Ionic liquid reactor with heat exchanger
09669377 ยท 2017-06-06
Assignee
Inventors
- Zhanping Xu (Iverness, IL, US)
- James Hagen (Arlington Heights, IL, US)
- Sanford A. Victor (Buffalo Grove, IL, US)
- Phillip F. Daly (Palatine, IL, US)
- Kurt Detrick (Glen Ellyn, IL, US)
Cpc classification
F28D7/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F9/0136
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01J2219/00103
PERFORMING OPERATIONS; TRANSPORTING
F28D7/1646
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01J2219/00085
PERFORMING OPERATIONS; TRANSPORTING
F28F2009/226
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D7/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D7/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
B01J19/00
PERFORMING OPERATIONS; TRANSPORTING
F28D7/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F9/013
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D7/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D7/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D7/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01J19/24
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An ionic liquid reactor unit and a process for controlling heat generation from an ionic liquid reactor unit. The ionic liquid reactor unit may include an external heat exchanger. The effluent from the reactor is separated in a separation zone allowing the hydrocarbon phase to transfer heat to a cooling fluid. The heat exchanger may be a tube-in-shell, a spiral plate heat exchanger, a hair pin heat exchanger. The heat exchanger accommodates the separation of the ionic liquid from the hydrocarbon phase, and may allow for the ion liquid to be drained.
Claims
1. An ionic liquid catalyst reactor unit comprising: a first reaction zone having an inlet for ionic liquid, an inlet for a hydrocarbon stream, and an outlet for an effluent stream; a separation zone configured to receive the effluent stream and separate the effluent stream into a hydrocarbon phase and an ionic liquid phase; and, a first heat exchange zone configured to receive at least a portion of the effluent stream from the first reaction zone and comprising: an outlet for a cooled effluent stream, and an outlet for ionic liquid wherein the first heat exchange zone comprises a heat exchanger with a shell and wherein the separation zone is disposed within the shell.
2. The ionic liquid catalyst reactor unit of claim 1 wherein the shell includes an inlet for the effluent stream disposed below the outlet for the cooled effluent stream.
3. The ionic liquid catalyst reactor unit of claim 1, wherein the first heat exchange zone comprises a heat exchanger comprising a shell and at least one baffle in the shell.
4. The ionic liquid catalyst reactor unit of claim 3 wherein the at least one baffle comprises a baffle selected from the group consisting of: a helical baffle; a rod baffle; a grid baffle; an expanded metal baffle; and, a segmental baffle.
5. The ionic liquid catalyst reactor unit of claim 3 wherein the heat exchanger is configured to receive the effluent stream in a direction countercurrent to a direction of cooling fluid through the heat exchanger.
6. The ionic liquid catalyst reactor unit of claim 1, wherein the first heat exchange zone comprises a spiral plate heat exchanger having a first flow path configured to receive the effluent stream and a second flow path configured to receive a cooling fluid.
7. The ionic liquid catalyst reactor unit of claim 6, wherein the spiral plate heat exchanger comprises a collection pan and at least one flow path includes one or more openings to allow ionic liquid to drain from the at least one flow path to the collection pan.
8. The ionic liquid catalyst reactor unit of claim 1 wherein the first heat exchange zone comprises at least one hair pin heat exchanger.
9. The ionic liquid catalyst reactor unit of claim 8 wherein the at least one hair pin heat exchanger includes a boot configured to allow ionic liquid to be drained from the at least one hair pin heat exchanger.
10. The ionic liquid catalyst reactor unit of claim 1 wherein first heat exchange zone comprises at least one tube-in-shell heat exchanger having a horizontal orientation and comprising tubes inside of a shell with an inlet for an effluent stream on a top of the shell, and an outlet for a cooled effluent stream on a bottom of the shell.
11. The ionic liquid catalyst reactor unit of claim 10 wherein the shell further comprises a boot configured to allow ionic liquid to be drained from the at least one tube-in-shell heat exchanger.
12. The ionic liquid catalyst reactor unit of claim 10 wherein the at least one tube-in-shell heat exchanger further comprises at least one grid baffle disposed within the shell.
13. The ionic liquid catalyst reactor unit of claim 1 further comprising: a second reaction zone having an inlet for ionic liquid, an inlet for a hydrocarbon stream, and an outlet for an effluent stream; a second heat exchange zone configured to receive at least a portion of the effluent stream from the second reaction zone and comprising an outlet for a cooled effluent stream and an outlet for ionic liquid, and wherein the first heat exchange zone is disposed between the first reaction zone and the second reaction.
14. The ionic liquid catalyst reactor unit of claim 1 further comprising: a plurality of reaction zone each having an inlet for ionic liquid, an inlet for a hydrocarbon stream, and an outlet for an effluent stream, the reaction zones arranged in series; and, a plurality of heat exchange zones, at least one heat exchange zone being disposed between successive reaction zones.
15. A process for controlling the temperature of a reaction performed in the presence of an ionic liquid catalyst, the process comprising: performing a reaction in the presence of an ionic liquid catalyst to form an effluent, wherein the reaction is performed in a reaction zone; removing heat from at least a portion of the effluent from the reaction zone in a heat exchange zone with a cooling fluid to provide a cooled effluent; separating the effluent in a separation zone into a hydrocarbon phase and an ionic liquid phase and; separating ionic liquid from the effluent from the reaction zone within the heat exchange zone.
16. The process of claim 15 further comprising: passing the ionic liquid separated from the effluent in the heat exchange zone to a second reaction zone.
17. The process of claim 16 further comprising: performing a reaction in the presence of an ionic liquid catalyst to form a second effluent, wherein the reaction is performed in the second reaction zone; and, passing the second effluent from the second reaction zone to a second heat exchange zone.
18. The process of claim 15 further comprising: separating ionic liquid from the second effluent in the second heat exchange zone; and, removing heat from the second effluent from the second reaction zone in the second heat exchange zone with a cooling fluid to provide a second cooled effluent.
Description
DETAILED DESCRIPTION OF THE DRAWINGS
(1) In the drawings of the present invention, one or more embodiments are shown in which like numerals denote like elements, and in which:
(2)
(3)
(4)
(5)
(6)
(7)
DETAILED DESCRIPTION OF THE INVENTION
(8) As mentioned above, an ionic liquid catalyst reactor and a process for controlling the heat of an ionic liquid catalyst reaction have been invented which utilize an external heat exchanger. The heat exchanger is designed to allow reactants and ionic liquid acid catalyst to be in liquid phase. A heat exchange fluid will absorb heat from the reactor effluent mixture. By controlling the temperature with the heat exchanger and, more importantly without vaporization of the reactants, products, or ionic liquid, it will be easier to control the reactor operation, ionic liquid dispersion and acid concentration.
(9) With these general principles of the present invention in mind, one or more exemplary embodiments of the present invention will now be described with the understanding that the following is exemplary in nature and is not intended to be limiting.
(10) As shown in
(11) In a preferred embodiment, a plurality of reaction zones 11a, 11b, 11c, 11d, 11e are provided. For example, each of the reaction zones 11a, 11b, 11c, 11d, 11e may comprise a reactor vessel 12a, 12b, 12c, 12d, 12e, with the reactor vessels 12a, 12b, 12c, 12d, 12e being arranged in series. It should be appreciated that although not depicted as such, a single reactor vessel could be used with multiple separate reaction zones 11a, 11b, 11c, 11d, 11e contained within the single vessel. The at least one heat exchanger 14a is disposed between the reaction zone 11a and the at least one separation vessel 16a. Preferably, one heat exchanger 14a, 14b, 14c, 14d from a plurality of heat exchangers 14a, 14b, 14c, 14d is disposed between successive reaction zones 11a, 11b, 11c, 11d, 11e, as shown in
(12) In a preferred embodiment, the reactor unit 10 is utilized for an alkylation reaction, and therefore the present invention will be described in relation to an alkylation reaction, with the understanding that the present invention is not necessarily limited to same and can be practiced in association with different exothermic reactions.
(13) As shown in
(14) An ionic liquid catalyst stream 22 is also passed into the first reactor vessel 12a. As shown, the ionic liquid catalyst stream 22 is mixed with the iC.sub.4 hydrocarbon stream 18 prior to being passed to the first reactor vessel 12a. This is merely preferred.
(15) In the first reactor vessel 12a, which is operated under proper conditions, such as at a temperature of between 4.4 to 37.8 C. (40 to 100 F.) under a pressure that keeps all reactants and catalysts in liquid phase, the olefinic hydrocarbons will react with the iC.sub.4 hydrocarbons to form alkylated hydrocarbons, primarily iso-octane and other trimethylpentanes. In order to mix the ionic liquid catalyst and the hydrocarbons, the first reactor vessel 12a includes an impeller 24a. The impeller 24a may also disperse the ionic liquid catalyst. The products of the reaction, as well as excess reactants (mainly iC.sub.4 hydrocarbons) and the ionic liquid catalyst are passed out of the first reactor vessel 12a in an effluent stream 26a.
(16) The effluent stream 26a from the first reactor vessel 12a is passed to the first heat exchanger 14a. As shown in
(17) The effluent stream 26a from the first reactor vessel 12a is preferably passed into the heat exchanger 14a into a lower or bottom portion that comprises a separation zone 32a. The separation zone 32a allows the heavier ionic liquid catalyst phase to separate from the effluent and accumulate on the bottom (due to the larger specific gravity compared to the hydrocarbons). The remaining components of the effluent will flow upwards in the shell 28a and contact the U-shaped tubes 30a with cooling fluid flowing through the tube side.
(18) As will be appreciated, the cooling fluid in the U-shaped tubes 30a will absorb heat from the effluent in a heat exchange zone 31a of the heat exchanger 14a. In this embodiment, the separation zone 32a and the heat exchange zone 31a are contained within the shell 28a, or housing, of the heat exchanger 14a. It is also contemplated, but not shown that the separation zone 32a is within a separate vessel so as to allow for separation of the ionic liquid phase and the hydrocarbon phase prior to the effluent (or at least a portion thereof) passing into the heat exchange zone 31a.
(19) Returning to
(20) A portion of a cooled effluent stream 36a may be passed from the heat exchanger 14a to the separator vessel 16a. A second portion of the cooled effluent stream 36a may be passed to the second reactor vessel 12b. Additionally, an ionic liquid catalyst stream 38a from bottom of the heat exchanger 14a may also be passed to the second reactor vessel 12b, passed to the first separation vessel 16a, or a combination thereof.
(21) The second reactor vessel 12b will receive iC.sub.4 hydrocarbons (and other hydrocarbons) from the cooled effluent stream 36a, a second olefin hydrocarbon stream 20b comprising C.sub.4 olefinic hydrocarbons, and a second ionic liquid stream, in this case, from the ionic liquid catalyst stream 38a from bottom of the heat exchanger 14a. The second reactor vessel 12b may also receive an ionic liquid stream that comprises ionic liquid that may have separated in the first reactor 12a. The second reactor vessel 12b preferably operates in the same manner and under similar conditions as the first reactor vessel 12a and, thus will likewise produce an effluent stream 26b containing more alkylate components than effluent stream 26a.
(22) The effluent stream 26b from the second reactor vessel 12b will be passed to the second heat exchanger 14b, which will function similarly to the first heat exchanger 14a. A cooled effluent stream 36b from the second heat exchanger 14b may be passed to a third reactor vessel 12c, and so on and so forth. As shown in
(23) In the first separation vessel 16a, a mixture comprised of the effluent streams from the reaction zones 11a, 11b, 11c, 11d, 11e and ionic liquid catalyst streams will separate into a lighter hydrocarbon phase 40 and a heavier, ionic liquid catalyst phase 42. Preferably, in the first separation vessel 16a, at least 50%, and more preferably at least 90% of the ionic liquid catalyst will be separated from the hydrocarbons due to the different densities of the phases. The ionic liquid catalyst phase 42 can be withdrawn in an ionic liquid catalyst stream 44, which can be reused in the process, which can be regenerated, which can be disposed of, or a combination thereof. The hydrocarbon phase 40 can be withdrawn in a hydrocarbon effluent stream 46 which may be passed to a second separation vessel 16b.
(24) In the second separation vessel 16b, entrained droplets of ionic liquid catalyst within the hydrocarbon phase 40 from the first separation vessel 16a may be further separated, for example with a coalescer material 48, such as glass beads, fibers or electrostatic separation devices. A second ionic liquid catalyst stream 50 (the numeral 52 near bottom of
(25) In another heat exchanger 100, shown in
(26) In the embodiment shown, the heat exchanger 100 comprises a shell 102 with an inlet 106 proximate a first end 108 of the shell 102 and an outlet 110 proximate a second end 112 of the shell 102. A plurality of U-shaped tubes 114 extend from one end of the shell 102, preferably the first end 108, towards the second end 112 of the shell 102. The U-shaped tubes 114 will receive cooling fluid, which can pass from a cooling fluid inlet 116 to an inlet manifold 118 which will distribute the cooling fluid to the tubes 114. The heated cooling fluid may flow to an outlet manifold 120 and then be withdrawn through an outlet 122 and used elsewhere if desired. The hydrocarbons and ionic liquid will pass from the inlet 106 of the shell 102 to the outlet 110 of the shell 102, with the flow path between the inlet 106 and the outlet 110 being partially counter-current to the flow of cooling fluid through the tubes 114. Straight tubes extending from the first end 108 of the shell 102 to the second end 112 can also be used in the heat exchanger 100. The heat exchanger may include one or more baffles 123.
(27) For example, a plurality baffles 123 may be disposed within the shell 102 between the inlet 106 and the outlet 110. As shown in
(28) Returning to
(29) Turning to
(30) In any orientation, the flow paths 306, 308 are preferably countercurrent in order to maximize the temperature difference between the two streams and increase the heat exchange, and thus the cooling, of the effluent stream. It is preferred that the inlet 318 for the second flow path 306 and the outlet 314 for the first flow path 308 are disposed 90 degrees apart along the side surface 316 of the heat exchanger 300.
(31) As can be seen in
(32) More specifically, the ionic liquid will be separated from the hydrocarbons along one of the flow paths 306, 308 containing ionic liquid and hydrocarbons inside the heat exchanger 300 as a result of the density difference between ionic liquid and the hydrocarbon. Additionally, centrifugal flow through the flow paths 306, 308 will accelerate the ionic liquid separation. In this case a separation zone and a heat exchange zone will both be contained within the housing 302 of the heat exchanger 300.
(33) The settled ionic liquid at the bottom of one of flow paths 306, 308 can be drained into the collection pan 322 via one or more openings 324. In order to minimize the amount of the hydrocarbon phase that may pass through the openings, it is preferred that the openings are sized and disposed such that less than 10% of the total hydrocarbons, and preferably less than 5% of the total hydrocarbons, passes there through. The ionic liquid is preferably drained through a bottom boot 326 as, for example the ionic liquid catalyst stream 38a as shown in
(34) The ionic liquid withdrawal rate from the separation zones and/or the ionic liquid level in the separation zones such as the bottom of heat exchangers in
(35) Since some of the more viscous and heavier ionic liquid and conjunct polymer is separated from the reactor effluent before or within the heat exchangers, the heat transfer is improved and pressure drop reduced along the flow path due to less ionic liquid and conjunct polymer being present in the heat exchange zone and contacting the heat exchange surface (i.e., the spiral plate 304).
(36) It is contemplated alternatively that the heat exchanger 300 with the spiral plate 304 is rotated 90 degrees (about the horizon) so that the flow of fluids is in a vertical direction (as opposed to a horizontal direction). In this case, the ionic liquid will not be separated from hydrocarbon in the spiral plate heat exchanger 300 and instead can be passed along to a sequential reactor or to a separation vessel or other equipment.
(37) Another possible heat exchange configuration that may be utilized in accordance with the present invention is shown in
(38) With reference to the first hairpin heat exchange 400a, the hairpin heat exchange 400a includes a shell 402a with an inlet 406a and an outlet 410a. Extending within the shell 402a is at least one tube 414a also having an inlet 416a and an outlet 422a. As will be appreciated, the hairpin heat exchange 400a is designed so that the flow on the tube side is countercurrent to the flow on the shell side. Thus, the inlet 406a for the shell 402a and the outlet 422a for the tube 414a are disposed proximate the same end of the hairpin heat exchange 400a. If the flow on the tube side and the flow on the shell side was co-current, the inlet 422a for the shell 402a and the inlet 416a on the tube 414a would be disposed proximate each other on the same end of the hairpin heat exchange 400a. The remaining disclosure will utilize a preferred countercurrent flow, as it maximize the temperature differences between the hot and the cold fluids, with the understanding that a co-current flow could be utilized. Furthermore, in a preferred embodiment, reactor effluent (for example the reactor effluent 26a,
(39) In use, the reactor effluent may pass through the inlet 406a of the shell 402a and flow towards the outlet 410a of the shell 402a. Ionic liquid may separate from the reactor effluent and can accumulate in one or more boots 424a disposed on the shell 402a. Any ionic liquid that separates out may be withdrawn from the heat exchanger 400a via an outlet 426a. Multiple boots 424a or one boot 424a connecting multiple draining nozzles along the bottom of the heat exchanger 400a can also be used. As shown preferably only the upper longitudinal portion of the heat exchanger 400a includes boots 424a for removing ionic liquid. The exact location and number of boots 424a, including none, can vary. Cooling fluid may pass through the inlet 416a of the tube 414a and flow towards the outlet 422a. As it passes through the tube 414a, it will absorb heat from the reactor effluent.
(40) While only one heat exchanger 400a may be used, as shown in
(41) It is preferred to remove ionic liquid at locations close to the effluent inlet in the first heat exchanger so that the impact of ionic liquid and the associated conjunct polymer on the heat transfer downstream can be minimized. Additional withdrawal of ionic liquid along the flow path of the reactor effluent is optional.
(42) With any of the various heat exchangers disclosed herein, it is believed that the fouling of the heat exchanger by the ionic liquid and conjunct polymer will be minimized through the separation of ionic liquid from reactor effluent, allowing the heat exchanger to remain effective for controlling the temperature of the reactor effluent.
(43) It should be appreciated and understood by those of ordinary skill in the art that various other components such as valves, pumps, filters, coolers, etc. were not shown in the drawings as it is believed that the specifics of same are well within the knowledge of those of ordinary skill in the art and a description of same is not necessary for practicing or understanding the embodiments of the present invention.
(44) While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.