Process for the dehydrogenation of hydrocarbons

Abstract

A hydrocarbon dehydrogenation process utilizing a novel catalyst composite. The catalyst composite comprises a Group VIII noble metal component, a Group IA or IIA metal component, and a component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium, or mixtures thereof, all on an alumina support comprising essentially theta-alumina, having a surface area from about 50 to about 120 m 2 /g, an apparent bulk density of at 0.5 g/cm 3 and a mole ratio of the Group VIII noble metal component to the component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium or mixtures thereof in the range from about 1.5 to about 1.7.

What is claimed:  
     
         1 . A hydrocarbon dehydrogenation process comprising the steps of contacting a hydrocarbon at dehydrogenation conditions with a catalytic composite comprising a first component selected from Group VIII noble metal components or mixtures thereof, a second component in an amount from 0.9 to 1.1 weight percent, based on the total composite weight selected from the group consisting of alkali or alkaline earth metal components or mixtures thereof and a third component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium and mixtures thereof, all on an alumina support comprising essentially theta-alumina and having a surface area from about 50 to about 120 m 2 /g and an apparent bulk density of at least 0.5 g/cm 3  wherein the mole ratio of the first component to the third component is in the range from about 1.5 to about 1.7.  
     
     
         2 . The process of  claim 1  wherein the first component is platinum.  
     
     
         3 . The process of  claim 1  wherein the second components is potassium.  
     
     
         4 . The process of  claim 1  wherein the third component is tin.  
     
     
         5 . The process of  claim 1  wherein the catalytic composite comprises from about 0.01 to about 5 weight percent platinum, from 0.9 to 1.1 weight percent potassium and from about 0.01 to about 5 weight percent tin.  
     
     
         6 . The process of  claim 1  wherein the hydrocarbon comprises dehydrogenatable hydrocarbons having from 2 to 30 carbon atoms.  
     
     
         7 . The process of  claim 1  wherein the hydrogenation conditions include a temperature from about 400 to about 900° C., a pressure from about 0.01 to about 10 atmospheres and a liquid hourly space velocity (LHSV) from about 0.1 to about 100 hr−1.  
     
     
         8 . The process of  claim 6  wherein the dehydrogenatable hydrocarbons having from 2 to 30 carbon atoms are comprised of normal paraffins and branched paraffins.  
     
     
         9 . The process of  claim 8  wherein the dehydrogenatable hydrocarbons are comprised of propane and butanes.  
     
     
         10 . A hydrocarbon dehydrogenation process comprising the steps of contacting a hydrocarbon at dehydrogenation conditions with a catalytic composite comprising platinum, a potassium component in an amount from 0.9 to 1.1 weight percent based on the total composite weight and a tin component, all on an alumina support comprising essentially theta-alumina and having a surface are from about 50 to about 120 m 2 /g and an apparent bulk density of at least 0.5 g/cm 3  wherein the mole ratio of the platinum to tin is in the range from about 1.5 to about 1.7.  
     
     
         11 . A hydrocarbon dehydrogenation process comprising the steps of contacting a hydrocarbon selected from the group consisting essentially of propane and butane at dehydrogenation conditions including a temperature from about 400° to about 900° C., a pressure from about 200 kPa to about 20 MPa (0.01 to 10 atmospheres) and a liquid hourly space velocity (LHSV) from about 0.1 to about 100 hr −1  with a catalytic composite comprising platinum, a potassium component in an amount from 0.9 to 1.1 weight percent based on the total composite weight and a tin component, all on an alumina support comprising essentially theta-alumina and having a surface area from about 50 to about 120 m 2 /g and an apparent bulk density of at least 0.5 g/cm 3  wherein the mole ratio of the platinum to tin is in the range from about 1.5 to about 1.7.