Reactor system and process for the manufacture of ethylene oxide

Abstract

A reactor system for the oxidation of ethylene to ethylene oxide. The reactor system includes a reactor tube that contains a packed bed of shaped support material that can include a catalytic component. The shaped support material has a hollow cylinder geometric configuration. The reactor system has specific combinations of reactor tube and catalyst system geometries.

That which is claimed is:  
     
         1 . A reactor system comprising: 
 an elongated tube having a tube length and a tube diameter of less than 28 mm which define a reaction zone; wherein contained within said reaction zone is a bed of shaped support material; wherein a major portion of said bed comprises said shaped support material; and wherein said shaped support material has a hollow cylinder geometric configuration defined by a ratio of nominal outside diameter-to-nominal inside diameter exceeding about 2.3, and a nominal length such that the ratio of said nominal length to said nominal outside diameter is greater than about 0.5.    
     
     
         2 . A reactor system as defined in  claim 1  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds about 2.6.  
     
     
         3 . A reactor system as defined in  claim 2  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds 2.9.  
     
     
         4 . A reactor system as defined in  claim 3  wherein said tube length is an effective tube length exceeding 3 meters.  
     
     
         5 . A reactor system as defined in  claim 4  wherein said major portion is at least half of said bed.  
     
     
         6 . A reactor system as defined in any one of claims  1  through  5  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from about 1.5 to about 7.  
     
     
         7 . A reactor system as defined in any one of claims  1  through  5  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from 2 to 6.  
     
     
         8 . A reactor system comprising: 
 an elongated tube having a tube length and a tube diameter of exceeding 28 mm which define a reaction zone; wherein contained within said reaction zone is a bed of shaped support material; wherein a major portion of said bed comprises said shaped support material; and wherein said shaped support material has a hollow cylinder geometric configuration defined by a ratio of nominal outside diameter-to-nominal inside diameter exceeding about 2.7, and a nominal length such that the ratio of said nominal length to said nominal outside diameter is greater than about 0.5.    
     
     
         9 . A reactor system as defined in  claim 8  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds about 3.0.  
     
     
         10 . A reactor system as defined in  claim 9  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds 3.3.  
     
     
         11 . A reactor system as defined in  claim 10  wherein said tube length is an effective tube length exceeding 3 meters.  
     
     
         12 . A reactor system as defined in  claim 11  wherein said major portion is at least half of said bed.  
     
     
         13 . A reactor system as defined in any one of claims  8  through  12  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from about 2 to about 10.  
     
     
         14 . A reactor system as defined in any one of claims  8  through  12  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from 2.5 to 7.5.  
     
     
         15 . A reactor system comprising: 
 an elongated tube having a tube length and a tube diameter of less than 28 mm which define a reaction zone; wherein contained within said reaction zone is a catalyst bed; wherein a major portion of said catalyst bed comprises a combination of a catalytic component and a shaped support material; and wherein said shaped support material has a hollow cylinder geometric configuration defined by a ratio of nominal outside diameter-to-nominal inside diameter exceeding about 2.3, and a nominal length such that the ratio of said nominal length to said nominal outside diameter is greater than about 0.5.    
     
     
         16 . A reactor system as defined in  claim 15  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds about 2.6.  
     
     
         17 . A reactor system as defined in  claim 16  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds 2.9.  
     
     
         18 . A reactor system as defined in  claim 17  wherein said tube length is an effective tube length exceeding 3 meters.  
     
     
         19 . A reactor system as defined in  claim 18  wherein said major portion is at least half of said bed.  
     
     
         20 . A reactor system as defined in any one of claims  15  through  19  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from about 1.5 to about 7.  
     
     
         21 . A reactor system as defined in any one of claims  15  through  19  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from 2 to 6.  
     
     
         22 . A reactor system comprising: 
 an elongated tube having a tube length and a tube diameter of exceeding 28 mm which define a reaction zone; wherein contained within said reaction zone is a catalyst bed; wherein a major portion of said catalyst bed comprises a combination of a catalytic component and a shaped support material; and wherein said shaped support material has a hollow cylinder geometric configuration defined by a ratio of nominal outside diameter-to-nominal inside diameter exceeding about 2.7, and a nominal length such that the ratio of said nominal length to said nominal outside diameter is greater than about 0.5.    
     
     
         23 . A reactor system as defined in  claim 22  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds about 3.0.  
     
     
         24 . A reactor system as defined in  claim 23  wherein said ratio of nominal outside diameter-to-nominal inside diameter exceeds 3.3.  
     
     
         25 . A reactor system as defined in  claim 24  wherein said tube length is an effective tube length exceeding 3 meters.  
     
     
         26 . A reactor system as defined in  claim 25  wherein said major portion is at least half of said bed.  
     
     
         27 . A reactor system as defined in any one of claims  22  through  26  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from about 2 to about 10.  
     
     
         28 . A reactor system as defined in any one of claims  22  through  26  wherein said reactor system is further defined as having a ratio of said tube diameter-to-said nominal outside diameter in the range of from 2.5 to 7.5.  
     
     
         29 . A reactor system; comprising: 
 an elongated tube having a tube length, an inlet tube end, an outlet tube end, and an inside tube surface which defines a reaction zone and a reaction zone diameter (D RX );    wherein contained within said reaction zone is a shaped support material having a hollow cylinder geometric configuration having a nominal inside diameter (ID), a nominal outside diameter (OD), and a nominal length (L);    wherein the ratio of said nominal length to said nominal outside diameter is at least about 0.5;    wherein the ratio of said reaction zone diameter to said nominal outside diameter is less than about 10; and    wherein the ratio of said nominal outside diameter to nominal inside diameter exceeds 2.3.    
     
     
         30 . A reactor system as defined in  claim 29  wherein the ratio of said nominal outside diameter to nominal inside diameter exceeds 2.9.  
     
     
         31 . A reactor system as defined in  claim 29  wherein the ratio of said nominal outside diameter to nominal inside diameter exceeds 3.0.  
     
     
         32 . A reactor system as defined in any one of claims  29  through  31  wherein the ratio of said reaction zone diameter to said nominal outside diameter is less than 7.5.  
     
     
         33 . A reactor system as defined in  claim 32  wherein said shaped support material further includes a catalytic component thereby providing a supported catalyst system.  
     
     
         34 . A process for manufacturing ethylene oxide, said process comprises: 
 providing a reactor system comprising an elongated tube having a tube length, an inlet tube end, an outlet tube end, and an inside tube surface which defines a reaction zone and a reaction zone diameter (D RX );    wherein contained within said reaction zone is a supported catalyst system, said supported catalyst system comprises a catalytic component supported by a shaped support material having a hollow cylinder geometric configuration having a nominal inside diameter (ID), a nominal outside diameter (OD), and a nominal length (L);    wherein the ratio of said nominal length to said nominal outside diameter is at least about 0.5;    wherein the ratio of said reaction zone diameter to said nominal outside diameter is less than about 5.5;    wherein the ratio of said nominal outside diameter to nominal inside diameter exceeds 2.3;    introducing into said inlet tube end a feedstock comprising ethylene and oxygen; and    withdrawing from said outlet tube end a reaction product comprising ethylene oxide and ethylene.    
     
     
         35 . A process as recited in  claim 34  wherein said reaction zone is maintained under suitable ethylene oxidative reaction conditions including a temperature in the range of from about 150° C. to about 400° C. and a pressure is in the range of from about 0.15 MPa to about 3 MPa.  
     
     
         36 . A process as recited in  claim 35 , wherein said shaped support material comprises predominantly alpha-alumina, and wherein said supported catalyst system is contained within a packed bed comprising a major portion of said supported catalyst system and having a tube packing density greater than about 550 kg per cubic meter.  
     
     
         37 . A process as recited in  claim 36 , wherein said reaction zone diameter exceeds about 20 mm.  
     
     
         38 . A process as recited in  claim 36 , wherein said tube length is 3 meters.  
     
     
         39 . A process as recited in  claim 36 , wherein said major portion is at least 80 percent of said packed bed.  
     
     
         40 . A process as recited in  claim 36 , wherein said ratio of said nominal length to said nominal outside is in the range of from about 0.8 to about 1.5, wherein said ratio of said reaction zone diameter to said nominal outside diameter is in the range of from about 2 to about 10; and wherein said ratio of said nominal outside diameter to said nominal inside diameter is in the range of from about 3 to about 500.  
     
     
         41 . A process as recited in  claim 34 , further comprising: 
 recovering from said reaction product a recovered ethylene product comprising ethylene and a recovered ethylene oxide product comprising ethylene oxide.    
     
     
         42 . A process as recited in  claim 41 , further comprising: 
 combining said recovered ethylene product with said feedstock prior to the introducing step.