Isomerized olefin etherification separation reaction system and method of operating the same

Abstract

This invention relates to an isomeric olefin etherification separation reaction system and its operation method. The etherification reactor includes a reactor body with an upper catalytic reaction section and a lower separation section. The catalytic reaction section is filled with a catalyst suitable for isomeric olefin etherification. The separation section is equipped with packing and / or multi-layer trays to separate the unreacted material from the catalytic reaction section and the mixture of ethers produced. The separation section returns a portion of the separated unreacted material to the catalytic reaction section through an outer ring passage of a condenser for continued etherification. This etherification reactor features high reaction efficiency, high isomeric olefin conversion rate, high etherified purity, and long reactor operating cycle. It also allows a single reactor to replace multiple reactors connected in series or parallel, simplifying the process flow. It is particularly suitable for the separation of long-chain isomeric olefins and n-olefins in Fischer-Tropsch synthesis products, and is also applicable to the etherification of catalytic cracking, coking light gasoline, and thermal cracking light gasoline.

Description

Technical Field

[0001] This invention belongs to the field of chemical production technology, and specifically refers to a system for the separation reaction of isomeric olefin etherification and its operating method. Background Technology

[0002] Fischer-Tropsch synthesis products are rich in α-olefins, making them suitable for fine processing and utilization. These are fine chemicals and specialty chemicals that are difficult to obtain through petrochemical routes, and have promising prospects for further development. Separating and purifying α-olefins from Fischer-Tropsch synthesis oils can yield linear α-olefins with higher carbon numbers, especially odd-numbered α-olefins that are unavailable through petroleum routes. These olefins can be widely used in the production of aldehydes and brominated alkanes, as well as as comonomers in polymer production. They are also important raw materials for manufacturing advanced plasticizers, synthetic lubricants, and other fine chemical products.

[0003] The most common method for separating and purifying Fischer-Tropsch synthesis products is distillation. However, α-olefins in Fischer-Tropsch synthesis products contain a variety of isomers, especially tertiary olefins. Since their boiling points are close to those of α-olefins, it is not economical to separate high-purity α-olefin products from these mixtures by simple distillation. Therefore, tertiary olefins need to be removed by etherification reaction before distillation.

[0004] Currently, most commonly used etherification reactors for tertiary olefins are fixed-bed reactors, resulting in low conversion rates of tertiary olefins in a single reactor. To improve tertiary olefin conversion, multiple reactors are often connected in series and / or parallel in industrial processes. Timely removal of the etherified products from the reactants via distillation is an effective way to improve the conversion rate of isomeric olefins. The process setup typically employs a reactor + distillation column + reactor configuration, or a series combination of multiple reactors and multiple distillation columns, leading to a complex process flow and high energy consumption. Furthermore, the small amount of olefin polymerization and trace impurities in the feedstock can cause frequent catalyst failure and replacement in the upstream reactors, affecting the stable operation of the process system.

[0005] While existing technologies employ catalytic reactive distillation to improve the conversion rate of tertiary olefins, these methods suffer from high investment costs and difficulties in catalyst loading. Furthermore, etherification reactions typically occur at temperatures between 55 and 85°C, while the operating temperature at the top of the distillation column for high-carbon-number olefins (such as C5+) and etherification products is relatively high. Although the operating temperature can be lowered by reducing the top pressure, the reduction is very limited. Therefore, catalytic reactive distillation is unsuitable for the etherification and separation of high-carbon-number olefins.

[0006] Developing a novel and efficient etherification reactor to systematically solve the above problems is of great significance for separating and purifying long-chain α-olefins from Fischer-Tropsch synthetic oils, obtaining high-purity straight-chain olefin products, while simplifying the process and reducing energy consumption. Summary of the Invention

[0007] To address the above technical problems, this invention provides a reaction system and its operation method for the etherification separation of isomeric olefins. The designed etherification reactor features high reaction efficiency, high isomeric olefin conversion rate, high purity of etherified products, and long reactor operation cycle. Furthermore, this invention achieves the replacement of multiple reactors in series or parallel by a single reactor, simplifying the process flow. It is particularly suitable for the separation of long-chain isomeric olefins and normal-chain olefins in Fischer-Tropsch synthesis products, and is also applicable to the etherification of catalytic cracking, coking light gasoline, and thermal cracking light gasoline.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A reaction system for the etherification separation of isomeric olefins includes a feed system, an etherification reactor, and an outer loop of the condenser.

[0010] The feeding system includes a mixture feed line and an alcohol feed line;

[0011] The etherification reactor includes a reactor body, which has a catalytic reaction section at the upper part and a separation section at the lower part.

[0012] The catalytic reaction section is provided with multiple catalyst beds arranged from top to bottom. Each catalyst bed is equipped with a mixture inlet, which is connected to a mixture feed pipeline. An alcohol feed inlet is also provided between adjacent catalyst beds, which is connected to an alcohol feed pipeline. The catalyst beds are filled with catalysts suitable for the etherification of isomeric olefins.

[0013] The separation section is internally packed with packing material and / or multiple layers of trays, and is used to separate the unreacted material from the catalytic reaction section and the mixture of generated ethers. The lower part of the separation section is provided with a liquid ether outlet.

[0014] The outer ring passage of the condenser connects the separation section and the catalytic reaction section, so as to return the unreacted material obtained from the separation section to the catalytic reaction section for continued etherification reaction.

[0015] In some technical solutions, the reaction system further includes a charging system and a discharging system. The upper and lower parts of the catalyst bed are respectively provided with a charging port and a discharging port for the catalyst. The charging port is connected to the charging system, and the discharging port is connected to the discharging system.

[0016] In some technical solutions, the charging system includes a fresh catalyst storage tank and a catalyst discharge pipeline connected in sequence. The fresh catalyst storage tank is connected to a branch of the alcohol feed pipeline, and the catalyst discharge pipeline is connected to the loading port of the catalyst bed; and / or,

[0017] The unloading system includes a catalyst feed pipeline and a spent catalyst storage tank connected in sequence, wherein the catalyst feed pipeline is connected to the unloading port of the catalyst bed; and / or

[0018] Both the loading and unloading systems are equipped with inert gas pressure-maintaining devices to enable online loading and / or unloading of the catalyst.

[0019] In some technical solutions, a support is provided at the bottom of the catalyst bed. The support is a horizontal plate, an arc-shaped plate, or a support plate with other deformations that are fixedly connected to the inner wall of the reactor body to facilitate the flow of particulate catalyst. The horizontal plate, arc-shaped plate, or support plate has flow holes that connect the catalyst bed layers at each level. The form and number of flow holes are to ensure that the liquid material after the reaction can flow smoothly downwards.

[0020] In some technical solutions, a partition plate is provided at the bottom of the catalytic reaction section. The partition plate and the adjacent support above it, or in combination with the inner wall of the reactor body, form a liquid collection chamber. A liquid downcomer is connected through the partition plate and is connected to the separation section.

[0021] In some technical solutions, a gas-liquid separator with upper and lower sealing plates is provided at the upper part of the separation section. The gas-liquid separator with upper and lower sealing plates and the partition plate are combined with the inner wall of the reactor body to form a gas collection chamber.

[0022] In some technical solutions, the gas collection chamber is provided with a gas phase outlet, and the reactor body below the gas-liquid separator is provided with a liquid phase circulating material inlet. The gas phase outlet and the liquid phase circulating material inlet are also connected through the outer ring passage of the condenser.

[0023] In some technical solutions, a gas phase condenser, a condensate storage tank, and a condensate booster pump are sequentially arranged along the flow direction of the unreacted material on the outer ring path of the condenser. The outlet of the condensate booster pump is provided with three paths: one path is connected back to the inlet of the mixture in the catalytic reaction section to form an etherification circulation pipeline; one path is connected back to the inlet of the liquid phase circulation material in the separation section to form a separation circulation pipeline; and the remaining path is connected to the outside of the reaction system to form a liquid phase hydrocarbon output pipeline.

[0024] In some technical solutions, the feeding system is equipped with a raw material mixer, the first input end of which is connected to the alcohol feed line, the second input end of which is connected to the raw hydrocarbon feed line, and the output end of which is connected to the mixed material feed line; and / or,

[0025] The lower part of the separation section is provided with a circulating liquid phase ether outlet and a circulating gas phase ether inlet, and the circulating liquid phase ether outlet and the circulating gas phase ether inlet are connected by a reboiler outer ring passage.

[0026] According to another aspect of the present invention, a method for operating a reaction system for the separation of isomeric olefin etherification is provided, comprising the following steps:

[0027] The mixed solution of alcohol and raw hydrocarbon input at the mixing inlet at the top of the reactor body comes into contact with the catalyst packed in the multi-stage catalyst bed from top to bottom to undergo etherification reaction. The alcohol-to-olefin ratio of the feed to each stage of the catalyst bed is adjusted by controlling the amount of alcohol feed between adjacent stages of the catalyst bed.

[0028] After the etherification reaction, the liquid material enters the separation section at the bottom of the reactor body. The multi-layer trays and / or packing installed in the separation section realize the mass and heat exchange between the gas and liquid phases. The liquid ether is then output from the bottom of the separation section, while the unreacted material obtained from the top of the separation section is fed back to the catalytic reaction section to continue the etherification reaction.

[0029] In some technical solutions, a feed valve is installed on the feed pipeline of the mixture;

[0030] Each catalyst bed is equipped with a charging system and a discharging system. The charging system is equipped with a fresh catalyst storage tank, and the discharging system is equipped with a waste catalyst storage tank. Both the charging system and the discharging system are equipped with an inert gas pressure maintaining device.

[0031] It also includes the following steps:

[0032] The pressure of the fresh catalyst storage tank and the spent catalyst storage tank are adjusted separately using an inert gas pressure-maintaining device to achieve online addition and / or unloading of catalyst;

[0033] When online addition and / or unloading of catalyst is performed on the upper catalyst bed in the reactor body, the feed valve of the upper catalyst bed is closed, while the feed valve of the lower catalyst bed is opened, and the mixed raw materials are fed from the top of the lower catalyst bed.

[0034] In some technical solutions, the multi-stage catalyst bed comprises two stages, namely an upper catalyst bed and a lower catalyst bed. The alcohol-to-olefin ratio of the feed to the upper catalyst bed is controlled to be 1 to 1.8, while the alcohol-to-olefin ratio of the feed to the lower catalyst bed is controlled to be 1 to 2.4.

[0035] In some technical solutions, the proportion of tertiary carbon isoolefins in the raw material hydrocarbon is 0.5–60 wt%, and the conversion rate of isoolefins after treatment by the reaction system is ≥99%; and / or,

[0036] The reaction system is suitable for the etherification of C4 to C18 isoolefins.

[0037] The present invention, by employing the above technical solution, has at least the following beneficial effects:

[0038] 1. The present invention proposes a reaction system for the etherification separation of isomeric olefins. The designed etherification reactor adopts an integrated structure design of an upper catalytic reaction section and a lower separation section, realizing the replacement of multiple reactors in series or parallel by a single reactor, simplifying the process flow. The catalytic reaction section is filled with a catalyst suitable for isomeric olefin etherification. In the separation section, the unreacted material from the catalytic reaction section and the mixture of generated ether are separated by distillation. Liquid ether is output from the bottom, and the unreacted material from the top is returned to the catalytic reaction section to continue the etherification reaction, which can simultaneously improve the reaction efficiency and the conversion rate of isomeric olefins.

[0039] 2. The present invention proposes a reaction system for the etherification separation of isomeric olefins. The etherification reactor is designed with a multi-stage catalyst bed at the top, which can further improve the conversion rate of isomeric olefins in a single reactor. At the same time, each stage of the catalyst bed is equipped with a loading system and a unloading system to realize online loading and / or unloading of the catalyst. A mixed feed inlet is also provided for each stage of the catalyst bed to realize separate feeding for each stage of catalytic etherification. Furthermore, an alcohol feed inlet is designed between adjacent catalyst beds to control the alcohol-olefin ratio of each stage of catalytic etherification reaction.

[0040] 3. The reaction system for the etherification separation of isomeric olefins proposed in this invention features a gas-liquid separator installed above the separation section of the etherification reactor. The gas phase separated above is fed back to the reactor body below the gas-liquid separator through the outer ring passage of the condenser, which can significantly improve the separation purity and separation efficiency of the etherified products.

[0041] 4. The reaction system for the etherification separation of isomeric olefins proposed in this invention has a reasonable equipment structure design, uniform fluid distribution, high catalytic reaction efficiency of a single unit, simple process flow, low operating energy consumption, and stable and reliable operation.

[0042] 5. The present invention proposes an operating method for a reaction system for isomeric olefin etherification separation, wherein when the catalyst is added and / or unloaded online in the upper catalyst bed, the feed to the lower catalyst bed is controlled and the feed alcohol-olefin ratio is adjusted, thus providing the possibility for long-term operation of the etherification reactor;

[0043] 6. The present invention proposes a method for operating a reaction system for the etherification and separation of isomeric olefins, wherein the proportion of tertiary carbon isomeric olefins in the feed hydrocarbon is 0.5-60 wt%, and the conversion rate of isomeric olefins after treatment by the reaction system is ≥99%. It is suitable for the etherification of C4-C18 isomeric olefins, and especially suitable for the etherification reaction and separation of C5-C12 tertiary carbon isomeric olefins. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings and their markings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the etherification reactor described in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the reaction system for isomeric olefin etherification separation as described in an embodiment of the present invention.

[0047] The meanings of the symbols marked in the figure are as follows:

[0048] 10—Upper catalyst bed, 11—Mixed material inlet, 12—Alcohol feedstock inlet, 13—Loading port, 14—Discharge port, 15—Support plate, 20—Lower catalyst bed;

[0049] 31—Separator plate, 32—Liquid downcomer, 33—Gas-liquid separator, 34—Upper sealing plate, 35—Lower sealing plate, 36—Gas phase outlet, 37—Liquid phase circulating material inlet, 38—Trade plate, 39—Liquid ether outlet, 40—Circulating liquid phase ether outlet, 41—Circulating gas phase ether inlet;

[0050] 51—Raw material mixer; 52—Fresh catalyst storage tank; 53—Waste catalyst storage tank;

[0051] 61—Vacuum-phase condenser; 62—Condensate storage tank; 63—Condensate booster pump;

[0052] 71—Reboiler. Detailed Implementation

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0054] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0055] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0056] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] In one embodiment, please refer to Figure 1 An etherification reactor is provided, comprising a reactor body having an upper catalytic reaction section and a lower separation section. The catalytic reaction section is filled with a catalyst suitable for the etherification of isomeric olefins, and the separation section is equipped with packing or multi-layer trays for separating unreacted materials from the catalytic reaction section and the mixture of generated ethers. The separation section returns a portion of the separated unreacted materials to the catalytic reaction section through an outer ring passage of a condenser to continue the etherification reaction.

[0058] This embodiment realizes the replacement of multiple reactors connected in series or parallel with a single reactor, and performs the etherification reaction of isomeric olefins and the removal of generated ethers in an integrated etherification reactor, which simplifies the process flow. It is particularly suitable for the separation of long-chain isomeric olefins and normal olefins in Fischer-Tropsch synthesis products, and is also suitable for the etherification of catalytic cracking, coking light gasoline and thermal cracking light gasoline.

[0059] In the above embodiments, the catalytic reaction section is provided with multiple catalyst beds from top to bottom. Each catalyst bed has a loading port 13 and a discharge port 14 at its upper and lower parts, respectively. The catalyst in the catalyst bed is added to the reactor body through the loading port 13 and discharged through the discharge port 14. A support member is provided at the bottom of the catalyst bed to support the catalyst, and the support member has flow holes connecting each catalyst bed level. Specifically, the support member can be a horizontal plate, an arc-shaped plate, or other deformed support plates 15 designed to facilitate the flow of solid catalyst particles based on the performance of the catalyst. A liquid mixture with a certain alcohol-to-olefin ratio enters the catalyst bed through the mixture inlet 11 at the top of the reactor body. Under the action of the catalyst, an etherification reaction occurs, where tertiary carbon isoolefins in the mixture react with alcohols to produce ethers. The reacted liquid material enters the lower catalyst bed through the flow holes of the lower support member.

[0060] In some preferred embodiments, each catalyst bed is equipped with a mixed feed inlet 11 to enable separate feeding of each stage of the catalytic etherification process, and an alcohol feed inlet 12 is provided between adjacent catalyst beds to control the alcohol-to-olefin ratio of each stage of the catalytic etherification reaction.

[0061] Specifically, the mixture inlet 11 is connected to a mixture distributor, and the alcohol raw material inlet 12 is connected to an alcohol raw material distributor. The spray nozzles on both the mixture distributor and the alcohol raw material distributor are evenly distributed along the radial direction of the reactor body.

[0062] In the above embodiments, by designing multi-stage catalyst beds, a liquid mixture with a certain alcohol-to-olefin ratio is brought into contact with the catalyst in each stage of the catalyst bed from top to bottom to carry out the etherification reaction, which significantly improves the conversion rate of isomeric olefins. The alcohol feedstock inlet 12 set between adjacent catalyst beds can be used to replenish the alcohol feedstock, which can further improve the conversion rate of isomeric olefins. When the catalyst is added and / or unloaded online in the upper catalyst bed, the feed to the lower catalyst bed can be controlled separately and the alcohol-to-olefin ratio can be adjusted to extend the operating cycle of the etherification reactor.

[0063] In the embodiments described in this application, the catalyst is any existing catalyst that can be used for etherification reaction; the number of catalyst beds in the upper part of the reactor body is not specifically limited, but includes at least two stages. When the upper catalyst bed needs to be loaded and unloaded, the stable feeding of the lower catalyst bed can be ensured, realizing the long-term stable operation of the etherification reactor. At the same time, the alcohol-olefin ratio of each stage of catalytic etherification reaction can be individually controlled, and the etherification reaction conditions can be precisely controlled, improving the conversion rate and reaction efficiency of isomeric olefins.

[0064] In some embodiments, a partition plate 31 is provided at the bottom of the catalytic reaction section. The partition plate 31 and the adjacent support above it or together with the inner wall of the reactor body form a liquid collection chamber. A liquid downcomer 32 is connected through the partition plate 31 and is connected to the separation section.

[0065] Specifically, the partition plate 31 is a solid plate, with a circular hole in the center of the partition plate 31, which is connected to the vertically downward liquid downcomer 32.

[0066] In the above embodiments, the separation section is internally equipped with trays 38, packing, or other elements with vapor-liquid balance separation function. A distillation process is used to separate the unreacted material from the catalytic reaction section and the mixture of ethers produced. Unreacted material is obtained at the top of the separation section, and a high-purity ether is obtained at the bottom. A gas-liquid separator 33 is installed at the top of the separation section. The gas-liquid separator 33 is connected to sealing plates at the top and bottom. The upper sealing plate 34, the lower sealing plate 35, and the gas-liquid separator 33 form a whole. The upper part of the separator, together with the partition plate 31 or combined with the inner wall of the reactor body, forms a gas collecting chamber, and the lower part is a gas-liquid mixing space. The mixture from the catalytic reaction section enters the separation section through a liquid downcomer 32. In the separation section, it undergoes distillation separation by separation elements. A liquid ether outlet 39 is provided at the bottom of the separation section.

[0067] In some preferred embodiments, the gas collecting chamber is provided with a gas phase outlet 36, and a liquid phase circulating material inlet 37 is provided on the reactor body below the gas-liquid separator 33. The gas phase outlet 36 and the liquid phase circulating material inlet 37 are also connected through the outer ring passage of the condenser. This embodiment significantly improves the separation purity and efficiency of etherified materials through the circulation and separation of some unreacted materials.

[0068] Specifically, in this case, the outer ring passage of the condenser is used to return unreacted materials in the separation section to the catalytic reaction section for further etherification after condensation, and to the upper part of the separation section for further separation to generate ethers. The remaining part is discharged as liquid-phase hydrocarbon products.

[0069] In some embodiments, a circulating liquid ether outlet 40 and a circulating gaseous ether inlet 41 are provided at the lower part of the separation section. The circulating liquid ether outlet 40 and the circulating gaseous ether inlet 41 are connected by a reboiler outer ring passage for heating, vaporizing and reflux of the liquid ether in the separation section, providing a heat source for gas-liquid separation in the separation section.

[0070] The etherification reactor equipment provided in this application has a reasonable structural design, uniform fluid distribution, high catalytic reaction efficiency of a single unit, simple process flow, low operating energy consumption, and stable and reliable operation.

[0071] Based on the above embodiments, a reaction system for isomeric olefin etherification separation is further provided, including a feed system, the above-mentioned etherification reactor, and a condenser outer ring passage.

[0072] The aforementioned feeding system includes a mixture feed line and an alcohol feed line. The mixture feed line is connected to the mixture inlet 11 configured in each stage of the catalyst bed, and the alcohol feed line is connected to the alcohol feed inlet 12 configured between two adjacent catalyst beds. The feeding system also includes a feed mixer 51. The first input end of the feed mixer 51 is connected to the alcohol feed line, the second input end of the feed mixer 51 is connected to the hydrocarbon feed line, and the output end of the feed mixer 51 is connected to the mixture feed line.

[0073] In some preferred embodiments, the reaction system further includes a charging system and a discharging system. The charging system is connected to the filling port 13 at the top of the catalyst bed, and the discharging system is connected to the discharging port 14 at the bottom of the catalyst bed. Specifically, the charging system includes a fresh catalyst storage tank 52 and a catalyst discharge pipeline connected in sequence. The fresh catalyst storage tank 52 is connected to a branch of the alcohol feed pipeline, and the catalyst discharge pipeline is connected to the filling port 13 of the catalyst bed. The discharging system includes a catalyst feed pipeline and a spent catalyst storage tank 53 connected in sequence, and the catalyst feed pipeline is connected to the discharging port 14 of the catalyst bed. Preferably, both the charging system and the discharging system are equipped with an inert gas pressure-maintaining device to realize online loading and / or unloading of the catalyst.

[0074] exist Figure 2 In a specific example, the alcohol feed line has three branches. One branch enters the raw material mixer 51, where it mixes with the circulating stream of raw hydrocarbons and unreacted materials to form a mixed liquid feed. The alcohol feed is metered and controlled to adjust the alcohol-to-olefin ratio of the mixed liquid feed. The second branch feeds the lower catalyst bed 20 of the reactor body. The alcohol feed rate is metered and controlled to adjust the alcohol-to-olefin ratio of the material entering the lower catalyst bed 20. The third branch feeds the fresh catalyst storage tank 52 for pretreatment of the fresh catalyst. The mixed material feed line has two branches: one is the feed line to the upper part of the upper catalyst bed 10; the other is the feed line to the upper part of the lower catalyst bed 20. Both feed lines are equipped with feed valves for feed control.

[0075] Along the direction of unreacted material flow, a gas phase condenser 61, a condensate storage tank 62, and a condensate booster pump 63 are sequentially arranged in the outer ring passage of the condenser. The outlet of the condensate booster pump 63 is provided with three paths: one path is connected back to the mixed material inlet 11 of the catalytic reaction section to form an etherification circulation pipeline; one path is connected back to the liquid phase circulation material inlet 37 of the separation section to form a separation circulation pipeline; and the remaining path is connected to the outside of the reaction system to form a liquid phase hydrocarbon output pipeline.

[0076] In some embodiments, the above-mentioned reaction system further includes a reboiler outer ring passage, which connects the circulating liquid phase ether outlet 40 and the circulating gas phase ether inlet 41 located at the lower part of the separation section, for heating and vaporizing the liquid phase ether in the separation section and reflux, providing a heat source for gas-liquid separation in the separation section.

[0077] Based on the above embodiments, this application further provides a method for operating a reaction system for isomeric olefin etherification separation, comprising the following steps:

[0078] The mixed solution of alcohol and raw material hydrocarbons fed into the mixture inlet 11 at the top of the reactor body comes into contact with the catalyst packed in the multi-stage catalyst bed from top to bottom to undergo an etherification reaction. The alcohol-to-olefin ratio of the feed to each stage of the catalyst bed is adjusted by controlling the amount of alcohol feed between adjacent stages of the catalyst bed.

[0079] After the etherification reaction, the liquid material enters the separation section at the bottom of the reactor body. The multi-layer trays and / or packing installed in the separation section realize the mass and heat exchange between the gas and liquid phases. The liquid ether is then output from the bottom of the separation section, while the unreacted material obtained from the top of the separation section is fed back to the catalytic reaction section to continue the etherification reaction.

[0080] In some preferred embodiments, the following steps are also included:

[0081] The pressure of the fresh catalyst storage tank 52 and the spent catalyst storage tank 53 are adjusted using an inert gas pressure-maintaining device to achieve online addition and / or unloading of catalyst. Specifically, the fresh catalyst in the storage tank is mixed with the alcohol feedstock, and a pressure difference is formed between the fresh catalyst storage tank 52 and the reactor body under the pressure regulation of the inert gas. This allows the fresh catalyst in the storage tank and the alcohol feedstock to be transported together into the reactor body, achieving online addition of catalyst. By adjusting the pressure of the spent catalyst storage tank 53, a pressure difference is formed between the reactor body and the spent catalyst storage tank 53, allowing the catalyst inside the reactor body to be discharged into the spent catalyst storage tank 53, achieving online unloading.

[0082] When online addition and / or unloading of catalyst is performed on the upper catalyst bed in the reactor body, the feed valve of the upper catalyst bed is closed, while the feed valve of the lower catalyst bed is opened, and the mixed raw materials are fed from the top of the lower catalyst bed.

[0083] See Figure 2In detail: Under normal operating conditions, hydrocarbons, alcohols, and unreacted liquid circulating materials are mixed in the raw material mixer 51. The mixed raw materials, after being metered, controlled, and adjusted to achieve a certain alcohol-to-olefin ratio, enter the upper catalyst bed 10 of the reactor body through the mixed material inlet 11 for catalytic reaction. The reacted material flows into the lower catalyst bed 20 through the support plate 15 at the bottom of the upper catalyst bed 10 to continue the reaction. To improve the conversion rate of isoolefins, some alcohol can be added to the lower catalyst bed 20 through the alcohol raw material inlet 12. The catalytically reacted material enters the separation section at the bottom of the reactor body through the liquid downcomer 32, where the ethers generated in the reaction are separated. Unreacted material is drawn out of the reactor body from the top of the separation section in gaseous form. After being condensed into liquid by the gas phase condenser 61, it is collected in the condensate storage tank 62. After being pressurized by the condensate booster pump 63, one stream returns to the separation section as liquid phase circulation, and the other stream circulates back to the raw material mixer 51 and then enters the mixed material inlet 11 to continue the etherification reaction. By metering and adjusting the amount of recycled material back to the mixed material inlet 11, the conversion rate of isomeric olefins can be improved. The remaining unreacted material is sent out. A portion of the etherified product is drawn out from the bottom of the reactor body, heated into gaseous form by the reboiler 71, and then returned to the reactor body for circulation. The other portion is sent out as liquid olefins.

[0084] As needed, the feed valves of the upper catalyst bed 10 and the lower catalyst bed 20 are opened simultaneously, with the upper catalyst bed 10 serving as the primary feed and the lower catalyst bed 20 as the auxiliary feed. When the upper catalyst bed 10 needs to be added and / or discharged online, the pressure of the reactor body and the spent catalyst storage tank 53 is adjusted to allow the upper catalyst in the reactor body to flow by gravity into the spent catalyst storage tank 53. The pressure of the fresh catalyst storage tank 52 and the reactor body is adjusted to add the catalyst from the fresh catalyst storage tank 52 into the reactor body. After the reactor body completes the online addition and / or discharge of catalyst, the feeding method of the reactor body switches to the normal operating feeding method.

[0085] Preferably, the alcohol-to-olefin ratio of the feed to the upper catalyst bed 10 is controlled to be 1 to 1.8, while the alcohol-to-olefin ratio of the feed to the lower catalyst bed 20 is controlled to be 1 to 2.4.

[0086] Preferably, the alcohol feedstock involved in this application can be a C1 to C8 alcohol, such as methanol, ethanol, and / or propanol. The alcohol can be used alone or in a mixture of two or more alcohols.

[0087] The etherification reactor and reaction system having the etherification separation of isomeric olefins in this application are suitable for tertiary carbon isomeric olefins in feed hydrocarbons with a proportion of 0.5 to 60 wt%. After passing through the etherification reactor, the isomeric olefin conversion rate reaches more than 99%. It is particularly suitable for the etherification of C4 to C18 tertiary carbon isomeric olefins, and especially suitable for the reaction and separation of C5 to C12 tertiary carbon isomeric olefins.

[0088] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A reaction system for etherification separation of isomeric olefins, characterized in that, This includes the feed system, etherification reactor, and condenser outer loop. The feeding system includes a mixture feed line and an alcohol feed line; The etherification reactor includes a reactor body, which has a catalytic reaction section at the upper part and a separation section at the lower part. The catalytic reaction section is provided with multiple catalyst beds arranged from top to bottom. Each catalyst bed is equipped with a mixture inlet, which is connected to a mixture feed pipeline. An alcohol feed inlet is also provided between adjacent catalyst beds, which is connected to an alcohol feed pipeline. The catalyst beds are filled with catalysts suitable for the etherification of isomeric olefins. The separation section is internally packed with packing material and / or multiple layers of trays, and is used to separate the mixture of unreacted material from the catalytic reaction section and the generated ether. The lower part of the separation section is provided with a liquid ether outlet. A support member is provided at the bottom of the catalyst bed, and a flow hole is provided on the support member to connect the catalyst bed at each level; A partition plate is provided at the bottom of the catalytic reaction section. The partition plate, the support member adjacent to it above, and the inner wall of the reactor body form a liquid collection chamber. A liquid downcomer is connected through the partition plate and is connected to the separation section. The upper part of the separation section is provided with a gas-liquid separator with upper and lower sealing plates. The gas-liquid separator with upper and lower sealing plates, together with the partition plate and the inner wall of the reactor body, form a gas collection chamber. The gas collection chamber is provided with a gas phase outlet, and the reactor body below the gas-liquid separator is provided with a liquid phase circulating material inlet; The condenser outer loop connects the separation section and the catalytic reaction section to return the unreacted material separated in the separation section to the catalytic reaction section for further etherification. The gas phase outlet and the liquid phase circulating material inlet are connected through the condenser outer loop. A gas phase condenser, a condensate storage tank, and a condensate booster pump are sequentially arranged along the flow direction of the unreacted material on the condenser outer loop. The condensate booster pump has three outlets: one is connected back to the mixed material inlet of the catalytic reaction section to form an etherification circulation pipeline; another is connected back to the liquid phase circulating material inlet of the separation section to form a separation circulation pipeline. The remaining line connects to the outside of the reaction system to form a liquid hydrocarbon output pipeline.

2. The reaction system according to claim 1, characterized in that, The reaction system also includes a charging system and a discharging system. The upper and lower parts of the catalyst bed are respectively provided with a catalyst loading port and a catalyst unloading port. The loading port is connected to the charging system, and the unloading port is connected to the unloading system.

3. The reaction system according to claim 2, characterized in that, The charging system includes a fresh catalyst storage tank and a catalyst discharge pipeline connected in sequence. The fresh catalyst storage tank is connected to a branch of the alcohol feed pipeline, and the catalyst discharge pipeline is connected to the loading port of the catalyst bed; and / or, The unloading system includes a catalyst feed pipeline and a spent catalyst storage tank connected in sequence, wherein the catalyst feed pipeline is connected to the unloading port of the catalyst bed; and / or Both the loading and unloading systems are equipped with inert gas pressure-maintaining devices to enable online loading and / or unloading of the catalyst.

4. The reaction system according to claim 1, characterized in that, The support is a horizontal plate or an arc-shaped plate that is fixedly connected to the inner wall of the reactor body.

5. The reaction system according to claim 1, characterized in that, The feeding system is equipped with a raw material mixer, the first input end of which is connected to the alcohol feed line, the second input end of which is connected to the raw material hydrocarbon feed line, and the output end of which is connected to the mixed material feed line; and / or, The lower part of the separation section is provided with a circulating liquid phase ether outlet and a circulating gas phase ether inlet, and the circulating liquid phase ether outlet and the circulating gas phase ether inlet are connected by a reboiler outer ring passage.

6. The method of operating a reaction system of any of claims 1-5, wherein, Includes the following steps: The mixed solution of alcohol and raw hydrocarbon input at the mixing inlet at the top of the reactor body comes into contact with the catalyst packed in the multi-stage catalyst bed from top to bottom to undergo etherification reaction. The alcohol-to-olefin ratio of the feed to each stage of the catalyst bed is adjusted by controlling the amount of alcohol feed between adjacent stages of the catalyst bed. After the etherification reaction, the liquid material enters the separation section at the bottom of the reactor body. The multi-layer trays and / or packing installed in the separation section realize the mass and heat exchange between the gas and liquid phases. The liquid ether is then output from the bottom of the separation section, while the unreacted material obtained from the top of the separation section is fed back to the catalytic reaction section to continue the etherification reaction.

7. The operating method according to claim 6, characterized in that, A feed valve is installed on the feed pipeline of the mixture; Each catalyst bed is equipped with a charging system and a discharging system. The charging system is equipped with a fresh catalyst storage tank, and the discharging system is equipped with a waste catalyst storage tank. Both the charging system and the discharging system are equipped with an inert gas pressure maintaining device. It also includes the following steps: The pressure of the fresh catalyst storage tank and the spent catalyst storage tank are adjusted separately using an inert gas pressure-maintaining device to achieve online addition and / or unloading of catalyst; When online addition and / or unloading of catalyst is performed on the upper catalyst bed in the reactor body, the feed valve of the upper catalyst bed is closed, while the feed valve of the lower catalyst bed is opened, and the mixed raw materials are fed from the top of the lower catalyst bed.

8. The operating method according to claim 7, characterized in that, The multi-stage catalyst bed comprises two stages: an upper catalyst bed and a lower catalyst bed. The alcohol-to-olefin ratio of the feed to the upper catalyst bed is controlled to be 1 to 1.8, while the alcohol-to-olefin ratio of the feed to the lower catalyst bed is controlled to be 1 to 2.

4.

9. The operating method according to claim 6, characterized in that, The proportion of tertiary carbon isoolefins in the raw material hydrocarbon is 0.5~60 wt%, and the conversion rate of isoolefins after treatment by the reaction system is ≥99%; and / or, The reaction system is suitable for the etherification of C4-C18 isoolefins.

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