Trifunction process in catalytic distillation

Abstract

A method for producing alkyl ethers, the method comprising: feeding a hydrocarbon feedstock and a first alcohol feedstock to a fixed bed reactor containing an etherification catalyst. The hydrocarbon feedstock and the first alcohol feedstock are contained in the first fixed bed reactor, and react an isoolefin with an alcohol in the presence of an etherification catalyst to produce a first product stream. The first product stream is fed together with a hydrogen feedstock and a second alcohol feedstock to a catalytic distillation reaction system, the catalytic distillation reaction system containing a trifunction catalyst, thereby simultaneously isomerizing at least a portion of the α-olefins, hydrogenating at least a portion of the diolefins, and etherifying at least a portion of the isoolefins and the alcohol to produce a bottoms product and an overhead product. The bottoms product comprises one or more ethers. The overhead product comprises n-alkanes, isoalkanes, unreacted α-olefins, unreacted internal olefins, unreacted isoolefins, and unreacted alcohol.

Description

Technical Field

[0001] (Field of Disclosure) The embodiments disclosed herein relate to a process (or step or method) of catalytic distillation (or catalytic rectification) for producing tertiary alkyl ethers.

Background Art

[0002] (Background) The production of tertiary alkyl ethers by the reaction of primary alcohols with isoolefins is well known in the art. The use of a distillation column reactor (or distillation tower reactor or distillation column reactor) that simultaneously performs the reaction of reactants and the distillation of products derived from these reactants has been found to be particularly beneficial in this usually equilibrium-limited reaction. Descriptions of processes using distillation column reactors and their variations are commonly disclosed in U.S. Patent Nos. 4,218,011; 4,232,177; 4,305,254; 4,504,687; 4,978,807; 5,118,873; 5,120,403; 5,248,836; 5,248,837; and 5,313,005. Catalytic distillation (or catalytic rectification) has been widely applied (or used) in the etherification of isoolefins. The etherification of isoolefins is also described in some of the patents listed above.

[0003] U.S. Patent No. 5,431,888 discloses a multi-purpose distillation column reactor (or distillation column reactor) (or multi-purpose distillation column reactor). In this U.S. patent, a hydrogenation catalyst (or hydrogenation catalyst) for hydrogenating (or hydrogenating) light naphtha containing isoolefins is positioned (or stacked) below an etherification catalyst (or etherification catalyst). The light naphtha containing isoolefins is derived from a fluid catalytic cracking unit (or fluid catalytic cracking unit) used to remove diolefins and mercaptans.

[0004] Typically, the olefins supplied to the etherification process (or process or method) are a mixed C4 stream. The mixed C4 stream contains linear butane (or n-butane or normal butane) and isobutane, linear butene (or n-butene or normal butene) and isobutene, and some butadiene. Isobutene (iC4 = ) reacts preferentially with primary alcohols to produce (or form) one or more ethers (e.g., methyl tert-butyl ether (MTBE) or ethyl tert-butyl ether (ETBE)). In a process (or step or method) using C5, tert-amyl ethyl ether (TAEE) and / or tert-amyl methyl ether (TAME) can be produced (or generated or formed). Unreacted C4 and C5 are frequently used as feedstock for the cold acid alkylation process (or process or method). In this process, a linear olefin (or n-olefin or normal olefin) (e.g., butene) is reacted with an isoalkane (e.g., isobutane) to produce (or form) an alkylate (e.g., isooctane).

[0005] Therefore, a process (or step or method) for the etherification of C4 using a catalytic distillation column (or catalytic distillation column or catalytic distillation column or catalytic distillation column) often comprises two first (or primary) fixed-bed reactors (or fixed-bed reactors). As shown in Figure 1, the feed (or feed) of C4 (or other light-cut naphtha feed) 2 is combined with fresh or recycled alcohol 4 and hydrogen 6 to produce (or form) a combined feed (or combined feed) 10. The combined feed 10 is supplied to a first fixed-bed reactor (or fixed-bed reactor) 12. The first fixed-bed reactor 12 comprises one or more beds (or beds) of one or more catalysts. These methods can be used to produce (or form) 2-butene by etherification of isobutene and positional isomerization of 1-butene, and to further produce (or form) n-butene and n-butane by hydrogenation of butadiene, thereby producing (or forming) a first intermediate product. The first intermediate product comprises one or more C4 atoms, one or more ethers, and unreacted alcohols.

[0006] The first intermediate product (or intermediate product or intermediate product) is separated into a recycling (or regeneration or circulation) 8 and a feed line (or feed line or supply line) 14 to a second fixed-bed reactor (or fixed-bed reactor or fixed-bed reactor) 16. The second fixed-bed reactor 16 comprises a second catalyst. The second catalyst is a single-function (or single-function or single-performance) catalyst and is a catalyst for the etherification of isobutene and alcohol. The stream (or flow) (or second intermediate product stream) 18 of the second intermediate product may contain one or more ethers, unreacted C4, and unreacted alcohol.

[0007] Next, a stream (or flow) (or second intermediate product stream) 18 of the second intermediate product is supplied to a catalytic distillation system (or catalytic distillation system) 22. The catalytic distillation system 22 comprises a single-function (or single-function or single-performance) etherification catalyst (or etherification catalyst). This etherification catalyst may be the same as or different from the second catalyst contained in the second fixed-bed reactor 16. Alternatively, the etherification catalyst in the catalytic distillation system 22 may be a combination of the catalyst from the first fixed-bed reactor 12 and the catalyst from the second fixed-bed reactor 16. If it is desirable to etherify (or etherify) the C4 remaining in the second intermediate product stream 18, additional alcohol may be supplied to the catalytic distillation system 22 via a feed line (or feed line or supply line) 20.

[0008] In the catalytic distillation reaction system 22, isobutene and alcohol react to produce (or form) further ethers, separating (or separating) one or more ethers from unreacted C4 and unreacted alcohol. One or more ethers may be recovered (or recovered) via the product stream (or product flow) 26. Unreacted C4, excess hydrogen, other lighter hydrocarbons, and unreacted alcohol may be recovered via the overhead stream (or overhead flow) 24. Such a process (or step or method) employs a multi-catalyst bed (or multi-catalyst bed or multiple catalyst bed). A multi-catalyst bed involves multiple types of catalysts in the catalytic distillation reaction system. The multi-catalyst bed is prepared based on the feedstock (or supply material) and the desired transformation (or conversion or conversion).

[0009] Furthermore, the processes (or steps or methods) mentioned above can generally hydrogenate dienes and isomerize and etherify C5 olefins, thereby producing TAME and / or TAEE. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] This process (or step or method) requires a first fixed-bed reactor 12 which needs to be operated at a relatively high pressure (e.g., a pressure greater than 15 barg). Its purpose is to maintain the compound feed (or combined feed (or feed or supply)) 10 in the liquid phase. This process (or step or method) requires a multi-functional catalyst of a precious metal, which must be operated (or run or operate) with a desired degree of efficiency (or capacity or efficiency). Furthermore, this process (or step or method) requires that the feed (or supply or feed) to the second (first) fixed-bed reactor (or fixed-bed reactor or fixed-bed reactor) 16 contains less than approximately 2% by weight of diolefin. The purpose of this is to avoid contamination (or poisoning) of the etherification catalyst. Therefore, the amount of diolefin in the feed (or supply) to the first fixed-bed reactor (or fixed-bed reactor or fixed-bed reactor) must be relatively small. Alternatively, the hydrogenation reaction (or hydrogenation reaction or hydrogenation reaction) in the first fixed-bed reactor (or fixed-bed reactor or fixed-bed reactor) must be fairly complete. [Means for solving the problem]

[0011] (Summary of the embodiments described in the claims) The inventors have found that various etherification catalysts (or etherification catalysts) that can be used in a second fixed-bed reactor (or fixed-bed reactor) exhibit low reactivity (or reactivity) of the diene. Therefore, the process (or steps or methods) for converting isoolefins to ethers can be greatly simplified (or simplified or simplified).

[0012] In one embodiment, embodiments disclosed herein relate to a process (or step or method) for producing (or generating or forming) alkyl ethers. The process includes a step of supplying (feeding) a hydrocarbon feedstock (or hydrocarbon feed material) and a first alcohol feedstock (or first alcohol feed material) to a fixed-bed reactor (or fixed-bed reactor) containing an etherification catalyst (or etherification catalyst). The hydrocarbon feedstock (or hydrocarbon feed material) comprises n-alkanes, isoalkanes, α-olefins (or alpha-olefins), internal olefins (or internal olefins), isoolefins, and diolefins. In a first fixed-bed reactor, a hydrocarbon feedstock and a first alcohol feedstock are brought into contact to react an isoolefin with an alcohol in the presence of an etherification catalyst to produce (or form) a first product stream. The first product stream comprises n-alkanes, isoalkanes, α-olefins, internal olefins, unreacted isoolefins, diolefins, and unreacted alcohols, along with one or more ethers. A catalytic distillation system (or catalytic distillation system) containing a trifunctional catalyst is supplied with a first product stream (or first product flow) along with a hydrogen feedstock (or hydrogen supply material) and a second alcohol feedstock (or second alcohol supply material). This simultaneously carries out the following isomerization, hydrogenation, and etherification. Isomerization is used to isomerize at least a portion of the α-olefin (or alpha-olefin) to produce (or form) an additional internal olefin (or internal olefin). Hydrogenation is used to hydrogenate at least a portion of the diolefin to produce (or form) additional internal olefins. Through etherification, at least a portion of the isoolefin and the alcohol are etherified to produce (or form) one or more ethers. By simultaneously carrying out the above-mentioned isomerization, hydrogenation, and etherification, a bottom product and an overhead product are generated (or formed). The bottom product consists of one or more ethers. The overhead product comprises an n-alkane, an isoalkane, an unreacted α-olefin (or alpha-olefin), an unreacted internal olefin (or internal olefin), an unreacted isoolefin, and an unreacted alcohol.

[0013] In another embodiment, embodiments disclosed herein relate to a system (or scheme) for producing alkyl ethers. The system includes a fixed-bed reactor (or fixed-bed reactor). The fixed-bed reactor comprises an etherification catalyst (or etherification catalyst). In this system, the fixed-bed reactor is configured to receive a hydrocarbon feedstock (or hydrocarbon feed material) and a first alcohol feedstock (or first alcohol feed material). The hydrocarbon feedstock (or hydrocarbon feed material) comprises n-alkanes, isoalkanes, α-olefins (or alpha-olefins), internal olefins (or internal olefins), isoolefins, and diolefins. Furthermore, in this system, a hydrocarbon feedstock (or hydrocarbon supply material) and a first alcohol feedstock (or first alcohol supply material) are brought into contact to generate (or form) a first product stream (or first product flow). The first product stream comprises n-alkanes, isoalkanes, α-olefins (or alpha-olefins), internal olefins (or internal olefins), unreacted isoolefins, diolefins, and unreacted alcohols, along with one or more ethers. The system further comprises a catalytic distillation reaction system (or catalytic distillation reaction system). The catalytic distillation reaction system comprises a single bed (or single bed or single platform) containing a trifunctional (or triplicate) catalyst. This catalytic distillation reaction system further comprises an inlet for a first product stream, an inlet for a hydrogen feedstock, an inlet for a second alcohol feedstock, an outlet for the bottom product, and an outlet for the overhead product. The inlet of the first product stream (or first product flow) is a single bed (or single bed or single bed) containing a trifunctional catalyst. Lower positionIt is located (or positioned or situated) in [location]. The hydrogen feedstock (or hydrogen supply raw material) inlet (or entry point) contains a trifunctional (or three-function) catalyst in a single bed (or single bed or single floor) On the bottom side (or bottom side) It is positioned (or located or situated). The inlet (or entrance) of the second alcohol feedstock (or second alcohol supply raw material) is a single bed (or single bed or single floor) containing a trifunctional catalyst. On the top side (or apex side) It is positioned (or located or situated). The outlet (or exit) for the bottom product (or bottom product or bottom product) is configured to release the bottom product (or bottom product or bottom product). The bottom product consists of one or more ethers. The outlet (or exit) for the overhead product (or head product or overhead product) is configured to release the overhead product (or head product or overhead product). The overhead product comprises an n-alkane, an isoalkane, an unreacted α-olefin (or alpha-olefin), an unreacted internal olefin (or internal olefin), an unreacted isoolefin, and an unreacted alcohol. A catalytic distillation reaction system (or catalytic distillation reaction system or catalytic distillation reaction system or catalytic distillation reaction system) is configured to simultaneously carry out the following isomerization, hydrogenation, and etherification. In isomerization, at least a portion of the α-olefin isomerized to produce (or form) an additional internal olefin. In hydrogenation (or hydrogenation), at least a portion of the diolefin is hydrogenated to produce (or form) additional internal olefins (or internal olefins). In etherification (or etherification), at least a portion of the isoolefin and an alcohol are etherified to produce (or form) one or more ethers.

[0014] Other aspects and advantages will be apparent from the following detailed description and the claims set forth below.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a flow diagram of a process (or process or method) showing a prior art process (or process or method) for etherification (or etherification). [Figure 2] FIG. 2 is a flow diagram of a process (or process or method) showing a process (or process or method) of etherification (or etherification) according to one or more embodiments disclosed herein.

Modes for Carrying Out the Invention

[0016] (Detailed Description) Embodiments of the present disclosure generally relate to systems (or systems) and processes (or processes or methods) for etherifying isoolefins.

[0017] As used in the embodiments disclosed herein, terms such as "contact distillation reaction system (or catalytic distillation reaction system or catalytic distillation reaction system)" mean a system (or system) for reacting compounds and at the same time separating (or separating) reactants (or reactants) and products (or products) using fractional distillation (or fractional distillation or fractional distillation). In some embodiments, the catalytic distillation reaction system may include a conventional catalytic distillation column reactor (or catalytic distillation column reactor or catalytic distillation column reactor or catalytic distillation column reactor). In a conventional catalytic distillation column reactor, the reaction and distillation proceed simultaneously under boiling point conditions (or boiling point conditions). In other embodiments, the catalytic distillation reaction system may include a distillation column (or distillation tower or distillation column), the distillation column being combined with at least one side reactor (or side reactor), which may be operated as a liquid-phase reactor (or liquid-phase reactor) or a boiling-point reactor (or boiling-point reactor). In a conventional liquid-phase reaction prior to separation, both of the catalytic distillation reaction systems described above may be preferred, but a catalytic distillation column reactor (or catalytic distillation column reactor or catalytic distillation column reactor or catalytic distillation column reactor) may have advantages in terms of reduced number (or number of parts or pieces or piece count), reduced capital cost, increased catalytic efficiency (or catalyst productivity) per pound of catalyst, efficient heat removal (the heat of reaction may be absorbed by the heat of vaporization of the mixture), and the potential to shift equilibrium.

[0018] A hydrocarbon feed (or hydrocarbon feed or hydrocarbon feed) to one or more reactors may include a stream (or flow) (or purified isoolefin stream) of purified isoolefins (e.g., a feed stream (or feed stream (or feed logistics) or feed stream (or feed flow)) containing isobutylene, isoamylene or a mixture thereof). In other embodiments, the hydrocarbon feed (or hydrocarbon feed or hydrocarbon supply) may include a cut of C4-C5, C4, or C5 light naphtha. When present as a mixture, tertiary olefins (e.g., isobutylene and isoamylene) are more reactive than linear olefin isomers (or normal olefin isomers) and preferentially react with alcohols to produce (or form) ethers. The isoalkanes in the C4-C5 light naphtha cut (or light naphtha cut) may include isobutane, isopentane, or mixtures thereof and may act as diluents inside the reactor. The hydrocarbon feedstock (or hydrocarbon feedstock) may contain up to 1% by weight of 1,2-pentadiene or isoprene and 10 to 50% by weight of isoamylene.

[0019] In some embodiments, a stream (or flow) (or C4-containing hydrocarbon stream), such as a cut of C4 naphtha, a cut of C4-C5 naphtha, or a cut of C4-C6 naphtha, may be supplied to a reactor (or reactor) and isomerized (or isomerized) from 1-butene to 2-butene. This allows for the hydrogenation (or hydrogenation) of butadiene, thereby generating (or forming) additional 2-butene. Isomerization (or isomerization) may be carried out in a fixed-bed reactor and in a catalytic distillation reaction system. For example, in some embodiments, a reaction system (or reaction scheme) comprising at least one bed containing a multifunctional catalyst may be supplied with a feed (or supply) comprising 1-butene, 2-butene, butadiene, isobutylene, n-butane, and isobutane. Isomerization from 1-butene to 2-butene and hydrogenation from butadiene to 2-butene, n-butane, and other hydrogenation products (or hydrogenation products or hydrogenation products) can be carried out simultaneously.

[0020] The resulting product (or product) may contain residues of 1-butene, 2-butene, isobutene, and any butanes, and the 1-butene content may be dilute (or lean). For example, depending on the severity of the reaction conditions used, the total amount of 1-butene in the product may be less than 1% by weight. In other embodiments, the total amount of 1-butene may be less than 0.5% by weight. In other embodiments, the total amount of 1-butene may be less than 0.1% by weight. In yet another embodiment, the total amount of 1-butene may be less than 500 ppm.

[0021] Such products may be suitable for the etherification of isobutylene and one or more alcohols, thereby producing (or forming) one or more C4 ethers (e.g., MTBE and / or ETBE). Furthermore, such processes (or steps or methods) described above may also be suitable for reactions (or transformations or conversions) of mixed C5 streams (or mixed C5 flows) to C5 ethers (e.g., TAME and / or TAEE).

[0022] C4 and / or C5 isoolefins may be treated according to embodiments of the present disclosure, thereby enabling etherification of the isoolefins. Catalysts used in reactors (or reactors) and distillation column reactors (or distillation column reactors or distillation column reactors) according to embodiments of the present disclosure may have functionality (or functionality) for selectively hydrogenating butadiene, isomerizing olefins, and etherifying isoolefins.

[0023] Typical conditions for the catalytic distillation MTBE reaction include the following: Temperature of the catalyst bed (or catalyst floor): Temperatures exceeding approximately 60°C Overhead (or top of head) pressure: pressure exceeding approximately 5.5 barg Equivalent liquid hourly space velocity: approximately 1.0-2.0 hr -1 The temperature of the column (or tower) is determined by the boiling point of the liquid mixture (or liquid mixture or liquid mixture) present at any given pressure. The temperature of the lower part of the column (or tower) reflects the composition of the material in that part of the column (or tower) and will be higher than the temperature of the overhead part. In other words, at a constant pressure, a change in temperature represents a change in the composition of the column (or tower). The pressure in the column (or tower) may be changed to alter the temperature. Therefore, temperature control in the reaction zone (or reaction area or reaction region) is controlled by pressure resulting from the application (or addition) of heat (or simply boiling) (the reaction is exothermic). Increasing pressure increases temperature (and vice versa). Even if a distillation column reactor (or distillation column reactor or distillation column reactor) is used, some of the isoolefin may remain unconverted and exit the column (or column) along with the overhead (or top of the head).

[0024] The ether product, being the material with the highest boiling point, is removed from the distillation column reactor as the bottom, accompanied by dimers present in the effluent originating from the upstream reactor. The overhead (or upper part of the head) may contain unreacted light alcohols (e.g., methanol or ethanol used in an upstream reactor) and / or reactants (reactants in a distillation column reactor) or isoolefins associated with light inerts (e.g., straight-chain butenes and butanes or pentenes and pentanes).

[0025] As an exemplary embodiment, a process (or step or method) for producing (or generating) methyl tert-butyl ether (MTBE) is illustrated in Figure 2. The process comprises isomerization of an olefin, hydrogenation of butadiene, and etherification of an isoolefin.

[0026] The mixed C4 stream (or mixed C4 flow) 100 may be combined with the alcohol stream (or alcohol flow) 102 and placed in a fixed-bed reactor (or fixed-bed reactor) 104 to produce (or form) MTBE. Here, the mixed C4 stream (or mixed C4 flow) 100 comprises alkanes, isoalkanes, 1-butene, 2-butene, butadiene, and isobutene (for example, comprising up to 1.2% by weight of butadiene and 10-50% by weight of isobutene). The alcohol stream (or alcohol flow) 102 comprises methanol. The fixed-bed reactor (or fixed-bed reactor) 104 comprises an etherification catalyst (or etherification catalyst). The etherification catalyst can react isobutene with an alcohol. In one or more embodiments, the mixed C4 stream (or mixed C4 flow) 100 may contain up to 5% by weight of n-butene and 10 to 50% by weight of isobutene.

[0027] The catalyst for etherification may be any known etherification catalyst (or etherification catalyst) (for example, an acidic cation exchange resin such as Amberlyst 15 supplied by DuPont Chemical Company). In this disclosure, an appropriate contact structure (or catalytic structure) may be used to arrange cation exchange resin particles on the bed (or floor) contained within a fixed-bed reactor. Furthermore, the temperature and pressure may be similar to those known in the art for carrying out specific reactions.

[0028] The effluent (or effluent) 106 from the fixed-bed reactor 104 may contain alkanes, 1-butene, 2-butene, butadiene, and isobutene, and MTBE produced (or formed) in the first fixed-bed reactor. The effluent (or effluent) 106 may be supplied to a catalytic distillation column reaction system (or catalytic distillation column reaction system or catalytic distillation column reaction system) 112. At this time, it may be combined with a second alcohol stream (or alcohol flow) 108 and a hydrogen feed stream (or hydrogen feed flow or hydrogen supply flow or hydrogen supply flow) 110. The catalytic distillation column reaction system 112 may have a single bed (or single bed or single bed) containing a trifunctional (or triplicate) catalyst. The trifunctional (or triplicate) catalyst can simultaneously hydrogenate (or hydrogenate) butadiene, isomerize (or isomerize) 1-butene to 2-butene, and etherify (or etherify) isobutene and alcohol, thereby generating (or forming) additional MTBEs. The catalyst may be similar to an etherification catalyst, but includes hydrogenation catalysts and isomerization catalysts of basic metal oxides known in the art. For example, a trifunctional catalyst system may be an ion exchange resin doped with a palladium (isomerization) catalyst and a precious metal (hydrogenation) catalyst, which possess multifunctionality. In some embodiments, the catalytic distillation reaction system may comprise one or more beds containing a trifunctional (or triplicate) catalyst.

[0029] In the catalytic distillation reaction system 112, for the etherification reaction, isobutene preferentially reacts with methanol in the reaction distillation zone (or reaction distillation area or reaction distillation region) to produce (or form) additional methyl tert-butyl ether. Since methyl tert-butyl ether has a higher boiling point than C4 or methanol, it is distilled and sent to the stripping section below. Here, C4 and methanol are boiled and returned to the reaction distillation zone (or reaction distillation area or reaction distillation region) for further reaction.

[0030] From the catalytic distillation column reaction system (or catalytic distillation column reaction system or catalytic distillation column reaction system or catalytic distillation reaction system) 112, the MTBE is withdrawn as the bottom via the flow line (or channel) 116. The overhead (or top layer) consists of most unreacted C4, excess hydrogen, and other lighter hydrocarbons. The overhead (or head portion) is removed via the flow line (or channel) 114. The overhead C4 stream may contain less than approximately 100 wppm of butadiene. In some cases, it may be as low as approximately 20 wppm. Furthermore, overhead (or top of the head) may contain MTBEs of less than 100 wppm. Overhead products may be supplied to any number of downstream processes (or steps or methods). Examples include, but are not limited to, the following processes (or steps or methods): A step of washing with water to recover (or recycle) unreacted methanol / alcohol for recycling (or regeneration or circulation), A separation system (or separation mechanism) (or separation system) for separating olefins from alkanes / paraffins. A process (or step) for recycling (or regenerating or circulating) olefins in an upstream process (or process or method), A process (or step) of feeding alkanes / paraffins to gasoline formulation (or compounding or blending), alkylation units (or alkylation units), or other hydrocarbon processes (or processes or methods).

[0031] With regard to hydrogenation reactions (or hydrogenation reactions or hydrogenation reactions), first, as with etherification reactions (or etherification reactions or etherification reactions), catalytic distillation (or catalytic distillation or catalytic distillation) is beneficial because the reaction proceeds simultaneously with the distillation (or distillation). The initial reaction product (or reaction product) and components from other streams (or flows) are removed from the reaction zone (or reaction area or reaction region) as quickly as possible. This is as rapid as reducing similar side reactions. Next, since all components (or components) are boiling, the reaction temperature is controlled (or controlled) at the boiling point of the mixture at the pressure of this system (or system). The heat of the reaction (or reaction heat) simply causes further boiling. However, at a given pressure, the temperature does not increase in any significant way. As a result, by adjusting the pressure of the system, a wide range of control over the reaction rate and the distribution of the products can be achieved. Furthermore, throughput (residence time (or retention time) = liquid space velocity) -1 By adjusting the ), the distribution of the product can be further controlled, and side reactions such as oligomerization can be controlled to some extent. A further advantage of this reaction being able to benefit from catalytic distillation (or catalytic distillation) is the washing effect, which is brought about by internal reflux (or internal backflow) of the catalyst. This reduces polymer formation (or construction or build-up) and coking. Excellent results can be obtained with internal reflux (or internal backflow or internal reflux) in the range of 0.4 to 5 L / D (weight of liquid directly below the catalyst bed / weight of distillate).

[0032] For hydrogenation, excess hydrogen, other lighter hydrocarbons, unreacted C4 olefins (including butadiene), and methanol zeotropes (about 4%) are brought to a boil and placed in the upper reaction distillation zone (or reaction distillation area or reaction distillation region or reaction distillation zone). In the reaction distillation zone, butadiene reacts with hydrogen, thereby reducing the butadiene content (or content or quantity) to about 20-100 wppm. In this manner (or method or manner), butadiene is hydrogenated to produce (or form) n-butene and n-butane.

[0033] A hydrogen stream (or hydrogen flow) may be supplied into the reaction distillation column (or reaction distillation tower) along with other reactants (or reactants) at a hydrogen partial pressure of approximately 0.1 psia to 70 psia, or at a reactor height higher than the effluent (or effluent) 10⁶. At the hydrogen partial pressure defined (or specified) in this way, use hydrogen that does not exceed the amount of hydrogen required to hydrogenate (or hydrogenate) a highly unsaturated compound (diene). This is because excess hydrogen is usually exhausted (or ventilated).

[0034] Isomerization is the process of converting various α-olefins (e.g., 1-butene) into internal olefins (e.g., 2-butene). While the text describes butene, other processes such as the conversion (or transformation) of 1-pentene to 2-pentene are also possible.

[0035] The reaction conditions disclosed herein can be carried out at temperatures in the range of 5°C to about 500°C, for example, in the range of 250°C to about 450°C. Furthermore, the reaction may be controlled (or managed) at a pressure within the range of atmospheric pressure to approximately 140 barg, for example, atmospheric pressure to 100 barg, or atmospheric pressure to 50 barg. Furthermore, the reaction may be controlled (or controlled) at approximately 3.5 barg or 6 barg to approximately 35 barg. Additionally, if necessary, pressurization may be performed under an inert atmosphere. The temperature and pressure may be appropriate for simultaneous etherification, isomerization, and hydrogenation.

[0036] A trifunctional catalyst may be placed (or positioned or located) in a single bed (or single bed or single floor) in a catalytic distillation reaction system (or catalytic distillation reaction system or catalytic distillation reaction system or catalyst distillation reaction system). Alternatively, it may be placed (or positioned or located) in a multi-bed (or multi-bed or multi-bed or multiple bed) configuration. Compared to conventional processes (or steps or methods) that pair a multifunction (or multifunctional) catalyst with a single function (or monofunctional) catalyst, or to conventional processes (or steps or methods) that use multiple single function (or monofunctional) catalysts, a single bed (or single bed or single floor) of a trifunction (or trifunctional) catalyst is considerably simpler to operate. For example, the order / height of the catalyst bed (or catalyst floor) is not important in terms of the overall function (or performance or function) of the bed (or floor) with respect to hydrogenation (or hydrogenation), isomerization (or isomerization), and etherification (or etherification).

[0037] Embodiments relating to a single bed (or single bed or single floor) of a trifunctional (or triplicate) catalyst may be advantageous over prior art processes (or steps or methods) in that they allow for simpler design and configuration. Furthermore, the catalyst loading (or catalyst support) operation can be simpler because fewer beds and fewer types of catalysts can be used. However, in some embodiments, it may be preferable to include a smaller second catalyst bed above or below the main bed containing the trifunctional catalyst. The second catalyst may be a single-function (or monofunctional) etherification catalyst or a single-function (or monofunctional) hydrogenation catalyst. Based on the composition of the feedstock (or raw material), the availability of hydrogen and / or alcohol feedstock (or raw material), and the desired conversion from olefin to ether, the type of catalyst, the placement of the trifunctional catalyst above or below, and the amount of the second catalyst can be determined.

[0038] One of the advantages of this process is that C4 derived from light naphtha cut (or light naphtha cut) can be used without pretreatment. This C4 stream (or flow) may contain up to approximately 50% by weight of isobutene and may be accompanied by 500 ppm to 2.5% by weight or more of butadiene. The remainder (or residue, dregs, or reminders) of this stream (or flow) is essentially butane and linear (or normal) butene. In such a process (or step or method), the overall average conversion (or inversion or conversion) of isobutene in the process may exceed 90% by weight. Furthermore, the purity of MTBE in the product stream may be 90% by weight or higher, for example, 92% by weight or higher, or 94% by weight or higher. This includes commercially available grades of MTBE products.

[0039] First, as described above, a process (or step or method) involving a mixture of C4 is used to etherify (or etherify) isobutene using methanol to produce (or form) MTBE. However, this process can be extended to include C5 and methanol, C4 and ethanol, C5 and ethanol, higher hydrocarbons, higher primary alcohols, and combinations thereof.

[0040] For example, steps (or processes) of a similar process (or procedure or method) may be used to convert (or transform or convert) isobutene and ethanol to produce (or form or manufacture) ETBE. Alternatively, isoamylene and methanol may be converted (or transform or convert) to produce (or form or manufacture) TAME. Alternatively, isoamylene and ethanol may be converted (or transform or convert) to produce (or form or manufacture) TAEE. Alternatively, a combination of these may be used. Similar processes (or steps or methods) may be used to convert (or transform or convert) mixtures of C4 and C5 and mixtures of methanol and ethanol to produce (or form or produce) mixtures containing two or more of MTBE, ETBE, TAME and / or TAEE.

[0041] Advantageously, processes (or steps or methods) and systems (or systems) according to one or more embodiments disclosed herein may have a reduced number of unit parts (or unit number or unit piece number or unit piece count) compared to processes (or steps or methods) of the prior art. Furthermore, this reduced portion (or number or number of pieces or piece count) may result in a reduction in CAPEX and OPEX costs. Furthermore, the overall H2 partial pressure in this system may be lower because there is no need to supply (feed) H2 to any upstream hydrogenation reactor (or hydrogenation reactor or hydrogenation reactor).

[0042] Unless otherwise defined (or specified), all technical and scientific terms used in this disclosure have the same meanings as those commonly understood by those skilled in the art to which such systems, apparatus, methods, processes, and compositions belong.

[0043] Unless otherwise explicitly stated in the context, the singular forms ("a," "an," and "the") can also refer to plural nouns.

[0044] As used in this disclosure and the attached claims, the terms “comprise,” “has,” and “include,” and all their grammatical variations, are intended to have an open and non-restrictive meaning (i.e., not to exclude additional components or processes (or steps)).

[0045] "Optionally" means that the event or situation described thereafter may or may not occur. Such description includes both cases in which the event or situation occurs and cases in which it does not occur.

[0046] When using the terms "approximately" or "about," these terms may mean that the value may vary by up to ±10%, up to 5%, up to 2%, up to 1%, up to 0.5%, up to 0.1%, or up to 0.01%.

[0047] The range may be described as ranging from approximately one specific value to another approximately specific value (inclusive). When such a range is described, it can be understood that another embodiment is from one specific value to another specific value, encompassing all specific values ​​within the range and any combinations thereof.

[0048] This disclosure includes a limited number of embodiments, but those skilled in the art who would benefit from such disclosure will find it useful. We understand that other embodiments may be conceived, and that such embodiments may fall within the scope of this disclosure. It is understood that this does not deviate from the scope. Therefore, according to the attached claims The scope should be limited. The disclosures in this specification may include the following aspects: (Aspect 1) A method for producing an alkyl ether, the method comprising the following steps: A step of supplying a hydrocarbon feedstock and a first alcohol feedstock to a fixed-bed reactor containing an etherification catalyst, wherein the hydrocarbon feedstock includes n-alkanes, isoalkanes, α-olefins, internal olefins, isoolefins, and diolefins; A step of contacting the hydrocarbon feedstock with the first alcohol feedstock, wherein the isoolefin reacts with the alcohol in the presence of the etherification catalyst to produce a first product stream, the first product stream comprising an n-alkane, an isoalkane, an α-olefin, an internal olefin, unreacted isoolefin, a diolefin, and an unreacted alcohol, and one or more ethers: A step of supplying the first product stream, a hydrogen feedstock, and a second alcohol feedstock to a catalytic distillation reaction system containing a trifunction catalyst, wherein isomerization, hydrogenation, and etherification are carried out simultaneously. In the isomerization described above, at least a portion of the α-olefin isomerized to form an additional internal olefin. In the hydrogenation process, at least a portion of the diolefin is hydrogenated to form additional internal olefins and alkanes. In the etherification process, at least a portion of the isoolefin and the alcohol are etherified to form one or more ethers. A bottom product containing one or more ethers is generated, A process that produces an overhead product comprising an n-alkane, an isoalkane, an unreacted α-olefin, an unreacted internal olefin, an unreacted isoolefin, excess hydrogen, and an unreacted alcohol. Methods that include... (Aspect 2) The method according to embodiment 1, further comprising the step of separating the overhead stream to produce one or more streams of saturated alkanes, residual olefins, and residual alcohols. (Aspect 3) The method according to embodiment 2, further comprising a step of recycling the stream of residual olefins in one or more of the fixed-bed reactor and the catalytic distillation reaction system. (Aspect 4) The method according to embodiment 2, further comprising a step of recycling the stream of residual alcohol in one or more of the fixed-bed reactor and the catalytic distillation reaction system. (Aspect 5) The method according to embodiment 1, further comprising operating the catalytic distillation reaction system at a pressure from atmospheric pressure to 140 barg and a temperature from 5°C to about 500°C. (Aspect 6) The method according to embodiment 1, wherein the hydrocarbon feedstock comprises up to 5% by weight of n-butene and 10 to 50% by weight of isobutene. (Aspect 7) The method according to embodiment 1, wherein the hydrocarbon feedstock contains 1.2% by weight or less of butadiene. (Pattern 8) The method according to embodiment 1, wherein the hydrocarbon feedstock comprises up to 1% by weight of 1,2-pentadiene or isoprene and 10 to 50% by weight of isoamylene. (Aspect 9) The method according to embodiment 1, wherein the first alcohol feedstock is methanol, ethanol, or a mixture thereof. (Aspect 10) A system for producing alkyl ethers, the system comprising a fixed-bed reactor and a catalytic distillation reaction system, The fixed-bed reactor includes an etherification catalyst, and is configured to receive a hydrocarbon feedstock and a first alcohol feedstock, and to contact the hydrocarbon feedstock with the first alcohol feedstock to generate a first product stream. The hydrocarbon feedstock includes n-alkanes, isoalkanes, α-olefins, internal olefins, isoolefins, and diolefins. The first product stream comprises an n-alkane, an isoalkane, an α-olefin, an internal olefin, an unreacted isoolefin, a diolefin, and an unreacted alcohol, and one or more ethers. The catalytic distillation system comprises a single bed containing a trifunction catalyst, and further comprises an inlet for a first product stream, an inlet for a hydrogen feedstock, an inlet for a second alcohol feedstock, an outlet for a bottom product, and an outlet for an overhead product. The inlet of the first product stream is located below the single bed containing the trifunction catalyst, The inlet of the hydrogen feedstock is positioned close to the top of the single bed containing the trifunction catalyst, The inlet of the second alcohol feedstock is positioned close to the bottom of the single bed containing the trifunction catalyst, The outlet of the bottom product is configured to produce a bottom product containing one or more ethers, The overhead product outlet is configured to discharge the overhead product, which comprises an n-alkane, an isoalkane, an unreacted α-olefin, an unreacted internal olefin, an unreacted isoolefin, and an unreacted alcohol. The catalytic distillation reaction system is configured such that isomerization, hydrogenation, and etherification proceed simultaneously. The isomerization is performed by isomerizing at least a portion of the α-olefin to form an additional internal olefin. The hydrogenation hydrogenates at least a portion of the diolefin to form an additional internal olefin. The etherification involves etherifying at least a portion of the isoolefin and the alcohol to form one or more ethers. system. (Aspect 11) The system according to embodiment 10, further comprising a separation system configured to separate the overhead products, thereby producing one or more streams of saturated alkanes, residual olefins, and residual alcohols. (Aspect 12) The system according to embodiment 10, further comprising an upstream separation system configured to produce a mixed C4 stream, the mixed C4 stream comprising, as the hydrocarbon feedstock, up to 2.5% by weight of butadiene and 10 to 50% by weight of isobutene. (Aspect 13) The system according to embodiment 10, further comprising an upstream separation system, the upstream separation system configured to produce a mixed C5 hydrocarbon feedstock, the mixed C5 hydrocarbon feedstock comprising, as the hydrocarbon feedstock, up to 1% by weight of pentadiene and 10 to 50% by weight of isoamylene.

Claims

1. A method for producing an alkyl ether, the method comprising the following steps: A step of supplying a hydrocarbon feedstock and a first alcohol feedstock to a fixed-bed reactor containing an etherification catalyst, wherein the hydrocarbon feedstock includes n-alkanes, isoalkanes, α-olefins, internal olefins, isoolefins, and diolefins; A step of contacting the hydrocarbon feedstock with the first alcohol feedstock, wherein the isoolefin reacts with the alcohol in the presence of the etherification catalyst to produce a first product stream, the first product stream comprising an n-alkane, an isoalkane, an α-olefin, an internal olefin, unreacted isoolefin, a diolefin, an unreacted alcohol, and one or more ethers: A step of supplying the first product stream, a hydrogen feedstock, and a second alcohol feedstock to a catalytic distillation reaction system containing a trifunction catalyst, wherein isomerization, hydrogenation, and etherification are carried out simultaneously. In the isomerization described above, at least a portion of the α-olefin isomerized to form an additional internal olefin. In the hydrogenation process, at least a portion of the diolefin is hydrogenated to form additional internal olefins and alkanes. In the etherification process, at least a portion of the isoolefin and the alcohol are etherified to form one or more ethers. A bottom product containing one or more ethers is generated, A process that produces an overhead product comprising an n-alkane, an isoalkane, an unreacted α-olefin, an unreacted internal olefin, an unreacted isoolefin, excess hydrogen, and an unreacted alcohol. Methods that include...

2. The method according to claim 1, further comprising the step of separating the overhead product to produce one or more streams of saturated alkanes, residual olefins, and residual alcohols.

3. The method according to claim 2, further comprising a step of recycling the stream of residual olefins in one or more of the fixed-bed reactor and the catalytic distillation reaction system.

4. The method according to claim 2, further comprising a step of recycling the stream of residual alcohol in one or more of the fixed-bed reactor and the catalytic distillation reaction system.

5. The method according to claim 1, further comprising operating the catalytic distillation reaction system at a pressure from atmospheric pressure to 140 barg and a temperature from 5°C to about 500°C.

6. The method according to claim 1, wherein the hydrocarbon feedstock comprises up to 5% by weight of n-butene and 10 to 50% by weight of isobutene.

7. The method according to claim 1, wherein the hydrocarbon feedstock contains 1.2% by weight or less of butadiene.

8. The method according to claim 1, wherein the hydrocarbon feedstock comprises up to 1% by weight of 1,2-pentadiene or isoprene and 10 to 50% by weight of isoamylene.

9. The method according to claim 1, wherein the first alcohol feedstock is methanol, ethanol, or a mixture thereof.

10. A system for producing alkyl ethers, the system comprising a fixed-bed reactor and a catalytic distillation reaction system, The fixed-bed reactor includes an etherification catalyst, and is configured to receive a hydrocarbon feedstock and a first alcohol feedstock, and to bring the hydrocarbon feedstock and the first alcohol feedstock into contact to generate a first product stream. The hydrocarbon feedstock comprises n-alkanes, isoalkanes, α-olefins, internal olefins, isoolefins, and diolefins. The first product stream comprises an n-alkane, an isoalkane, an α-olefin, an internal olefin, an unreacted isoolefin, a diolefin, an unreacted alcohol, and one or more ethers. The catalytic distillation system comprises a single bed containing a trifunction catalyst, and further comprises an inlet for a first product stream, an inlet for a hydrogen feedstock, an inlet for a second alcohol feedstock, an outlet for a bottom product, and an outlet for an overhead product. The inlet of the first product stream is located lower than the single bed containing the trifunction catalyst. The inlet of the hydrogen feedstock is located on the bottom side of the single bed containing the trifunction catalyst, The inlet of the second alcohol feedstock is located on the top side of the single bed containing the trifunction catalyst, The outlet of the bottom product is configured to produce a bottom product containing one or more ethers, The overhead product outlet is configured to discharge the overhead product, which comprises an n-alkane, an isoalkane, an unreacted α-olefin, an unreacted internal olefin, an unreacted isoolefin, and an unreacted alcohol. The catalytic distillation reaction system is configured such that isomerization, hydrogenation, and etherification proceed simultaneously. The isomerization is performed by isomerizing at least a portion of the α-olefin to form an additional internal olefin. The hydrogenation hydrogenates at least a portion of the diolefin to form an additional internal olefin. The etherification involves etherifying at least a portion of the isoolefin and the alcohol to form one or more ethers. system.

11. The system according to claim 10, further comprising a separation system configured to separate the overhead products, thereby producing one or more streams of saturated alkanes, residual olefins, and residual alcohols.

12. The system according to claim 10, further comprising an upstream separation system configured to produce a mixed C4 stream, the mixed C4 stream comprising, as the hydrocarbon feedstock, up to 2.5% by weight of butadiene and 10 to 50% by weight of isobutene.

13. The system according to claim 10, further comprising an upstream separation system configured to produce a mixed C5 hydrocarbon feedstock, wherein the mixed C5 hydrocarbon feedstock comprises, as the hydrocarbon feedstock, up to 1% by weight of pentadiene and 10 to 50% by weight of isoamylene.

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