Production of alkyl aromatic compounds

Abstract

Improved integrated processes for the production of alkyl aromatic compounds are disclosed wherein aromatic compounds which may be treated for removal of deleterious substances are reacted with olefin compounds, which may also be treated for contaminant removal, in the presence of acidic zeolite catalyst(s) to produce the desired alkyl aromatic compound(s). The aromatic and preferably also the olefin feeds are treated substantially to remove contaminants, particularly the nitrogen compounds contained therein, before they are brought together for reaction in the presence of the zeolite catalyst(s). In accordance with the present invention, it has been found that feed pretreatment for removal of nitrogen compounds significantly improves the run length and life of the acidic zeolite catalyst(s). The feed pretreatment of this invention may include the steps of distillation, extraction, and/or adsorption by solid adsorbent, which may be regenerated in accordance with further embodiments of this invention.

1 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the olefin feed, or the aromatic feed, or both, contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising steps (a) to (f) below in any order followed by step (g), said steps being:
 (a) treating the olefin feed to said reaction section by distillation to substantially separate relatively high volatility nitrogen contaminants, or relatively low volatility nitrogen contaminants, or both from the olefin feed, if such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s) and are not substantially separated by another treatment method herein;   (b) treating the aromatic feed to said reaction section by distillation to substantially separate relatively high volatility nitrogen contaminants, or relatively low volatility nitrogen contaminants, or both from the aromatic feed, if such contaminants are present in the aromatic feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s) and are not substantially separated by another treatment method herein;   (c) treating the olefin feed to said reaction section by extraction with a suitable extractant to substantially separate nitrogen contaminants which are preferentially soluble in said extractant from the olefin feed, if such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s) and are not substantially separated by another treatment method herein;   (d) treating the aromatic feed to said reaction section by extraction with a suitable extractant to substantially separate nitrogen contaminants which are preferentially soluble in said extractant from the aromatic feed, if such contaminants are present in the aromatic feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalysts and are not substantially separated by another treatment method herein;   (e) treating the olefin feed to said reaction section by selective adsorption with a regenerable adsorbent to substantially separate nitrogen contaminants not substantially removed by another treatment method herein from the olefin feed if such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s) and periodically regenerating said adsorbent in-situ;   (f) treating the aromatic feed to said reaction section by selective adsorption with a regenerable adsorbent to substantially separate nitrogen contaminants not substantially removed by another treatment method herein from the aromatic feed if such contaminants are present in the aromatic feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s) and periodically regenerating said adsorbent in-situ; and,   (g) passing the olefin feed pretreated in accordance with one or more of steps (a), (c) or (e), if the olefin feed contained at least one nitrogen contaminant, and the aromatic feed pretreated in accordance with one or more of steps (b), (d) or (f) if the aromatic feed contained at least one nitrogen contaminant, to said reaction section.   
     
     
         2 . A process according to  claim 1 , wherein the olefin feed is pretreated as it enters the process, together with other pretreatment and/or purification steps, or after other pretreatment and/or purification steps but prior to entering the reaction section. 
     
     
         3 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a distillation step. 
     
     
         4 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a distillation step in which at least a nitrogen contaminant is removed at or near the top of a distillation column and the pretreated olefin feed is recovered at or near the bottom of the column. 
     
     
         5 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a distillation step in which at least a nitrogen contaminant is removed at or near the bottom of a distillation column and the pretreated olefin feed is recovered at or near the top of the column. 
     
     
         6 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a distillation step in which at least a light nitrogen compound and/or other light impurities are removed at or near the top of a distillation column, at least a heavy nitrogen compound and/or other heavy impurities are removed at or near the bottom of the distillation column, and the pretreated olefin feed is recovered as a side draw. 
     
     
         7 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least an extraction step. 
     
     
         8 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least an extraction step in which the olefin feed is extracted with water and/or acidified water. 
     
     
         9 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a selective adsorption step with at least one regenerable adsorbent selected from the group consisting of acidic clay, zeolite catalysts, molecular sieves, aluminas, silicas, activated alumina, activated carbon, silica gel and ion exchange resins. 
     
     
         10 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert gas, said inert gas being selected from the group consisting of nitrogen, air, natural gas, liquefied petroleum gas, methane, ethane, propane, butanes, pentanes, steam, and mixtures thereof. 
     
     
         11 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert liquid, said inert liquid being selected from the group consisting of liquefied petroleum gas, ethane, propane, butanes, pentanes, hexanes, benzene, toluene, ethylbenzene, xylenes, and mixtures thereof. 
     
     
         12 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of displacing the adsorbed contaminants by other compound(s) which is (are) preferentially adsorbed on the adsorbent more strongly than the contaminants. 
     
     
         13 . A process according to  claim 1 , wherein said olefin feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of acid treatment. 
     
     
         14 . A process according to  claim 1 , wherein the aromatic feed is pretreated as it enters the process, together with other pretreatment and/or purification steps, or after other pretreatment and/or purification steps but prior to entering the reaction section. 
     
     
         15 . A process according to  claim 1 , wherein the aromatic feed is pretreated together with other stream(s) in the process or after it is pretreated and/or purified together with other stream(s) in the process by other pretreatment and/or purification steps. 
     
     
         16 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a distillation step. 
     
     
         17 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a distillation step in which at least a nitrogen contaminant is removed at or near the top of a distillation column and the pretreated aromatic feed is recovered at or near the bottom of the column. 
     
     
         18 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a distillation step in which at least a nitrogen contaminant is removed at or near the bottom of a distillation column and the pretreated aromatic feed is recovered at or near the top of the column. 
     
     
         19 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a distillation step in which at least a light nitrogen compound and/or other light impurities are removed at or near the top of a distillation column, at least a heavy nitrogen compound and/or other heavy impurities are removed at or near the bottom of the distillation column, and the pretreated aromatic feed is recovered as a side draw. 
     
     
         20 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least an extraction step. 
     
     
         21 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least an extraction step in which the aromatic feed is extracted with water and/or acidified water. 
     
     
         22 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a selective adsorption step with at least one regenerable adsorbent selected from the group consisting of acidic clay, zeolite catalysts, molecular sieves, aluminas, silicas, activated alumina, activated carbon, silica gel and ion exchange resins. 
     
     
         23 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert gas, said inert gas being selected from the group consisting of nitrogen, air, natural gas, liquefied petroleum gas, methane, ethane, propane, butanes, pentanes, steam, and mixtures thereof. 
     
     
         24 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert liquid, said inert liquid being selected from the group consisting of liquefied petroleum gas, ethane, propane, butanes, pentanes, hexanes, benzene, toluene, xylenes, and mixtures thereof. 
     
     
         25 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of displacing the adsorbed contaminants by other compound(s) which is (are) preferentially adsorbed on the adsorbent more strongly than the contaminants. 
     
     
         26 . A process according to  claim 1 , wherein said aromatic feed pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of the spent adsorbent includes a step of acid treatment. 
     
     
         27 . A process according to  claim 1 , wherein said olefin feed contains olefins containing 2 to 4 carbon atoms. 
     
     
         28 . A process according to  claim 1 , wherein said olefin feed contains at least one member selected from the group consisting of ethylene, propylene, 1-butene, cis-2-butene, trans-2-butene, isobutene, and mixtures thereof. 
     
     
         29 . A process according to  claim 1 , wherein said aromatic feed contains at least one member selected from the group consisting of: benzene, toluene, ethylbenzene, xylenes, cumene, n-propyl benzene, butylbenzenes and mixtures thereof. 
     
     
         30 . A process according to  claim 1 , wherein said aromatic feed comprises benzene. 
     
     
         31 . A process according to  claim 1 , wherein said desired alkyl aromatic compound(s) consists of at least one member selected from the group consisting of ethylbenzene, cumene, n-propyl benzene, butylbenzenes, diethylbenzenes, diisopropylbenzenes, dibutylbenzenes, ethyltoluenes, cymenes, butyltoluenes, ethylcumenes, butyl ethylbenzenes, butylcumenes, and mixtures thereof. 
     
     
         32 . A process according to  claim 1 , wherein said desired alkyl aromatic compound(s) consists of at least one member selected from the group consisting of: ethylbenzene, cumene, diethylbenzene isomer mixture, para-diethylbenzene, meta-diethylbenzene, diisopropylbenzene isomer mixture, para-diisopropylbenzene, meta-diisopropylbenzene, and mixtures thereof. 
     
     
         33 . A process according to  claim 1 , wherein said reaction section contains one or more acidic zeolite catalysts. 
     
     
         34 . A process according to  claim 1 , wherein said reaction section contains one or more acidic zeolite catalysts selected from the group consisting of: zeolite beta, zeolite Y, ZSM-5, ZSM-12, MCM-22, MCM-36, MCM-49, MCM-56, MCM-58, MCM-68, Faujasite, Mordenite, zirconium phosphate, and porous crystalline magnesium silicates. 
     
     
         35 . A process for production of desired alkyl aromatic compound(s) from an aromatic feedstock and an olefin feedstock utilizing acidic zeolite catalyst(s) wherein: (a) the aromatic feedstock or the olefin feedstock is pretreated to remove or substantially reduce nitrogen compound(s) that can lead to deactivation of the acidic zeolite catalyst(s) used in the reaction section of the plant utilizing one or more pretreatment steps including at least one selected from the group consisting of distillation, extraction, and selective adsorption; (b) the selective adsorption step(s) utilizes at least one regenerable adsorbent selected from the group consisting of zeolites, zeolite catalysts, molecular sieves, silicates, aluminas, activated aluminas, activated carbon, silica gels, and ion exchange resins; (c) spent adsorbent is regenerated at least two times in situ by at least one of the following procedures: (i) subjecting the spent adsorbent under elevated temperatures to a flow of an inert gas or inert liquid; (ii) displacing the adsorbed contaminants by other compound(s) which is (are) preferentially adsorbed on the adsorbent more strongly than the contaminants, and (iii) acid treatments; (d) the treated aromatic and/or olefin feedstocks are then reacted in the reaction section to produce the desired alkyl aromatic compound(s); and, (e) a distillation section is used to isolate the desired alkyl aromatic compound(s), recycle unreacted feedstock and recoverable byproducts, and purge unrecoverable byproducts. 
     
     
         36 . A process according to  claim 35 , wherein the feedstock is pretreated as it enters the process, together with other pretreatment and/or purification steps, or after other pretreatment and/or purification steps but prior to entering the reaction section. 
     
     
         37 . A process according to  claim 35 , wherein the feedstock is pretreated together with other stream(s) in the process or after it is pretreated and/or purified together with other stream(s) in the process by other pretreatment and/or purification steps. 
     
     
         38 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a step of selective adsorption with a regenerable adsorbent, and further wherein regeneration of spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert gas selected from the group consisting of nitrogen, air, natural gas, liquefied petroleum gas, methane, ethane, propane, butanes, pentanes, steam and mixtures thereof. 
     
     
         39 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a selective adsorption step with a regenerable adsorbent, and further wherein regeneration of spent adsorbent includes a step of subjecting spent adsorbent at elevated temperatures to a flow of a substantially inert liquid selected from the group consisting of liquefied petroleum gas, ethane, propane, butanes, pentanes, hexanes, benzene, toluene, xylenes and mixtures thereof. 
     
     
         40 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a distillation step. 
     
     
         41 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a distillation step, in which at least one nitrogen contaminant is removed at or near the top of a distillation column and the pretreated feedstock is recovered at or near the bottom of the column. 
     
     
         42 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a distillation step, in which at least one nitrogen contaminant is removed at or near the bottom of a distillation column and the pretreated feedstock is recovered at or near the top of the column. 
     
     
         43 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least a distillation step, in which at least one light nitrogen compound and/or other light impurities are removed at or near the top of a distillation column, at least one heavy nitrogen compound and/or other heavy impurities are removed at or near the bottom of the distillation column, and the pretreated feedstock is recovered as a side draw. 
     
     
         44 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least an extraction step. 
     
     
         45 . A process according to  claim 35 , wherein at least one feedstock pretreatment includes at least an extraction step, in which the aromatic feedstock is extracted with water and/or acidified water. 
     
     
         46 . A process according to  claim 35 , wherein said olefin feedstock contains olefins having 2 to 4 carbon atoms. 
     
     
         47 . A process according to  claim 35 , wherein said olefin feedstock is selected from the group consisting of ethylene, propylene, 1-butene, cis-2-butene, trans-2-butene, isobutene, and mixtures thereof. 
     
     
         48 . A process according to  claim 35 , wherein said aromatic feedstock is selected from the group consisting of: benzene, toluene, ethylbenzene, xylenes, cumene, n-propyl benzene, butylbenzenes and mixtures thereof. 
     
     
         49 . A process according to  claim 35 , wherein said aromatic feedstock is benzene. 
     
     
         50 . A process according to  claim 35 , wherein said desired alkyl aromatic compound(s) comprise of at least one selected from the group consisting of ethylbenzene, cumene, n-propyl benzene, butylbenzenes, diethylbenzenes, diisopropylbenzenes, dibutylbenzenes, ethyltoluenes, cymenes, butyltoluenes, ethylcumenes, butyl ethylbenzenes, butylcumenes, and mixtures thereof. 
     
     
         51 . A process according to  claim 35 , wherein said desired alkyl aromatic compound(s) comprise of at least one selected from the group consisting of ethylbenzene, cumene, diethylbenzene isomer mixture, para-diethylbenzene, meta-diethylbenzene, diisopropylbenzene isomer mixture, para-diisopropylbenzene, meta-diisopropylbenzene, and mixtures thereof. 
     
     
         52 . A process according to  claim 35 , wherein said reaction section contains one or more acidic zeolite catalysts. 
     
     
         53 . A process according to  claim 35 , wherein said reaction section contains one or more acidic zeolite catalysts selected from the group consisting of zeolite beta, zeolite Y, ZSM-5, ZSM-12, MCM-22, MCM-36, MCM-49, MCM-56, MCM-58, MCM-68, Faujasite, Mordenite, zirconium phosphate, and porous crystalline magnesium silicates. 
     
     
         54 . A process for production of desired alkyl aromatic compound(s) from an aromatic feedstock and an olefin feedstock utilizing acidic zeolite catalyst(s) wherein: (a) the aromatic feedstock and the olefin feedstock are pretreated to remove or substantially reduce nitrogen compound(s) that can lead to deactivation of the acidic zeolite catalyst(s) used in the reaction section of the plant utilizing one or more pretreatment steps including at least one selected from the group consisting of distillation, extraction, and selective adsorption; (b) the selective adsorption step(s) utilizes at least one regenerable adsorbent selected from the group consisting of zeolites, zeolite catalysts, molecular sieves, silicates, aluminas, activated aluminas, activated carbon, silica gels, and ion exchange resins; (c) spent adsorbent is regenerated at least two times in situ by at least one of the following procedures: (i) subjecting the spent adsorbent under elevated temperatures to a flow of an inert gas or inert liquid; (ii) displacing the adsorbed contaminants by other compound(s) which is (are) preferentially adsorbed on the adsorbent more strongly than the contaminants, and (iii) acid treatments; (d) the treated aromatic and/or olefin feedstocks are then reacted in the reaction section to produce the desired alkyl aromatic compound(s); and, (e) a distillation section is used to isolate the desired alkyl aromatic compound(s), recycle unreacted feedstock and recoverable byproducts, and purge unrecoverable byproducts. 
     
     
         55 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the aromatic feed contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising:
 (a) treating the aromatic feed to said reaction section by distillation to substantially separate nitrogen contaminants having high volatility relative to said aromatic feed, or nitrogen contaminants having low volatility relative to said aromatic feed, or both from the aromatic feed, such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s); wherein said nitrogen contaminant(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia; and,   (b) passing the aromatic feed pretreated in accordance with step (a) to said reaction section.   
     
     
         56 . In a process for production of desired alkyl aromatic compound(s) from an aromatic feedstock and an olefin feedstock utilizing acidic zeolite catalyst(s) wherein:
 (a) the aromatic feedstock is pretreated to remove or substantially reduce nitrogen compound(s) that can lead to deactivation of the acidic zeolite catalyst(s) used in the reaction section of the plant utilizing a distillation step to remove said nitrogen compounds from the aromatic feedstock; wherein said nitrogen compound(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia;   (b) the treated aromatic feedstock is then reacted with the olefin feedstock in the reaction section to produce the desired alkyl aromatic compound(s); and,   (c) a distillation section is used to isolate the desired alkyl aromatic compound(s), recycle unreacted feedstock and recoverable byproducts, and purge unrecoverable byproducts.   
     
     
         57 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the aromatic feed contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising:
 (a) treating the aromatic feed to said reaction section by extraction with a suitable extractant to substantially separate nitrogen contaminants which are preferentially soluble in said extractant from the aromatic feed, such contaminants are present in the aromatic feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s); wherein said nitrogen contaminant(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia; and,   (b) passing the aromatic feed pretreated in accordance with step (a) to said reaction section.   
     
     
         58 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the aromatic feed contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising:
 (a) treating the aromatic feed to said reaction section by selective adsorption with a regenerable adsorbent to substantially separate nitrogen contaminants, such contaminants are present in the aromatic feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s); wherein said nitrogen contaminant(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia; and,   (b) passing the aromatic feed pretreated in accordance with step (a) to said reaction section.   
     
     
         59 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the olefin feed contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising:
 (a) treating the olefin feed to said reaction section by selective adsorption with a regenerable adsorbent to substantially separate nitrogen contaminants, such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s); wherein said nitrogen contaminant(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia; and,   (b) passing the olefin feed pretreated in accordance with step (a) to said reaction section.   
     
     
         60 . In a process for producing desired alkyl aromatic compound(s) by reacting an olefin feed with an aromatic feed in a reaction section in the presence of acidic zeolite catalyst(s) wherein the olefin feed contains at least a contaminant in an amount sufficient to adversely affect the performance of the acidic zeolite catalyst(s), the improvements comprising:
 (a) treating the olefin feed to said reaction section by extraction with a suitable extractant to substantially separate nitrogen contaminants which are preferentially soluble in said extractant from the olefin feed, such contaminants are present in the olefin feed in amounts sufficient to adversely affect the performance of the acidic zeolite catalyst(s); wherein said nitrogen contaminant(s) comprises at least one of n-formyl morpholine, n-methylpyrrolidinone and ammonia; and,   (b) passing the olefin feed pretreated in accordance with step (a) to said reaction section.