Apparatus for mixed staged injection of methanol

Abstract

The present disclosure relates to an apparatus for the methylation of aromatic hydrocarbons in an aromatic complex for producing xylene isomer products. More particularly, the present disclosure relates to an apparatus for the selective methylation of toluene and / or benzene in an aromatic complex to produce para-xylene by using treated toluene instead of crude toluene.

Description

[0001] This application is a divisional application of Chinese invention patent application entitled "Apparatus for Mixing and Staged Methanol Injection", filed on December 20, 2018, with application number 201880087324.X and international application number PCT / US2018 / 066636. Technical Field

[0002] This disclosure relates to apparatus for methylating aromatics in an aromatics complex used to produce xylene isomer products. More specifically, this disclosure relates to using riser deslippage technology to improve methanol feed and catalyst contact, which will improve product yield. Background Technology

[0003] Xylene isomers are produced in large quantities from petroleum and are used in a variety of important chemicals. The most important xylene isomer is para-xylene, a key feedstock for polyesters, which continues to enjoy high growth rates due to substantial basic demand. o-Xylene is used to produce phthalic anhydride, supplying a high-volume but relatively mature market. m-Xylene is used less, but its use in products such as plasticizers, azo dyes, and wood preservatives is increasing. Ethylbenzene is commonly found in xylene mixtures and is sometimes recycled for styrene production, but it is generally considered a less desirable component of C8 aromatics.

[0004] Among aromatic hydrocarbons, xylene is as important as benzene as a feedstock for industrial chemicals. Xylene and benzene are produced from petroleum through naphtha reforming, but this is insufficient to meet demand, necessitating the conversion of other hydrocarbons to increase the yield of xylene and benzene. Typically, toluene is dealkylated to produce benzene, or selectively disproportionated to produce benzene and recover the various C8 aromatics of xylene isomers.

[0005] It has been proposed to use oxygen-containing compounds (such as methanol) to methylate toluene or benzene as a route to produce xylene, and to increase the methyl to phenyl ratio in aromatic complexes to maximize xylene production. For toluene methylation methods, adding methanol at various locations above the main feed injection point offers yield advantages. The reactor is a riser configuration, where the feed and catalyst flow co-currently upwards along the riser. Under this riser configuration and operating conditions, a radial catalyst velocity gradient exists, with some catalyst decelerating and beginning to fall along the riser wall. Furthermore, the high upward momentum of the catalyst far from the wall does not allow methanol to be injected from the side of the riser to permeate and mix into the mainstream catalyst. This reduces the effectiveness of methanol injection and may therefore prevent yield improvements.

[0006] Therefore, it is desirable to provide improved equipment for methylating aromatic compounds such as toluene and benzyl in aromatic complexes. Summary of the Invention

[0007] This invention relates to apparatus for the methylation of toluene and / or benzene in an aromatic complex for producing xylene isomers. More specifically, this disclosure relates to apparatus for toluene methylation in which riser deslippage technology is used to improve methanol feed and catalyst contact, which will improve product yield.

[0008] In the foregoing, all temperatures are expressed in degrees Celsius, and all parts and percentages are by weight unless otherwise specified. Other objects, advantages, and applications of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. Additional objects, advantages, and novel features of the examples will be set forth in part in the detailed description that follows, and will also become apparent in part to those skilled in the art upon examination of the following detailed description and accompanying drawings, or may be learned by production or operation of the examples. The objects and advantages of the concepts can be realized and obtained through the methods, tools, and combinations thereof of the invention. Attached Figure Description

[0009] Figure 1 A cross-sectional view of the equipment used for toluene methylation is shown, demonstrating the use of riser deslip technology to improve methanol feed and catalyst contact. Detailed Implementation

[0010] The following detailed description is exemplary in nature only and is not intended to limit the application and use of the described embodiments. Furthermore, it is not intended to be bound by the foregoing background art or any theory presented in the following detailed description.

[0011] Reference attached Figure 1 A description of the device of the present invention is presented. Figure 1 This is a simplified diagram illustrating a preferred embodiment of the invention and is not intended to unduly limit the general scope of the invention. Certain hardware, such as valves, pumps, compressors, heat exchangers, instruments, and controls, has been omitted because such hardware is not essential for a clear understanding of the invention. The use and application of such hardware are entirely within the scope of the art.

[0012] The various embodiments described herein relate to equipment for the methylation of toluene and / or benzene in an aromatic complex used to produce xylene isomers. For example... Figure 1 As shown, the apparatus 10 includes a riser 12, which is a toluene methylation-grade methanol injection riser reactor. Within the riser, a falling catalyst 14 and a majority catalyst 16 are present. The falling catalyst falls downwards onto the edge of the riser 12, while the majority catalyst rises within the riser 12 along with vapor 18. The riser 12 includes at least one riser anti-slip technology, hereinafter referred to as baffle 20.

[0013] In one embodiment, the baffle 20 is positioned symmetrically around the circumference of the riser tube 12. In another embodiment, the baffle 20 is arranged asymmetrically. In some embodiments, the baffle 20 may cover a smaller portion of the circumference if desired. For example, typically at least 30% of the circumference is covered by the baffle 20, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95%.

[0014] The baffle 20 extends inward from the wall to a distance of up to 25% of the riser tube radius, typically ranging from 10% to 30%. The length depends in part on the radius of the riser tube 12 and its angle with the wall. The angle of the baffle 20 ranges from 5° to 80° with respect to the vertical. The baffle 20 can be combined with an additional lining to ensure corrosion resistance.

[0015] The riser 12 advantageously has at least two rows of baffles 20 along its length so that the ring core structure does not return to its initial state as it flows upward along the riser 12. However, if there are too many rows of baffles 20, the upward-flowing catalyst-carrying vapor will simply bypass the baffles 20 completely, thus effectively reducing the diameter of the riser 12.

[0016] Several factors can be considered when determining the appropriate angle of the baffle 20 in a particular riser 12. One factor is mixing; larger angles produce greater mixing. Another factor is the amount of corrosion, which is greater at larger angles. Yet another factor is the pressure drop generated by the baffle 20, which is greater for baffles 20 with larger angles than for those with smaller angles. Furthermore, the effect of thermal differential growth should be evaluated. When the angle is 90°, the wall and baffle may expand at different rates, which could lead to rupture. At smaller angles, such as 10° to 45°, the relatively long inclined support plates provide a longer path for heat transfer. This minimizes the thermal differential growth of the baffles, especially under transient conditions such as start-up or shutdown.

[0017] The baffle 20 is made of a material with sufficient corrosion resistance and temperature resistance to withstand the conditions of the riser pipe. Suitable materials include metal plates, such as stainless steel plates, which are covered with ceramic on at least the front side facing upward flow to prevent corrosion. The back side away from the flow can be covered with an abrasion-resistant and fire-resistant material. Alternatively, both sides can be covered with ceramic.

[0018] The riser 12 also includes a plurality of dispensers 30 for delivering methanol into the riser 12. In one embodiment, the dispensers 30 may be located above a baffle 20. In another embodiment, the dispensers 30 may be positioned through the baffle 20, thereby allowing dispensed methanol to enter the interior of the riser 12 at different radial locations. In yet another embodiment, the dispensers 30 may be located below the baffle 20. The dispensers 30 deliver methanol into the riser 12.

[0019] Although the invention has been described with respect to embodiments that are now considered preferred, it should be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the scope of the invention.

[0020] Specific implementation plan

[0021] While the following description is given in conjunction with specific embodiments, it should be understood that the description is intended to illustrate rather than limit the scope of the invention.

[0022] A first embodiment of the invention is an apparatus comprising a cylindrical riser tube including an outer wall and an inner wall, a bottom opening and a top opening, and at least one distributor, wherein the inner wall includes at least one baffle attached to the inner wall and extending inwardly into the riser tube. An embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the first embodiment, wherein the baffle extends around the entire inner wall of the riser tube reactor. An embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the first embodiment, wherein the distributor is located above the baffle. An embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the first embodiment, wherein the distributor is located below the baffle. An embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the first embodiment, wherein the distributor extends through the baffle to different radial locations within the riser tube reactor. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the angle between the distributor and the riser wall ranges from 30 degrees to 120 degrees. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the distributor is located at two different axial positions within the riser reactor. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein at least two rows of baffles are present. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the baffles are arranged symmetrically around the riser wall. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the baffles substantially cover the entire circumference of the riser. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the riser reactor is a toluene methylation riser reactor. An apparatus includes a cylindrical riser tube comprising an outer wall and an inner wall, a bottom opening and a top opening, and two distributors, wherein the inner wall includes at least one baffle attached to the inner wall extending inwardly into the riser tube substantially covering its entire circumference, and the two distributors are located above the baffle. One embodiment of the invention is one, any, or all of the preceding embodiments described in this paragraph up to the first embodiment described in this paragraph, wherein the distributors extend through the baffles to different radial locations within the riser tube reactor.One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the angle between the distributor and the riser wall ranges from 30 degrees to 120 degrees. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein at least two rows of baffles are present. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the baffles are arranged symmetrically around the riser wall. One embodiment of the invention is one, any, or all of the previous embodiments from this paragraph up to the first embodiment in this paragraph, wherein the riser reactor is a toluene methylation riser reactor.

[0023] A second embodiment of the invention is a device comprising a cylindrical riser tube, the riser tube including an outer wall and an inner wall, a bottom opening and a top opening, and two distributors, wherein the inner wall includes at least one baffle attached to the inner wall extending inward into the riser tube substantially covering the entire circumference of the riser tube, and the two distributors are located below the baffle. One embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the second embodiment, wherein the distributors extend through the baffles to different radial locations within the riser tube reactor. Another embodiment of the invention is one, any, or all of the preceding embodiments from this paragraph up to the second embodiment, wherein the angle between the distributors and the riser tube wall ranges from 30 degrees to 120 degrees.

[0024] Although no further detailed description has been provided, it is believed that those skilled in the art will be able to fully utilize the invention by using the foregoing description and will be able to readily identify the essential features of the invention without departing from its spirit and scope, making various changes and modifications to adapt it to various uses and situations. Therefore, the foregoing preferred embodiments should be understood as illustrative only and not as limiting the remainder of this disclosure in any way, and are intended to cover various modifications and equivalent arrangements within the scope of the invention. In the foregoing, all temperatures are expressed in degrees Celsius, and all parts and percentages are by weight unless otherwise specified.

Claims

1. A riser reactor, comprising: A cylindrical riser tube, comprising an outer wall and an inner wall; At least one baffle is attached to the inner wall and extends inward into the riser tube; and At least one distributor configured to inject methanol into the riser, wherein the at least one distributor is located above the at least one baffle, below the at least one baffle, extends through the at least one baffle and into different radial locations within the riser reactor, or a combination thereof.

2. The riser reactor according to claim 1, wherein the at least one baffle extends around the entire inner wall of the riser reactor.

3. The riser reactor according to claim 1, wherein the at least one distributor forms an angle of 30 degrees to 120 degrees relative to the inner wall.

4. The riser reactor according to claim 1, further comprising a second distributor, wherein the distributor is located at two different axial positions within the riser reactor.

5. The riser reactor according to claim 1, wherein at least two rows of baffles are present.

6. The riser reactor according to claim 1, further comprising a plurality of baffles, wherein the baffles are arranged symmetrically around the inner wall of the riser.

7. The riser reactor of claim 1, further comprising a plurality of baffles, wherein the baffles substantially cover the entire circumference of the riser.

8. The riser reactor according to claim 1, wherein the riser reactor is a toluene methylation riser reactor.

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