Catalyst and Its Use in Hydrocarbon Conversion Process

Abstract

The invention relates to catalysts and their use in processes for conversion of hydrocarbon feedstock to a product comprising single-ring aromatic hydrocarbons having six or more carbon atoms, to the methods of making such catalysts, to processes for using such catalysts, and to apparatus and systems for carrying out such processes. One of more of the catalysts comprise a crystalline aluminosilicate having a Constraint Index in the range of 1 to 12, a first metal and/or a second metal, and at least one selectivating agent, such as, for example, an organo-silicate.

1 . A catalyst comprising:
 (a) a crystalline aluminosilicate having a Constraint Index in the range of 1 to 12;   (b) a first metal; and   (c) at least one selectivating agent selected from the group consisting of an organo-aluminate, an organo-phosphate, and mixtures thereof.   
     
     
         2 . The catalyst of  claim 1 , further comprising a second metal, wherein said second metal is different from said first metal. 
     
     
         3 . A catalyst comprising:
 (a) a crystalline aluminosilicate having a Constraint Index in the range of 1 to 12;   (b) a first metal and a second metal, wherein said second metal is different from said first metal; and   (c) at least one organo-silicate selectivating agent.   
     
     
         4 . The catalyst of  claim 3 , wherein said second metal is selected from the group consisting of lanthanum, rhenium, silver, palladium, tin, molybdenum, and mixtures of two or more thereof. 
     
     
         5 . The catalyst of  claim 3 , wherein said second metal is lanthanum. 
     
     
         6 . The catalyst of  claim 3 , wherein said catalyst has from about 0.005 wt. % to about 1.5 wt. % of said second metal, based on the weight of said catalyst. 
     
     
         7 . The catalyst of  claim 3 , wherein said organo-silicate selectivating agent is a tetraalkyl orthosilicate selected from the group consisting of a tetramethyl orthosilicate (TMOS), a tetraethyl orthosilicate (TEOS), a tetrapropyl orthosilicate (TPOS), and mixtures of two or more thereof. 
     
     
         8 . The catalyst of  claim 3 , wherein said crystalline aluminosilicate zeolite has a Constraint Index of 1 to 12 is selected from the group consisting of a MCM-22 family material, ZSM-5, ZSM-11, ZSM-12, ZSM-21, ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48, ZSM-50, ZSM-57, MCM-68, and mixtures of two or more thereof. 
     
     
         9 . The catalyst of  claim 3 , wherein said first metal is selected from the group consisting of zinc, gallium, platinum, copper, rhenium, iron, and mixtures of two or more thereof. 
     
     
         10 . The catalyst of  claim 3 , wherein said first metal is zinc. 
     
     
         11 . The catalyst of  claim 3 , wherein said catalyst has from about 0.005 wt. % to about 1.5 wt. % of said first metal, based on the weight of said catalyst. 
     
     
         12 . The catalyst of  claim 3 , wherein said catalyst has at least about 0.005 wt. % of said selectivating agent, based on the weight of said catalyst. 
     
     
         13 . The catalyst of  claim 3 , wherein said catalyst has over about 40% reaction selectivity to single-ring aromatic hydrocarbon and/or less than about 10% reaction selectivity to multiple-ring aromatic compounds, in a process for conversion of a light paraffinic hydrocarbon feedstock comprising one or more light hydrocarbons having no more than five carbon atoms to form a product comprising at least one single-ring aromatic hydrocarbon under conversion conditions which include at least a temperature in the range of about 450° C. to about 750° C., a pressure in the range of from about 35 kPa to about 1480 kPa and a WHSV from about 0.1 hr −1  to about 20 hr −1 , wherein said single-ring aromatic hydrocarbon is selected from the group consisting of benzene, toluene and xylene, and mixtures of two or more thereof, and said multiple-ring compound is naphthalene. 
     
     
         14 . A selectivated catalyst comprising:
 (a) ZSM-5 or ZSM-11;   (b) zinc;   (c) lanthanum; and   (d) at least 0.005 wt. % of a tetraalkyl orthosilicate selectivating agent, based on the weight of said selectivated catalyst, said tetraalkyl orthosilicate selectivating agent is selected from the group consisting of a tetramethyl orthosilicate (TMOS), a tetraethyl orthosilicate (TEOS), a tetrapropyl orthosilicate (TPOS), and mixtures of two or more thereof,   wherein said selectivated catalyst provides over about 40% reaction selectivity to benzene, toluene or xylenes, and mixtures thereof, and/or less than about 10% reaction selectivity to naphthalene, in a process for conversion of a light paraffinic hydrocarbon feedstock comprising one or more light hydrocarbons having no more than five carbon atoms to form a product comprising at least one single-ring aromatic hydrocarbon under conversion conditions which include at least a temperature in the range of about 450° C. to about 750° C., a pressure in the range of from about 35 kPa to about 1480 kPa and a WHSV from about 0.1 hr −1  to about 20 hr −1 .   
     
     
         15 . The selectivated catalyst of  claim 14 , wherein said zinc and said lanthanum each, individually comprises 0.005 wt. % to 1.5 wt. %, based on the weight of said selectivated catalyst. 
     
     
         16 . A method of making a selectivated catalyst comprising the steps of:
 (a) providing a crystalline aluminosilicate comprising ZSM-5 or ZSM-11;   (b) contacting said crystalline aluminosilicate with a source of a first metal and a source of a second metal under conditions effective to deposit said first metal and said second metal on said crystalline aluminosilicate and form a metal-containing crystalline aluminosilicate, wherein said first metal is different from said second metal, said first metal is selected from the group consisting of zinc, gallium, platinum, copper, rhenium, iron, and mixtures of two or more thereof, and said second metal is selected from the group consisting of lanthanum, rhenium, silver, palladium, tin, molybdenum, and mixtures of two or more thereof; and   (c) selectivating said metal-containing crystalline aluminosilicate of step (b) by contacting with a selectivating agent under conditions effective to deposit said selectivating agent on said metal-containing crystalline aluminosilicate and form said selectivated catalyst, wherein said selectivating agent is a tetraalkyl orthosilicate selected from the group consisting of a tetramethyl orthosilicate (TMOS), a tetraethyl orthosilicate (TEOS), a tetrapropyl orthosilicate (TPOS), and mixtures of two or more thereof.   
     
     
         17 . The method of  claim 16 , wherein said selectivating step (c) is performed before said contacting step (b). 
     
     
         18 . The method of  claim 16 , which further comprises the step:
 (d) calcining said selectivated catalyst at a temperature of about 550° C. for 1 or more hours.   
     
     
         19 . The method of  claim 16 , wherein said first metal is zinc and said source of zinc is selected from the group consisting of zinc nitrate, zinc titanate, zinc silicate, zinc borate, zinc fluorosilicate, zinc fluorotitanate, zinc molybdate, zinc chromate, zinc tungstate, zinc zirconate, zinc chromite, zinc aluminate, zinc phosphate, zinc acetate dihydrate, diethyl zinc, zinc 2-ethylhexanoate, and mixtures of two or more thereof. 
     
     
         20 . The method of  claim 16 , wherein said second metal is lanthanum and said source of lanthanum is a lanthanum salt, a lanthanum nitrate, or a mixture thereof. 
     
     
         21 . A process for conversion of a light paraffinic hydrocarbon feedstock comprising one or more light hydrocarbons having no more than five carbon atoms to form a product comprising at least one single-ring aromatic hydrocarbon having six or more carbon atoms, said process comprising the step of contacting said feedstock under suitable conversion conditions in the presence of a catalyst of  claim 3 . 
     
     
         22 . The process of  claim 21 , wherein said one or more light hydrocarbons is selected from the group consisting of methane, ethane, propane, butane, and mixtures of two or more thereof. 
     
     
         23 . The process of  claim 21 , wherein said single-ring aromatic hydrocarbon is selected from the group consisting of benzene, toluene, xylenes, and mixtures of two or more thereof. 
     
     
         24 . The process of  claim 21 , wherein said suitable conversion conditions include at least a temperature of in the range of about 450° C. to about 750° C., a pressure in the range of from about 35 kPa to about 1480 kPa and a WHSV from about 0.1 hr −1  to about 20 hr −1 . 
     
     
         25 . The process of  claim 24 , wherein said catalyst provides over about 40% reaction selectivity to benzene, toluene or xylenes, and mixtures thereof, and/or less than about 10% reaction selectivity to naphthalene, in a process for conversion of a light paraffinic hydrocarbon feedstock comprising one or more light hydrocarbons having no more than five carbon atoms to form a product comprising at least one single-ring aromatic hydrocarbon under said suitable conversion conditions.