Process for the preparation of hydrogenated hydrocarbon compounds

Abstract

A process for the dehydrogenation of a paraffinic hydrocarbon compound, such as an alkane or alkylaromatic hydrocarbon compound to produce an unsaturated hydrocarbon compound, such as an olefin or vinyl aromatic compound or mixture thereof, in which a dehydrogenation catalyst contacts gaseous reactant hydrocarbons in a reactor at dehydrogenation conditions.

1 . A process for dehydrogenating an alkylaromatic hydrocarbon consisting essentially of ethylbenzene, propylbenzene, isopropyl benzene and methyl benzene comprising contacting a gaseous stream containing the at least one alkylaromatic hydrocarbon with a dehydrogenation catalyst at reaction temperature and in concurrent upward flow through a dehydrogenation riser reactor wherein the average contact time between the hydrocarbon and catalyst within the dehydrogenation riser reactor is from about 0.5 to about 10 seconds, and wherein the catalyst has an average residence time within the dehydrogenation riser reactor from about 0.5 to about 40 seconds;
 transferring the hydrocarbon and catalyst from the dehydrogenation reactor to a separation device wherein the average contact time between the hydrocarbon and catalyst while at reaction temperature in the separation device is less than about 10 seconds; and   transferring a portion of the catalyst from the separation device to a fluid bed catalyst regenerator, wherein the catalyst is regenerated.   
     
     
         2 . (canceled) 
     
     
         3 . A process of  claim 1  wherein the catalyst is gallium-based and the average residence time of the catalyst within the dehydrogenation riser reactor is from about 1.0 to about 12.0 seconds. 
     
     
         4 . A process of  claim 1  wherein the total average contact time between the hydrocarbon and catalyst while at reaction temperature in the dehydrogenation riser reactor and separation device is less than about 10 seconds. 
     
     
         5 . A process of  claim 4  wherein the average contact time between the hydrocarbon and the catalyst within the dehydrogenation riser reactor is from about 1 to about 4 seconds, the average contact time between the hydrocarbon and catalyst while at reaction temperature in the separation device is less than about 5 seconds, and the total average contact time in the dehydrogenation riser reactor is less than about 7 seconds. 
     
     
         6 .- 9 . (canceled) 
     
     
         10 . A process of  claim 1  wherein the temperature within the dehydrogenation reactor is from about 500 to about 800° C., and the pressure is from about 25.5 (3.7) to about 446 (64.7) kilopascals (psia). 
     
     
         11 .- 13 . (canceled) 
     
     
         14 . A process of  claim 10  wherein the catalyst from the recycle loop and regenerator are combined and introduced into the dehydrogenation reactor. 
     
     
         15 . The process of  claim 1  wherein the dehydrogenation catalyst comprises gallium carried by an alumina or alumina silica support. 
     
     
         16 . The process of  claim 15  wherein the catalyst comprises an alkali or alkaline earth metal selected from at least one of: sodium, lithium, potassium, rubidium, magnesium, calcium, strontium and barium, and further comprises promoter selected from at least one of: manganese and platinum. 
     
     
         17 .- 20 . (canceled) 
     
     
         21 . A process of  claim 1  wherein the contacting occurs in the absence of steam. 
     
     
         22 . A process of  claim 1  wherein the gaseous stream further contains one or more inert diluent carrier gases.