Catalytic cracking of glyceride oils using phosphorus-containing ZSM-5 light olefin additives

Abstract

A process for catalytic cracking of a glyceride oil feedstock using a catalyst composition including a phosphorus-containing ZSM-5 soft olefin additive is provided.

Description

[Technical Field]

[0001] The present disclosure relates to catalytic cracking of glyceride oils, and more particularly to the use of phosphorus-containing ZSM-5 as a catalyst. Light for catalytic cracking of triglyceride materials using a modified olefin additive. [Background technology]

[0002] Catalytic cracking, particularly fluid catalytic cracking (FCC), is routinely used to convert heavy hydrocarbon feedstocks into lighter products such as gasoline and distillate range fractions. Additionally, there is an ever-increasing need to increase the yield of petrochemical components such as propylene, ethylene, and aromatics (such as benzene, toluene, and xylenes) in the product slate from catalytic cracking processes.

[0003] FCC catalysts are often mixtures of catalytically active large-pore zeolite components (e.g., FAU framework zeolites) with additives containing other zeolites. These catalysts typically contain about 10 to about 50 wt.% crystalline zeolite, with the remainder being matrix or diluent. The large-pore component catalyzes the cracking of primary products from the catalytic cracking reaction into clean products such as naphtha and distillates for fuel and olefins for chemical feedstock. Traditional additives often include phosphorus-activated ZSM-5, a medium-pore zeolite that selectively converts primary cracking products (e.g., gasoline olefins) to C3 and C4 olefins, improving gasoline octane. Phosphorus-enhanced activity or selectivity is known to enhance the effectiveness of ZSM-5. Additives for FCC processes typically account for less than 10% of the total catalyst.

[0004] To reduce dependence on fossil fuels, it is desirable to produce fuels and other useful materials from renewable resources, such as natural oils. Natural oils primarily contain glycerides, particularly triglycerides. Natural oils are susceptible to catalytic cracking, but using conventional catalysts, such as commercial FCC catalysts, yields and product distributions are lower than desired.

[0005] According to the present disclosure, phosphorus-containing ZSM-5 based Light The high olefin additive can be used as a base catalyst for catalytic cracking of renewable feedstocks; Light It was found that the catalysts produced surprisingly high yields of heavy olefins and aromatics-rich naphtha, and also improved the octane of the gasoline fraction compared to conventional large pore FCC catalysts. Summary of the Invention

[0006] In one aspect, a process for catalytic cracking of glyceride oil is provided, the process comprising: (a) catalytically cracking glyceride oil through at least 80% by weight of phosphorus-containing ZSM-5 Light (b) contacting the hydrocarbon fraction with a cracking catalyst containing a heavy olefin additive under catalytic cracking conditions to obtain a product stream containing hydrocarbons; and (b) separating at least one hydrocarbon fraction from the product stream. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram for the experimental setup in section Example, in accordance with an illustrative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] definition The term "glyceride oil," as used herein, refers to an oil or fat that contains triglycerides as a primary component. For example, the triglyceride component may comprise at least 50% by weight of the glyceride oil. The glyceride oil may also comprise monoglycerides and / or diglycerides. Glyceride oils include vegetable oils, marine oils, and animal oils / fats, which also typically contain phospholipid components in their unrefined form.

[0009] The term "triglyceride" refers to a triester of glycerol with three fatty acid units. The fatty acid units present in a triglyceride may be the same as or different from one another.

[0010] The term "fatty acid" is used to refer to aliphatic monocarboxylic acids having a chain of 4 to 28 carbons (usually unbranched and even numbered) that can be saturated or unsaturated (cis or trans, mono- or polyunsaturated).

[0011] The term "hydrocarbon" refers to a class of compounds containing hydrogen bonded to carbon and includes (i) saturated hydrocarbon compounds, (ii) unsaturated hydrocarbon compounds, and (iii) mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different numbers of carbon atoms.

[0012] The term "Cn" refers to hydrocarbon(s) having n carbon atoms(s) per molecule, where n is a positive integer. As used herein, the term "Cn+" refers to hydrocarbon compositions defined by hydrocarbons having "n" or more carbon atoms, where "n" is an integer greater than 0. This includes paraffins, olefins, cyclic hydrocarbons, aromatics, and isomers thereof. Similarly, the term "Cn-" refers to hydrocarbon compositions defined by hydrocarbons having "n" or fewer carbon atoms, where "n" is an integer greater than 0. This includes paraffins, olefins, cyclic hydrocarbons, aromatics, and isomers thereof.

[0013] term" Light "Mixed olefin" is used herein to refer to olefins having from 2 to 4 carbon atoms (eg, ethylene, propylene, and butylene).

[0014] The term "large pore" means a molecular sieve framework having a maximum ring size of at least 12 tetrahedral atoms, "medium pore" means a molecular sieve framework having a maximum ring size of at least 10 tetrahedral atoms, and the term "small pore" means a molecular sieve framework having a maximum ring size of at least 8 tetrahedral atoms.

[0015] The term "wt %" refers to the weight percent of a component based on the total weight of the material including the component. In a non-limiting example, 10 grams of a component in 100 grams of material is 10 wt % of the component.

[0016] Glyceride oil Glyceride oil is derived from a renewable or biological source or renewable resources or biological sources, and is meant here to include sources other than those obtained from crude oil (mineral oil) or shale oil or coal.

[0017] Glyceride oils can be derived from plants, animals, algae, fish and microbiological processes.

[0018] Glyceride oils contain at least 50% by weight (at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%) triglycerides. Glyceride oils may also contain monoglycerides and / or diglycerides, free fatty acids, and other substances normally present at low levels in fats and oils derived from natural sources. Glyceride oils may contain a single type of triglyceride, but more typically contain a mixture of two or more different triglycerides.

[0019] Representative glyceride oils include rapeseed oil, rapeseed oil, canola oil, tall oil, sunflower oil, soybean oil, hempseed oil, cottonseed oil, corn oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, camellia oil, jatropha oil, oils derived from microbial sources (potentially genetically modified and including at least algae, bacteria, molds and fungi), animal fats, fish oil, lard, tallow, whale oil, recycled fats from the food industry, and any mixture of oils.

[0020] The glyceride oil may be pretreated to remove impurities before contacting it with the cracking catalyst, which may include passing the glyceride oil through an adsorbent to remove metals, filtering the glyceride oil to remove sediment, or other processes.

[0021] cracking catalyst The cracking catalysts of the present disclosure are at least 80 wt. % (e.g., at least 85 wt. %, at least 90 wt. %, at least 95 wt. %, or at least 99 wt. %) phosphorus-containing ZSM-5 Light Contains quality olefin additives.

[0022] Light Any conventional phosphorus-containing ZSM-5 typically used in FCC processes for the production of heavy olefins. Light Modified olefin additives may also be used in the present disclosure.

[0023] Phosphorus-containing ZSM-5 Light The polymeric olefin additive may include (a) 25 to 50 wt. % (e.g., 40 to 50 wt. %) ZSM-5 zeolite, (b) 3 to 15 wt. % (e.g., 5 to 10 wt. %) phosphorus (measured as P2O5), (c) 5 to 40 wt. % (e.g., 10 to 20 wt. %) clay, and (d) 5 to 20 wt. % (e.g., 10 to 20 wt. %) binder.

[0024] The clay may be selected from the group consisting of kaolin, halloysite, bentonite, and any combination thereof, hi some embodiments, the clay is kaolin.

[0025] The binder may be selected from the group consisting of silica sol, alumina sol, pseudoboehmite alumina, bayerite alumina, gamma alumina, and any combination thereof.

[0026] Suitable P / ZSM-5 LightExamples of high-quality olefin additives include those commercially available from Grace (e.g., OlefinsMax®, OlefinsUltra®, OlefinsUltra® HZ, OlefinsUltra® MZ, and OlefinsUltra® XZ), those commercially available from Johnson Matthey (e.g., INTERCAT™, PENTACAT™ HP, PROPYLMAX™, SUPERZ™, SUPERZ EXCEED, SUPERZEXCEED, ISOCAT™, and OCTAMAX™), and those commercially available from BASF (e.g., ZIP Olefin Additive).

[0027] The cracking catalyst further comprises phosphorus-containing ZSM-5 Light In addition to the heavy olefin additive, the cracking catalyst may also contain a large pore molecular sieve component. The large pore molecular sieve component may, for example, comprise a *BEA framework-type zeolite (e.g., beta zeolite) and / or a FAU framework-type zeolite (e.g., Y zeolite). When used, the large pore molecular sieve component is typically present in an amount of 20 wt. % or less (e.g., 0.1 to 20 wt. %, or 1 to 15 wt. %) based on the weight of the cracking catalyst. Optionally, the additional molecular sieve component may further comprise a matrix, binder, and / or clay.

[0028] The cracking catalyst may be in the form of a shaped particulate, such as a microsphere. As used herein, "particulate" refers to a particle having a size between 0.1 microns and 100 microns. The size of a particulate refers to the maximum length from one side of the particle to the other, measured along the longest distance of the particulate.

[0029] Cracking catalysts may be deactivated by contact with steam before use in reactors for converting feedstocks. The purpose of steaming is to accelerate the hydrothermal aging that occurs in operating FCC regenerators to obtain an equilibrium catalyst. Steaming may remove aluminum from the framework, reducing the number of potential framework hydrolysis sites under hydrothermal and thermal conditions. This aluminum removal results in improved thermal and hydrothermal stability in dealuminated zeolites. The catalyst may be subjected to steaming in a 5% to 100% steam atmosphere at a temperature of at least 300°C (e.g., 300°C to 800°C) for at least 1 hour (e.g., 1 hour to 200 hours).

[0030] Catalytic cracking The catalytic process can be either a fixed bed, a moving bed, or a fluidized bed, and the feed flow can be either cocurrent or countercurrent to the catalyst flow. The process is particularly applicable to fluid catalytic cracking (FCC) processes.

[0031] The disclosed process is particularly applicable to fluid catalytic cracking (FCC), where the cracking catalyst is typically a fine powder. This powder is generally suspended in the feedstock and propelled upward through a reaction zone. The feedstock is mixed with the cracking catalyst to form a fluidized suspension, which is cracked at high temperature in an elongated reactor or riser to produce a mixture of lighter hydrocarbon products. Gaseous reaction products and spent catalyst are discharged from the riser to a separator (e.g., a cyclone unit) located in the upper section of a closed stripping vessel or stripper, where the reaction products are conveyed to a product recovery zone and the spent catalyst enters a dense catalyst bed in the lower section of the stripper. An inert stripping gas (e.g., steam) is passed through the catalyst bed to remove entrained hydrocarbons from the spent catalyst before conveying it to a catalyst regenerator unit, where such hydrocarbons are desorbed and conveyed to the product recovery zone. The fluidized catalyst is continuously circulated between the riser and the regenerator. The fluidized catalyst serves to transfer heat from the latter to the former, thereby providing the necessary heat for the cracking reaction, which is endothermic.

[0032] Typically, FCC conversion conditions include a riser top temperature of 450°C to 650°C (e.g., 450°C to 600°C, or 500°C to 575°C), a pressure of 100 kPa to 1100 kPa (e.g., 200 kPa to 400 kPa), a catalyst-to-oil mass ratio of 3 to 12 (e.g., 4 to 11, or 5 to 10), and a catalyst residence time of 0.1 to 15 seconds (e.g., 0.2 to 10 seconds). Suitable regeneration temperatures include temperatures in the range of 600°C to 800°C at pressures in the range of 100 kPa to 1100 kPa.

[0033] A mineral oil component, such as that typically obtained from crude or shale oil that has optionally been subjected to one or more separation and / or other refining processes, may be combined with the glyceride oil feedstock. However, given the different cracking characteristics of glyceride oil and mineral oil feedstocks, it is typically preferred to perform the cracking in equipment dedicated to bio-feedstock cracking, i.e., with a feedstock that is entirely composed of bio-component(s).

[0034] The product stream resulting from the cracking step, comprising cracked renewable hydrocarbons, may be separated into one or more hydrocarbon fractions, for example, using a fractionator, including dry gas (e.g., one or more of hydrogen, methane, and ethane), liquefied petroleum gas (e.g., one or more of propane and butane), and / or liquefied petroleum gas (e.g., one or more of propane and butane). Light These include heavy olefins (e.g., one or more of ethylene, propylene, and butylene), gasoline (boiling range C5 to 221°C), light cycle oil (boiling range 221°C to 343°C), and heavy cycle oil (boiling range 343°C to final boiling temperature). Some heavier hydrocarbons may be recycled to the reactor.

[0035] In some embodiments, the product stream may contain 30 wt% to 60 wt% (e.g., 40 wt% to 50 wt%) gasoline boiling range hydrocarbons as determined by ASTM D2887. In some embodiments, the gasoline boiling range hydrocarbons may contain at least 80 wt% (e.g., at least 85 wt%, or 85 wt% to 95 wt%) C6 to C8 aromatics. The resulting gasoline fraction may be useful as a high-quality renewable gasoline and / or naphtha fuel, or as a blending component for these fuels.

[0036] In some embodiments, the product stream may contain xylenes within the xylene fraction with a para-xylene selectivity of 50% to 99.9% (e.g., 60% to 80%). Of the xylene isomers, para-xylene is particularly valuable because it is useful in the production of terephthalic acid, an intermediate in the production of synthetic fibers and synthetic resins.

[0037] In some embodiments, the product stream comprises at least 25 wt. % (25 wt. % to 40 wt. %, or 30 wt. % to 40 wt. %) of cellulose as determined by ASTM D2887. Light The renewable C3 and C4 product olefins may be sent to a petrochemical unit or alkylation unit to produce isoparaffins (e.g., isobutane) and one or more Light High octane gasoline can be produced by reaction with heavy olefins (usually propylene and butylene). The renewable ethylene product can be sent to a petrochemical unit for further processing.

[0038] The hydrocarbon fraction may be subjected to further processing before commercial utilization. Examples of such processing may include hydrotreating and the addition of additives. [Example]

[0039] The following illustrative examples are intended to be non-limiting.

[0040] example A series of laboratory tests were conducted to study the cracking of soybean oil or vacuum gas oil (VGO) under FCC conditions using three different catalysts: a commercial phosphorus-containing ZSM-5-based FCC additive, a spent FCC equilibrium catalyst (FCC ECAT), and a 50 / 50 by weight mixture of ZSM-5 additive and FCC ECAT. The spent FCC ECAT was obtained from an FCC unit processing hydroprocessing feedstock and had a total metal (Ni + V) content of less than 500 ppm and a total surface area of ​​185 m. 2 / g, and the unit cell size was 24.34 Å. Before use, the ZSM-5 additive was subjected to a 50% steam treatment at 800°C for 24 hours.

[0041] Catalytic cracking experiments were conducted using an Advanced Cracking Evaluation (ACE) Model C apparatus (manufactured by Kayser Technology). A schematic diagram of the ACE Model C apparatus is shown in Figure 1. The reactor used in the ACE apparatus was a 1.6 ccmID fixed-flow reactor. Nitrogen was used as the fluidizing gas, introduced from both the bottom and the top. The top fluidizing gas carried the feedstock, which was injected from a calibrated syringe feed pump through a three-way valve. Catalytic cracking of the feedstock was conducted at atmospheric pressure and 975°F. In each experiment, a fixed amount of feedstock was injected at a rate of 1.2 g / min for 75 seconds. The catalyst-to-oil mass ratio was maintained at 7 for each catalyst tested. After the 75-second feedstock injection, the catalyst was stripped with nitrogen for 525 seconds.

[0042] During the catalytic cracking and stripping process, liquid products were collected in sample vials attached to a glass receiver, which was located at the end of the reactor outlet and maintained at -15°C. Gaseous products were collected in a sealed stainless steel vessel (12.6 L) pre-filled with 1 atmosphere of N2. Immediately after feed injection was completed, the gaseous products were mixed with an electric stirrer rotating at 60 rpm. After stripping, the gaseous products were mixed for an additional 10 minutes to ensure homogeneity. The final gaseous products were then analyzed using a refinery gas analyzer (RGA).

[0043] After the stripping process was completed, in-situ catalyst regeneration was performed at 1300°F in the presence of air. The regenerated exhaust gas passed through a catalytic converter packed with CuO pellets (LECO) to oxidize CO to CO2. The regenerated exhaust gas was then analyzed by an online infrared (IR) analyzer placed downstream of the catalytic converter. The coke deposited during the cracking process was calculated from the CO2 concentration measured by the IR analyzer.

[0044] As previously described, the gaseous products (mainly C1–C7 hydrocarbons) were separated in an RGA. The RGA was a customized Agilent 7890B gas chromatograph (GC) equipped with three detectors: a flame ionization detector for hydrocarbons and two thermal conductivity detectors for nitrogen and hydrogen. A methanizer was also installed on the RGA to quantify trace amounts of CO and CO2 in the gas products. The gas products were classified into dry gas (C2 hydrocarbons and H2) and liquefied petroleum gas (C3 and C4 hydrocarbons). CO and CO2 were excluded from the dry gas. The liquid products were weighed and analyzed in a simulated distillation GC (Agilent 6890) using ASTM D2887. The liquid products were divided into gasoline (C5–430°F), light cycle oil (430°F+–650°F), and heavy cycle oil (650°F+). The gasoline (C5+ hydrocarbons) in the gaseous product was combined with the gasoline in the liquid product to give the total gasoline. The light ends (C5-) in the liquid product were also subtracted from the liquid product and converted back to C3 and C4 species using several empirical distributions. In most experiments, the mass balance was between 98 and 101%.

[0045] Detailed hydrocarbon analysis (DHA) using an Agilent 6890A (Separation Systems Inc.) was also performed on the gasoline portion of the liquid product for PONA (paraffins, olefins, naphthenes, and aromatics) and octane (RON and MON). DHA analysis was not performed on the gasoline portion of the gaseous product. Therefore, no adjustment for overall gasoline properties was made. Nevertheless, the DHA results provided valuable information for characterizing the catalytic cracking products. Table 1 Catalytic cracking of soybean oil and VGO [Table 1]

[0046] The results show that in the catalytic cracking of soybean oil, as the amount of P / ZSM-5 additive in the cracking catalyst formulation increases, Light The results showed that the conversion and yield of heavy olefins and gasoline aromatics increased. Light It was observed that the conversion and yield of heavy olefins and gasoline decreased. Without being bound by theory, it is believed that the pore size of ZSM-5 limits the accessibility of the active sites to the VGO feedstock molecules. Various aspects or embodiments that can be included in the present invention are summarized as follows. [1]. 1. A process for catalytic cracking of glyceride oils, comprising: (a) contacting the glyceride oil with a cracking catalyst comprising at least 80 wt. % of a phosphorus-containing ZSM-5 light olefin additive under catalytic cracking conditions to obtain a product stream comprising hydrocarbons; (b) separating at least one hydrocarbon fraction from said product stream. [2]. The phosphorus-containing ZSM-5 light olefin additive is (a) 25 to 50 wt. % ZSM-5; (b)P 2 O 5 3 to 15 wt. % phosphorus measured as (c) 5 to 45 wt. % clay; (d) 5 to 20 wt. % of a binder. [3]. The process of item 1, wherein the cracking catalyst further comprises a large pore molecular sieve component. [4]. 4. The process according to item 3, wherein the large pore molecular sieve component is selected from *BEA framework-type zeolite and FAU framework-type zeolite. [5]. 4. The process according to item 3, wherein the cracking catalyst contains 0.1 to 20% by weight of the large pore molecular sieve component. [6]. The process according to item 1, wherein the glyceride oil comprises at least 80% by weight of triglycerides. [7]. 2. The process according to item 1, wherein the glyceride oil is selected from rapeseed oil, rapeseed oil, canola oil, tall oil, sunflower oil, soybean oil, hempseed oil, cottonseed oil, corn oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, camellia oil, jatropha oil, microbial oil, animal fat, fish oil, lard, tallow, whale oil, recycled fat from the food industry, and any combination thereof. [8]. The process according to item 1 above, wherein the process is a fluid catalytic cracking process. [9]. The process according to the above item 1, wherein the catalytic cracking conditions include a temperature of 450°C to 650°C, a pressure of 100 kPa to 1100 kPa, and a catalyst to oil mass ratio of 3 to 12.

[10] . 2. The process of claim 1, further comprising fractionating the product stream into one or more hydrocarbon fractions.

[11] . 2. The process of claim 1, wherein the one or more hydrocarbon streams are selected from light olefins and gasoline.

Claims

1. 1. A process for catalytic cracking of glyceride oils, comprising: (a) contacting the glyceride oil with a cracking catalyst comprising a phosphorus-containing ZSM-5 light olefin additive under catalytic cracking conditions to obtain a product stream comprising hydrocarbons; (b) separating at least one hydrocarbon fraction from the product stream; The phosphorus-containing ZSM-5 light olefin additive comprises: (a) 25 to 50 wt. % ZSM-5; (b) P ２ O ５ 3 to 15 wt. % phosphorus measured as (c) 5 to 45 wt. % clay; (d) 5 to 20 wt. % of a binder; The process.

2. 10. The process of claim 1, wherein the glyceride oil comprises at least 80% by weight of triglycerides.

3. 2. The process of claim 1, wherein the glyceride oil is selected from rapeseed oil, tall oil, sunflower oil, soybean oil, hempseed oil, cottonseed oil, corn oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, camellia oil, jatropha oil, microbial oil, animal fat, recycled fat from food industry, and any combination thereof.

4. The process of claim 1, wherein the process is a fluid catalytic cracking process.

5. 2. The process of claim 1, wherein the catalytic cracking conditions comprise a temperature of 450°C to 650°C, a pressure of 100 kPa to 1100 kPa, and a catalyst to oil mass ratio of 3 to 12.

6. 10. The process of claim 1, further comprising fractionating the product stream into one or more hydrocarbon fractions.

7. 10. The process of claim 1, wherein the at least one hydrocarbon fraction is selected from light olefins and gasoline.

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