PROCESSES AND SYSTEMS FOR TREATING AROMATIC FEED INCLUDING AN AROMATIC COMPONENT AND NITROGEN-CONTAINING IMPURITIES, AND PROCESSES AND SYSTEMS FOR PREPARING A REACTION PRODUCT OF THE AROMATIC COMPONENT
Processes and systems for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities, as well as processes and systems for preparing a reaction product of an aromatic component from an aromatic feed comprising the aromatic component and nitrogen-containing impurities, are provided herein. In an embodiment, a process for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities includes adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities. The treated aromatic feed and water are mixed to produce a hydrated aromatic feed. A purified aromatic feed and a water component are distilled from the hydrated aromatic feed in a distillation stage, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component.
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The present invention generally relates to processes and systems for treating an aromatic feed that includes an aromatic component and nitrogen-containing impurities, as well as processes and systems for preparing a reaction product of an aromatic component from the aromatic feed. In particular, the present invention relates to processes and systems for removing nitrogen-containing impurities from the aromatic feed.
BACKGROUNDReaction products of aromatic compounds, such as alkylated aromatic compounds, are common petrochemical products that are useful as intermediates for the preparation of other widely-used industrial compounds. For example, cumene (also known in the art as isopropyl benzene) is widely used as an intermediate in the production of phenol and acetone, and ethylbenzene is widely used as an intermediate in the production of styrene.
Alkylated aromatic compounds are generally prepared by reacting aromatic compounds with olefins in the presence of an aromatic alkylation catalyst, such as phosphoric acid catalysts or recently developed zeolitic acid catalysts. Processes of and systems for producing alkylated aromatic compounds are known in the art.
Aromatic feed including aromatic compounds to be reacted often includes nitrogen-containing impurities such as indoles; pyridines; quinolones; diethanol amine (DEA); and morpholines including N-formyl-morpholine (NFM) and N-methyl-pyrrolidone (NMP). The presence of nitrogen-containing impurities in aromatic feed is generally undesirable for various reasons. For example, nitrogen-containing impurities may form deposits on aromatic alkylation catalysts during alkylation of the aromatic compounds, thereby contaminating the aromatic alkylation catalysts. Such contamination adversely affects catalyst performance and catalyst life and increases regeneration frequency of the aromatic alkylation catalysts. During regeneration, accumulated nitrogen compounds and coke are combusted from the aromatic alkylation catalysts to regenerate the catalysts. Even very low nitrogen concentrations in the aromatic feed may increase catalyst regeneration frequency due to formation of deposits from the nitrogen-containing impurities on the aromatic alkylation catalysts.
Techniques have been sought to address the impact of nitrogen-containing impurities from aromatic feed on the aromatic alkylation catalysts. For example, techniques have been developed for treating the aromatic alkylation catalysts themselves, such as through desorption of the impurities from the aromatic alkylation catalysts after contamination thereof. As another example, adsorption techniques have been developed, using guard bed systems, for adsorbing nitrogen-containing impurities from aromatic feed prior to alkylation in the presence of the aromatic alkylation catalyst. In the guard bed systems, the aromatic feed is passed over a fixed bed of adsorbent material that is capable of chemically adsorbing the nitrogen-containing impurities from the aromatic feed. However, existing guard bed systems are generally incapable of adsorbing all nitrogen-containing impurities from the aromatic feed. As a result, residual nitrogen-containing impurities generally remain in the treated aromatic feed after passing through the guard bed systems. Simply increasing capacity of the guard bed systems is an undesirable and often imperfect approach to removing greater amounts of nitrogen-containing impurities from the aromatic feed due to the nitrogen-containing impurities in the aromatic feed having different degrees of basicity with some of the nitrogen-containing impurities having basicity that falls outside of an operating range of the guard bed systems.
Accordingly, it is desirable to provide processes and systems that are configured to assist with removal of residual nitrogen-containing impurities from aromatic feed after adsorption of a portion of the nitrogen-containing impurities from the aromatic feed. In addition, it is desirable to remove the residual nitrogen-containing impurities from the aromatic feed without increasing capacity of the guard bed systems. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
BRIEF SUMMARYProcesses and systems for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities, as well as processes and systems for preparing a reaction product of an aromatic component from an aromatic feed comprising the aromatic component and nitrogen-containing impurities, are provided herein. In an embodiment, a process for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities includes adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities. The treated aromatic feed and water are mixed to produce a hydrated aromatic feed. A purified aromatic feed and a water component are distilled from the hydrated aromatic feed, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component.
In another embodiment, a process for preparing a reaction product of an aromatic component from an aromatic feed comprising the aromatic component and nitrogen-containing impurities includes adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities. The treated aromatic feed and water are mixed to produce a hydrated aromatic feed. A purified aromatic feed and a water component are distilled from the hydrated aromatic feed in a distillation stage, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component. The purified aromatic feed is reacted in a reaction stage to produce a reactor effluent comprising the reaction product of the aromatic component and an unreacted aromatic component.
In another embodiment, a system for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities includes an adsorption stage for receiving the aromatic feed and for adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities. A water input is downstream of the adsorption stage for mixing the treated aromatic feed and water to form a hydrated aromatic feed. A distillation stage is in fluid communication with the adsorption stage, with the water input in fluid communication with the distillation stage or upstream thereof, for distilling a purified aromatic feed and a water component from the hydrated aromatic feed. The water component comprises residual nitrogen-containing impurities from the treated aromatic feed and the purified aromatic feed comprises the aromatic component.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
Processes and systems for treating an aromatic feed that includes an aromatic component and nitrogen-containing impurities, as well as processes and systems for preparing a reaction product of an aromatic component from the aromatic feed, are provided herein. Referring to
Aromatic feed, as referred to herein, is the feed that is subject to adsorption (STEP 12,
In an embodiment, and as shown in
After adsorption (STEP 12,
To provide sufficient amounts of water for removing the residual nitrogen-containing impurities from the treated aromatic feed during distilling (STEP 16), the treated aromatic feed and water may be mixed with water present in an amount of from about 10 to about 10,000 parts per million by weight (wt ppm), such as from about 200 to about 500 wt ppm, based upon the total weight of the combined aromatic feed and water. With such amounts of water mixed with the treated aromatic feed in STEP 14, a desirable hydration level of the hydrated aromatic feed during distilling (STEP 16) may be established to ensure that the residual nitrogen-containing impurities can be distilled with the water from the hydrated aromatic feed in STEP 16.
During or after mixing the treated aromatic feed and water in STEP 14, and as shown in
In an embodiment, as alluded to above and as shown in
A wide variety of aromatic alkylation catalysts can be used in the alkylation processes. Particularly suitable aromatic alkylation catalysts include those that may be impacted by the presence of nitrogen-containing impurities in the aromatic feed in view of the fact that such catalysts may benefit from the processes and systems described herein. One example of a suitable aromatic alkylation catalyst that may benefit from the processes and systems described herein is a zeolitic catalyst, which may be used in combination with a refractory inorganic oxide binder such as alumina or silica. Suitable zeolitic catalysts include zeolite beta, ZSM-5, PSH-3, MCM-22, MCM-36, MCM-49, and MCM-56. Such zeolitic catalysts are known in the art.
Exemplary embodiments of systems 10, 110 for treating aromatic feed 11, as well as for preparing a reaction product of an aromatic component from the aromatic feed, are shown in
Exemplary processes will now be described with respect to an exemplary embodiment of the system 10 as shown in
In another embodiment, the treated aromatic feed 24 and water are mixed (STEP 14,
In the embodiment shown in
Although the purified aromatic feed 30 and the water component 32 are distilled from the hydrated aromatic feed, the water component 32 may include an entrained aromatic component therewith after distillation. In an embodiment, and as shown in
In this embodiment, the reaction stage 19 may include one or more reactors 55 that each include one or more catalyst beds 57 including, for example, the alkylation catalyst as described above, for reacting (STEP 18,
Exemplary processes will now be described with respect to the exemplary embodiment of the system 110 as shown in
In this embodiment, adsorption (STEP 12,
In the embodiment shown in
In the embodiment shown in
In the embodiment shown in
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.
Claims
1. A process for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities, said process comprising the steps of:
- adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities;
- mixing the treated aromatic feed and water to produce a hydrated aromatic feed;
- distilling a purified aromatic feed and a water component from the hydrated aromatic feed, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component.
2. The process of claim 1, wherein the treated aromatic feed and water are mixed in liquid form prior to distilling.
3. The process of claim 1, wherein the treated aromatic feed and water are mixed during distilling.
4. The process of claim 1, wherein the treated aromatic feed and water are mixed with water present in an amount of from about 10 to about 10,000 parts per million by weight based upon the total weight of the combined treated aromatic feed and water.
5. The process of claim 1, wherein the purified aromatic feed and the water component are distilled in the presence of a reactor effluent comprising a reaction product of the aromatic component and an unreacted aromatic component.
6. The process of claim 5, wherein the treated aromatic feed and water are mixed in the presence of the reactor effluent.
7. The process of claim 5, wherein the reactor effluent, the purified aromatic feed, and the water component are in direct vapor communication during distilling and wherein direct liquid flow is hindered between the reactor effluent and the purified aromatic feed.
8. The process of claim 1, wherein the water component distilled from the hydrated aromatic feed comprises entrained aromatic component, and wherein the entrained aromatic component and water are separated from the water component with the entrained aromatic component recycled and introduced during distilling.
9. The process of claim 1, wherein the purified aromatic component is substantially free of water after distilling.
10. The process of claim 1, wherein the step of adsorbing the portion of the nitrogen-containing impurities produces the treated aromatic feed including residual nitrogen-containing impurities in an amount of from about 1 to about 5000 parts per billion by weight based upon the total weight of all components present in the treated aromatic feed.
11. The process of claim 1, wherein the portion of the nitrogen-containing impurities is adsorbed from the aromatic feed comprising the aromatic component including an aromatic compound chosen from benzene, naphthalene, anthracene, phenanthrene, substituted derivatives thereof, and combinations thereof.
12. A process for preparing a reaction product of an aromatic component from an aromatic feed comprising the aromatic component and nitrogen-containing impurities, said process comprising the steps of:
- adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities;
- mixing the treated aromatic feed and water to produce a hydrated aromatic feed;
- distilling a purified aromatic feed and a water component from the hydrated aromatic feed in a distillation stage, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component; and
- reacting the purified aromatic feed in a reaction stage to produce a reactor effluent comprising the reaction product of the aromatic component and an unreacted aromatic component.
13. The process of claim 12, wherein the treated aromatic feed and water are mixed in liquid form prior to the distillation stage.
14. The process of claim 12, wherein the treated aromatic feed and water are mixed in the distillation stage.
15. The process of claim 14, wherein the water is in vapor form and is mixed with the treated aromatic feed below an input of the treated aromatic feed in the distillation stage.
16. The process of claim 12, wherein the distillation stage comprises a common distillation column and wherein the purified aromatic feed and water component are distilled in the presence of the reactor effluent in the common distillation column.
17. The process of claim 16, wherein the common distillation column includes separate sections including a first section and a second section located above the first section, and wherein the purified aromatic feed and the water component are distilled from the hydrated aromatic feed in the second section.
18. The process of claim 12, wherein the water component distilled from the hydrated aromatic feed comprises an entrained aromatic component, and wherein the entrained aromatic component and water are separated from the water component with the entrained aromatic component recycled to the distillation stage.
19. The process of claim 12, wherein the step of reacting the purified aromatic feed is further defined as alkylating the aromatic component from the purified aromatic feed and wherein the reaction product of the aromatic component is further defined as an alkylated aromatic component.
20. A system for treating an aromatic feed comprising an aromatic component and nitrogen-containing impurities, said system comprising:
- an adsorption stage for receiving the aromatic feed and for adsorbing a portion of the nitrogen-containing impurities from the aromatic feed to produce a treated aromatic feed comprising the aromatic component and residual nitrogen-containing impurities;
- a water input downstream of the adsorption stage for mixing the treated aromatic feed and water to form a hydrated aromatic feed;
- a distillation stage in fluid communication with the adsorption stage, with the water input in fluid communication with the distillation stage or upstream thereof, for distilling a purified aromatic feed and a water component from the hydrated aromatic feed, wherein the water component comprises residual nitrogen-containing impurities from the treated aromatic feed and wherein the purified aromatic feed comprises the aromatic component.
Type: Application
Filed: Feb 22, 2012
Publication Date: Aug 22, 2013
Applicant: UOP LLC (Des Plaines, IL)
Inventors: Chad A. Williams (Des Plaines, IL), Wugeng Liang (Elgin, IL), Patrick Jerome Bullen (Elmhurst, IL)
Application Number: 13/402,371
International Classification: C07C 7/12 (20060101); B01D 15/00 (20060101);