TWI524928B - System and process for recovering products using simulated-moving-bed adsorption - Google Patents

Description

System and process for product recovery by simulated moving bed adsorption

The present invention relates to a process for the adsorptive separation of a preferentially adsorbed component from a feed stream. More specifically, the present invention relates to a process for continuous simulated countercurrent adsorption separation of aromatic hydrocarbons.

The present application claims the benefit of U.S. Provisional Application Nos. 61/570,938 and 61/570,940, filed on Dec. 15, 2011.

Paraxylene and meta-xylene are important raw materials in the chemical and fiber industries. Terephthalic acid derived from para-xylene is used to produce polyester fabrics and other articles that are widely used today. Meta-xylene is a raw material used in the manufacture of a large number of useful products including insecticides and isophthalic acid. A combination of adsorptive separation or adsorptive separation, crystallization and fractionation has been used to obtain these xylene isomers, wherein the adsorptive separation captures the vast majority of the market share of new plants that are primarily para-xylene isomers.

The procedure for adsorption separation is extensively described in the literature. For example, a general description of paraxylene recovery is presented on page 70 of the September 1970 issue of Chemical Engineering Progress (Vol. 66, No. 9). A useful reference has been made for a long history of useful adsorbents and desorbents, mechanical parts of simulated moving bed systems including rotary valves for dispensing liquid streams, interiors of adsorbent chambers, and control systems. The principle of continuously separating the components of the fluid mixture by contact with a solid adsorbent using a simulated moving bed is as set forth in U.S. Patent 2,985,589. US 3,997,620 of the simulated moving bed principle is applied from a feed stream comprising C ₈ aromatics recovery of para-xylene, and the teachings of US 4,326,092 from paraxylene recovery between C ₈ aromatics stream.

Processing C ₈ aromatics of the adsorptive separation unit and the general use of the adsorbent simulated countercurrent moving into the stream. The simulation is performed using established commercial techniques in which the adsorbent is held in place in one or more cylindrical adsorbent chambers, and the flow involved in the flow enters and exits the chamber slowly along the length of the bed. Ground shift. A typical adsorptive separation unit is illustrated in Figure 8 and includes at least four streams (feed, desorbent, extract, and raffinate) used in the process, and the feed stream and desorbent stream enter the chamber and The positions of the extract stream and the raffinate stream exiting the chamber are simultaneously displaced at set intervals in the same direction. Each displacement of the location of the delivery point delivers liquid to a different bed within the chamber or removes liquid from a different bed within the chamber. In general, in order to simulate the countercurrent movement of the adsorbent relative to the fluid flow in the chamber, the flow is displaced in the general direction of the fluid flow (ie, the downstream direction) within the chamber to simulate the solid adsorbent in the opposite direction (also That is, moving in the upstream direction. As each stream enters or leaves the associated bed, the pipeline at these transfer points is reused, and thus each of the four process streams is carried at each point of the cycle.

This technique suggests that the presence of residual compounds in the transfer line can have a detrimental effect on the simulated moving bed process. US 3,201,491, US 5, 750, 820, US 5, 884, 777, US 6, 004, 518 and US 6, 149, 874 teach rinsing a line for delivering a feed stream to a sorbent chamber as a means of increasing the purity of the recovered extract or sorbate component. This flushing avoids contamination of the extract stream by the raffinate component of the feed remaining in the line as the line is subsequently used to extract the extract stream from the chamber. US 5,912,395 teaches that when this line is used to deliver a feed stream to the sorbent chamber, the line is flushed just The raffinate stream is removed to avoid contamination of the feed by the raffinate. All of these references teach rinsing the lines back into the sorbent chamber, thus increasing the separation load within the chamber. US 7,208,651 discloses rinsing the contents of a transfer line previously used to remove a raffinate stream by one or both of the feed mixture and the material extracted from the adsorption zone away from the adsorbent chamber. The residual raffinate in the transfer line is flushed to join the raffinate stream as a feed to the raffinate column. US 6,149,874 discloses flushing residual feed from a common section of a fluid distribution conduit to a boost circuit.

A prior exemplary system utilizes up to three flushes to dispose of residual fluid remaining in the transfer line. The initial flushing displaces the residual extract from the transfer line that is just used to remove the extract stream by the fluid from the desorption zone of the chamber directly below the desorbent stream, and directs the residual extract to just use the rotary valve To inject the feed line into the feed stream. Because the volume in the transfer line is equal, the extract plus desorbent fluid displaces the residual feed previously in the transfer line into the sorbent chamber directly above the current feed stream position so that the residual feed can be The feed stream within the adsorptive separation chamber separates and prevents the extract stream from being contaminated by residual feed remaining in the transfer line as the extract stream is subsequently displaced to the transfer line previously occupied by the feed stream. In addition, the residual extract from the initial flush is used to displace the feed remaining in the transfer line for subsequent withdrawal from the extract stream, thereby increasing the yield of the extracted product.

An exemplary system sometimes includes a secondary flush. The secondary flush utilizes a flushing fluid (typically a desorbent) through the transfer line and into the chamber directly below the extract line. The secondary rinse provides "washing" of the transfer line by a desorbent to minimize the inclusion of raffinate, feed, and residual transport after the initial rinse. The amount of contaminants in other components in the pipeline is such that the materials are not extracted from the transfer line by the extract. Since the transfer line was previously flushed by the first rinse by the desorbent and the extract, the secondary rinse is typically used in applications requiring high purity extracts. The secondary rinse will push the extract and desorbent material previously in the transfer line back into the adsorption separation chamber. The secondary rinse is an optional rinse that is used to meet the high purity requirements of the extracted product.

In some systems, a third flush is also utilized. The third flush includes flushing the transfer line previously occupied by the raffinate draw stream. The third rinse is used to remove residual raffinate from this transfer line to limit this raffinate to be injected back into the adsorbent chamber as the feed stream subsequently reaches the transfer line. Because the raffinate stream consumes the desired extract component, a third flush is performed such that the residual raffinate is not injected back into the adsorptive separation chamber that would otherwise increase the separation requirement to remove this additional raffinate material. The third flush is accomplished by flushing the transfer line with fluid from an interface adjacent to the chamber of the transfer line away from the adsorptive separation chamber.

According to various methods, a process for separating components in a feed stream by simulating countercurrent adsorption separation is provided. The process includes introducing a feed stream and a desorbent stream into two different interfaces via two different corresponding transfer lines along a multi-bed adsorption separation chamber. The feed stream has at least one preferential adsorption component and at least one non-preferential adsorption component. The multi-bed adsorption separation chamber has a plurality of beds connected in series in fluid communication and includes a predetermined number of spaced interfaces and in communication with the interfaces for introducing fluid into and from the adsorption separation chamber The separation chamber removes the corresponding transfer line of fluid. The The process also includes extracting an extract stream and a raffinate stream through two different corresponding transfer lines via two different interfaces of the multi-bed adsorption separation chamber. The process according to this method includes extracting one of the extract stream and the raffinate stream away from the adsorptive separation chamber via a transfer line containing one of the residual fluids. The process further includes directing an initial portion of one of the extract stream and the raffinate stream comprising at least a portion of the residual fluid drawn through the one transfer line to a first destination. The process also includes directing a subsequent portion of the extract stream and one of the raffinate streams drawn through a transfer line to a second destination.

According to one aspect, the second destination is an inlet to one of an extract fractionation column and a raffinate fractionation column. According to another aspect, the first destination is a destination different from an inlet of one of the extract fractionation columns or one of the inlets of the raffinate fractionation column. In this manner, the process limits at least the portion of the residual fluid to one of the extract fractionation column and the raffinate fractionation column, at least the portion of the residual fluid otherwise contaminating a product from the fractionation column Or increase energy consumption. According to one aspect, the first destination is a recycle line for recycling the one of the extract stream and the raffinate stream and the portion of the residual fluid to the adsorptive separation chamber to reduce energy requirements .

Those skilled in the art will understand that the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions and/or relative orientations of some of the elements in the figures may be exaggerated with respect to other elements to help improve the understanding of various embodiments of the invention. Again Common, easy-to-understand elements that are useful or necessary in commercially viable embodiments are often not depicted in order to facilitate a less obscuring view of the various embodiments of the present invention. It will be further appreciated that certain actions and/or steps may be described in a particular order of appearance, and those skilled in the art will understand that this particularity of the order is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meanings as they are understood by those skilled in the art, as they are understood by those skilled in the art. Except in the case.

Adsorption separation is used for the recovery of a variety of hydrocarbons and other chemical products. The chemical separation using the disclosed method involves separating a mixture of aromatic hydrocarbons into specific aromatic isomers, separating linear aliphatic hydrocarbons and olefins from non-linear aliphatic hydrocarbons and olefins, and treating any of paraffin or aromatic hydrocarbons. Separation of a feed mixture comprising both aromatics and paraffins, separation of palmitic compounds for pharmaceuticals and fine chemicals, separation of oxidizing agents such as alcohols and ethers, and separation of carbohydrates such as sugars. The aromatic hydrocarbon isolate comprises a mixture of a dialkyl substituted monocyclic aromatic hydrocarbon and a mixture of dimethylnaphthalene. Referring to the previous case and the formation of the present invention described below concerns the case in the present invention is not so limited as the major commercial applications like this is generally attributed to the high purity requirements of the products from a mixture of C ₈ aromatics recovery of paraxylene And / or m-xylene. These C ₈ aromatic hydrocarbons are typically derivatized in an aromatic hydrocarbon complex by catalytic recombination of naphtha followed by extraction and fractionation, or by transalkylation or isomerization of an aromatic-rich stream. these complexes derived; C ₈ aromatics generally comprise a mixture of xylene isomers and ethylbenzene. Using simulated moving bed adsorptive system processing C ₈ aromatics generally related to the recovery of high purity meta-xylene or xylene high purity; high purity usually is defined as at least 99.5 wt based -% of the desired product, and preferably at least 99.7 wt -%. It should be understood that although the following detailed description focuses on the recovery of high purity paraxylene from the mixed xylene and ethylbenzene streams, the invention is not limited thereto, and may also be applied to self-containing two or more components from other components. Separated in the stream. As used herein, the term "preferentially adsorbed component" refers to one or more components of a feed stream that is more preferentially adsorbed than one or more non-preferentially adsorbed components of the feed stream.

The present invention is generally used in the adsorption separation process for the countercurrent movement of the simulated adsorbent and the surrounding liquid as described above, but the present invention can also be used in the same-flow flow of the same-flow continuous process as disclosed in US 4,402,832 and US 4,478,721. Practice in a continuous process. The function and nature of the sorbent and desorbent in the chromatographic separation of the liquid components are well known, and additional description of the basic principles of such adsorption can be found in U.S. Patent 4,642,397, incorporated herein by reference. Countercurrent moving bed or simulated moving bed countercurrent flow systems have much greater separation efficiency than fixed bed systems because of the continuous feed stream and continuous production of extracts and raffinate, adsorption and The desorption operation occurs continuously. A comprehensive explanation of the simulated moving bed process is given in the Adsorptive Separation section on page 563 of the Kirk-Othmer Encyclopedia of Chemical Technology.

Figure 1 is a simplified diagram of a simulated moving bed adsorption process in accordance with one aspect. The process sequentially routes feed stream 5 with adsorbent and desorbent stream 10 contained in a vessel to separate extract stream 15 and raffinate stream 20. In a simulated moving bed counterflow flow system, multiple liquid feeds and product access points or interfaces 25 are drawn along The applicator chambers 100 and 105 are gradually displaced downward to simulate the upward movement of the adsorbent contained in the chamber. The adsorbent in the simulated moving bed adsorption process is contained in a plurality of beds in one or more vessels or chambers; the two chambers 100 and 105 in series are shown in Figure 1, but can be used as shown in Figure 13 A single chamber 902 or other number of chambers in series is illustrated. Each of the vessels 100 and 105 contains a plurality of adsorbent beds in the processing space. Each of the vessels has a number of ports 25 associated with the number of adsorbent beds, and the positions of feed stream 5, desorbent stream 10, extract stream 15 and raffinate stream 20 are displaced along interface 25 to simulate Move the adsorbent bed. The circulating liquid containing the desorbent, extract, and raffinate is circulated through the chamber via pumps 110 and 115, respectively. A system for controlling the flow of circulating liquid is described in US 5,595,665, but the details of such systems are not required for the invention. The rotary disk type valve 300, as characterized, for example, in US Pat. No. 3,040,777 and US Pat. Although a spin valve 300 is described herein, other systems and devices for displacing a flow along a sorbent chamber are contemplated herein, including the use of multiple valves to control flow to and from the sorbent chamber 100 and A system of flow of / or 105, as described, for example, in US 6,149,874.

Referring to Figure 9, a simplified exploded view of an exemplary rotary valve 300 for use in an adsorption separation system and process is depicted. The backplane 474 includes a number of interfaces 476. The number of interfaces 476 is equal to the total number of transfer lines on the chamber. The bottom plate 474 also includes a plurality of tracks 478. The number of rails 478 is equal to the number of net input, output, and flush lines for the adsorption separation unit (not shown in Figure 9). The net input, output, and flush lines are each in fluid communication with a dedicated track 478. A given track 478 is in fluid communication with a given interface 476 across line 470. In a real In the example, the net input includes a feed input and a desorbent input, the net output includes an extract output and a raffinate output, and the flush line includes a flush line between one and four. Each track 478 is in fluid communication with the next continuous interface 476 by spanning line 470 as the rotor 480 rotates as indicated. A sealing sheet 472 is also provided.

The various flows involved in the simulated moving bed adsorption as illustrated in the figures and discussed further below with respect to various aspects of the invention described herein can be characterized as follows. The "feed stream" is a mixture containing one or more extract components or preferentially adsorbed components and one or more raffinate components or non-preferentially adsorbed components to be separated by the process. The "extract stream" comprises an extract component which is relatively easy to select or preferentially adsorbed by the adsorbent, usually the desired product. The "raffinate stream" contains one or more raffinate components that are not susceptible to selective adsorption or non-preferential adsorption. "Desorbent" refers to a material that is capable of desorbing the extract component, which is generally inert to the components of the feed stream and can be readily separated, for example, from the extract and the raffinate via distillation.

The extract stream 15 and the raffinate stream 20 from the illustrated embodiment contain a desorbent between 0% and 100% relative to the concentration of the individual products from the process. The desorbent is typically separated in the raffinate column 150 and the extract column 175 as illustrated in Figure 1 by conventional fractionation of the raffinate and extract components, and by the raffinate bottom pump The 160 and extract bottoms pump 185 is recycled to stream 10' to return to the process. Figure 1 shows the desorbent as bottoms from the respective column, implying that the desorbent is heavier than the extract or raffinate; C ₈ aromatics for separation of different light or heavy commercial unit using the desorbent, and Thus in some applications, the desorbent can be separated at different locations along fractionation columns 150 and 175. 150 and 175 in the respective columns from the extract stream and the raffinate stream recovered from the raffinate product of the process and the product was extracted 170 195; C the product was extracted from the separation of _aromatics comprising 195 typically primarily on the m-xylene and p-xylene one or both, wherein the primary raffinate product 170 non-adsorbed C ₈ aromatics and ethylbenzene.

The sorbent chamber is passed through the liquid stream entering or leaving the sorbent chambers 100 and 105 via the active liquid take-up point or interface 25 (e.g., feed stream 5, sorbent stream 10, raffinate stream 20, and extract stream 15). 100 and 105 are effectively divided into separate partitions that move as the stream moves along interface 25. It should be noted that although many of the discussion herein refers to the locations of the flows in Figures 1 and 1, Figure 1 illustrates only the current location or flow of a flow at a single step when the flow is typically shifted downstream at different steps of the cycle. The instantaneous state (snapshot). As the flow is displaced downstream, the fluid composition and corresponding zones are displaced downstream therewith. In one method, the position of the flow with respect to the pick-up points or interfaces 25 of the adsorptive separation chambers 100 and 105 remains substantially constant relative to each other as the streams progress downstream simultaneously along the interface 25. In one example, for each step, the streams each advance downstream to a single interface 25, and each stream occupies each interface 25 once during the entire cycle. According to an example, the streams are simultaneously stepped to the subsequent interface 25 by rotating the rotary valve 300 and maintaining a predetermined step time interval at a particular interface 25 or step. In one method, there are 4 and 100 interfaces 25, in another method there are 12 and 48 interfaces, and in yet another method there are 20 and 30 interfaces, And there are an equal number of corresponding transfer lines. In one example, one or more of the adsorptive separation chambers 100 and 105 includes 24 interfaces, and each stream is shifted to each of the 24 interfaces 25 during a full cycle such that each stream occupies during the cycle According to each interface 25 and the corresponding transfer line. In this example, the cycle can be between 20 minutes and 40 minutes in one method and between 22 minutes and 35 minutes in another method. In one method, the step time interval is between 30 seconds and 2 minutes. In another method, the step time interval is between 45 seconds and 1 minute 30 seconds. In yet another method, the step time interval is between 50 seconds and 1 minute 15 seconds. An example of a typical step time interval can be 1 minute.

With this in mind, FIG. 8 illustrates the transient state of the composition distribution of the fluid in the adsorption separation chamber (the single adsorption separation chamber 100 is illustrated in FIG. 8 for the sake of simplicity) and the corresponding division of the adsorption separation chamber 100. Partition. The adsorption zone 50 is located between the feed inlet stream 5 and the raffinate outlet stream 20. In this zone, feed stream 5 contacts the adsorbent, adsorbs the extract component, and extracts the raffinate stream 20. As illustrated, the raffinate stream 20 can be withdrawn at a location where the composition includes raffinate fluid 454 and a little, if any, extract fluid 450. The purification zone 55 is immediately upstream with respect to the fluid stream, and the purification zone 55 is defined as the adsorbent between the extract outlet stream 15 and the feed inlet stream 5. In the purification zone 55, the raffinate component is displaced from the non-selective void volume of the adsorbent and desorbed from the pore volume or surface of the adsorbent, displaced by the portion of the extract stream material leaving the desorption zone 60. So far in the partition. The desorption zone 60 flowing over the purification zone 55 is defined as the adsorbent between the desorbent stream 10 and the extract stream 15. The desorbent delivered to this zone displaces the extract component adsorbed in the adsorption zone 50 by previous contact with the feed. The extract stream 15 can be withdrawn at a location in the chamber 100 that includes the extract fluid 450 and a little, if any, raffinate fluid 454. A buffer zone 65 between the raffinate outlet stream 20 and the desorbent inlet stream 10 prevents contamination of the extract Dyeing, because the portion of the desorbent stream enters the buffer zone to displace the raffinate material present in the partition into the adsorption zone 50. The buffer zone 65 contains sufficient adsorbent to prevent the raffinate component from passing into the desorption zone 60 and contaminating the extract stream 15.

Each of the partitions described above is typically implemented via a plurality of compartments or "beds" as described in US 2,985,589. The locations of the various streams described are structurally separated from each other by a horizontal liquid collection/distribution grid. Each grid is connected to a transfer line defining a transfer point at which the process stream enters and exits the sorbent chamber. This configuration promotes the distribution of fluid within the chamber via the elimination channel and other ineffective components, prevents convective reverse mixing of the fluid in the opposite direction of the primary fluid flow, and prevents migration of the adsorbent through the chamber. Each of the partitions described above typically comprises a plurality (2 to 10, and more typically 3 to 8) beds. A typical simulated moving bed adsorption unit contains 24 adsorbent beds.

As is readily apparent in Figure 1, when the transfer line at the take-up point 25 for transporting a particular stream into or out of the sorbent chamber remains idle at the end of a step, it will retain all of the compound forming the flow until These compounds are removed from the pipeline by a second flow stream. In this regard, it should be noted that only the active transfer lines (i.e., the lines that currently facilitate fluid flow therethrough) are illustrated in FIG. 1, but the intermediate transfer lines are present in the interface 25 along chambers 100 and 105. One facilitates fluid flow as the fluid flow is displaced to the subsequent interface 25. The residual fluid or compound remaining in the unused pipeline after the flow is shifted to the subsequent transfer line will therefore be extracted from the process as an initial part of the process stream removed from the process or transported to the pipeline at the transfer line Forced press into the sorbent chamber while in the sorbent chamber. FIG. 13 illustrates the use of an unused delivery line as a dashed line and showing the delivery line currently occupied by the flow (eg, stream 920) as a solid line extending from the interface of the adsorptive separation chamber 902.

Returning to Figure 1, as described above, the presence of residual fluid in the transfer line can have a detrimental effect on the performance of the simulated moving bed adsorption separation process. For example, the residual raffinate in the transfer line previously used to remove the raffinate stream 20 from the adsorbent chamber may be passed through the feed stream 5 as the feed stream 5 is displaced to the transfer line in a subsequent step. Flush into the sorbent chamber 105. Similarly, the residual feed previously used to introduce feed stream 5 into the transfer line of the adsorbent chamber can be moved from the transfer line by the extract stream 15 as the extract stream 15 is displaced to the transfer line in a subsequent step. except. Likewise, residual extract from the transfer line previously used to remove the extract stream from the adsorbent chamber may be flushed back to the adsorbent chamber 100 by the desorbent stream 10 as the desorbent stream 10 subsequently reaches the transfer line. in.

According to one aspect, the initial flushing of the process and system includes a first flush 30, and the initial flush 30 flushes the residual feed in the transfer line previously occupied by feed stream 5 into the adsorptive separation chamber 105, and more specifically Rinse into purification zone 55. The initial flush 30 can advantageously be directed to a transfer line in the vicinity of the transfer line currently occupied by the feed stream 5 to the purification zone 55 to introduce residual feed to the vicinity of the feed stream 5 in the adsorptive separation chamber 105, such that The residual feed can be separated in the adsorptive separation chamber 105. In one example, the initial flush 30 can be directed to a transfer line in the two transfer lines of the feed stream 5 of the purification zone 55, and more preferably to a transfer line adjacent to the feed stream 5, such as This is illustrated in Figure 1. In one method, the initial rush into 30 uses the main A rinse fluid comprising a preferentially adsorbed component, a desorbent, and/or an inert component. In other words, the rinsing fluid preferably includes a minor, if any, non-preferentially adsorbed component of the feed to limit contamination of the extract stream 15 as the extract stream reaches the transfer line during subsequent steps.

The initial flushing of the process and system can include flushing the residual extract fluid from the transfer line previously occupied by the extract stream away from the initial flushing 35 of the adsorbent chamber. The extract fluid, along with the initial flushing flushing fluid, is passed to the flushing fluid for delivery to the initial flushing 30 transfer line, and is used to flush the residual feed from the transfer line previously occupied by the feed stream to the purification zone of the adsorptive separation chamber 105. Medium as described previously. In one method, the initial flush 35 utilizes fluid from the desorption zone 60 of the chamber 100 to flush the transfer line that primarily includes the desorbent. In this manner, after the initial flushing 35 flushes the residual extract fluid in the transfer line previously occupied by the extract stream 15, very little extract fluid remains in the transfer line. Advantageously, by coupling the initial flush 35 to the initial flush 30, the residual fluid in the transfer line can be used to flush other transfer lines, thereby reducing the total amount of fluid required for the process and by capturing such fluids. Increasing the yield of the process while achieving the previously discussed transfer line flushing objectives. In addition, the primary flush pair provides a flushing fluid for the primary flushing 30 that primarily includes the desorbent and the preferential adsorbent component from the residual extract fluid. Again, this pairing provides a flushing fluid for the initial flushing of 30, including very few non-preferentially adsorbed components. In one example, the rinse fluid for the first flush 30 comprises greater than 99% by weight of the desorbent and preferentially adsorbed components. In another example, the rinsing fluid comprises less than 0.005% by weight of the non-preferentially adsorbed component.

According to one method, the secondary flush 40 is used to flush residual fluid from the transfer line that is subsequently occupied by the extract stream 15 to remove contamination from the transfer line. The secondary flush 40 advantageously provides increased purity of the extract stream from the transfer line prior to use of the transfer line to extract the extract stream 15 therethrough. Previous systems utilized flushing the desorbent into the transfer line and toward the adsorptive separation chamber to flush the contents of the transfer line that would then be used to extract the extract stream. This rinsing is carried via the transfer line towards the adsorption separation chamber and into the purification section of the adsorption separation chamber to provide its purification.

The secondary flush of the prior system previously discussed has been identified to produce utility or energy penalties. Specifically, since the secondary rinse 40 uses a desorbent to flush the residual preferential adsorbent component/desorbent fluid in the transfer line to the adsorption separation chamber, the transfer line almost completely includes the off after the second flush. Attachment. The residual desorbent in the transfer line is then withdrawn as an initial surge of fluid by the extract stream prior to removal of the extract. The surge stream comprising the residual desorbent is directed to an extract fractionation column 175 where the extract stream is fractionated as a bottoms product and recycled to the first chamber 100 with the desorbent recycle stream. However, in order to enter column 175, the surge of residual desorbent in the transfer line at the beginning of removal of the extract must also be heated prior to entering extract column 175 for fractionation. For example, when para-xylene is separated from the feed stream of the mixed xylene, the desorbent extracted by the extract stream is heated from 150 ° C to 300 ° C, resulting in energy or utility penalties. In other words, because the initial residual slug of the desorbent contains very little, if any, of the product to be extracted, a considerable energy input is required to raise the temperature to the outlet temperature of the extract fractionator, while not Providing increased extraction products Yield benefits.

To avoid this utility and energy penalty, according to one aspect, the secondary flush 40 flushes residual fluid from the transfer line 45 away from the adsorptive separation chamber 100 (ie, as opposed to the previous system) such that residual desorbent is not accumulated in the transport. Inside line 45. It should be noted that in the step illustrated in Figure 1, the transfer line 45 is used for the secondary flush 40, however, during the previous or subsequent steps, the secondary flush 40 may be displaced along with the flow and used to move from other transfer lines In addition to residual fluid. More specifically, the residual fluid is flushed from the transfer line 45 using a desorbent stream (which may include primarily the preferential adsorbent components and desorbent remaining in the transfer line after the initial flush 30), from adjacent The fluid in the purification zone corresponding to the transfer line interface 45' of the transfer line is used to flush the residual fluid away from the adsorbent chamber 100. A secondary flush stream can then be delivered for further processing. In one method, the secondary flush stream is delivered to fluid recirculation line 10' by line 40'. The fluid recirculation line 10' may primarily include a desorbent that is separated via fractionation columns 150 and 175 and recycled back to the adsorptive separation chamber 100, where the desorbent is reused in the process. In one method, the secondary flush stream is conveyed via line 40' to the bottom portion 155 of the raffinate fractionation column 150 where the secondary flush stream is separated from the raffinate fractionation column 150 by desorption. The agents are combined and delivered to the fluid recirculation line 10' via a raffinate pump 160. In another method, the secondary flush stream is conveyed via line 40' to the bottom portion 180 of the extract fractionation column 175 where the secondary flush stream is separated from the extractant by the extract fractionation column 175. Combined and transported via an extract bottom pump 185 to the fluid recirculation line 10'.

Because the composition of this fluid from the purification zone 55 is similar to the extract stream 15 that is subsequently withdrawn from the transfer line 45, the composition of residual fluid remaining in the bed line after the modified secondary rinse 40 will advantageously be similar The desired extract composition. To this end, in one example, by means of a transfer line or interface within the two transfer lines or ports of the transfer line currently occupied by the extract stream 15 and preferably from the transfer line currently occupied by the extract stream 15 The secondary rinse 40 flushes the transfer line 45 because the purified zone fluid adjacent to the interface near the extract transfer line will have the composition most similar to the extract stream 15 . In one example, the purified zoned fluid has greater than 99% desorbent and preferentially adsorbed components. In another example, the purified zoned fluid has less than 0.005% of the non-preferentially adsorbed components. Furthermore, when the initial flush 30 is used to flush the residual feed as previously described, the secondary flush 40 according to a method is positioned at the transfer line currently occupied by the extract stream 15 and the transfer line currently occupied by the first flush 30. In between, the transfer line 45 is primarily filled by residual fluid from the initial flush 30 rather than the feed stream 5. This method advantageously reduces the extent to which the extract stream 15 is contaminated by residual feed.

Further, in one method, the fluid in the transfer line 45 drawn by the extract stream 15 will then be transported to the extract fractionation column 175 for separation via distillation. The residual fluid in the transfer line 45 that is transported by the extract stream to the extract fractionation column 175 is heated in the extract fractionation column 175. Since the composition of this residual fluid is similar to the extract stream 15, fractional distillation of this fluid will result in increased recovery of the desired product 195. Thus, unlike previous systems, it is then carried by the extract stream 15 and transported to the extract fractionation column. The remaining fluid from the secondary flush 40 remaining in the transfer line 45 will not cause unnecessary utility penalties because the distillation of this fluid will result in an additional yield of the desired product 195 rather than primarily a desorbent.

According to another aspect illustrated in Figure 2, the extract stream 15 can be withdrawn via a transfer line during a step as previously described. In this method, the extract stream 15 is withdrawn along with the residual fluid remaining in the transfer line such that the extract stream flushes the residual fluid away from the transfer line. An initial residual block flow of the extract stream comprising at least a portion of the residual fluid is directed to the first destination via a transfer line. Subsequent portions of the extract stream are then directed to the second destination via a transfer line. At least a portion of the residual fluid within the transfer line is directed to the first destination. In an example, at least 90% of the residual fluid is directed to the first destination. In another example, at least 95% of the residual fluid is directed to the first destination. In one method, the second destination is the inlet 190 of the extract fractionation column 175. The first destination may be a recycle line 10' for recycling the extract stream and a portion of the residual fluid to the adsorptive separation chamber 100.

As illustrated in Figure 2, the initial flush 30 can be used to flush residual feed fluid remaining in the transfer line previously occupied by feed stream 5 into the adsorptive separation chamber 105 (as previously described) to limit residuals. The feed fluid is withdrawn from the extract stream as the residual fluid in the transfer line as it reaches the transfer line in the subsequent step. The rinsing fluid preferably comprises primarily a desorbent and/or a preferentially adsorbed component and includes very few non-preferentially adsorbed components such that residual fluid remaining in the transfer line after initial flushing 30 comprises very few non-preferentially adsorbed components. In one method, the rinsing fluid comprises less than 1% non- The component is preferentially adsorbed, and in another example, less than 0.005% of the non-preferentially adsorbed component is included. As previously described, the residual extract remaining in the transfer line previously occupied by the extract stream 15 can be flushed from the transfer line via the initial flush 35, and the residual extract fluid can be delivered to the initial flush 30 transfer line for use as The first flushing of 30 flushing fluid. The residual extract fluid can be flushed through the first flush 35 by drawing fluid from the desorption zone 60 adjacent to the interface 25 in communication with the primary flush 35 delivery line. In this regard, the residual fluid in the transfer line as the extraction stream 15 is displaced to the transfer line may primarily comprise residual extract and flushing fluid drawn from the desorption section 60 via the initial flush 35 (eg, residual extract and desorption) Agent).

Turning now to more detail in Figure 2, according to this method, the extract stream 15 is withdrawn via a transfer line comprising residual fluid such that the initial residual block flow of the extract stream will include the remainder remaining in the transfer line before the extract stream 15 arrives. fluid. As previously mentioned, this initial residual block flow of the extract stream can be sent to the recycle line 10' for recycle back to the adsorptive separation chamber 100. To this end, the initial residual block stream of the extract stream can be passed to the raffinate fractionation column bottom portion 155. At the bottom portion 155 of the raffinate, the residual block flow of the fluid is combined with the fluid exiting the bottom of the raffinate fractionation column 150, which in one example primarily includes the desorbed desorption in the raffinate fractionation column 150. Agent. The raffinate bottoms pump 160 can be used to direct this residual block flow of fluid and desorbent back to the adsorptive separation chamber 100 via the recirculation line 10'. Alternatively, the initial residual block stream of the extract stream can be passed to the extract fractionation column bottom portion 180. At the bottom portion 180 of the extract, the residual block flow of fluid is combined with the fluid exiting the bottom of the extract fractionation column 175, which fluid is primarily A desorbent that has been separated in the extract fractionation column 175 is included. The extract bottoms pump 185 can be used to direct this residual block flow of fluid and desorbent back to the adsorptive separation chamber 100 via the recycle line 10'.

In this manner, at least a portion of the residual fluid withdrawn by the extract stream 15 is not directed to the extract fractionator inlet 190. Since the residual fluid in the transfer line from the initial flush 30 will contain a greater percentage of desorbent than the extract stream 15, this excess desorbent is advantageously not separated in the extract fractionation column 175. Because the fluid entering the extract fractionation column inlet 190 is heated, if excess desorbent in the residual fluid is introduced into the extract fractionation column 175, the desorbent will be heated to the bottom outlet temperature without providing an extract product. The additional yield, and thus the energy penalty. Thus, by splitting the initial residual block flow of the fluid such that no excess desorbent is introduced into the extract fractionation column 175, the amount of energy required by the system is reduced.

According to one aspect, the extract stream 15 is withdrawn from the adsorptive separation chamber 100 and transported along the transfer line 15'. In one method, a rotary valve 300 is provided such that the extract stream 15 is withdrawn via a transfer line and directed to a rotary valve in which the extract stream 15 is combined with a single extract transfer line 15' as illustrated in FIG. Other configurations are contemplated herein, including providing a dedicated extract delivery line 15' for each of the adsorption separation chambers 100 and 105. The transfer line 15' can have an extract inlet line 205 in fluid communication with the extract fractionation column inlet 190. The transfer line 15' can have another bottom portion line 210 that communicates with one or both of the extract bottoms portion 180 and the raffinate bottom portion 155. A valve 215 can be provided for flowing the extract stream 15 between the extract column inlet line 205 and the extract bottoms portion line 210. Dynamic shunting. In this manner, the process includes moving the valve 215 to a first position to direct an initial portion of the extract stream 15 comprising at least a portion of the residual fluid to the extract bottoms portion 180 and the raffinate column via the extract bottoms portion line 210. One of the bottom portions 155. In this example, the process includes splitting valve 215 to a second location to direct extract stream 15 through extract column inlet line 205 and toward extract fractionator inlet 190 for separating extract stream 15 therein.

According to one aspect, the first predetermined time or a predetermined portion of the step time interval (when the extract stream occupies the current transfer line) will include an extraction stream guide comprising at least a portion of the residual fluid flushed from the transfer line by the extract stream. To the first destination, for example, one or both of the extract bottoms portion 180 and the raffinate bottom portion 155. The extract stream is then directed to a second destination, such as the inlet of extract fractionation column 175, within a predetermined portion of the second predetermined time or step time interval. A first predetermined time may be selected based on the flow rate of the extraction stream to flush a predetermined amount of residual fluid in the delivery line to a second destination or to flush a predetermined amount of fluid to a second destination. In an example, the first predetermined time may be sufficient to direct 50% to 250% of the volume of the volume of the transfer line and associated valve assembly to the first destination, and in another example the volume to the transfer line And 80% to 150% of the volume of the associated valve assembly is directed to the first destination. In one method, the second predetermined time may be the remainder of the step time interval such that the extract stream 15 is directed to the extract column inlet 190 for use in the extract fractionation column 175 over the remainder of the step time interval. The extraction stream 15 is separated. Optionally, a predetermined time may be selected to bring all or at least the residual fluid in the transfer line A portion is directed to the first destination such that residual fluid is not introduced into the extract fractionation column to provide energy savings. Similarly, a first predetermined volume of the extract stream can be directed to the first destination and a second predetermined volume of the extract stream can be directed to the second destination. The first predetermined volume may be the same as described above for the first predetermined time. The second predetermined volume may be the remaining volume of the extract stream drawn via the transfer line during the step time interval. In an example, the first predetermined time is between 10% and 90% of the step time interval. In this example, the second predetermined time is between 10% and 90% of the step time interval. In another example, the first predetermined time is between 20% and 40% of the step time interval. In this other example, the second predetermined time is between 60% and 80% of the step time interval.

In another method, the process includes monitoring the composition of the extract stream (including any residual fluid) to determine the amount or percentage of the components within the composition. For example, the component can be one of a preferentially adsorbed component, a desorbent component, or a non-preferentially adsorbed component. The process according to the method comprises directing the extract stream 15 and any residual fluid to the first destination when the composition comprises the first predetermined amount of the component, and extracting the extract stream when the composition comprises the second predetermined amount of the component 15 leads to the second destination. For example, the process can include monitoring the composition of the extract stream 15 to determine the amount of desorbent present in the stream. According to this example, the process can include directing the extract stream to the first destination when the amount of desorbent is above a threshold level and directing the extract stream to the second when the amount of desorbent is below a threshold level destination. In this manner, the amount of desorbent delivered to the extract fractionator inlet 190 can be reduced.

Advantageously, according to this method, the secondary flush 40 of the prior system can be omitted. In this way, the process can use less of one active transfer line. For example, the process can use only six or seven transfer lines instead of the seven or eight transfer lines as required in previous systems. In one method, the process can use a rotary valve 300 having only six or seven tracks including the extract stream, the raffinate stream, the feed stream and the desorbent stream, and the initial flush 35. Initially rush into 30 and rinsing the track of 46 for the third time. This method advantageously allows trimming an existing adsorptive separation system having six and seven orbital rotary valves to utilize the invention in accordance with this method.

Turning now to Figure 3, an adsorption separation system and process according to another aspect will be described. According to this aspect, the raffinate stream 20 can be withdrawn via a transfer line during a step as previously described. In this method, the raffinate stream 20 is withdrawn along with the residual fluid remaining in the raffinate stream transfer line such that the raffinate stream 20 flushes the residual fluid away from the transfer line. This aspect is similar to that described above and illustrated in Figure 2 in that the initial residual block flow of the raffinate stream is directed to the first destination. The subsequent portion of the raffinate stream is then directed to the second destination. At least a portion of the residual fluid within the transfer line is directed to the first destination. In an example, at least 90% of the residual fluid is directed to the first destination. In another example, at least 95% of the residual fluid is directed to the first destination. In one aspect, the second destination is the inlet 165 of the raffinate fractionation column 150. The first destination may be a recycle line 10' for recycling a portion of the raffinate stream and residual fluid to the adsorptive separation chamber 100. In this regard, by recycling a portion of the fluid back to the adsorptive separation chamber 100, the amount of fluid treated by the raffinate fractionation column 150 is reduced.

As illustrated in Figure 3, in one method, previously occupied by desorbent stream 10 A transfer line occupied by the raffinate stream 20. In this regard, the transfer line may primarily comprise residual desorbent fluid as the raffinate stream reaches the transfer line in a subsequent step.

Turning now to more detail in Figure 3, according to this aspect, the raffinate stream 20 is withdrawn via a transfer line comprising residual fluid such that the initial residual block flow of the raffinate stream will be included before the raffinate stream 20 arrives. Residual fluid in the pipeline. As previously mentioned, this initial residual block flow of the raffinate stream can be passed to the recycle line 10' for recycle back to the adsorptive separation chamber 100. To this end, the initial residual block flow of the raffinate stream 20 can be carried to the raffinate fractionation column bottom portion 155, similar to the method previously described with respect to FIG. At the bottom portion 155 of the raffinate, the residual block flow of the fluid is combined with the fluid exiting the bottom of the raffinate fractionation column 150, which in one example primarily includes the desorbed desorption in the raffinate fractionation column 150. Agent. The raffinate bottoms pump 160 can be used to direct this residual block flow of fluid and desorbent back to the adsorptive separation chamber 100 via the recirculation line 10'. Alternatively, the initial residual block stream of the raffinate stream 20 can be passed to the extract fractionation column bottom portion 180. At the bottom portion 180 of the extract, the residual block flow of fluid is combined with the fluid exiting the bottom of the extract fractionation column 175, which in one example primarily includes the desorbent that has been separated in the extract fractionation column 175. Similarly, the extract bottoms pump 185 can be used to direct this residual block flow of fluid and desorbent back to the adsorptive separation chamber 100 via the recycle line 10'.

In this manner, at least a portion of the residual fluid withdrawn by the raffinate stream 20 is not directed to the raffinate fractionator inlet 165. Because the residual fluid in the transfer line will contain a greater percentage of desorbent than the raffinate stream, This excess desorbent is advantageously not transported into the raffinate fractionation column 150 and separated in the raffinate fractionation column 150. Since the fluid entering the raffinate fractionation column inlet 165 is heated in the column, if excess desorbent in the residual fluid is introduced into the raffinate fractionation column 150, the desorbent will be heated without providing extraction. The additional yield of the product, and thus the energy penalty. Thus, by splitting the initial residual block flow of the fluid such that no excess desorbent is introduced into the raffinate fractionation column 150, the amount of energy required by the system is reduced.

In one method, the raffinate stream 20 is withdrawn from the adsorptive separation chamber 100 and transported along the transfer line 20'. In one method, a rotary valve 300 is provided such that the raffinate stream 20 is withdrawn via a transfer line and directed to a rotary valve 300 where the raffinate stream 20 is transported with a single raffinate as illustrated in FIG. Line 20' is combined, but other configurations are contemplated herein, including providing a dedicated raffinate delivery line 20' for each of the adsorption separation chambers 100 and 105. The transfer line 20' can have a raffinate inlet line 305 in fluid communication with the raffinate fractionation column inlet 165. The transfer line 20' can have another bottom portion line 310 in fluid communication with one or both of the extract bottoms portion 180 and the raffinate bottom portion 155. A valve 315 can be provided for splitting the flow of the raffinate stream 20 between the raffinate column inlet line 305 and the raffinate bottoms portion line 310. In this manner, the process includes moving the valve 315 to a first position to direct an initial portion of the raffinate stream 20 including at least a portion of the residual fluid to the extract bottom portion 180 and the raffinate via the raffinate bottom portion line 310. One of the bottom portions 155 of the tower. In this example, the process includes moving valve 315 to a second position to direct raffinate stream 20 through raffinate column inlet line 305 and toward raffinate fractionation column inlet 165 for use in The raffinate stream 20 is separated therein.

In one aspect, at least a portion of the residual fluid that is flushed from the transfer line by the raffinate stream is within a predetermined portion of the first predetermined time or step time interval (when the raffinate stream occupies the current transfer line) The remainder stream 20 is directed to a first destination, such as one or both of the extract bottoms portion 180 and the raffinate bottom portion 155. The raffinate stream is then directed to a second destination, for example, a raffinate fractionation column inlet 165, within a predetermined portion of the second predetermined time or step time interval. A first predetermined time may be selected based on the flow rate of the raffinate stream 20 to flush a predetermined amount of residual fluid in the transfer line to a second destination or to flush a predetermined amount of total fluid to a second destination. In an example, the first predetermined time may be sufficient to direct 50% to 250% of the volume of the volume of the transfer line and associated valve assembly to the first destination, and in another example the volume to the transfer line And 80% to 150% of the volume of the associated valve assembly is directed to the first destination. In one method, the second predetermined time may be the remainder of the step time interval such that the raffinate stream 20 is directed to the raffinate column inlet 165 for use in the raffinate in the remainder of the step time interval The raffinate stream 20 is separated in the fractionation column 150. The predetermined time may also be selected as other values to direct all or at least a portion of the residual fluid in the transfer line to the first destination such that residual fluid is not introduced into the raffinate fractionation column 150 to provide energy savings. In an example, the first predetermined time is between 10% and 90% of the step time interval. In this example, the second predetermined time is between 10% and 90% of the step time interval. In an example, the first predetermined time is between 10% and 30% of the step time interval. In this example, the second predetermined time is at the step time interval Between 70% and 90%. Similarly, a first predetermined volume of raffinate stream can be directed to the first destination and a second predetermined volume of raffinate stream can be directed to the second destination. The first predetermined volume may be a percentage of the volume of the transfer line and associated valve assembly as described above for the first predetermined time. The second predetermined volume may be the remaining volume of the raffinate stream drawn via the transfer line during the step time interval.

In another aspect, the process includes monitoring a composition of the raffinate stream 20 (including any residual fluid) to determine the amount or percentage of components within the composition. For example, the component can be one of a preferentially adsorbed component, a desorbent component, or a non-preferentially adsorbed component. The process according to the method includes directing the raffinate stream 20 and any residual fluid to the first destination when the composition includes the first predetermined amount of the component, and extracting the composition when the composition includes the second predetermined amount of the component The remainder stream 20 is directed to a second destination. For example, the process can include monitoring the composition of the raffinate stream to determine the amount of desorbent present in the stream. According to this example, the process can include directing the raffinate stream to the first destination when the amount of desorbent is above a threshold level and directing the raffinate stream to the raffinate stream when the amount of desorbent is below a threshold level Second destination. In this manner, the amount of desorbent delivered to the raffinate fractionation column inlet 165 can be reduced.

Turning to Figure 4, in accordance with another aspect, the adsorptive separation process includes a first flush 405 for initial flushing between the transfer line occupied by feed stream 5 and the transfer line occupied by extract stream 15 The residual fluid in the intermediate transfer line of the purification zone 55 is moved away from the adsorptive separation chambers 100 and 105 to remove at least a portion of the residual fluid from the intermediate transfer line. The process according to this aspect further includes the dismantling of the intermediate transfer line The remaining fluid is directed to another transfer line that is not a transfer line for purification zone 55 to limit the introduction of residual fluid into purification zone 55. In this manner, as in the prior system, the residual fluid in the intermediate transfer line is not injected back into the purification zone where the components of the residual fluid will be separated, but not flowed through the extract stream 15 at the top of the purification zone 55 before being withdrawn. The benefit of the entire purification zone 55.

In one aspect, the residual fluid flushed by the initial flush 405 is sent to the feed stream 5 and combined with the feed stream 5 to be introduced into the adsorptive separation chamber 105 via the feed stream transfer line with the feed stream 5. . In this manner, the components of the residual fluid introduced with the feed stream can be separated from the feed fluid introduced via feed stream 5 within the adsorptive separation unit. This situation provides a more complete component separation than if the residual fluid was introduced directly into the purification zone 55 via the intermediate transfer line, as the components in the residual fluid can flow through the feed stream 5 prior to extraction via the extract stream 15 The entire purification zone 55 is separated from the extraction stream 15. This method increases the purity of the extract stream 15 due to a more complete separation of the components of the residual fluid.

The residual fluid remaining in the intermediate transfer line via the first flush 405 flush according to a method may include residual feed fluid. To this end, the intermediate transfer line may have previously been occupied by the feed stream 5 such that the intermediate transfer line includes residual feed fluid at the end of the step as the feed stream is displaced away therefrom. The residual feed fluid can advantageously be combined with the feed stream 5 and injected into the purification zone via the feed stream transfer line and interface, thus separating the residual feed fluid to the same extent as the composition of the feed stream 5 itself. Component.

Because the pressure in the initial 405 delivery line can be lower than the feed stream. The pressure in the line, so it may be necessary to pump the initial flushing fluid to overcome the pressure differential and combine it with the feed stream 5. In this regard, a pump 410 can be provided for pumping the primary flushing fluid through the intermediate transfer line and combining the primary flushing fluid with the feed stream 405. In one method, the system can include a rotary valve wherein the initial flush flow is flushed through the intermediate transfer line and to the rotary valve 300 where the initial flush flow is combined with the feed stream 5. However, where two or more adsorptive separation chambers 100 and 105 are used, the pressure at feed stream 5 may be high at certain transfer lines or ports 25 along adsorption separation chambers 100 and 105. At the pressure of the first flushing stream 405, wherein the initial flushing stream 405 is transported between the transfer lines near the bottom of the adsorptive separation chambers 100 and 105 to be near the top of the other of the adsorptive separation chambers 100 and 105. The feed stream 5 is joined. In such locations, residual feed in the line can be flushed into the extract stream because the adjacent transfer lines are often in fluid communication with one another in the process utilizing the rotary valve 300. Thus, in one method, pump 410 is positioned downstream of the rotary valve as illustrated in FIG. 4 to limit residual feed in the intermediate transfer line when the flow is located at certain locations along adsorption separation chambers 100 and 105. Rinse back into the extract stream 15.

According to one aspect, the initial flush 405 includes pumping fluid from the purification zone 55 of the adsorptive separation chamber 100 via the interface 25 of the transfer line 415. The purified zone fluid is withdrawn from the location in the purification zone 55 adjacent to the interface 25 and delivered to the intermediate transfer line to flush the residual fluid in the intermediate transfer line away from the adsorptive separation chamber 100. Flushing the intermediate transfer line 415 by purifying the zoned fluid advantageously fills the transfer line 415 by preferentially adsorbing the component at a higher concentration than the non-preferentially adsorbed component of the fluid to be in the extract stream 15 The contamination of the extract stream 15 is reduced when the intermediate transfer line 415 is reached in a subsequent step. In one method, the purified zone material is drawn into a transfer line at a location near the transfer line currently occupied by the extract stream 15 such that the composition of fluid within the purge zone 55 being extracted is similar to the extract stream fluid. In one method, the purified zone fluid is withdrawn via interface 25 and extracted into a transfer line within two transfer lines from the transfer line currently occupied by the extract stream 15 . In another method, the purified zone fluid is withdrawn via interface 25 and extracted into the intermediate transfer line of the purification zone 55 adjacent to the transfer line currently occupied by the extract stream 15 . In this manner, the composition of the purified zone fluid remaining in the transfer line for flushing the intermediate transfer line after the initial flush will be similar to the composition of the extract stream fluid and includes only a small amount from the feed stream (if any) Otherwise, the non-preferentially adsorbed component of the extract stream 15 will be contaminated when the extract stream 15 reaches the intermediate transfer line during subsequent steps. In one example, the purified zoned fluid extracted from the adsorptive separation chamber comprises less than 0.5% of the non-preferentially adsorbed components. In another example, the purified partition material for the initial flush 405 includes less than 0.005% of the non-preferentially adsorbed components. As will be readily appreciated, in accordance with this aspect, by delivering the initial flush 405 and combining it with the feed stream 5, it can be compared to a system that delivers residual fluid from the first flush to another intermediate transfer line. Less need for a transfer line.

A flow and system for the adsorptive separation of components from a feed stream according to another aspect is illustrated in FIG. The flow according to this aspect may include an initial flush 505 similar to the initial flush described above with respect to FIG. However, in contrast to the initial rush 405 described above, the initial rush based on this aspect The 505 is directed to another transfer line of the purification zone 55 instead of being combined with the feed stream 5. More specifically, the process includes flushing residual fluid in the intermediate transfer line 510 between the feed zone 5 and the extract stream 15 transfer line to the adsorption separation chamber 100 or 105 for the first time. The flush 505 removes at least a portion of the residual fluid from the intermediate transfer line 510. The flow further includes directing residual fluid flushed from the intermediate transfer line 510 to another intermediate transfer line 515 of the purification section 55 to flush residual fluid in the other intermediate transfer line 515 to adjacent to the other intermediate via the initial flush 520 In the purification zone of transfer line 515.

According to one aspect, the other intermediate transfer line 515 includes residual feed fluid remaining in the intermediate transfer line 515 from the feed stream 5 that occupies the intermediate transfer line 515 during the previous step. Thus, when the flushing fluid is introduced into the intermediate transfer line 515 during the initial flush 520, the residual feed fluid is introduced into the purification zone 55 of the adsorptive separation chamber 100 or 105. However, because the feed stream has been moved downstream of the initial flushing transfer line 515, the residual feed is introduced into the intermediate position of the purification zone. Thus, in one method, to increase the amount of separation of components occurring in the residual feed material in the purification zone 55, the initial flushing transfer line 515 is positioned at the initial flushing transfer line 510 and is currently occupied by the feed stream 5. Between the transfer lines, residual feed fluid is introduced into the portion of the purification zone near the feed stream. In one example, the primary flushing transfer line 515 is positioned within the two transfer lines of the feed stream transfer line and, in another example, is positioned within one of the feed stream transfer lines to be added to the purification zone 55. The amount of separation of the components of the residual feed fluid that occurred.

The above description of the initial flush 405 (with respect to Figure 4) also applies to the initial flush 505 according to the aspect illustrated in Figure 5, except that the residual fluid in the intermediate transfer line is delivered to the initial flush 520. The transfer line 515 will initially not include the feed fluid at the beginning of the initial flush out of the initial flush 405 as described above. In this regard, the residual fluid in the intermediate transfer line 510 will instead include the previously flushed from the initial flush transfer line 510 to the first flush into the transfer line 515 during the previous step and thus will primarily include purification from the purification zone 55. The zoned fluid is as described above for the initial flush 405.

Turning now to Figure 6, a flow of adsorption separation for a component of a feed stream according to another aspect is shown. According to this aspect, the extract stream 15 is withdrawn from the adsorptive separation chamber 100 as previously described. The extract stream 15 can be passed to an extract separation device (e.g., extractive fractionation column 175) for separating the preferential adsorbed components from the extract stream 15. The extract stream 15 can be directed to the extract fractionator inlet 190 via an extract stream removal line 15'.

The flow according to this aspect includes flushing the intermediate transfer line 610 of the desorption section 60 between the extract stream 15 transfer line and the desorbent stream 10 transfer line via the secondary flush 605 away from the adsorptive separation chamber 100, thereby Transfer line 610 removes residual fluid. The process further includes directing residual fluid flushed from the intermediate transfer line 610 to a downstream separation device to separate components of the residual fluid. According to one aspect, since the intermediate transfer line 610 was previously occupied by the extract stream 15, the residual fluid in the intermediate transfer line 610 primarily includes the extract fluid at the beginning of the secondary flush 605. In this regard, the residual extract fluid can be directed to a downstream separation unit to prioritize the adsorption group. The fraction is separated from the extract fluid to increase the yield of the preferentially adsorbed component.

According to one aspect, the residual extract fluid flushed from the intermediate transfer line 610 is directed to the extract fractionator inlet 175 such that the preferential adsorbed component can be separated from the residual extract fluid via distillation to increase the yield of the extract product 195. .

By one aspect, the secondary flush 605 includes flushing residual fluid in the intermediate transfer line 610 from the desorption zoned flushing fluid drawn from the desorption section 60 of the adsorptive separation chamber 100 via a corresponding interface of the intermediate transfer line 610. In one example, the intermediate transfer line 610 is within the two transfer lines of the transfer line currently occupied by the desorbent stream 10, and in another example, one of the transfer lines currently occupied by the desorbent stream 10 Within the composition, the composition of the desorption zoned flushing fluid is similar to the desorbent stream 10. In this manner, the desorption zoned flushing fluid remains in the intermediate transfer line 610 after the secondary flush 605 has occurred. After the desorbent stream is displaced to the intermediate transfer line 610 in a subsequent step, the residual desorbed zoned fluid remaining in the intermediate transfer line 610 is introduced into the adsorptive separation chamber 100 by a desorbent stream, such that desorption The composition of the agent partitioning fluid is similar to the desorbent stream 10.

According to another aspect, a process for adsorptive separation of components of a feed stream is provided, the process comprising flushing both of the feed stream 5, the extract stream 15, the desorbent stream 10, and the raffinate stream 20 The intermediate transfer line is between removing residual fluid from the intermediate transfer line. Flow according to this aspect generally includes flushing the intermediate transfer line at a dynamic or non-constant volume flow rate during at least two different portions of the step time interval.

As described previously, in accordance with various aspects of the invention, countercurrent adsorption separation Including introducing a feed stream 5 comprising at least one preferential adsorption component and at least one non-preferred adsorption component and a desorbent stream 10 to two different interfaces via a plurality of different adsorption lines along a multi-bed adsorption separation chamber And extracting the extract stream 15 and the raffinate stream 20 through two different interfaces of the multi-bed adsorption separation chamber through two different corresponding transfer lines, the multi-bed adsorption separation chamber having a plurality of fluidly connected series The beds and a predetermined number of spaced interfaces and corresponding transfer lines in fluid communication with the interfaces for introducing fluid into and removing fluid from the adsorptive separation chamber. The various streams introduced into the adsorptive separation chambers 100 and 105 and extracted from the adsorptive separation chambers 100 and 105 are sequentially shifted or stepped downstream to the subsequent interface. The various flows are typically stepped to the subsequent interface 25, for example, by rotating the rotary valve 300, and maintained at a particular interface 25 or step for a predetermined step time interval. As discussed above, in one method, there are 4 and 100 interfaces 25, in another method there are 12 and 48 interfaces, and in yet another method there are 20 and 30 The interface between them, and there are an equal number of corresponding transfer lines. In one example, one or more of the adsorptive separation chambers 100 and 105 includes 24 interfaces, and each stream is shifted to each of the 24 interfaces 25 during a full cycle such that each stream occupies each during the cycle Interface 25 and corresponding transfer line. In this example, the cycle can be between 20 minutes and 40 minutes in one method and between 22 minutes and 35 minutes in another method. In one method, the step time interval is between 30 seconds and 2 minutes. In another method, the step time interval is between 45 seconds and 1 minute 30 seconds. In yet another method, the step time interval is between 50 seconds and 1 minute 15 seconds.

In this regard, the process includes non-uniformity or during the stepping interval The dynamic volume flow rate flushes the intermediate transfer line between the two lines currently occupied by both of the typical streams, including the feed stream 5, the desorbent stream 10, the extract stream 15, and the raffinate stream 20. According to one aspect, the process includes flushing the intermediate transfer line at a first flow rate within the first portion of the step time interval. The process includes flushing the intermediate transfer line at a second flow rate during a second portion of the step time interval of the first portion during the step time interval. In this manner, a larger volume of fluid is flushed from the intermediate transfer line during one of the first portion and the second portion of the step time interval than during the other portion. Flushing the transfer line at a non-constant flow rate can provide a compositional advantage in the composition of the fluid flushed into or from the intermediate transfer line and the timing of introducing the fluid into or from the intermediate transfer line.

In one aspect, the non-constant flow rate can include a ramp change that increases or decreases during at least a portion of the step time interval or a flow rate that increases or decreases exponentially. In this regard, the ramping flow rate may increase or decrease during portions of the step time interval and may vary linearly or non-linearly (eg, exponentially during the time period). By way of another aspect, the non-constant flow rate can include a step increase or decrease in flow rate such that one or both of the first flow rate and the second flow rate are constant and the first flow rate and the second flow One of the rates is different from the other. In yet another aspect, the non-constant flow rate can include a combination of a ramping portion of the volumetric flow rate and a step increase and decrease. The non-constant flow rate may also include an additional flow rate during an additional portion of the step time interval. The flow rate can be increased, decreased, or maintained during any particular step. In addition, flow The rate can be changed from an initial value to a higher value, a lower value, or zero at the end of the step. 10 through 12 illustrate examples of non-constant flow rates in accordance with various aspects of the present invention. Figure 10 illustrates the ramping flow rate 1015 that increases over time 1020 during at least a portion of the step time interval. In this example, the first flow rate 1005 is lower than the second flow rate 1010 such that a larger volume of fluid is flushed during the second portion of the step time interval than during the first portion. In another example, the ramping flow rate decreases over time such that the first flow rate is higher than the second flow rate such that a larger volume of fluid is flushed during the first portion of the step time interval than during the second portion . On the other hand, Figure 11 illustrates an example of a non-constant step flow rate. In this example, the flow rate 1115 is at a first substantially constant flow rate 1105 during the first portion of the step time interval 1120 and increases to a second and substantially constant during the second portion of the step time interval 1120. The higher flow rate is 1110. In another example, the step flow rate has a second substantially constant flow rate that is lower than the first flow rate during the second portion of the step time interval such that more is flushed during the first portion of the step time interval Volume of fluid. According to various aspects, the volumetric flow rate during one of the first portion and the second portion may be zero. In yet another example illustrated in FIG. 12, the flow rate 1215 at the first portion of the step time interval 1220 begins at a first flow rate 1205 and is then included over time during a second portion of the step time interval 1220. The second flow rate is reduced by an index of 1210. According to various aspects of the present invention, other flow rate distributions having different first flow rates and second flow rates during corresponding first and second portions of the step time interval are also contemplated, and there may be stepping The time interval has an additional portion of another flow rate.

According to one aspect, one of the first flow rate and the second flow rate is sufficient to flush between 50% and 400% of the volume of the flushed delivery line and associated valve assembly such that the step time interval is Most or all of the residual fluid in the transfer line is flushed during a portion or second portion. According to another aspect, one of the first flow rate and the second flow rate is sufficient to flush between 75% and 200% of the transfer line and associated valve assembly during the first portion or the second portion of the step time interval volume. In still another aspect, one of the first flow rate and the second flow rate is sufficient to flush between 90% and 150% of the transfer line and associated valve during the first portion or the second portion of the step time interval Component volume. According to various aspects, the other of the first flow rate and the second flow rate may be sufficient to flush between 0% and 75% of the transfer line and valve assembly volume in one method, and flush in 0 in another method. The transfer line and valve assembly volume between % and 50%, and in another method flushes the transfer line valve assembly volume between 0% and 25%.

According to one aspect, the first flow rate is higher than the second flow rate such that a larger volume of fluid is flushed during the first portion of the step time interval than during the second portion of the step time interval. The flow according to this aspect can be particularly beneficial when the process includes flushing residual fluid in the intermediate transfer line into the adsorptive separation chambers 100 and 105 such that the residual fluid has a flow rate before being subsequently extracted. The residence time in chambers 100 and 105 is large if the step time interval is constant or if the second flow rate is greater than the first flow rate.

According to another aspect, the second flow rate is higher than the first flow rate such that A larger volume of fluid is flushed during the second portion of the step time interval than during the first portion of the step time interval. The flow according to this aspect can be particularly useful in the case where the residual fluid is flushed away from the adsorptive separation chambers 100 and 105 by the flushing fluid drawn from the adsorptive separation chambers 100 and 105. In this regard, the rinsing fluid is provided for a residence time in the sorption separation chamber that is greater than when a constant flow rate is used or when the first flow rate is greater than the second flow rate. This situation advantageously provides for greater separation of the components in the flushing fluid such that the composition of the flushing fluid will be more similar than the subsequent streams withdrawn from or introduced into the adsorptive separation chambers 100 and 105.

Turning to more detail, the following examples generally include the process of introducing feed stream 5 and desorbent stream 10 into different interfaces 25 via different transfer lines of adsorption separation chambers 100 and 105. The extract stream 15 and the raffinate stream 20 are withdrawn via two other ports 25 via two different transfer lines of adsorptive separation chambers 100 and 105. According to an aspect, as illustrated, for example, in Figure 7, the initial flushing 720 includes flushing between the transfer line currently occupied by the feed stream 5 during the step and the transfer line occupied by the extract stream 15 during the step. Intermediate transfer line 715. The residual fluid in the transfer line 715 can primarily include residual feed fluid. The flow according to this aspect includes flushing the transfer line 715 at a first volumetric flow rate that is higher than the second volumetric flow rate during the second portion of the stepped time interval during the first portion of the step time interval. In this manner, a larger volume of residual feed fluid is flushed into the adsorptive separation chamber 100 or 105 during the initial first portion of the step time interval than during the subsequent second portion. In this regard, flushing into the adsorption separation chamber 100 or 105 The residual feed fluid is provided for a greater residence time in the adsorptive separation chambers 100 and 105, and the adsorbent in the chamber is taken for separation prior to extraction of the residual feed fluid via the extract stream 15 in a subsequent step. The components are preferentially adsorbed. According to another aspect, the process includes a first flush 710, and the initial flush 710 includes flushing the intermediate transfer line 705 with fluid drawn from the adsorptive separation chamber 100 or 105 away from the chamber, as previously described. In an example, the process includes flushing the delivery line 705 with a first volumetric flow rate of the second volumetric flow rate during a second subsequent portion of the step time interval during the first portion of the step time interval, the delivery line 705 A residual extract fluid from a transfer line 705 previously occupied by the extract stream can be included. In this manner, the irrigation fluid drawn from the desorption zone 60 can include a fluid similar to the composition of the desorbent stream 10. The process can include flushing residual extract fluid from intermediate transfer line 705 to intermediate transfer line 715 to flush residual feed fluid in intermediate extract stream 715 into purification zone 55. In one method, the process includes flushing the fluid at a first flow rate of the second flow rate during the second portion of the step time interval at a first portion of the step time interval such that during an earlier portion of the step time interval A larger volume of residual feed fluid is introduced into the purification zone 55 such that more separation of the feed fluid can be achieved in the purification zone 55 before the extract stream 15 subsequently reaches the intermediate transfer line 715 and is withdrawn via the intermediate transfer line 715, To increase the purity of the extraction stream.

Similarly, referring briefly to Figure 6 as previously described, the process may alternatively include a secondary flush 605 that includes flushing the intermediate transfer line 610 and directing residual fluid flushed from the intermediate transfer line 610 to a downstream portion. The off-gas separation device, in one example, includes an extract separation column 175 that separates the preferential adsorption component from the residual extract fluid in the intermediate transfer line 610. The flow according to this aspect can include flushing the intermediate transfer line 610 during a first portion of the step time interval at a first volumetric flow rate that is lower than a second volumetric flow rate during a second subsequent portion of the step time interval. In this manner, the irrigation fluid drawn from the desorption zone 60 can include a fluid similar to the composition of the desorbent stream 10.

According to another aspect, the intermediate transfer line 725 can be flushed by flushing fluid to introduce residual fluid in the intermediate transfer line into the purification zone 55. In accordance with this aspect, the process can include flushing the intermediate transfer line 725 at a first flow rate during a second portion of the subsequent second portion of the step time interval during the first portion of the step time interval such that at the step time A larger volume of residual fluid in the transfer line 725 is flushed into the purification zone 55 during the first portion of the interval than during the second portion. In this manner, residual fluid will be present in the purification zone for a longer residence time for the residual fluid to separate the components therein prior to extraction by the extract stream 15 as the extract stream 15 reaches the intermediate transfer line 725 in a subsequent step.

In another aspect, the intermediate transfer line 735 can be flushed by the flushing fluid away from the adsorptive separation chamber 100 or 105 to remove residual fluid from the intermediate transfer line 735. In one method, the intermediate transfer line includes residual raffinate from the raffinate stream 20 that occupies the intermediate transfer line 735 during the previous step of the cycle. In accordance with this aspect, the process includes flushing the intermediate transfer line with the flushing fluid drawn from the adsorption section 50 at a first flow rate of the second portion below the step time interval during the first portion of the step time interval 735. In this manner, the flushing fluid will be present in the adsorptive separation chamber 100 or 105 for a greater amount of time before being drawn through the intermediate transfer line for flushing the residual feed fluid from the intermediate transfer line. Thus, the flushing fluid from the adsorption zone 50 will have a composition similar to the feed stream and will include fewer non-preferentially adsorbed components of the raffinate stream. After flushing the intermediate transfer line, the flushing fluid will remain therein as a residual fluid that will be introduced with the feed stream 5 as it is introduced via the intermediate transfer line 735 during the subsequent step to reduce excess The preferential adsorption component is contaminated by the feed stream.

Referring to Figures 1, 4 and 5, the intermediate transfer line 45, 415 or 510 can be flushed away from the adsorptive separation chamber 100 or 105, thereby moving from the intermediate transfer line, according to various aspects as previously described. In addition to residual fluid. The intermediate transfer line 45, 415 or 510 can be flushed by drawing the flushing fluid from the purification section 55 into the intermediate transfer line to displace the residual fluid away from the adsorptive separation chamber 100 or 105, and then by the purification zone A residual flushing fluid of 55 is used to fill. According to one aspect, the process includes flushing the intermediate transfer line 45 at a first flow rate during a first portion of the step time interval and at a second flow rate greater than the first flow rate during a subsequent second portion of the step time interval, 415 or 510. In this manner, the rinsing fluid is provided with additional time in the purification zone 55 and the adsorbent therein is taken for separation of the non-preferentially adsorbed components such that the purified zoned fluid is withdrawn for rinsing the intermediate transfer line 45, 415 or At 510 hours, the composition of the flushing fluid will be similar to the extract stream 15 that will be withdrawn through the intermediate transfer lines during subsequent steps. According to the flow of this aspect, the remaining intermediate pipe is advantageously reduced The amount of non-preferentially adsorbed components in the residual fluid in line 45, 405 or 510, thereby increasing the purity of the extract stream 15, which will otherwise be contaminated during extraction of the extract stream 15 via the intermediate transfer lines. Logistics 15. In one method, as previously described, the intermediate transfer line 415 is in communication with the feed stream transfer line such that the residual fluid flushed from the intermediate transfer line is combined with the feed stream 5. In another method, as described above, the intermediate transfer line 510 is in communication with another intermediate transfer line 515 such that residual fluid in the intermediate transfer line 510 is flushed to another intermediate transfer line 515 to pass another intermediate transfer line 515 The residual feed fluid is flushed into the downstream portion of the purification zone 55.

According to various aspects, a valve assembly and controller can be used to control the volumetric flow rate of fluid passing through the transfer line during dynamic flushing of the transfer line. The valve assembly can be incorporated into the transfer line itself to control or limit the volumetric flow rate of the fluid flowing through the transfer line. A controller can be provided for controlling the flow rate of the valve and the fluid passing through the transfer line. The valve assembly can also be incorporated into other locations within the system, such as on the downstream side of the rotary valve 300 when incorporated into a rotary valve, or downstream of a downstream assembly for delivering fluid to the system (eg, Used to separately deliver fluid to lines 15' and 20') of extract fractionation column 175 or raffinate fractionation column 150.

When selecting an adsorbent for the simulated moving bed process of the present invention, the only limitation is the effectiveness of the particular adsorbent/desorbent combination in the desired separation. An important characteristic of the adsorbent is the rate at which the desorbent is exchanged for the extract component of the feed mixture material or, in other words, the relative rate at which the extract component is desorbed. This property is directly related to the amount of desorbent material that must be used in the desorbent material. The extract component is recovered from the adsorbent in the process. The faster exchange rate reduces the amount of desorbent material required to remove the extract component and, therefore, permits a reduction in the operating cost of the process. At faster exchange rates, less desorbent material must be pumped through the process and separated from the extract stream for reuse in the process.

The practice of the present invention is thus not related to the use of any particular adsorbent or combination of adsorbent/desorbent or to any particular adsorbent or combination of adsorbent/desorbent, as is the use of different screen/desorbent combinations. Separated in different ways. The adsorbent may or may not be a zeolite. Examples of the adsorbent which can be used in the process of the present invention include non-zeolitic molecular sieves comprising carbon-based molecular sieves, enamel rocks, and crystalline aluminosilicate molecular sieves classified into X zeolites and Y zeolites. Details regarding the synthesis of the composition and a plurality of such microporous molecular sieves are provided in U.S. Patent 4,793,984, the disclosure of which is incorporated herein. Information on the sorbent is also available from US 4,385,994, US 4,605, 492, US 4,310, 440, and US 4,440,871.

In a process of continuous operation at a substantially constant pressure and temperature to ensure a liquid phase adsorption separation process, the desorbent material must be selected to meet several criteria. First, the desorbent material should displace the extract component from the adsorbent at a reasonable mass flow rate without itself being strongly adsorbed, thereby unduly preventing the extract from being subsequently adsorbed. The component displaces the desorbent material. In terms of selectivity, the adsorbent for all of the extract components relative to the raffinate component is preferably more selective than the desorbent material used relative to the raffinate component. Second, the desorbent material must be compatible with the particular adsorbent and the particular feed mixture. More specifically, the desorbent material is not The capacity or selectivity of the adsorbent for the extract component relative to the raffinate component can be reduced or destroyed. In addition, the desorbent material should not chemically react with or cause any of the chemical components of either the extract component or the raffinate component. Both the extract stream and the raffinate stream are typically removed from the void volume of the adsorbent mixed with the desorbent material and involve any chemistry of the desorbent material and the extract component or raffinate component or both. The reaction will complicate product recovery or prevent product recovery. The desorbent should also be readily separated from the extract and raffinate components, such as by fractional distillation. Finally, the desorbent material should be easy to use and cost effective. The desorbent may include a heavy or light desorbent depending on the particular application. The terms heavy and light are in terms of the boiling point of the desorbent relative to the C8 aromatics (i.e., ortho-xylene, meta-xylene, p-xylene, and ethylbenzene). Those skilled in the art will appreciate that the designation "C8" refers to a compound containing eight (8) carbon atoms. In certain embodiments, the de- chelating agent is selected from the group consisting of p-diethylbenzene, p-diisopropylbenzene, tetralin, and the like, and combinations thereof. In certain embodiments, toluene and the like can be used as a light desorbent. p-Diethylbenzene (p-DEB) has a higher boiling point than the C8 aromatic isomer, and thus p-DEB is the bottom (ie, heavy) product when separated from the C8 isomer in a fractionation column. Similarly, toluene has a lower boiling point than the C8 aromatic isomer, and thus toluene is the overhead (i.e., light) product when separated from the C8 isomer in a fractionation column. p-DEB has become the commercial standard for use as a desorbent in the separation of para-xylene.

The adsorption conditions generally include a temperature range from 20 ° C to 250 ° C, with from 60 ° C to 200 ° C being preferred for para-xylene separation. The adsorption conditions also include a pressure sufficient to maintain the liquid phase, which may range from atmospheric pressure to 2 MPa. Desorption conditions generally include the same range of temperatures and pressures as used for the adsorption conditions. Different conditions are preferred for other extract compounds.

The above description and examples are intended to illustrate the invention and not to limit the scope thereof. While the invention has been described and described with respect to the specific embodiments of the present invention, it will be understood that Such changes and modifications.

5‧‧‧feed inlet flow

10‧‧‧Desorbent/desorbent inlet flow

10'‧‧‧Fluid recirculation line

15‧‧‧Extract stream of extract

15'‧‧‧Extraction transfer line / extraction stream removal line

20‧‧‧Extracted matter export stream

20'‧‧‧Extraction pipeline

25‧‧‧Liquid feed and product access points or interfaces

30‧‧‧First entry

35‧‧‧First rushing out

40‧‧‧Second flushing

40'‧‧‧ pipeline

45‧‧‧Intermediate transfer pipeline

45'‧‧‧Transport line interface

46‧‧‧ Third flush

50‧‧‧Adsorption zone

55‧‧‧purified partition

60‧‧‧Decoupled partition

65‧‧‧Buffered partition

100‧‧‧Adsorption separation chamber/container

105‧‧‧Adsorption separation chamber/container

110‧‧‧ pump

115‧‧‧ pump

150‧‧‧Extracted fractionation tower

155‧‧‧The bottom part of the raffinate fractionation tower

160‧‧‧Extracted bottom pump

165‧‧‧Extraction fractionation tower inlet

170‧‧‧ raffinate products

175‧‧‧Extraction Fractionator

180‧‧‧ extract fractionation bottom part

185‧‧ ‧ extract bottom pump

190‧‧ ‧ extract fractionation tower inlet

195‧‧‧Extracted products

205‧‧‧Extraction tower inlet pipeline

210‧‧‧Extracted bottom part of the pipeline

215‧‧‧ valve

300‧‧‧Rotary valve/turntable valve

305‧‧‧Extraction tower inlet pipeline

310‧‧‧The bottom part of the raffinate

315‧‧‧ valve

405‧‧‧First rush/primary rush/feed stream/intermediate transfer line

410‧‧‧ pump

415‧‧‧Intermediate transfer line

450‧‧‧Extract fluid

454‧‧‧Residual fluid

470‧‧‧cross pipeline

472‧‧‧Seal sheet

474‧‧‧floor

476‧‧‧ interface

478‧‧‧ Track

480‧‧‧Rotor

505‧‧‧ first rushed out

510‧‧‧Intermediate transfer pipeline

515‧‧‧Intermediate transfer pipeline

520‧‧‧First rush

605‧‧‧Secondary flushing

610‧‧‧Intermediate transfer pipeline

705‧‧‧Intermediate transfer line

710‧‧‧First rushing out

715‧‧‧Intermediate transfer line / intermediate extraction stream

720‧‧‧First rush

725‧‧‧Intermediate transfer line

735‧‧‧Intermediate transfer pipeline

902‧‧‧Adsorption separation chamber

920‧‧‧ flow

1005‧‧‧First flow rate

1010‧‧‧Second flow rate

1015‧‧‧Slope change flow rate

1020‧‧‧Time

1105‧‧‧First substantially constant flow rate

1110‧‧‧Second and substantially constant higher flow rate

1115‧‧‧ flow rate

1120‧‧‧step time interval

1205‧‧‧First flow rate

1210‧‧‧Second flow rate

1215‧‧‧ Flow rate

1220‧‧‧step time interval

1 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; FIG. 2 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; A simplified diagram of a simulated moving bed adsorption process; FIG. 4 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; and FIG. 5 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; 6 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; FIG. 7 is a simplified diagram of a simulated moving bed adsorption process in accordance with various embodiments of the present invention; Simulating a moving bed adsorption composition diagram of a fluid in a separation chamber; Figure 9 is a perspective view of a rotary valve in accordance with various embodiments of the present invention; Figures 10 through 12 are graphs illustrating volumetric flow rates of fluid through a transfer line in accordance with various embodiments of the present invention; and Figure 13 is a prior art A simplified diagram of the simulated moving bed adsorption process.

5‧‧‧feed inlet flow

10‧‧‧Desorbent/desorbent inlet flow

10'‧‧‧Fluid recirculation line

15‧‧‧Extract stream of extract

15'‧‧‧Extraction transfer line / extraction stream removal line

20‧‧‧Extracted matter export stream

20'‧‧‧Extraction pipeline

25‧‧‧Liquid feed and product access points or interfaces

30‧‧‧First entry

35‧‧‧First rushing out

40‧‧‧Second flushing

40'‧‧‧ pipeline

45‧‧‧Intermediate transfer pipeline

45'‧‧‧Transport line interface

46‧‧‧ Third flush

50‧‧‧Adsorption zone

55‧‧‧purified partition

60‧‧‧Decoupled partition

65‧‧‧Buffered partition

100‧‧‧Adsorption separation chamber/container

105‧‧‧Adsorption separation chamber/container

110‧‧‧ pump

115‧‧‧ pump

150‧‧‧Extracted fractionation tower

155‧‧‧The bottom part of the raffinate fractionation tower

160‧‧‧Extracted bottom pump

165‧‧‧Extraction fractionation tower inlet

170‧‧‧ raffinate products

175‧‧‧Extraction Fractionator

180‧‧‧ extract fractionation bottom part

185‧‧ ‧ extract bottom pump

190‧‧ ‧ extract fractionation tower inlet

195‧‧‧Extracted products

300‧‧‧Rotary valve/turntable valve

Claims (10)

A process for separating components of a feed stream by simulated countercurrent adsorption separation comprising: comprising at least one preferentially adsorbed component along a multi-bed adsorption separation chamber via two different corresponding transfer lines And one of the at least one non-preferred adsorption component feed stream and one desorbent stream are introduced into two different interfaces and extracted through two different corresponding transfer lines via two different interfaces of the multi-bed adsorption separation chamber An extract stream and a raffinate stream, the multi-bed adsorptive separation chamber having a plurality of beds connected in series in fluid communication and comprising a predetermined number of spaced interfaces and in fluid communication with the interfaces for introducing a fluid to the adsorptive separation a corresponding transfer line for removing fluid from the chamber and from the adsorptive separation chamber; extracting one of the extract stream and the raffinate stream away from the adsorptive separation chamber via a transfer line containing one of the residual streams; An initial portion of the extract stream and the one of the raffinate streams comprising at least a portion of the residual fluid drawn through the one transfer line leading to a first destination; Extracting a subsequent portion of the guide through the one of the transfer line of the extract stream and the raffinate stream of a second one of the destinations. The process of claim 1 wherein the first destination is a recycle line for recycling the one of the extract stream and the raffinate stream and the portion of the residual fluid to the adsorptive separation chamber. The process of claim 1, wherein the one of the extract stream and the raffinate stream is the extract stream, and the second destination is an extract fractionation The inlet of the column and the first destination is a destination different from the inlet of one of the extract fractionation columns to limit at least that portion of the residual fluid from entering the extract fractionation column and contaminating an extract product. The process of claim 3, further comprising, prior to extracting the extract stream via the transfer line, by including a preferential adsorption component having a concentration higher than the concentration in the feed stream and a concentration lower than the feed A flushing fluid flush of the non-preferentially adsorbed component of the concentration in the stream is positioned between the feed stream transfer line and a previous extract stream transfer line to displace residual feed from the transfer line, The residual fluid in the one of the transfer lines primarily contains the flushing fluid when the extract stream is subsequently withdrawn via the one transfer line. The process of claim 4, wherein the flushing stream system is extracted from a transfer line previously occupied by the extract stream and adjacent to a desorption zone, the desorption zone being defined as the desorption zone of the adsorption separation chamber A flow of agent is introduced into the zone between the interface in the adsorptive separation chamber and the interface from the adsorptive separation chamber to extract the extract stream. The process of claim 3, wherein the extract stream comprising at least a portion of the residual fluid is transported via the transfer line to at least one of an extract fractionator and a raffinate fractionator as the first destination a bottom portion for recycling back to the adsorptive separation chamber such that the residual fluid is not introduced into at least one of an extract fractionation column inlet and a raffinate fractionator inlet to contaminate The product produced by the tower. The process of claim 1, wherein the one of the extract stream and the raffinate stream is the raffinate stream, and the second destination is a raffinate fractionation The inlet of the column and the first destination is a destination different from the inlet of one of the extract fractionation columns to limit at least that portion of the residual fluid to the raffinate fractionation column to reduce energy consumption. The process of claim 7, wherein the one transfer line was previously occupied by the desorbent stream such that the residual fluid in the one transfer line primarily comprises a desorbent. The process of claim 7, wherein the raffinate stream including at least a portion of the residual fluid extracted via the one transfer line is transported to a raffinate fractionation column and an extract fractionator as the first destination. a bottom portion of one of the bottom portions for recycling back to the adsorptive separation chamber such that the portion of the residual fluid is not introduced into the raffinate fractionator inlet and the extract fractionator inlet In order to reduce energy consumption. The process of claim 1 further comprising monitoring the composition of the extract stream comprising the residual stream from the one of the transfer lines and the one of the raffinate streams, and in the extract stream and the raffinate stream One of the extract stream and the raffinate stream is directed to the first destination when a residual fluid component included in the one is greater than a predetermined amount, and the residual fluid included in the fluid The fluid is directed to the second destination when the component is less than the predetermined amount.