Process and system for producing ethers
Through the two-stage etherification reactor system and the method of frequently changing active catalysts, the catalyst deactivation problem caused by impurities in olefin raw materials and alcohols is solved, and the efficient production of tertiary alkyl ethers is achieved, reducing costs and environmental impacts.
Patent Information
- Application Number
- CN202380059235.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-08-26
- Filing Date
- 2023-08-07
- Publication Date
- 2025-03-21
AI Technical Summary
In the production of tertiary alkyl ethers, impurities exist in the olefin feedstock and alcohols, resulting in catalyst deactivation and inefficiency in production, and commonly used water washing methods require additional equipment, which increases cost and environmental impact.
A two-stage etherification reactor system is adopted, the first etherification reactor system serves as a protective bed reactor, removes undesired components and frequently replaces the active catalyst material to prevent deactivation, and the second etherification reactor system further produces ether and extracts the final product through the distillation column.
Effectively remove impurities, extend the service life of the catalyst, improve production efficiency, reduce the use of the washing tower, and reduce costs and environmental impact.
Smart Images
Figure CN119677709A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to the production of ethers, such as tertiary alkyl ethers that can be used as components of, for example, motor fuels. The ethers produced can include, for example, methyl tertiary butyl ether, ethyl tertiary butyl ether, tertiary amyl methyl ether, tertiary amyl ethyl ether, or mixtures thereof, as well as possibly heavier tertiary alkyl ethers. More specifically, the present disclosure relates to methods for producing ethers and systems for producing ethers. Background Art
[0002] Tertiary alkyl ethers can be used as gasoline additives to improve anti-knock properties and reduce harmful components in exhaust gases. It has been found that the oxygen-containing ether groups of tertiary alkyl ethers are conducive to improving the combustion process of automobile engines and other similar engines. Examples of suitable tertiary alkyl ethers are: methyl tertiary butyl ether "MTBE", ethyl tertiary butyl ether "ETBE", tertiary amyl methyl ether "TAME", tertiary amyl ethyl ether "TAEE", tertiary hexyl methyl ether "THME" and tertiary hexyl ethyl ether "THEE". These can be produced by etherification reaction of olefin feedstock containing tertiary isoolefins with monovalent aliphatic alcohols (i.e., alkanols). The etherification reaction can be carried out in a fixed bed reactor, a fluidized bed reactor, an ebullated bed reactor, a boiling point reactor, a tubular reactor or a catalytic distillation tower.
[0003] In many cases, the available data on olefin feedstocks and on the data on the alcohols used in the etherification process lack detailed information on the impurities present in the olefin feedstock and / or the alcohols. In addition, it is well known that typical commercial ethanol feedstocks contain compounds that have a degrading and / or deactivating effect on the etherification catalyst due to fermentation or, more likely, storage and / or transportation. On the other hand, olefin liquefied petroleum gas "LPG" derived from fluid catalytic cracking "FCC" in particular contains basic nitrogen compounds, which are direct catalyst poisons, in addition to other basic substances, ionic metal compounds and other deactivators. Depending on the upstream processing facilities, the material stream from butadiene extraction may also contain basic nitrogen in the form of acetonitrile "ACN", dimethylformamide "DMF", and / or potentially harmful light compounds, especially in the event of an upset. A common approach to address these problems is to water wash the olefin feedstock or both the olefin feedstock and the alcohol feedstock. However, this approach requires an additional scrubber and its ancillary equipment, produces wastewater as a continuous effluent, and saturates the hydrocarbon feed with water, which promotes the formation of by-products and leads to corrosion of the production equipment. Summary of the invention
[0004] A simplified summary is presented below to provide a basic understanding of some embodiments of the present invention. This summary is not an extensive overview of the present invention. It is neither intended to identify key or important elements of the present invention nor to define the scope of the present invention. The following summary only presents some concepts of the present invention in a simplified form as a preface to a more detailed description of exemplary embodiments of the present invention.
[0005] According to the present invention, a new method for producing ethers (such as tert-alkyl ethers) is provided, which tert-alkyl ethers may include, for example, methyl tert-butyl ether "MTBE", ethyl tert-butyl ether "ETBE", tert-amyl methyl ether "TAME", tert-amyl ethyl ether "TAEE", tert-hexyl methyl ether "THME", tert-hexyl ethyl ether "THEE" and / or mixtures thereof.
[0006] The method according to the present invention comprises:
[0007] - alcohol and olefin raw materials (such as C 4-7 olefins) to a first etherification reactor system containing a first catalyst to produce a first reaction effluent,
[0008] - supplying the first reaction effluent from the first etherification reactor system to a second etherification reactor system containing a second catalyst to produce a second reaction effluent,
[0009] - supplying the second reaction effluent to the distillation column at a feed point situated between the bottom and the top of the distillation column, and
[0010] - The produced ether is taken out from the bottom of the distillation column.
[0011] The volume of the first catalyst contributing to the production of the first reaction effluent in the first etherification reactor system is at most 15% of the total volume of the first catalyst and the second catalyst contributing to the production of the second reaction effluent in the second etherification reactor system. The method includes replacing the deactivated first catalyst with an active catalyst material more frequently in response to the deactivation of the first catalyst than replacing the deactivated second catalyst with an active catalyst material in response to the deactivation of the second catalyst.
[0012] The first etherification reactor system described above acts as a guard bed reactor, which at least partially removes undesirable components from the feed supplied to the second etherification reactor system, so that the first etherification reactor system, in addition to contributing to the main process of producing ethers, also protects the second etherification reactor system from catalyst deactivation. The catalyst of the first etherification reactor system needs to be replaced more frequently than the catalyst of the second etherification reactor system, but the cost of the first etherification reactor system, the cost of the catalyst material to be replaced, and the cost of replacing the catalyst material in the first etherification reactor system are all less than the corresponding capital and operating costs associated with the water washing method mentioned in the background section of this document.
[0013] According to the present invention, a new system for producing ether is also provided. The system according to the present invention comprises:
[0014] - a first etherification reactor system containing a first catalyst and configured to produce a first reaction effluent when supplied with an alcohol and an olefin feedstock,
[0015] a second etherification reactor system containing a second catalyst and configured to produce a second reaction effluent when supplied with the first reaction effluent from the first etherification reactor system, and
[0016] a distillation column configured to receive the second reaction effluent at a feed point between the bottom and the top of the distillation column and comprising an outlet configured to remove the produced ether from the bottom of the distillation column,
[0017] wherein the volume of the first catalyst contributing to the production of the first reaction effluent in the first etherification reactor system is at most 15% of the total volume of the first catalyst contributing to the production of the first reaction effluent and the second catalyst contributing to the production of the second reaction effluent in the second etherification reactor system.
[0018] Exemplary and non-limiting embodiments of the invention are described in the appended dependent claims.
[0019] Various exemplary and non-limiting embodiments and methods of operation of the present invention, together with further objects and advantages thereof, will be best understood from the following description of specific exemplary embodiments when read in connection with the accompanying drawings.
[0020] The verbs "to comprise" and "to include" are used in this document as open limitations that neither exclude nor require the existence of unrecited features.
[0021] Unless explicitly stated otherwise, the features recited in the attached dependent claims are mutually freely combinable.
[0022] Furthermore, it is to be understood that the use of "a" or "an" (ie in the singular) throughout this document does not exclude a plurality. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Exemplary and non-limiting embodiments of the invention and their advantages are explained in more detail below by way of example and with reference to the accompanying drawings, in which:
[0024] Figure 1 A system for producing ethers according to an exemplary and non-limiting embodiment is shown,
[0025] Figure 2 A system for producing ethers according to an exemplary and non-limiting embodiment is shown,
[0026] Figure 3 A system for producing ethers according to an exemplary and non-limiting embodiment is shown, and
[0027] Figure 4 A flow chart of a process for producing ethers according to an exemplary and non-limiting embodiment is shown. DETAILED DESCRIPTION
[0028] The specific examples provided in the following description should not be construed as limiting the scope and / or applicability of the appended claims. Unless expressly stated otherwise, the lists and groups of examples provided in the description are not exhaustive.
[0029] Figure 1 A system for producing ethers (such as tert-alkyl ethers) according to an exemplary and non-limiting embodiment is shown, which tert-alkyl ethers may include, for example, methyl tert-butyl ether "MTBE", ethyl tert-butyl ether "ETBE", tert-amyl methyl ether "TAME", tert-amyl ethyl ether "TAEE", tert-hexyl methyl ether "THME", tert-hexyl ethyl ether "THEE" and / or mixtures thereof. Figure 1 The exemplary system shown includes a first etherification reactor system 101 containing a first catalyst in a reaction zone and configured to produce a first reaction effluent 102 when supplied with an alcohol and an olefin feedstock. The olefin feedstock may include, for example, C 4-7 Olefins, the C 4-7The olefins include one or more of the following compounds: isobutylene, 2-methyl-1-butene, 2-methyl-2-butene, 2-methyl-1-pentene, 2-methyl-2-pentene, 2,3-dimethyl-1-butene, 2,3-dimethyl-2-butene, 2-ethyl-1-butene, 2-methyl-2-hexene, 2,3-dimethyl-1-pentene, 2,3-dimethyl-2-pentene, cis-3-methyl-2-pentene, trans-3-methyl-2-pentene, 2,4-dimethyl-1-pentene, 2-ethyl-1-pentene, 1-methylcyclopentene and 2-ethyl-2-pentene. The first catalyst may include, for example, a cation exchange resin or a zeolite. In this exemplary system, the first etherification reactor system 101 includes a reactor 106.
[0030] Figure 1 The exemplary system shown includes a second etherification reactor system 103 containing a second catalyst in a plurality of reaction zones and configured to produce a second reaction effluent 104 when supplied with the first reaction effluent 102 from the first etherification reactor system 101. The second catalyst may include, for example, a cation exchange resin or a zeolite. Figure 1 In the exemplary system shown, the second etherification reactor system 103 includes three reactors 108, 109 and 110 connected in series.
[0031] The system includes a distillation column 105 configured to receive a second reaction effluent 104 at a feed point between the bottom and the top of the distillation column 105. The distillation column 105 includes an outlet 113 configured to remove produced ether from the bottom of the distillation column 105. The system may further include a side stream feedback device from the distillation column 105 to one or more suitable locations in the first etherification reactor system 101 and / or the second etherification reactor system 103.
[0032] The system may further include an apparatus 140 for further processing the material stream withdrawn from the upper part of the distillation column 105. The apparatus 140 may include, for example, another distillation column whose operating pressure is higher than that of the distillation column 105. The operating pressure of the distillation column 105 may generally be in the range of 600 kPa to 900 kPa, and in actual operation is less than 1000 kPa. The operating pressure of another distillation column may generally be in the range of 1500 kPa to 2400 kPa, and in actual operation is less than 3000 kPa. The apparatus 140 may further include a side stream feedback device from another distillation column to one or more suitable locations in the first etherification reactor system 101 and / or the second etherification reactor system 103. For example, the side stream feedback device may be configured to withdraw a side stream from a suitable location of another distillation column and supply the side stream to the inlet of the first etherification reactor system 101. In Figure 1In the figure, the side stream feedback device from another distillation column is represented by a dotted line.
[0033] The first etherification reactor system 101 serves as a guard bed reactor that removes undesirable components from the feed supplied to the second etherification reactor system 103. Therefore, the first etherification reactor system 101, in addition to contributing to the main process of producing ether, can also protect the second etherification reactor system 103 from catalyst deactivation. Figure 1 The exemplary system shown may not have, and does not have, a water scrubber. The catalyst material of the first etherification reactor system 101 needs to be replaced more frequently than the catalyst material of the second etherification reactor system 103, but the equipment cost of the first etherification reactor system 101, the material cost of the catalyst material to be replaced, and the labor cost of replacing the catalyst material in the first etherification reactor system 101 are lower than the corresponding capital cost and operating cost associated with, for example, a water scrubber. The volume of the first catalyst contained in the reactor 106 of the first etherification reactor system 101 is at most 15% of the total volume of the first catalyst and the second catalyst contained in the reactors 108-110 of the second etherification reactor system 103. In other words, the volume of the first catalyst in the reactor 106 is at most about 18% of the volume of the second catalyst contained in the reactors 108-110. Advantageously, the volume of the first catalyst is 10% to 15% of the total volume of the first and second catalysts. Each of the reactors 106 and 108-110 can be, for example, a fixed bed reactor, a fluidized bed reactor, an ebullated bed reactor, a boiling point reactor, or a tubular reactor. In a fixed bed reactor, the reaction zone of the reactor is a catalyst bed. In a fluidized bed reactor, the reaction zone is a fluidized catalyst bed, in an ebullated bed reactor, the reaction zone is an ebullated catalyst bed, in a boiling point reactor, the reaction zone is a fixed catalyst bed, and, in a tubular reactor, the reaction zone is formed by parallel tubes, each of which contains catalyst material and each constitutes a sub-zone.
[0034] The first etherification reactor system 101 further includes a heat exchanger 124 for controlling the temperature of the feed material supplied to the reactor 106. Accordingly, the second etherification reactor system 103 includes heat exchangers 121, 122 and 123 for controlling the temperature of the material supplied to the reactors 108-110. Figure 1In the embodiment of the present invention, the temperature control device connected to the heat exchanger 121-124 is not shown. The input temperature of the etherification reactor is generally in the range of 30°C to 60°C, more advantageously in the range of 40°C to 45°C, and the output temperature of the etherification reactor is advantageously at most in the range of 70°C to 80°C, and more advantageously below 70°C. The pressure in each etherification reactor is advantageously set to a value so that in the case of a boiling point reactor configuration, the evaporation of C4 hydrocarbons can be avoided or controlled to maintain the desired temperature level in the reactor. The pressure in each etherification reactor is advantageously in the range of 1700 kPa to 1900 kPa.
[0035] The following references Figure 1 An operational embodiment of a system of the type described above is described. In this example scenario, the system is configured to produce ethyl tert-butyl ether "ETBE":
[0036] Table 1. Hydrocarbon feed 18150.6 kg / h
[0037]
[0038] Table 2. Ethanol feed 7672.5 kg / h
[0039]
[0040] Table 3. Reactor dimensions, i.e., catalyst volume
[0041]
[0042] Total conversion of isobutylene: 97.65%
[0043] Table 4. ETBE product 16502 kg / h
[0044]
[0045]
[0046] The following is a corresponding operation example of a system according to the prior art, which includes a water scrubber configured to wash a hydrocarbon feed. The main purpose of the water scrubber is to remove acetonitrile from the hydrocarbon feed. In this operation example, the diameter of the water scrubber is 1.2 m, the height of the water scrubber is 23 m, and the water scrubber has 40 trays. In the case of an acetonitrile concentration of 50 wt ppm in a hydrocarbon feed having a flow rate of 18150 kg / h, the required wash water is about 11000 kg / h to achieve an acetonitrile concentration target level of 1 wt ppm.
[0047] In this exemplary case according to the prior art, the etherification reactor system comprises three reactors connected in series, and the catalyst volumes of these reactors are:
[0048]
[0049] The first reactor after the water scrubber is provided with a feedback loop around the first reactor to limit the temperature in the first reactor so that the outlet temperature of the first reactor does not exceed 70° C. to avoid a decrease in the selectivity of ETBE at higher temperatures. In the above examples according to embodiments of the present invention and including guard bed reactors, a feedback loop of the above type is not required.
[0050] Table 5. Hydrocarbon feed 18150.6 kg / h
[0051]
[0052]
[0053] Table 6. Ethanol feed 7669.8 kg / h
[0054]
[0055] Total conversion of isobutylene: 97.64%
[0056] Table 7. ETBE product 16500 kg / h
[0057]
[0058] By comparing the above embodiments, it can be seen that the system according to the embodiment of the present invention has the same total volume of catalyst material of 70m 3 In the case of the guard bed reactor, substantially the same performance is provided, but without the need for a water scrubber, and the investment cost and operating cost of the water scrubber are higher than those of the guard bed reactor. In addition, the water scrubbing process generates about 11000 kg / h of wastewater. The operating temperature of the water scrubber may be, for example, in the range of 15°C to 50°C, more advantageously 20°C to 40°C, and the operating pressure of the water scrubber may be in the range of 800 kPa to 1000 kPa.
[0059] Figure 2 A system for producing an ether, such as a tertiary alkyl ether or a mixture of tertiary alkyl ethers, according to an exemplary and non-limiting embodiment is shown. Figure 2 The system shown is otherwise similar to Figure 1The system shown is similar, but the first etherification reactor system 201 includes two reactors 206 and 207 connected in parallel, and valves 211 and 212 for disconnecting each of the reactors 206 and 207 from the other reactor of the first etherification reactor system 201. The valves 211 and 212 enable each of the reactors 206 and 207 to be disconnected when it is necessary to replace the catalyst material in the reactor in question with an active catalyst material, and to reconnect the disconnected reactor to operation after replacing its catalyst material, or to make it ready for operation. The catalyst materials of the reactors 206 and 207 can be replaced alternately, so that while the catalyst material of one of the reactors 206 and 207 is being replaced, the other of the reactors 206 and 207 can be used for the main process of producing ether. Therefore, there is no need to stop the main process during the replacement of the catalyst material of the first etherification reactor system 201. The volume of the catalyst contributing to the production of the first reaction effluent 102 in the first etherification reactor system 201 is at most 15% of the total volume of the catalyst contributing to the production of the first reaction effluent 102 and the catalyst contributing to the production of the second reaction effluent 104 in the second etherification reactor system 103. Therefore, in the case where only one of the reactors 206 and 207 is used at a time, the volume of the catalyst in each of the reactors 206 and 207 is at most 15% of the above total volume. Accordingly, in the case where both the reactors 206 and 207 are used simultaneously, the volume of the catalyst in each of the reactors 206 and 207 is at most 7.5% of the above total volume. Each of the reactors 206, 207, 108-110 can be, for example, a fixed bed reactor, a fluidized bed reactor, an ebullating bed reactor, a boiling point reactor, or a tubular reactor.
[0060] Figure 3 A system for producing ethers (such as tertiary alkyl ethers or mixtures of tertiary alkyl ethers) according to an exemplary and non-limiting embodiment is shown. In this exemplary system for producing ethers, the first etherification reactor system 201 is connected to Figure 2 The system shown is similar, and the second etherification reactor system 303 includes two reactors 308 and 309 connected in series. Figure 3 The system shown comprises a side stream outlet 316 connected to a withdrawal point located between the feed point of the distillation column 105 and the top of the distillation column. The side stream outlet 316 is configured to withdraw a side stream 317 from the distillation column 105. The side stream 317 is advantageously in the gas phase. As an alternative, the side stream can be taken from another distillation column comprised by the apparatus 140. This alternative is Figure 3317 is indicated by a dotted line. The system advantageously includes a heat exchanger system 318 configured to control the temperature of the side stream 317. In the case where the side stream 317 is a gas phase side stream, the heat exchanger system 318 is advantageously configured to condense the gas phase side stream into a liquid. The system includes a third etherification reactor system 314, which contains a third catalyst in a reaction zone and is configured to receive the side stream 317 to produce a third reaction effluent 315. The system includes a pipeline 319, which is configured to mix the third reaction effluent 315 with the second reaction effluent 104 and supply the mixture of the third and second reaction effluents to the feed point of the distillation column 105. The system may further include an inlet pipeline 320, which is configured to supply a portion of the alcohol feed to the third etherification reactor system 314 to increase the ether conversion rate in the third etherification reactor system 314. Figure 3 Each reactor shown in can be, for example, a fixed bed reactor, a fluidized bed reactor, an ebullating bed reactor, a boiling point reactor or a tubular reactor.
[0061] The etherification reactions occurring in the first, second and third etherification reactor systems 201, 303 and 314 are equilibrium reactions, and generally, in the reactor under consideration, the reaction rate slows down as the ether concentration increases. The side stream outlet 316 is located at a position in the distillation column 105 such that the side stream 317 is substantially free of ether, or at least the relative concentration of ether in the side stream 317 is low. Thus, the input feed to the third etherification reactor system 314 is substantially free of ether, so that for a given amount of catalyst material, the third etherification reactor system 314 is more efficient than the first etherification reactor system 314. Figure 1 and Figure 2 The reactor 110 shown in FIG. 1 can produce more ether. Therefore, thanks to Figure 3 The side stream recycle arrangement shown allows more ether to be produced using the same amount of catalyst material, or correspondingly, allows the same amount of ether to be produced using a smaller amount of catalyst material.
[0062] exist Figure 3 In the exemplary system shown, heat exchanger system 318 is configured to transfer heat from side stream 317 to the mixture of second and third reaction effluents 104 and 315 before the mixture of the second and third reaction effluents is supplied to distillation column 105. This reduces the consumption of the system for producing ethers.
[0063] The following references Figure 3 An operational embodiment of a system of the type described above is described. In this exemplary case, the system is configured to produce ethyl tert-butyl ether "ETBE".
[0064] Through simulation, it is found that the side stream 317 withdrawn from the distillation column 105 and returned to the inlet of the third etherification reactor system 314 has a beneficial effect on the amount of catalyst required, that is, for a given amount of ETBE product, the amount of catalyst can be reduced. In this example, the side stream 317 is a gas phase side stream.
[0065] Table 8 shows the Figure 3 Systems and methods for the production of ethyl tert-butyl ether "ETBE" Figure 2 The comparison between the systems Figure 2 In the system, a side stream is withdrawn from the distillation column and returned to the inlet of the first etherification reactor 201.
[0066] By comparing Table 8 with Figure 2 System and basis Figure 3 The system-related towers can be seen according to Figure 3 The system provides essentially the same performance, but with a 45m2 reduction in the total volume of catalyst. 3 In these systems, the reactor system (Figure reference 201) used as a guard bed reactor is the same.
[0067] Table 8
[0068]
[0069]
[0070] By selecting the position of the side stream outlet 316 in the vertical direction of the distillation column 105 in an advantageous manner and selecting the flow rate (kg / h) of the side stream 317, the flow rate (kg / h) of the side stream 317 can be optimized according to Figure 3 The isobutylene conversion rate of the system, the ETBE content weight % of the product and the ethanol content weight % of the product.
[0071] Figure 4 A process flow diagram for producing an ether (such as a tertiary alkyl ether or a mixture of tertiary alkyl ethers) according to an exemplary and non-limiting embodiment is shown. The method comprises the following steps:
[0072] - Step 401: supplying alcohol and olefin feedstock to a first etherification reactor system comprising a first catalyst in one or more reaction zones to produce a first reaction effluent,
[0073] - Step 402: supplying the first reaction effluent from the first etherification reactor system to a second etherification reactor system containing a second catalyst in one or more reaction zones to produce a second reaction effluent, the volume of the first catalyst contributing to the production of the first reaction effluent in the first etherification reactor system being at most 15% of the total volume of the first catalyst contributing to the production of the first reaction effluent and the second catalyst contributing to the production of the second reaction effluent in the second etherification reactor system.
[0074] - step 403: supplying the second reaction effluent to the distillation column at a feed point located between the bottom and the top of the distillation column, and
[0075] - Step 404: Taking out the produced ether from the bottom of the distillation column.
[0076] The above method further comprises step 405: replacing the deactivated first catalyst in the first etherification reactor system with an active catalyst material more frequently than replacing the deactivated second catalyst in the second etherification reactor system with an active catalyst material. The first etherification reactor system acts as a guard bed reactor, which removes undesirable components from the feed supplied to the second etherification reactor system. Therefore, the first etherification reactor system, in addition to contributing to the main process of producing ethers, also protects the second etherification reactor system from catalyst deactivation. Therefore, the catalyst of the first etherification reactor system needs to be replaced more frequently than the catalyst of the second etherification reactor system.
[0077] The above method is advantageously a continuous process, as indicated by the arrow from step 404 returning to step 401, and the arrow from step 405 returning to step 405 (ie returning to itself).
[0078] In the method according to an exemplary and non-limiting embodiment, the volume of the first catalyst in each reactor of the first etherification reactor system is 10% to 15% of the total volume of the first and second catalysts contained in the first and second etherification reactor systems.
[0079] In the method according to an exemplary and non-limiting embodiment, the first catalyst and the second catalyst are the same catalyst material.
[0080] In the method according to an exemplary and non-limiting embodiment, the first catalyst includes a cation exchange resin or a zeolite, and the second catalyst includes a cation exchange resin or a zeolite.
[0081] In a method according to an exemplary and non-limiting embodiment, the first etherification reactor system comprises at least two reactors connected in parallel and a valve for disconnecting each reactor from one or more other reactors of the first etherification reactor system, and the method comprises:
[0082] - disconnecting one of the reactors in the first etherification reactor system using a valve in response to the first catalyst in one of the reactors having deactivated,
[0083] - replacing the first catalyst of the disconnected reactor with active catalyst material, and
[0084] - Reconnecting a disconnected reactor to operation or making it ready for operation after replacing its first catalyst.
[0085] The method according to an exemplary and non-limiting embodiment includes alternately replacing the first catalyst of at least two reactors of the above-mentioned first etherification reactor system according to a predetermined schedule.
[0086] In a process according to an exemplary and non-limiting embodiment, the second etherification reactor system includes two or more reactors connected in series.
[0087] The method according to an exemplary and non-limiting embodiment comprises:
[0088] - withdrawing a side stream from the distillation column from a withdrawal point situated between the feed point of the distillation column and the top of the distillation column,
[0089] - supplying the side stream to a third etherification reactor system containing a third catalyst in one or more reaction zones to produce a third reaction effluent, and
[0090] - Before supplying the mixture of the second and third reaction effluents to the distillation column, the third reaction effluent is mixed with the second reaction effluent.
[0091] In the method according to an exemplary and non-limiting embodiment, the side stream is a gas-phase side stream, and the method includes condensing the gas-phase side stream into a liquid before supplying the side stream to the third etherification reactor system.
[0092] In the method according to an exemplary and non-limiting embodiment, the first catalyst, the second catalyst and the third catalyst are the same catalyst material.
[0093] In a process according to an exemplary and non-limiting embodiment, alcohol is supplied to the third etherification reactor system in addition to the side stream.
[0094] The method according to an exemplary and non-limiting embodiment includes transferring heat from the side stream to the mixture of the second and third reaction effluents through a heat exchanger, thereby cooling the side stream and heating the mixture of the second and third reaction effluents to be supplied to the distillation column.
[0095] In the process according to an exemplary and non-limiting embodiment, the olefin feedstock comprises C 4-7 Olefins, the C4-7 Olefins include one or more of the following compounds: isobutylene, 2-methyl-1-butene, 2-methyl-2-butene, 2-methyl-1-pentene, cis-3-methyl-2-pentene, trans-3-methyl-2-pentene, 2-methyl-2-pentene, 2,3-dimethyl-1-butene, 2,3-dimethyl-2-butene, 2-ethyl-1-butene, 2-methyl-2-hexene, 2,3-dimethyl-1-pentene, 1-methylcyclopentene, 2,3-dimethyl-2-pentene, 2,4-dimethyl-1-pentene, 2-ethyl-1-pentene and 2-ethyl-2-pentene.
[0096] The specific examples provided in the above description should not be construed as limiting. Therefore, the present invention is not limited to the above exemplary and non-limiting embodiments. Unless otherwise expressly stated, the lists and groups of examples provided in the specification are not exhaustive.
Claims
1. A method for producing ether, the method comprising: - (401) supplying alcohol and olefin feedstock to a first etherification reactor system (101, 201) containing a first catalyst to produce a first reaction effluent (102), - (402) supplying the first reaction effluent from the first etherification reactor system to a second etherification reactor system (103, 303) containing a second catalyst to produce a second reaction effluent (104), - (403) supplying the second reaction effluent to a distillation column (105) at a feed point located between the bottom and the top of the distillation column, and - (404) removing the produced ether from the bottom of the distillation column, characterised in that the volume of the first catalyst contributing to the production of the first reaction effluent (102) in the first etherification reactor system is at most 15% of the total volume of the first catalyst contributing to the production of the first reaction effluent and the second catalyst contributing to the production of the second reaction effluent (104) in the second etherification reactor system, and the method comprises (405) replacing the deactivated first catalyst with an active catalyst material more frequently in response to the deactivation of the first catalyst than replacing the deactivated second catalyst with an active catalyst material in response to the deactivation of the second catalyst.
2. The method according to claim 1, wherein: The volume of the first catalyst is 10% to 15% of the total volume of the first catalyst and the second catalyst.
3. The method according to claim 1 or 2, wherein: The first etherification reactor system (201) comprises at least two reactors (206, 207) connected in parallel and valves (211, 212) for disconnecting each of the reactors from one or more other reactors of the first etherification reactor system, and the method comprises: - disconnecting one of the reactors (206, 207) in the first etherification reactor system using the valve (211, 212) in response to the first catalyst in one of the reactors having been deactivated, - replacing said first catalyst of the disconnected reactor with an active catalyst material, and - Reconnecting a disconnected reactor to operation or making it ready for operation after replacing its first catalyst.
4. The method according to claim 3, wherein: The method includes alternately replacing the first catalyst in the at least two reactors (206, 207) of the first etherification reactor system (201) according to a predetermined schedule.
5. The method according to any one of claims 1 to 4, wherein: The second etherification reactor system (103, 303) includes two or more reactors (108-110, 308, 309) connected in series.
6. The method according to any one of claims 1 to 5, wherein: The method comprises: - withdrawing a side stream (317) from the distillation column via a withdrawal point between the feed point of the distillation column and the top of the distillation column, - supplying the side stream to a third etherification reactor system (314) containing a third catalyst to produce a third reaction effluent (315), and - mixing the third reaction effluent with the second reaction effluent, and then supplying the mixture of the second reaction effluent and the third reaction effluent to the distillation column (105).
7. The method according to claim 6, wherein: The side stream (317) is a gas phase side stream, and the method includes condensing the gas phase side stream into a liquid before supplying the side stream to the third etherification reactor system.
8. The method according to claim 6 or 7, wherein: In addition to the side stream, alcohol is also supplied to the third etherification reactor system.
9. The method according to any one of claims 6 to 8, wherein: The method includes cooling the side stream and heating the mixture of the second reaction effluent and the third reaction effluent to be supplied to the distillation column by transferring heat from the side stream to the mixture of the second reaction effluent and the third reaction effluent using a heat exchanger.
10. The method according to any one of claims 1 to 9, wherein: The first catalyst and the second catalyst are made of the same material.
11. The method according to any one of claims 1 to 10, wherein: The ether is a tertiary alkyl ether or a mixture of tertiary alkyl ethers.
12. The method according to any one of claims 1 to 11, wherein: The first catalyst includes a cation exchange resin or a zeolite, and the second catalyst includes a cation exchange resin or a zeolite.
13. The method according to any one of claims 1 to 12, wherein: The olefin raw material includes C 4-7 Olefins, the C 4-7 The olefins include one or more of isobutylene, 2-methyl-1-butene, 2-methyl-2-butene, 2-methyl-1-pentene, 2-methyl-2-pentene, 2,3-dimethyl-1-butene, 2,3-dimethyl-2-butene, 2-ethyl-1-butene, 2-methyl-2-hexene, 2,3-dimethyl-1-pentene, cis-3-methyl-2-pentene, trans-3-methyl-2-pentene, 2,3-dimethyl-2-pentene, 2,4-dimethyl-1-pentene, 2-ethyl-1-pentene, 1-methylcyclopentene and 2-ethyl-2-pentene.
14. A system for producing ethers, the system comprising: a first etherification reactor system (101, 201) containing a first catalyst and configured to produce a first reaction effluent (102) when supplied with alcohol and olefin feedstocks, a second etherification reactor system (103, 303) containing a second catalyst and configured to produce a second reaction effluent (104) when supplied with the first reaction effluent from the first etherification reactor system, and a distillation column (105) configured to receive the second reaction effluent at a feed point between the bottom and the top of the distillation column and comprising an outlet (113) configured to remove the produced ether from the bottom of the distillation column, characterised in that the volume of the first catalyst contributing to the production of the first reaction effluent (102) in the first etherification reactor system is at most 15% of the total volume of the first catalyst contributing to the production of the first reaction effluent and the second catalyst contributing to the production of the second reaction effluent (104) in the second etherification reactor system.
15. The system of claim 14, wherein: The volume of the first catalyst is 10% to 15% of the total volume of the first catalyst and the second catalyst.
16. The system according to claim 14 or 15, wherein: The first etherification reactor system (201) comprises at least two reactors (206, 207) connected in parallel and valves (211, 212) for disconnecting each of the reactors from one or more other reactors of the first etherification reactor system, the valves enabling each reactor of the first etherification reactor system to be disconnected in response to a need to replace the first catalyst of the reactor with an active catalyst material and, after replacing the first catalyst of the reactor, enabling the disconnected reactor to be reconnected to operation or made ready for operation.
17. The system according to any one of claims 14 to 16, wherein: The second etherification reactor system (103, 303) includes two or more reactors (108-110, 308, 309) connected in series.
18. The system according to any one of claims 14 to 17, wherein: The system comprises: - a side stream outlet (316) between the feed point of the distillation column (105) and the top of the distillation column, the side stream outlet being configured to withdraw a side stream (317) from the distillation column, a third etherification reactor system (314) containing a third catalyst and configured to receive the side stream to produce a third reaction effluent (315), and a conduit (319) configured to mix the third reaction effluent with the second reaction effluent and to supply the mixture of the third reaction effluent and the second reaction effluent to the feed point of the distillation column (105).
19. The system of claim 18, wherein: The system includes an inlet conduit (320) configured to supply alcohol to the third etherification reactor system (314).
20. The system according to claim 18 or 19, wherein: The system includes a heat exchanger system (318) configured to transfer heat from the side stream (317) to the mixture of the second reaction effluent and the third reaction effluent (104, 315) to be supplied to the distillation column (105), and the third etherification reactor system (314) is configured to receive the side stream from the heat exchanger system.
21. The system of claim 20, wherein: The heat exchanger system (318) is configured to condense the side stream from a gas to a liquid.