Process for production of high-octane gasoline

Abstract

The invention provides a process for production of high-octane gasoline from a C 6 -C 10 hydrocarbon feed stream by selective dehydrogenation of cycloparaffins without substantially affecting aromatics and paraffins present in the feed. It involves a catalyst comprising a Group VIII metal supported on a substantially non-acidic porous material with concentration of acidic sites lower than 1 μmole/g. The catalyst in the selective dehydrogenation typically comprises palladium, platinum, rhodium, iridium or mixtures thereof in an amount of 0.1 wt % to 1.0 wt % supported on a carrier material selected from silica, alumina, zirconia, titania, or mixtures thereof, other oxides, carbons, carbides and nitrides. The process for the production of high-octane gasoline from a C 6 -C 10 hydrocarbon feed can be a combination of a catalytic dehydrogenation step, a catalytic isomerisation step and one or more separation steps.

1 . A process for production of high-octane gasoline from a C 6 -C 10  hydrocarbon feed stream comprising the step of selective dehydrogenation of cycloparaffins, wherein the dehydrogenation takes place in presence of a catalyst comprising one or more Group VIII metal supported on a porous material with concentration of acidic sites lower than 1 μmole/g.  
   
   
       2 . A process according to  claim 1 , wherein the catalyst in the dehydrogenation step comprises palladium, platinum, rhodium, iridium or mixtures thereof in an amount of 0.1 wt % to 1.0 wt % supported on a carrier material selected from silica, alumina, zirconia, titania, or mixtures thereof, other oxides, carbons, carbides and nitrides.  
   
   
       3 . A process according to  claim 1 , wherein the dehydrogenation step is performed at temperatures between 350° C. and 550° C., in presence of hydrogen, at a total pressure between 5 to 50 bar and with a hydrogen to hydrocarbon molar ratio between 1 to 5.  
   
   
       4 . A process according to  claim 1 , comprising further steps of 
 catalytic isomerization step converting linear and mono-branched isomers to multi-branched paraffins and/or cyclo-pentane derivates to cyclo-hexane derivates, and separation step separating aromatic compounds and multi-branched isomers from non-converted cyclo-alkanes, linear and mono-branched paraffins.    
   
   
       5 . A process according to  claim 4 , wherein the catalyst in the isomerisation step comprises an acidic mesoporous material.  
   
   
       6 . A process according to  claim 5 , wherein the mesoporous material comprises tungsten oxide supported on zirconia, titania, alumina, silica, hafnia or tin oxide or mixture thereof with tungsten content between 5 wt % to 50 wt % and palladium, platinum or mixtures thereof with a loading 0.01 wt % to 2 wt %.  
   
   
       7 . A process according to  claim 4 , wherein the isomerisation step is performed in the presence of hydrogen with a hydrogen to hydrocarbon molar ratio between 0.1 to 5, in the temperature range 150° C. to 300° C., at a total pressure between 1 and 40 bar and with a liquid space velocity LHSV between 0.1 to 30 h −1.    
   
   
       8 . A process according to  claim 4 , wherein the non-converted cyclo-alkanes, the linear and the mono-branched paraffins are separated from the multi-branched paraffins and the aromatic compounds and said non-converted cyclo-alkanes and linear and mono-branched paraffins are recycled to the isomerisation or to the dehydrogenation step.