 , wherein the treated hydrocarbon product is used as feed for an atmospheric distillation process.

43. The process of claim 1 , wherein the treated hydrocarbon product is used as feed for a downstream FCC unit.

44. The process of claim 1 , wherein the treated hydrocarbon product is used as feed for a downstream hydroprocessing unit.

45. The process of claim 1, wherein the liquid hydrocarbon feed has an initial acid number of at least 10, and wherein the final total acid number is at least 50% lower than the initial total acid number.

46. The process of claim 1 , wherein the metal titanate has a perovskite structure.

47. A process for refining a low acid crude oil and a high acid crude oil feed comprising separately introducing a relatively low acid crude oil feed and a relatively high acid crude oil feed to an atmospheric distillation column, wherein the relatively high acid crude oil feed is contacted with a catalyst comprising a metal titanate having an MT1O₃ structure, wherein M is a metal having a valence of 2+ prior to introduction to the atmospheric distillation column.

48. A process for removing oxygen from a liquid hydrocarbon feed comprising a biologically derived oil, comprising: contacting the feed comprising a biologically derived oil comprising fatty acids and/or fatty acid esters having an initial oxygen content with a catalyst comprising a metal titanate having an MT1O₃ structure wherein M is a metal having a valence of 2+,

thereby resulting in a product having a final oxygen content less than the initial oxygen content of the feed.

49. A process for reducing the total acid number of a liquid hydrocarbon feed, comprising contacting a liquid hydrocarbon feed having an initial total acid number of at least 0.5 with a catalyst comprising a metal titanate having an MT1O₃ structure, wherein M is a metal having a valence of 2+ at a temperature of between 200° C. and 400° C, thereby resulting in a treated hydrocarbon product having a final total acid number at least 10% lower than the initial total acid number.

50. The process of any of claims 1-2, 8-9, 47-49, wherein the feed is contacted with the catalyst under inert conditions.