CATALYTIC CRACKING BACKGROUND OF THE INVENTION

[0001] This application relates to methods for converting hydrocarbon feedstocks, such as used lubricating oil, into high value products.

[0002] Distillation of crude oil produces various hydrocarbon fractions, each of which may be processed to generate valuable products. One hydrocarbon fraction generated from crude oil distillation is vacuum gas oil (VGO). VGO consists primarily of hydrocarbons boiling between about 255°C and 582°C. Light VGO includes hydrocarbons having a boiling point less than about 343°C and is typically converted into light, valuable, and clean fuels, such as motor gasoline, kerosene, and olefinic gasses (methane, ethane, propane, butanes). Heavy VGO includes hydrocarbons having a boiling point greater than about 343°C and is typically converted into lubricating oil (e.g., motor oil). While fuels, such as those derived from light VGO, are physically consumed during use, lubricating oils are not. Thus, theoretically, lubricating oil (e.g., used motor oil) could be recycled for reuse.

[0003] Light VGO is converted into valuable fuels by a process referred to as cracking, which breaks (“cracks”) the hydrocarbons into smaller molecules for incorporating into a fuel distillate pool. A fuel distillate pool may then be subsequently converted into highly valued motor gasoline, kerosene, diesel fuel, jet fuel, and/or liquid petroleum gas. Heavier hydrocarbons, such as those in heavy VGO or lubricating oil, may be subjected to a similar cracking process. However, while the chemical structure of lubricating oil remains intact after use, the bulk composition is typically contaminated with material that precludes efficient conversion into smaller hydrocarbons by cracking. For example, the cracking reaction is typically facilitated by a catalyst (thus termed “catalytic cracking”), which is adversely affected by many contaminants found in used lubricating oils. Additionally, some contaminants are corrosive to a cracking unit’s components, while yet others pose an issue if present in a resulting product.

[0004] Some, but not all, contamination may be removed through re-refining. However, re refinement of used lubricating oil is typically carried out by small processors using various processes tailored to the available collected used lubricating oil, product demands, and local environmental considerations. Procedures and processes for re-refining are decentralized, non- uniform, and produce re-refined used lubricating oil feedstocks of inconsistent quality. Despite the abundance of potentially valuable used lubricating oils, most lubricating oil is not re-refined and just discarded as waste because re-refining is so cumbersome. Thus, used lubricating oil remains underutilized to its fullest potential. [0005] What is needed is a method for optimizing used lubricating oil recycling so that the highest economic gain may be realized by their reuse. Such a method will positively impact the environment as well, as lubricating oils will be less likely to be discarded as waste.

SUMMARY

[0006] This application relates generally to processing and evaluation of hydrocarbon-based feedstocks and, more specifically, to the processing and evaluation of re-refined used lubricating oils for use as feedstock for fluid catalytic cracking.

[0007] Disclosed herein are methods that include a method comprising: defining a set of disposition criteria comprising a plurality of measurable properties selected from the group consisting of boiling point range, specific gravity, total reactive sulfur, total nitrogen, basic nitrogen, S:N ratio, chlorine, acidity, coking tendency, aniline point, aromaticity, paraffin content, naphthenes, aliphatic unsaturation, sedimentation, water content, flash point, concentration of polychlorinated biphenyls, and the content of one or more of the following elements: S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, and Ba, wherein each of the measurable properties has associated therewith a pre-defined value; testing one or more samples of a potential catalytic cracking feedstock to generate a plurality of measured properties corresponding to the plurality of measurable properties, wherein each of the measured properties is characterized by a quantitative measured value; comparing each quantitative measured value to each pre-defined value; identifying each measured property whose quantitative measured value does not comport with the corresponding pre-defined value; and processing the potential catalytic cracking feedstock by either (a) or (b): (a) supplying the potential catalytic cracking feedstock to a catalytic cracking unit when no measured properties are identified, or (b) subjecting the potential catalytic cracking feedstock to one or more processes to modify the quantitative measured value to comport with the threshold value when one or more measured properties are identified, thereby generating a modified catalytic cracking feedstock; and supplying the modified catalytic cracking feedstock to the catalytic cracking unit. [0008] Another example method includes defining a set of disposition criteria comprising a plurality of measurable properties selected from the group consisting of boiling point range, specific gravity, total reactive sulfur, total nitrogen, basic nitrogen, S:N ratio, chlorine, acidity, coking tendency, aniline point, aromaticity, paraffin content, naphthenes, aliphatic unsaturation, sedimentation, water content, flash point, concentration of polychlorinated biphenyls, and the content of one or more of the following elements: S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, and Ba, wherein each of the measurable properties has associated therewith a pre-defined value; testing one or more samples of a potential catalytic cracking feedstock to generate a plurality of measured properties corresponding to the plurality of measurable properties, wherein each of the measured properties is characterized by a quantitative measured value; comparing each quantitative measured value to each pre-defined value; identifying each measured property whose quantitative measured value does not comport with the corresponding pre-defined value; and processing the potential catalytic cracking feedstock by either (a) or (b): (a) supplying the potential catalytic cracking feedstock to a catalytic cracking unit when no measured properties are identified, or (b) combining a least a portion of the first potential catalytic cracking feedstock with at least a portion of a second potential catalytic cracking feedstock to generate a combined catalytic cracking feedstock when one or more measured properties are identified; and supplying the combined catalytic cracking feedstock to a catalytic cracking unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following figure is included to illustrate certain aspects of the embodiments and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to those skilled in the art and having the benefit of this disclosure.

[0010] Figure 1 illustrates an example flow diagram of the methods disclosed herein for the assessment and utilization of a potential hydrocarbon-based feedstock in catalytic cracking. DETAILED DESCRIPTION

[0011] The present disclosure relates to methods for reliably characterizing the disposition of a hydrocarbon-based feedstock (e.g., used lubricating oil) to maximize its potential for conversion into highly valuable and clean-burning fuels.

[0012] From a purely chemical aspect, lubricating oil may be cracked under similar conditions employed in cracking VGO. Prior attempts to process used lubricating oil in this fashion have failed, however, as cracking catalysts are highly susceptible to and deactivated by many of the contaminants found in used lubricating oil. Additionally, various refinery components are susceptible to fouling (which is expensive to remedy) by common contaminants· Thus, it is a common belief in the industry that used lubricating oil poses too high of a risk to be converted by catalytic cracking.

[0013] Methods are provided herein that reduce such a risk. Described herein are methods for determining if and how a potential catalytic cracking feedstock may be subjected to catalytic cracking.

[0014] Methods include defining a set of disposition criteria comprising a plurality of measurable properties which may include, but are not limited to, boiling point range, specific gravity, total reactive sulfur, total nitrogen, basic nitrogen, S:N ratio, chlorine, acidity, coking tendency, aniline point, aromaticity, paraffin content, naphthenes, aliphatic unsaturation, sedimentation, water content, flash point, concentration of polychlorinated biphenyls, and the content of one or more of the following elements: S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, and Ba. Combinations of the foregoing may also be used. Each of the plurality of measurable properties has associated therewith a pre-defined value. As used herein, “value” refers to a numerical value that may be a single value, an upper limit, a lower limit, or a range of values. One or more samples of a potential catalytic cracking feedstock may be tested, generating a plurality of measured properties that correspond to the plurality of measurable properties in the set of disposition criteria. Each of the measured properties is characterized by a quantitative measured value and each of the measurable properties is characterized by a pre-defined value. Each quantitative measured value may then be compared to each pre-defined value, and measured properties whose quantitative measured value do not comport with the corresponding pre-defined value may be identified. For example, a set of disposition criteria may set forth a range of acceptable sulfur levels. The sulfur level of a potential catalytic cracking feedstock may be measured and compared to the range of acceptable sulfur levels defined in the set of disposition criteria.

[0015] If no measured properties are identified as not comporting with the corresponding pre defined value, the potential catalytic cracking feedstock may be supplied to a catalytic cracking unit. When one or more measured properties are identified as not comporting with the corresponding pre-defined value, the potential catalytic cracking feedstock may be subjected to one or more processes to modify the quantitative measured value to comport with the pre-defined value, thereby generating a modified catalytic cracking feedstock; and supplying the modified catalytic cracking feedstock to the catalytic cracking unit.

[0016] In any embodiment, multiple measured properties may be identified. Thus, processing may include multiple steps to effectively modify the quantitative measured value of each measured property to generate a potential catalytic cracking feedstock wherein each measured property value comports with each corresponding pre-defined value.

[0017] Alternatively or additionally, the potential catalytic cracking feedstock may be divided into fractions. The dividing may be based on a simple percentage of the potential catalytic cracking feedstock (e.g., 10 wt. %, 20 wt. %, 50 wt. %, 75 wt. % of the potential catalytic cracking feedstock). One or more fractions may be combined with one or more fractions of a second potential catalytic cracking feedstock to generate a combined potential catalytic cracking feedstock having a disposition wherein the quantitative measured value of each measured property comports with the corresponding pre-defined value.

[0018] One or more illustrative embodiments incorporating the invention embodiments disclosed herein are presented herein. Not all features of a physical implementation are described or shown in this application for the sake of clarity. It is understood that in the development of a physical embodiment incorporating the embodiments of the present invention, numerous implementation- specific decisions must be made to achieve the developer’s goals, such as compliance with system-related, business-related, government-related, and other constraints, which vary by implementation and from time to time. While a developer’ s efforts might be time- consuming, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in the art and having benefit of this disclosure.

[0019] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0020] While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.

Potential Catalytic Cracking Feedstocks [0021] A potential catalytic cracking feedstock may be any hydrocarbon composition, for example, one or more petroleum products derived from crude oil (e.g., shale oil), one or more products derived from pyrolysis oils (e.g., upgraded biocrude), or any blend thereof. Examples of suitable potential catalytic cracking feedstocks include lubricating oils (including used lubricating oils), pyrolysis oils, or any blend thereof.

[0022] As used herein, “lubricating oil” and grammatical variations thereof refer to a hydrocarbon composition characterized by a boiling point range from about 300°C to about 400°C. One example of lubricating oil is motor oil. Used lubricating oil may be a mixture of different types and grades of oils derived from different sources. Used lubricating oil may have been optionally re -refined. Used lubricating oil may contain contaminants such as, but not limited to, motor oil additives, water, metals, organometallics, polymeric components, grease, brake fluid, transmission oil, transformer oil, railroad lubricant, crude oil, antifreeze, dry cleaning fluid, degreasing solvents, edible fats and oils, mineral acids, soot, earth, or any combination thereof.

[0023] As used herein, “pyrolysis oil” (also called biocrude or bio-oil) and grammatical variations thereof refer to a hydrocarbon composition derived from the product of heating dried biomass in the absence of oxygen.

[0024] Optionally, a potential catalytic cracking feedstock may have been hydroprocessed or desalted before processing by catalytic cracking. Examples of hydroprocessing include, but are not limited to, hydrotreating, hydrocracking, catalytic dewaxing, hydrofinishing/aromatic saturation, and combinations thereof. Examples of hydrotreating include, but are not limited to, hydrogenolysis (e.g., hydrosulfurization, hydrodenitrogenation, hydrodeoxygenation, hydrodemetallization, hydrodeasphalteneization), hydrogenation, (e.g., olefin saturation, aromatic saturation), and combinations thereof. In any embodiment, a potential catalytic cracking feedstock may be sourced from a re-refinery.

[0025] For example, a process for re-refining lubricating oil may include partially vaporizing (“dehydrating”) lubricating oil to remove water, gasoline, solvents, glycols, lighter organics, or combinations thereof. This may be carried out at atmospheric pressure at a temperature of about 160°C. Water and/or lighter organics may be condensed and separated from lubricating oil, generating a dehydrated lubricating oil. The dehydrated lubricating oil may then be stripped under vacuum to remove light gasoil and adjust the flash point to generate gasoil. The gasoil may then be distilled under vacuum under conditions effective to recover a VGO fraction. This may be carried out, for example, at a high temperature with a thin film evaporator. When using a thin film evaporator, the oil may experience a short residence time (about 10 seconds) therein, and, when combined with a low wall temperature and high flow turbulence, clean lubricating oil may be recovered as a distillate, separated from heavier components such as additives, metals, and degradation products, which may be concentrated in a residue.

[0026] A recovered VGO fraction may be further processed to remove various impurities. For example, hydroprocessing or acid washing (e.g., with sulfuric acid, hydrochloric acid, nitric acid, and/or acetic acid) may remove contaminants such as, but not limited to, chlorinated compounds, sulfurous compounds, oxygenated organic compounds, polyaromatic hydrocarbons, or combinations thereof.

[0027] Examples of measurable properties comprising a potential catalytic cracking feedstock’ s disposition that influence suitability for catalytic cracking include, but are not limited to, boiling point range, specific gravity, sulfur (S), total nitrogen, basic nitrogen, total chlorine, polychlorinated biphenyl (PCB) content, acidity, reactive sulfur content, coking tendency, aniline point, aromaticity, bromine number, flash point, sedimentation and water levels, cycloparaffin content, paraffin content, pour point, nickel (Ni), vanadium (V), iron (Fe), sodium (Na), calcium (Ca), copper (Cu), arsenic (As), silicon (Si), barium (Ba), boron (B), phosphorus (P), zinc (Zn), magnesium (Mg), molybdenum (Mo), potassium (K), tin (Sn), aluminum (Al), chromium (Cr), and any combinations thereof.

[0028] Certain measurable properties of a potential catalytic cracking feedstock disposition are discussed below to illustrate their effect on catalytic cracking, for example, the reaction itself, the equipment used, the quality of a resulting product stream, or environmental impact. Properties of the disposition are discussed below along with the potential effects of the various properties on suitability in cracking. However, one of skill in the art could readily determine the effect of these properties in different refinery processes or identify other properties that may be important.

[0029] The cracking reaction is highly endothermic, driven by extremely high temperatures and entropy change due to fragmenting a large molecule into several small pieces. A catalytic cracking feedstock may be vaporized by a hot catalyst, effectively reducing energy required to break carbon-carbon bonds. Properties of a catalytic cracking feedstock disposition that influence any of these variables will, in turn, affect the efficiency and/or selectivity of the cracking reaction.

[0030] The molecular weight and relative amount of a particular hydrocarbon in a potential catalytic cracking feedstock may be inferred by boiling point range as well as, to some extent, specific gravity. Light hydrocarbons may vaporize too quickly. Conversely, heavy hydrocarbons may potentially not vaporize at all. Additionally, hydrocarbon molecular weight is linked to tendency for cracking. Thus, the hydrocarbon molecular weight distribution in a potential catalytic cracking feedstock directly affects yield. Molecular weight distribution may be modified by distillation to separate and remove unwanted fractions.

[0031] Saturation and aromaticity also affect a hydrocarbon’s tendency to crack. For example, unsaturated aliphatic hydrocarbons (olefins) are typically amenable to cracking whereas saturated aliphatic hydrocarbons (paraffins, cyclic paraffins) and aromatic hydrocarbons are resistant to cracking. The aliphatic nature of a potential catalytic cracking feedstock may be characterized by bromine number. Aromaticity may be characterized by aniline number or refractive index. Pour point, a measure of the lowest temperature at which an oil will flow when cooled without stirring under standard cooling conditions, may be indicative of paraffin content. [0032] Saturation and aromaticity also affect a potential catalytic cracking feedstocks tendency to coke. In general, highly unsaturated hydrocarbons (e.g., aromatics) and larger hydrocarbons (e.g., boiling above about 565°C) adsorb preferentially to a catalyst surface and produce the most coke. Other properties that increase coke formation include, but are not limited to, the presence of basic nitrogen, sulfur, zinc, and free elemental iron. Potential catalytic cracking feedstocks may be catalytically hydrotreated to remove basic nitrogen and sulfur. Iron removal is more difficult, and generally requires re-refining for removal.

[0033] In addition to coking, a catalyst may be inactivated by metals such as, but not limited to, nickel, sodium, vanadium, potassium, calcium, iron, barium, phosphorus, and magnesium. Arsenic oxide is also a catalyst poison. Many of these poisons originate in the crude oil from which a catalytic cracking feedstock is derived. Hydrotreating and/or re -refining may remove some of these components, though with variable efficacy. The presence of water in a potential catalytic cracking feedstock breaks apart catalyst particles and may cause vapor locking in furnace passes.

[0034] Some properties of a potential catalytic cracking feedstock’s disposition affect the logistics of storing and transporting a potential catalytic cracking feedstock. For example, hydrocarbon compositions require proper storage. Flash point measures the temperature at which a feedstock gives off enough vapor to ignite in air. Generally, if the flash point of a potential catalytic cracking feedstock is not within a set range, the potential catalytic cracking feedstock cannot be safely stored and transported and should not be purchased.

[0035] Some properties of a potential catalytic cracking feedstock’s disposition affect various components of refinery equipment. For example, salts, acid, nitrogen, and sulfur (including total reactive sulfur) in a catalytic cracking feedstock may lead to equipment corrosion. Examples of reactive sulfur include, but are not limited to, hydrogen sulfide, mercaptans, aliphatic sulfides, aliphatic disulfides, elemental sulfur, and polysulfides. Equipment integrity may also be compromised by a low sulfur to nitrogen ratio (S:N ratio). Feedstock may be hydrotreated and/or desalted to modify any of these properties, to some extent, but often a corrosive feedstock may be routed for processing elsewhere. A low S:N ratio may be increased by adjusting sulfur, nitrogen, or both. Methods for addressing sulfur and/or nitrogen are disclosed above.

[0036] While many contaminants in a potential catalytic cracking feedstock affect the cracking reaction and/or equipment negatively, some contaminants may be beneficial. For example, barium may reduce adverse effects of contaminating metals (e.g., vanadium, iron, nickel) on a catalyst. The treating of cracking catalyst with barium for this purpose is disclosed, for example, in U.S. Patent No. 4,377,494, which is incorporated herein by reference with respect to its disclosure of using barium to reduce catalyst poisoning. Additionally, boron (in the form of a boron oxide) may also be able to reduce the adverse effects of contaminating metals, for example, per the disclosure of U.S. Patent No. 4,192,770, which is incorporated herein by reference with respect to its disclosure of using boron to reduce catalyst poisoning. Antimony is also used as a nickel passivation additive to reduce adverse effects of nickel. However, if the antimony concentration is too high, downstream fouling, in particular, on the main fractionator, may occur. Additionally, nitrogen oxide (NO _x ) emissions may be increased.

[0037] Some contaminants that may be found in a feedstock derived from used lubricating oil may not be found in typical catalytic cracking feeds and thus their full impact on catalytic cracking has not been thoroughly investigated. Nonetheless, such atypical contaminants may be relevant and their presence may be documented to better understand their impact. For example, barium may be present in tight oil extraction chemicals as barium sulfate. While it has been documented to have a positive impact, as described above, barium may negatively affect zeolitic catalysts in a similar fashion as other alkali metals such as sodium, magnesium, calcium, and potassium. In another example, phosphorus typically does not occur naturally in crude oil (with the possible exception of those crudes from Western Canada), but is present in additives used in oil wells in the form of di-alkyl phosphate ester (DAPE) and decomposes to phosphorus during distillation. Phosphorus may also be present in shale oil. Phosphorus may contribute to fouling, plugging, and hard deposits of catalytic cracking equipment and may contribute to catalyst poisoning in fractionating and hydrotreating downstream of a catalytic cracking unit. Other examples of atypical contaminants where little information regarding the impact on catalytic cracking is known include tin, aluminum, and chromium.

Methods of Assessing the Disposition of a Potential Catalytic Cracking Feedstock [0038] Each of the properties defining the disposition of a potential catalytic cracking feedstock may be determined by a plurality of analytical tests. One or more samples of a potential catalytic cracking feedstock may be obtained. One of skill in the art will be familiar with appropriate methods for obtaining, storing, handling, and processing samples of a potential catalytic cracking feedstock.

[0039] Then, one or more of the samples may then be subjected to plurality of analytical tests comprising a plurality of quantitative and qualitative analyses. Each test is designed to measure one or more properties of the potential catalytic cracking feedstock. Each sample may be subjected to one or more quantitative analyses. Examples of qualitative tests include, for example, identification of specific contaminants. Examples of quantitative analyses may include, but are not limited to, measuring one or more of the following: contamination concentration, flash point, boiling point range, pour point, acidity, specific gravity, aliphatic unsaturation, aromaticity, and tendency for forming coke. The particular quantitative tests that comprise the plurality of analytical tests may be guided by a potential catalytic cracking feedstock’s origin. For example, if a potential catalytic cracking feedstock is derived from virgin source (i. e. , has not been previously used), fewer analyses may be sufficient to adequately determine its suitability for cracking. If the potential catalytic cracking feedstock is not derived from a virgin source, additional analyses may be necessary to characterize its disposition more thoroughly. For example, a potential catalytic cracking feedstock may be subjected to a plurality of quantitative analyses that measure components commonly added to lubricating oils (e.g., motor oil additives) or introduced during use in a motor (e.g., components of engine wear).

[0040] The plurality of quantitative analyses may include analytical techniques such as, but not limited to, chromatography (e.g., gas, liquid, high-performance liquid, thin layer, size exclusion), spectrophotometry (e.g., infrared, near infrared, Fourier transform infrared, florescence), and titration (e.g., coulometric, potentiometric). Each of the plurality of quantitative tests may be performed according to standardized American Society for Testing and Materials (ASTM) and Universal Oil Products (UOP) tests, which are listed in the Analysis Methods section below.

Generating Qualified Catalytic Cracking Feedstocks

[0041] Each measured property whose value does not comport with the pre-defined value of the corresponding property in the set of disposition criteria may then be identified. If there is no measured property value identified that does not comport the value of the corresponding property in the set of disposition criteria, the potential catalytic cracking feedstock may be considered to be a qualified catalytic cracking feedstock and may be conveyed to a catalytic cracking unit for conversion. In other words, if the value of all measured properties comport with the pre-defined value of all corresponding properties in the set of disposition criteria, the potential catalytic cracking feedstock is deemed a qualified catalytic cracking feedstock and may be conveyed to a catalytic cracking unit.

[0042] If the value of at least one measured property does not comport with the value of the corresponding property in the set of disposition criteria, the value of the at least one measured property may be modified. Modification of the at least one measured property may generate a potential catalytic cracking feedstock having a disposition where the value of the at least one measured property comports with the pre-defined value of the corresponding property in the set of disposition criteria. In any embodiment, modification may include multiple steps to modify multiple measured property values so that each modified measured property value comports with each pre-defined value of the corresponding property in the set of disposition criteria.

[0043] Alternatively or additionally, the potential catalytic cracking feedstock may be divided into fractions. The dividing may be based on a simple percentage of the potential catalytic cracking feedstock (e.g., 10 wt. %, 20 wt. %, 50 wt. %, 75 wt. % of the potential catalytic cracking feedstock). One or more fractions may be combined with one or more fractions of a second potential catalytic cracking feedstock to generate a combined potential catalytic cracking feedstock having a disposition such that the value of each measured property comports with each pre-defined value of the corresponding property in the set of disposition criteria.

[0044] Alternatively or additionally, non-fixed parameters of a catalytic cracking refinery process may be adjusted or chosen based on the disposition of a potential catalytic cracking feedstock. Examples of non-fixed parameters that may be adjusted or chosen include, but are not limited to, temperature, pressure, catalyst choice, type of catalyst bed (e.g., moving, fixed, fluidized bed), use of additives, and/or the like. One of skill in the art will be familiar with various method and system parameters that may be modified to increase compatibility with a potential catalytic cracking feedstock.

[0045] The one or more modifications that may be carried out in order to generate a qualified catalytic cracking feedstock may depend on a number of factors, for example, but not limited to, availability of refinery equipment and/or cost to make said modifications. For example, if the value of one or more properties defining a potential catalytic cracking feedstock’s disposition may be modified easily and inexpensively by one or more simple processes, such modifications would be undertaken. Conversely, if the value of one or more properties of a potential catalytic cracking feedstock’s disposition cannot be readily modified and the potential catalytic cracking feedstock is unable to be combined, in whole or in part, with a second potential catalytic cracking feedstock to generate a combined potential catalytic cracking feedstock having a suitable disposition, the potential feedstock may be rejected. Careful consideration should be given as to the cost required to modify a potential catalytic cracking feedstock against the economic gain that may be achieved by its sale. A skilled person in the art would be able to make such a judgement. [0046] By employing one or more of the methods disclosed above, a qualified catalytic cracking feedstock may be generated that is compatible for conversion by catalytic cracking. Catalytic Cracking Processes

[0047] As used herein, “catalytic cracking” and any grammatical variations thereof refer to the catalyzed breaking of one or more carbon-carbon bonds in a hydrocarbon molecule to generate shorter, smaller hydrocarbons. Examples of catalytic cracking processes include, but are not limited to, hydrocracking and fluidized catalytic cracking. Examples of suitable catalytic catalysts include any commonly used in the industry, for example (but not limited to) zeolitic catalysts, bauxite, silica-alumina, aluminum hydrosilicate, and the like.

[0048] Methods are provided herein that include thoroughly characterizing the disposition of a potential catalytic cracking feedstock. Thus, the previously perceived high risk associated with using a catalytic cracking feedstock of unknown disposition is substantially reduced if not eliminated.

[0049] By performing the methods disclosed herein, a potential catalytic cracking feedstock may be utilized to its maximum potential. The methods include identifying any measured property of a potential catalytic cracking feedstock whose value does not comport with a pre defined value or range of values in a set of disposition criteria, modifying one or more of those properties and/or combining at least a portion of the potential catalytic cracking feedstock with at least a portion of an additional potential catalytic cracking feedstock to generate a qualified catalytic cracking feedstock.

[0050] The processes described herein may be utilized prior to purchasing a potential catalytic cracking feedstock. Thus, a potential catalytic cracking feedstock deemed unsuitable might simply be rejected and not purchased. However, it is possible that a decision must be made to purchase a potential catalytic cracking feedstock before it is possible to assess its disposition, and in such instances, the methods herein may be used to determine how to use a potential catalytic cracking feedstock to its fullest potential.

Example Methods

[0051] The Figure illustrates a flow diagram for characterizing the disposition of a potential catalytic cracking feedstock to generate a qualified catalytic cracking feedstock. The source of the potential catalytic cracking feedstock is determined at 2. When the source of the potential catalytic cracking feedstock is virgin, the method proceeds to 4a where one or more samples of the potential catalytic cracking feedstock are subjected to a plurality of quantitative analyses (“Panel A”). The plurality of analytical tests generates a plurality of measured properties that characterizes the potential catalytic cracking feedstock’s disposition. When the source of the potential catalytic cracking feedstock is non-virgin, the method proceeds to 4b where one or more samples of the potential catalytic cracking feedstock are subjected to a plurality of quantitative analyses (“Panel B”). Panel A analyses may include, for example, determination of one or more of boiling point ran, pour point, flash point, specific gravity, aromaticity, aliphatic unsaturation, sulfur, total reactive sulfur, sedimentation, water content, total nitrogen, basic nitrogen, chlorine, acidity, Condradson carbon residue, basic sedimentation and water, Ni, V, Fe, Na, Cu, and Ca. Panel B analyses may include, for example, any or all of Panel A analyses, along with analyses that identify and measure known contaminants of used lubricating oil. For example, Panel B may identify and measure engine wear components and common additives. Examples include, but are not limited to, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, Ba, PCBs, and any combination thereof. The plurality of qualitative analyses comprising each of Panel A and Panel B may include any combination of the above-described analyses.

[0052] At 6, the value of each measured property in the plurality of measured properties may then be compared to a pre-defined value in a corresponding property in a set of disposition criteria. Each measured property whose value does not comport with the pre-defined value of the corresponding property in the set of disposition criteria may then be identified. If there is no measured property value identified that does not comport with the value of the corresponding property in the set of disposition criteria, the potential catalytic cracking feedstock may be considered to be a qualified catalytic cracking feedstock and may be conveyed to a catalytic cracking unit for conversion. In other words, if the value of all measured properties comport with the pre-defined value of all corresponding properties in the set of disposition criteria, the potential catalytic cracking feedstock is deemed a qualified catalytic cracking feedstock and may be conveyed to a catalytic cracking unit 14.

[0053] If the value of at least one measured property does not comport with the value of the corresponding property in the set of disposition criteria, the method proceeds to step 8 where it is determined whether or not it is economically and/or physically viable to modify each identified measured property whose value does not comport with the pre-defined value of the corresponding property in the set of disposition criteria to generate a qualified catalytic cracking feedstock. If it would not be economically and/or physically viable to modify at least one of each identified measured property whose value does not comport with the pre-defined value of the corresponding property in the set of disposition criteria, the potential catalytic cracking feedstock may be rejected 15. If it is determined that it would be economically and/or physically viable to modify at least one of each identified measured property whose value does not comport with the pre-defined value of the corresponding property in the set of disposition criteria, the method proceeds to step 8, where it may be determined the most economically viable process for generating a qualified catalytic cracking feedstock from the potential catalytic cracking feedstock.

[0054] For example, from 8, a potential catalytic cracking feedstock may be conveyed for processing to modify the disposition of a potential catalytic cracking feedstock 10, generating a modified potential catalytic cracking feedstock having a disposition with fewer properties whose values do not comport with the value or value range of the corresponding property in the set of disposition criteria. If a modified potential catalytic cracking feedstock is generated wherein all measured property values comport with the pre-defined value for each corresponding property in the set of disposition criteria, the modified potential catalytic cracking feedstock may be considered to be a qualified catalytic cracking feedstock and may be conveyed to a catalytic cracking unit for conversion 14.

[0055] Alternatively, from 8, all or part of a potential catalytic cracking feedstock may be combined with one or more potential catalytic cracking feedstocks 12 to generate a combined potential catalytic cracking feedstock having a disposition such that the value of each measured property comports with each pre-defined value of the corresponding property in the set of disposition criteria. The combined potential catalytic cracking feedstock may be considered a qualified catalytic cracking feedstock and conveyed to a catalytic cracking unit for conversion 14.

[0056] The Figure depicts a dashed line with a double arrow between steps 10 and 12 where, optionally, a potential catalytic cracking feedstock may undergo processing at both steps 10 and 12 to generate a qualified catalytic cracking feedstock that is then conveyed to a catalytic cracking unit for conversion 14.

[0057] The catalytic cracking unit to which a qualified catalytic cracking feedstock is conveyed may be any type of catalytic cracking unit. For example, a catalytic cracking unit may employ fixed catalyst beds, moving catalyst beds, fluidized beds, or any combination thereof. A catalytic cracking unit may comprise an inlet for supplying hydrogen to a catalyst bed. A catalytic cracking unit may comprise apparatus and equipment for catalyst regeneration.

[0058] It should be noted that while catalytic cracking is used herein to illustrate most clearly the advantages gained from use of described methods to maximize the potential of a hydrocarbon feedstock, catalytic cracking is merely used as an example of a suitable refining process. The methods disclosed may be used to determine the disposition of any feedstock as it relates to suitability for any refining process.

Methods for Performing the Plurality of Quantitative Analyses

[0059] As noted in previous sections, samples of potential catalytic cracking feedstock may be subjected to a plurality of quantitative analyses that measure one or more of boiling point range, specific gravity, pour point, flash point, acidity, Condradson carbon residue, basic sedimentation and water content, total reactive sulfur, total nitrogen, basic nitrogen, aliphatic unsaturation, aromaticity, cycloparaffin content, paraffin content, naphthene content, chlorine, PCBs, S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, or Ba.

[0060] Table 1 below lists each of the above properties as well as ASTM or UOP methods that may be employed to measure each.

Table 1

[0061] Using the processes and methods described herein, used lubricating oil may be converted into high value, clean-buming fuels through catalytic cracking. The methods disclosed herein are practical and reliable on an industrial scale and may be used as a standard operating procedure for any process in which the disposition of a hydrocarbon feedstock is important to know. The methods disclosed herein provide confidence and reduce risk in using hydrocarbon compositions from various or unknown sources in catalytic cracking. Thus, previously underutilized and undervalued hydrocarbon products (e.g. , lubricating oil, upgraded pyrolysis oil) may be reclaimed through catalytic cracking, greatly increasing their worth, while, at the same time, providing an environmental benefit of producing cleaner-burning fuels and reducing waste. [0062] Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present invention. The invention illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein.

Example Embodiments

[0063] One nonlimiting example embodiment is a method comprising: defining a set of disposition criteria comprising a plurality of measurable properties selected from the group consisting of boiling point range, specific gravity, total reactive sulfur, total nitrogen, basic nitrogen, S:N ratio, chlorine, acidity, coking tendency, aniline point, aromaticity, paraffin content, naphthenes, aliphatic unsaturation, sedimentation, water content, flash point, concentration of polychlorinated biphenyls, and the content of one or more of the following elements: S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, and Ba, wherein each of the measurable properties has associated therewith a pre-defined value; testing one or more samples of a potential catalytic cracking feedstock to generate a plurality of measured properties corresponding to the plurality of measurable properties, wherein each of the measured properties is characterized by a quantitative measured value; comparing each quantitative measured value to each pre-defined value; identifying each measured property whose quantitative measured value does not comport with the corresponding pre-defined value; and processing the potential catalytic cracking feedstock by either (a) or (b): (a) supplying the potential catalytic cracking feedstock to a catalytic cracking unit when no measured properties are identified, or (b) subjecting the potential catalytic cracking feedstock to one or more processes to modify the quantitative measured value to comport with the threshold value when one or more measured properties are identified, thereby generating a modified catalytic cracking feedstock; and supplying the modified catalytic cracking feedstock to the catalytic cracking unit. Optionally, the embodiment may include one or more of the following Elements: Element 1: the method wherein the potential catalytic cracking feedstock is derived from lubricating oil; Element 2: the method wherein the potential catalytic cracking feedstock comprises used lubricating oil; Element 3: the method wherein the potential catalytic cracking feedstock comprises re-refined used lubricating oil; Element 4: the method wherein the potential catalytic cracking feedstock comprises motor oil; Element 5: the method wherein the potential catalytic cracking feedstock comprises a product of biomass pyrolysis; Element 6: the method wherein the potential catalytic cracking feedstock comprises upgraded biocrude; Element 7: the method wherein the potential catalytic cracking feedstock comprises shale oil; Element 8: the method wherein the potential catalytic cracking feedstock comprises used lubricating oil that has been subjected to a re-refining process comprising acid washing; Element 9: the method wherein the potential catalytic cracking feedstock comprises used lubricating oil that has been subjected to a re-refining process comprising thin film evaporation; Element 10: the method wherein the one or more processes are selected from the group consisting of desalting, hydrodesulfurization, hydrodemetallization, hydrodeoxygenation, hydrodenitrogenation, aromatic desaturation, and any combination thereof; Element 11: the method wherein the catalytic cracking unit uses fluidized catalyst bed; Element 12: the method, further comprising combining at least a portion of the first potential catalytic cracking feedstock with at least a portion of a second potential catalytic cracking feedstock prior to supplying the modified catalytic cracking feedstock to the catalytic cracking unit. Examples of suitable combinations include, but are not limited to, Element 1 in combination with one or more of Elements 2-12; Element 2 in combination with one or more of

Elements 3-12; Element 3 in combination with one or more of Elements 4-12; Element 4 in combination with one or more of Elements 5-12; Element 5 in combination with one or more of

Elements 6-12; Element 6 in combination with one or more of Elements 7-12; Element 7 in combination with one or more of Elements 8-12; Element 8 in combination with one or more of Elements 9-12; and Element 9 in combination with one or more of Elements 10-12; Element 10 in combination with one or more of Elements 11-12; and Element 11 in combination with Element 12.

[0064] Another nonlimiting example embodiment is a method comprising: defining a set of disposition criteria comprising a plurality of measurable properties selected from the group consisting of boiling point range, specific gravity, total reactive sulfur, total nitrogen, basic nitrogen, S:N ratio, chlorine, acidity, coking tendency, aniline point, aromaticity, paraffin content, naphthenes, aliphatic unsaturation, sedimentation, water content, flash point, concentration of polychlorinated biphenyls, and the content of one or more of the following elements: S, Ni, V, Fe, Na, Cu, Ca, Si, B, P, Zn, Mg, Mo, K, Sn, Al, Cr, Ag, Ti, Sb, Pb, and Ba, wherein each of the measurable properties has associated therewith a pre-defined value; testing one or more samples of a potential catalytic cracking feedstock to generate a plurality of measured properties corresponding to the plurality of measurable properties, wherein each of the measured properties is characterized by a quantitative measured value; comparing each quantitative measured value to each pre-defined value; identifying each measured property whose quantitative measured value does not comport with the corresponding pre-defined value; and processing the potential catalytic cracking feedstock by either (a) or (b): (a) supplying the potential catalytic cracking feedstock to a catalytic cracking unit when no measured properties are identified, or (b) combining at least a portion of the first potential catalytic cracking feedstock with at least a portion of a second potential catalytic cracking feedstock to generate a combined catalytic cracking feedstock when one or more measured properties are identified; and supplying the combined catalytic cracking feedstock to a catalytic cracking unit. Optionally, the embodiment may include one or more of the following Elements: Element 1, Element 2, Element 3, Element 4, Element 5, Element 6, Element 7, Element 8, Element 9, Element 10, Element 11, and Element 13: the method further comprising subjecting the potential catalytic cracking feedstock to one or more processes to modify the quantitative measured value prior to supplying the combined catalytic cracking feedstock to a catalytic cracking unit. Examples of suitable combinations include, but are not limited to, Element 1 in combination with one or more of Elements 2-11 and 13; Element 2 in combination with one or more of Elements 3-11, and 13; Element 3 in combination with one or more of Elements 4-11 and 13; Element 4 in combination with one or more of Elements 5-11 and 13; Element 5 in combination with one or more of Elements 6-11 and 13; Element 6 in combination with one or more of Elements 7-11 and 13; Element 7 in combination with one or more of Elements 8-11 and 13; Element 8 in combination with one or more of Elements 9-11 and 13; Element 9 in combination with one or more of Elements 10 and 11; Element 10 in combination with one or more of Elements 11 and 13; and Element 11 in combination with Element 13.