Method For Producing Catalysts Having Increased Strength And Decreased Volume Reduction

Abstract

A method for producing catalysts containing copper, in particular for producing catalyst moldings having increased mechanical strength and low volume reduction, to the catalysts produced by means of the method according to the invention, and to the use of said catalysts as catalysts or as precursors and components for catalysts. The catalysts are suitable in particular for the synthesis of methanol and for the low-temperature conversion of CO into CO2.

1 . A method for the synthesis reaction of methanol from synthesis gas containing CO 2 , CO and H 2  comprising the step of exposing the reaction to a shaped body catalyst obtained by the process comprising the steps of:
 (a) combining an alkaline solution with a copper-containing solution obtained by dissolving and/or suspending a copper compound, a zinc compound and an aluminum compound, to form a precipitate;   (b) isolating the precipitate, with optional washing and/or optional drying thereof, to give a solid catalyst precursor;   (c) thermally treating a first part of the solid catalyst precursor at a temperature in the range from 450° C. to 600° C. to provide a thermally-treated mixed oxide containing copper, zinc and aluminum, while not thermally treating a second part of the solid catalyst precursor to provide a thermally-untreated solid catalyst precursor containing copper, zinc and aluminum;   (d) mixing the thermally-untreated solid catalyst precursor with the thermally-treated mixed oxide in a weight ratio of solid catalyst precursor to thermally-treated mixed oxide in the range of 5:95 to 15:85, to give a mixture; and   (e) tableting the mixture of the thermally-untreated solid catalyst precursor and the thermally-treated mixed oxide obtained in step (d),   wherein a Cu/Zn atomic ratio of the shaped catalyst body is from 15:85 to 85:15 and a Zn/Al atomic ratio of the shaped catalyst body is from 60:40 to 80:20.   
     
     
         2 . A method for the conversion reaction of CO into CO 2  comprising the step of exposing the reaction to a shaped body catalyst obtained by the process comprising the steps of:
 (a) combining an alkaline solution with a copper-containing solution obtained by dissolving and/or suspending a copper compound, a zinc compound and an aluminum compound, to form a precipitate;   (b) isolating the precipitate, with optional washing and/or optional drying thereof, to give a solid catalyst precursor;   (c) thermally treating a first part of the solid catalyst precursor at a temperature in the range from 450° C. to 600° C. to provide a thermally-treated mixed oxide containing copper, zinc and aluminum, while not thermally treating a second part of the solid catalyst precursor to provide a thermally-untreated solid catalyst precursor containing copper, zinc and aluminum;   (d) mixing the thermally-untreated solid catalyst precursor with the thermally-treated mixed oxide in a weight ratio of solid catalyst precursor to thermally-treated mixed oxide in the range of 5:95 to 15:85, to give a mixture; and   (e) tableting the mixture of the thermally-untreated solid catalyst precursor and the thermally-treated mixed oxide obtained in step (d),   wherein a Cu/Zn atomic ratio of the shaped catalyst body is from 15:85 to 85:15 and a Zn/Al atomic ratio of the shaped catalyst body is from 60:40 to 80:20.   
     
     
         3 . The method as claimed in  claim 1 , wherein the reaction occurs at a space velocity in the range from 2000 to 22 000 h −1 , a pressure in the range from 60 to 100 bar and/or a temperature in the range from 200° C. to 300° C. 
     
     
         4 . The method as claimed in  claim 1 , wherein the synthesis gas consists of from 5% by volume to 25% by volume of carbon monoxide, from 6% by volume to 12% by volume of carbon dioxide, from 10% by volume to 30% by volume of inert gases, with hydrogen as balance. 
     
     
         5 . The method as claimed in  claim 2 , wherein the reaction occurs at a pressure in the range from 1 to 40 bar and a temperature in the range from 170° C. to 270° C. 
     
     
         6 . The method as claimed in  claim 2 , wherein the reaction occurs at a pressure in the range from 10 to 35 bar and a temperature in the range from 190° C. to 240° C. 
     
     
         7 . The method as claimed in  claim 1 , wherein the shaped catalyst body has a lateral compressive strength based on the pellet weight of 500 N/g or more. 
     
     
         8 . The method as claimed in  claim 1 , wherein the shaped catalyst body has a loss on ignition of 7.5% by weight or less. 
     
     
         9 . The method as claimed in  claim 1 , wherein the copper-containing solution in step (a) comprises an aluminum hydroxide sol. 
     
     
         10 . The method as claimed in  claim 1 , wherein the copper-containing solution has a pH of 3.0. 
     
     
         11 . The method as claimed in  claim 1 , wherein the shaped catalyst body has a volume shrinkage upon reduction of 6% or less. 
     
     
         12 . The method as claimed in  claim 1 , further comprising the step of:
 (f) reduction of the tableted mixture obtained in step (e).   
     
     
         13 . The method as claimed in  claim 12 , wherein reduction is carried about by means of hydrogen. 
     
     
         14 . The process as claimed in  claim 1 , wherein the Cu/Zn atomic ratio of the shaped catalyst body is from 60:40 to 75:25. 
     
     
         15 . The method as claimed in  claim 1 , wherein the Zn/Al atomic ratio of the shaped catalyst body is from 70:30 to 80:20. 
     
     
         16 . The method as claimed in  claim 1 , wherein the thermally-untreated solid catalyst is mixed with the mixed oxide in a weight ratio of thermally-untreated solid catalyst precursor to mixed oxide in the range of 10:90 to 15:85. 
     
     
         17 . The process of  claim 1 , wherein the mixed oxide has a BET surface area in the range of 80 m 2 /g to 140 m 2 /g. 
     
     
         18 . The method as claimed in  claim 1 , wherein the Cu/Zn atomic ratio of the shaped catalyst body is from 60:40 to 75:25 and the Zn/Al atomic ratio of the shaped catalyst body is from 70:30 to 80:20. 
     
     
         19 . The method as claimed in  claim 1 , wherein the shaped catalyst body has a lateral compressive strength based on the pellet weight of 500 N/g or more and a loss on ignition of 7.5% by weight or less. 
     
     
         20 . The method as claimed in  claim 1 , wherein the shaped catalyst body has a lateral compressive strength based on the pellet weight of 500 N/g or more and a volume shrinkage upon reduction of 6% or less.