阅读说明：本技术 由正丁烷脱氢使1-丁烯生产最大化的方法 (Method for maximizing 1-butene production by n-butane dehydrogenation ) 是由 谢赫扎达·胡拉姆 穆罕默德·H·海德 哈马德·M·穆迪 于 2019-08-27 设计创作，主要内容包括：公开了用于生产1-丁烯的系统和方法。该方法包括使丁烷脱氢以形成包含丁烯异构体的混合物。使用包括萃取蒸馏装置和膜的系统从混合物中分离1-丁烯。该系统还包括用于异构化顺-2-丁烯和反-2-丁烯以形成另外的1-丁烯的异构化装置。(Systems and methods for producing 1-butene are disclosed. The process includes dehydrogenating butane to form a mixture comprising butene isomers. 1-butene is separated from the mixture using a system comprising an extractive distillation apparatus and a membrane. The system also includes an isomerization unit for isomerizing cis-2-butene and trans-2-butene to form additional 1-butene.)

1. A process for producing 1-butene, the process comprising:

dehydrogenating n-butane to produce a first stream comprising 1-butene, isobutene, trans-2-butene, cis-2-butene, and n-butane;

separating the first stream by extractive distillation to produce a second stream comprising predominantly n-butane and a third stream comprising predominantly 1-butene, isobutene, trans-2-butene, cis-2-butene;

distilling the third stream in a distillation column to form a fourth stream comprising primarily isobutylene and 1-butene and a fifth stream comprising primarily trans-2-butene and cis-2-butene; and

the fourth stream is separated to produce a sixth stream comprising primarily isobutylene and a seventh stream comprising primarily 1-butene.

2. The process of claim 1, wherein the conditions for performing dehydrogenation comprise a temperature of 500 ℃ to 650 ℃, a pressure of 0 bar to 10 bar, and 1000h^-1To 5000h^-1GHSV of (1).

3. The process according to any one of claims 1 and 2, wherein dehydrogenation is catalyzed by a catalyst comprising platinum and/or tin.

4. The method of any one of claims 1 to 2, wherein the fourth stream is separated using a membrane.

5. The method of claim 4, wherein the membrane comprises a Zeolitic Imidazolate Framework (ZIF).

6. The method of any one of claims 1 to 5, further comprising:

isomerizing at least some of the trans-2-butene and at least some of the cis-2-butene of the fifth stream to form 1-butene contained in the eighth stream.

7. The process of claim 6, wherein the conditions for carrying out the isomerization comprise a temperature of from 50 ℃ to 60 ℃, a pressure of from 0MPa to 5MPa, and 1000h^-1To 2000h^-1Space velocity of (a).

8. The process of any of claims 1-7, wherein the fourth stream comprises 90 to 95 wt.% 1-butene and 5 to 10 wt.% isobutylene.

9. The process of any of claims 1-8, wherein the sixth stream comprises 98 wt.% to 99 wt.% isobutylene.

10. The process of any of claims 1-9, wherein the seventh stream comprises from 99 wt% to 99.8 wt% 1-butene.

11. The process of any of claims 1-10, wherein the first stream comprises 20 to 30 wt% 1-butene, 2 to 5 wt% isobutene, 25 to 35 wt% trans-2-butene, 20 to 30 wt% cis-2-butene, and 30 to 50 wt% n-butane.

12. The process according to any one of claims 1 to 11, wherein the second stream is recycled to the dehydrogenation reactor where the dehydrogenation is carried out.

13. The method of any of claims 1-12, wherein the second stream comprises 98 wt.% to 99 wt.% n-butane.

14. The process of any of claims 1 to 13, wherein the third stream comprises 30 to 40 wt% 1-butene and 2 to 5 wt% isobutene, 30 to 40 wt% trans-2-butene and 20 to 30 wt% cis-2-butene.

15. The process of any one of claims 1 to 14, wherein the conditions for performing the distillation comprise an overhead boiling range of-7 ℃ to 0 ℃, a reboiler boiling range of 1 ℃ to 5 ℃, and a pressure of 0.01MPa to 1 MPa.

16. The process of any of claims 1-15, wherein the fifth stream comprises from 50 wt% to 60 wt% trans-2-butene and from 40 wt% to 50 wt% cis-2-butene.

17. The process of any of claims 1-16, wherein the eighth stream comprises from 99 wt% to 99.8 wt% 1-butene.

18. The method of any one of claims 1 to 16, further comprising:

the seventh stream and the eighth stream are combined to form a ninth stream.

19. The process of claim 18, where the ninth stream comprises from 99 wt% to 99.8 wt% 1-butene.

Technical Field

The present invention relates generally to the production of 1-butene. More particularly, the invention relates to dehydrogenating butene to form a mixture comprising butene isomers and recovering 1-butene from the mixture.

Background

1-butene is commonly used as a comonomer in the production of polyethylene. A process for preparing 1-butene from C₄Separated from refinery streams. These C₄Refinery streams are formed during steam cracking or fluid catalytic cracking of hydrocarbon feedstocks to produce ethylene. 1-butene is also prepared by dehydrogenating n-butane to form isomers of butene, including 1-butene, and one or more of isobutene, trans-2-butene, and cis-2-butene. After dehydrogenation, the 1-butene is separated from the other isomers. In a production process involving dehydrogenation of n-butane to form butenes, separation of 1-butene from other butene isomers is a major obstacle to overcome if a high quality 1-butene product is desired.

Separation of 1-butene from other butene isomers is very difficult because the boiling points of these materials are very close. Thus, conventional separation methods such as distillation are relatively ineffective. In addition, the conversion of n-butane to 1-butene in these processes is relatively low, so it is difficult to obtain a suitable 1-butene production capacity in existing refineries.

Disclosure of Invention

In view of the above-mentioned problems associated with 1-butene production, processes have been developed that can achieve the desired 1-butene production capacity at the desired purity. In the process, n-butane is dehydrogenated to form a mixture comprising butene isomers and unreacted n-butane. The mixture is separated by techniques including extractive distillation and the unreacted n-butane in the separation is returned as recycle to the dehydrogenation. The isobutylene and 1-butene recovered from the separation process are sent to a membrane to separate the isobutylene from the 1-butene. The mixture of trans-2-butene and cis-2-butene from the separation process may be used as a feed to an isomerization unit. In the isomerization unit, both trans-2-butene and cis-2-butene are converted to 1-butene.

Embodiments of the invention include a process for producing 1-butene. The process includes dehydrogenating n-butane to produce a first stream comprising 1-butene, isobutylene, trans-2-butene, cis-2-butene, and n-butane. The process also includes separating the first stream by extractive distillation to produce a second stream comprising predominantly n-butane and a third stream comprising predominantly 1-butene, isobutene, trans-2-butene, and cis-2-butene. Further, the process includes distilling the third stream in a distillation column to form a fourth stream comprising primarily isobutylene and 1-butene and a fifth stream comprising primarily trans-2-butene and cis-2-butene. The process also involves separating the fourth stream to produce a sixth stream comprising primarily isobutylene and a seventh stream comprising primarily 1-butene.

Embodiments of the invention include a process for producing 1-butene. The process includes dehydrogenating n-butane to produce a first stream comprising 1-butene, isobutene, trans-2-butene, cis-2-butene, and n-butane. The process also includes separating the first stream by extractive distillation to produce a second stream comprising predominantly n-butane and a third stream comprising predominantly 1-butene, isobutene, trans-2-butene, and cis-2-butene. Further, the process includes distilling the third stream in a distillation column to form a fourth stream comprising primarily isobutylene and 1-butene and a fifth stream comprising primarily trans-2-butene and cis-2-butene together. The process also involves separating the fourth stream to produce a sixth stream comprising primarily isobutylene and a seventh stream comprising primarily 1-butene, wherein the fourth stream is separated using a membrane. The process also includes isomerizing at least some of the trans-2-butene and at least some of the cis-2-butene of the fifth stream to form 1-butene.

The following includes definitions of various terms and phrases used throughout this specification.

The term "about" or "approximately" is defined as being approximately as understood by one of ordinary skill in the art. In one non-limiting embodiment, the term is defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

The terms "weight%", "volume%" or "mole%" refer to the weight percent, volume percent, or mole percent of a component, respectively, based on the total weight, volume, or total moles of the material comprising the component. In one non-limiting example, 10 mole of a component in 100 moles of material is 10 mole percent of the component.

The term "substantially" and variations thereof are defined as ranges that include within 10%, within 5%, within 1%, or within 0.5%.

The terms "inhibit" or "reduce" or "prevent" or "avoid" when used in the claims and/or the specification includes any measurable reduction or complete inhibition to achieve a desired result.

As used in this specification and/or in the claims, the term "effective" means suitable for achieving a desired, expected, or expected result.

When used in conjunction with the terms "comprising," including, "" containing, "or" having "in the claims or specification, the absence of a numeral preceding an element may mean" one, "but it is also consistent with the meaning of" one or more, "" at least one, "and" one or more than one.

The words "comprising," "having," "including," or "containing" are inclusive or open-ended and do not exclude additional unrecited elements or method steps.

The methods of the present invention can "comprise," "consist essentially of," or "consist of" certain ingredients, components, compositions, etc. disclosed throughout this specification.

As used herein the specification and/or claims, the term "substantially" means greater than any of 50% by weight, 50% by mole, and 50% by volume. For example, "predominantly" can include 50.1% to 100% by weight and all values and ranges therebetween, 50.1% to 100% by mole and all values and ranges therebetween, or 50.1% to 100% by volume and all values and ranges therebetween.

Other objects, features and advantages of the present invention will become apparent from the following drawings, detailed description and examples. It should be understood, however, that the drawings, detailed description and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not intended to be limiting. In addition, it is contemplated that variations and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.

Brief description of the drawings

For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a system for producing 1-butene according to an embodiment of the present invention; and

FIG. 2 is a process for producing 1-butene according to an embodiment of the present invention.

Detailed Description

A process has been found for producing 1-butene with improved productivity and purity compared to conventional processes. In the discovered process, n-butane is dehydrogenated to form a mixture comprising butene isomers and unreacted n-butane. Unreacted n-butane was separated from the mixture. The unreacted n-butane from this separation is returned as recycle to the dehydrogenation. The separation process may include the use of distillation, including extractive distillation. The isobutylene and 1-butene recovered from the separation process are sent to a membrane to separate the isobutylene from the 1-butene. The mixture of trans-2-butene and cis-2-butene from the separation process may be used as a feed to an isomerization unit. In the isomerization unit, both trans-2-butene and cis-2-butene are converted to 1-butene.

FIG. 1 shows a system 10 for producing 1-butene according to an embodiment of the present invention. FIG. 2 shows a process 20 for producing 1-butene according to an embodiment of the present invention. Method 20 may be implemented with system 10. In embodiments of the invention, the mass numbers of the streams shown in fig. 1 can vary, and the mass number of each stream can include from 10% less than the mass number shown to 10% greater than the mass number shown, including all ranges and values therebetween.

A method 20 implemented using the system 10 may include flowing a feed stream 100 comprising primarily n-butane into a dehydrogenation reactor 110 at block 200. In an embodiment of the present invention, the feed stream 100 may be combined with the recycled n-butane stream 102 to form a combined stream 117 that is flowed to the dehydrogenation reactor 110. Alternatively or additionally, the feed stream 100 and the recycled n-butane stream 102 may be fed separately to the dehydrogenation reactor 110. According to an embodiment of the invention, feed stream 100 may be from a feedstock and may comprise from 99 wt% to 99.5 wt% n-butane.

In block 201, the process 20 may also involve dehydrogenating n-butane in the feed stream 100 in the dehydrogenation reactor 110 to produce the reactor effluent stream 101. According to an embodiment of the invention, the reactor effluent stream 101 is a mixture comprising one or more than one of 1-butene, isobutylene, trans-2-butene, cis-2-butene, and n-butane. In an embodiment of the invention, the reaction conditions under which reactor 110 is operated to provide feed stream 100 include a temperature of 500 ℃ to 650 ℃, a pressure of 0 bar to 10 bar, and 1000h^-1To 5000h^-1GHSV of (1). According to an embodiment of the invention, the reactor effluent stream 101 comprises 20 to 30 wt% 1-butene, 2 to 5 wt% isobutene, 25 to 35 wt% trans-2-butene, 20 to 30 wt% cis-2-butene, and 30 to 50 wt% n-butane. In addition, the present invention is directed toIn embodiments of (a), the dehydrogenation reaction occurring in reactor 110 may be catalyzed by a catalyst comprising platinum and/or tin.

In accordance with an embodiment of the present invention, the method 20 includes flowing the reactor effluent stream 101 into the extractive distillation apparatus 111 at block 202. The extractive distillation apparatus 111 may include a solvent extraction column 111A and a solvent recovery column 111B. According to an embodiment of the invention, the reactor effluent stream 101 enters a solvent extraction column 111A. Then, in an embodiment of the invention, at block 203, the solvent extraction column 111A performs extractive distillation on the reactor effluent stream 101 to produce a recycled n-butane stream 102 and an intermediate raffinate stream 115. According to an embodiment of the invention, the conditions for performing the extractive distillation comprise a temperature of 10 ℃ to 50 ℃, a pressure of 0.01MPa to 1 MPa. In an embodiment of the invention, the solvent used for carrying out the extraction is selected from the list consisting thereof and combinations thereof. In an embodiment of the invention, the recycled n-butane stream 102 comprises primarily n-butane and an intermediate raffinate stream 115 comprising primarily isobutylene, 1-butene, trans-2-butene, and cis-2-butene. In an embodiment of the invention, the recycled n-butane stream 102 comprises from 98% to 99% by weight n-butane. According to an embodiment of the invention, the intermediate raffinate stream 115 comprises 20 to 30 wt% 1-butene, 2 to 5 wt% isobutene, 25 to 35 wt% trans-2-butene, 20 to 30 wt% cis-2-butene and 30 to 50 wt% n-butane.

At block 204 of the process 20, the intermediate raffinate stream 115 is flowed into the solvent recovery column 111B. Then, at block 205, the solvent recovery column 111B removes solvent from the intermediate raffinate stream 115 to produce a recycle solvent stream 116 (comprising primarily solvent) and a raffinate stream 103.

According to an embodiment of the invention, the method 20 includes flowing the raffinate stream 103 into the distillation apparatus 114 at block 206. Then, in an embodiment of the invention, at block 207, the distillation column 114 distills the raffinate stream 103 to produce an overhead stream 104 and a bottoms stream 105. According to an embodiment of the invention, the conditions for performing the distillation comprise an overhead boiling range of-7 ℃ to 0 ℃, a reboiler boiling range of 1 ℃ to 5 ℃ and a pressure of 0.01MPa to 1 MPa. In an embodiment of the invention, the overhead stream 104 comprises mainly 1-butene and isobutene and the bottoms stream 105 comprises mainly trans-2-butene and cis-2-butene.

In an embodiment of the invention, the overhead stream 104 is sent to the membrane separation device 112 at block 208. According to an embodiment of the present invention, the membrane separation device 112 comprises a membrane suitable for separating hydrocarbon mixtures based on molecular size. In an embodiment of the invention, at block 209, the membrane separation device 112 separates the overhead stream 104 into a stream 107 comprising primarily 1-butene and a stream 106 comprising primarily isobutene.

According to an embodiment of the present invention, the membrane of the membrane separation device 112 comprises a crystalline microporous material, such as one or more Zeolitic Imidazolate Frameworks (ZIFs). ZIFs are structurally comparable to zeolites and/or other crystalline materials, but have different synthetic building blocks. The pore size of ZIFs is typically less than 2 nm. Its regular pore structure makes it possible to distinguish gas molecules on the basis of molecular size. ZIFs in this technology have been developed and functionalized to be effective and stable membranes for gas separation in powder form or continuous membrane form. See U.S. patent application No. 13/709155. Preferably, overhead stream 104 is fed to membrane separation device 112 in a substantially vapor phase. In embodiments of the invention, the separation process performed by the membrane separation device 112 at block 209 may involve C_2-Hydrocarbons (e.g. hydrogen, methane, ethane and ethylene) with C₃₊Separation of hydrocarbons (e.g. propane, propylene, butane, butenes, isobutene).

In an embodiment of the invention, stream 106 comprises from 98 wt% to 99 wt% isobutylene. In an embodiment of the invention, stream 107 comprises from 99 wt% to 99.8 wt% 1-butene.

The method 20 at block 210 may include flowing the bottoms stream 105 into an isomerization unit 113. According to an embodiment of the invention, the bottom stream 105 comprises from 50 to 60% by weight of trans-2-butene and from 40 to 50% by weight of cis-2-butene. The isomerization unit 113 is adapted to isomerize cis-2-butene and isobutene to form 1-butene. Therefore, according to an embodiment of the present invention, block 211 comprises causingAt least some of the trans-2-butene and at least some of the cis-2-butene in the bottoms stream 105 isomerize to form 1-butene. As shown in fig. 1, according to an embodiment of the present invention, such 1-butene is contained in an isomerization unit effluent stream 108, which exits from isomerization unit 113, at block 212. According to an embodiment of the present invention, at block 211, the isomerization unit 113 is operated by using a positional sulfonic acid cation exchanger to provide reaction conditions for performing the isomerization, which include a temperature of 50 ℃ to 60 ℃, a pressure of 0MPa to 5MPa, and 1000h^-1To 2000h^-1Space velocity of (a). In an embodiment of the invention, the isomerization unit effluent stream 108 comprises from 99 wt% to 99.8 wt% 1-butene.

In embodiments of the invention, at block 213, method 20 involves combining stream 174 with isomerization unit effluent stream 108 to form combined product stream 109. According to an embodiment of the invention, the combined product stream 109 comprises 99 wt.% to 99.8 wt.% 1-butene.

Although embodiments of the present invention have been described with reference to the blocks of FIG. 2, it should be understood that the operations of the present invention are not limited to the specific blocks and/or the specific order of the blocks illustrated in FIG. 2. Accordingly, embodiments of the invention may use various blocks in a different order than that of FIG. 2 to provide the functionality as described herein.

In the context of the present invention, at least the following 19 embodiments are described. Embodiment 1 is a process for producing 1-butene. The process includes dehydrogenating n-butane to produce a first stream containing 1-butene, isobutene, trans-2-butene, cis-2-butene, and n-butane. The process also includes separating the first stream by extractive distillation to produce a second stream comprising predominantly n-butane and a third stream comprising predominantly 1-butene, isobutene, trans-2-butene, cis-2-butene. The process also includes distilling the third stream in a distillation column to form a fourth stream comprising primarily isobutylene and 1-butene and a fifth stream comprising primarily trans-2-butene and cis-2-butene. The process also includes separating the fourth stream to produce a sixth stream comprising primarily isobutylene and a seventh stream comprising primarily 1-butene. Embodiment 1 is the method of embodiment 1, wherein for effecting exfoliationThe hydrogen conditions include a temperature of 500 ℃ to 650 ℃, a pressure of 0 bar to 10 bar and 1000h^-1To 5000h^-1GHSV of (1). Embodiment 3 is the method of embodiment 1 or 2, wherein the dehydrogenation is catalyzed by a catalyst comprising platinum and/or tin. Embodiment 4 is the method of embodiment 1 or 2, wherein the fourth stream is separated using a membrane. Embodiment 5 is the method of embodiment 4, wherein the membrane comprises a Zeolitic Imidazolate Framework (ZIF). Embodiment 6 is the process of any one of embodiments 1 to 5, further comprising isomerizing at least some of the trans-2-butene and at least some of the cis-2-butene in the fifth stream to form 1-butene included in the eighth stream. Embodiment 7 is the process of embodiment 6, wherein the conditions for performing the isomerization comprise a temperature of 50 ℃ to 60 ℃, a pressure of 0MPa to 5MPa, and 1000h^-1To 2000h^-1Space velocity of (a). Embodiment 8 is the process of any one of embodiments 1 to 7, wherein the fourth stream comprises 90 to 95 weight percent 1-butene and 5 to 10 weight percent isobutene. Embodiment 9 is the method of any one of embodiments 1 to 8, wherein the sixth stream comprises 98 to 99 weight percent isobutylene. Embodiment 10 is the process of any one of embodiments 1 to 9, wherein the seventh stream comprises 99 to 99.8 weight percent 1-butene. Embodiment 11 is the method of any one of embodiments 1 to 10, wherein the first stream comprises 20 to 30 weight percent 1-butene, 2 to 5 weight percent isobutylene, 25 to 35 weight percent trans-2-butene, 20 to 30 weight percent cis-2-butene, and 30 to 50 weight percent n-butane. Embodiment 12 is the method of any one of embodiments 1 to 11, wherein the second stream is recovered to the dehydrogenation reactor where the dehydrogenation is performed. Embodiment 13 is the method of any one of embodiments 1 to 12, wherein the second stream comprises 98 wt% to 99 wt% n-butane. Embodiment 14 is the method of any one of embodiments 1 to 13, wherein the third stream comprises 30 to 40 weight percent 1-butene and 2 to 5 weight percent isobutene, 30 to 40 weight percent trans-2-butene, and 20 to 30 weight percent cis-2-butene. Embodiment 15 is any one of embodiments 1 to 14The process, conditions for carrying out the distillation include an overhead boiling range of-7 ℃ to 0 ℃, a reboiler boiling range of 1 ℃ to 5 ℃, and a pressure of 0.01MPa to 1 MPa. Embodiment 16 is the process of any one of embodiments 1 to 15, wherein the fifth stream comprises 50 to 60 weight percent trans-2-butene and 40 to 50 weight percent cis-2-butene. Embodiment 17 is the process of any one of embodiments 1 to 16, wherein the eighth stream comprises 99 to 99.8 weight percent 1-butene. Embodiment 18 is the method of any one of embodiments 1 to 16, further comprising combining the seventh stream and the eighth stream to form a ninth stream. Embodiment 19 is the process of embodiment 18, wherein the ninth stream comprises 99 to 99.8 wt.% 1-butene.

Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure set forth above, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.