Bimetallic Catalytic Reforming with Water Addition

Claim 2

A process as defined in claim 1 wherein the platinum group metal component of the composite is palladium metal.

Claim 3

A process as defined in claim 1 wherein the platinum group metal component of the composite is iridIum metal.

Claim 4

A process as defined in claim 1 wherein the porous carrier material is a refractory inorganic oxide.

Claim 5

A process as defined in claim 5 wherein the refractory inorganic oxide is alumina.

Claim 6

A process as defined in claim 1 wherein the halogen component of the composite is combined chloride.

Claim 7

A process as defined in claim 1 wherein the tin component of the composite is in the form of tin oxide.

Claim 8

A process as defined in claim 1 wherein the catalytic composite contains, on an elemental basis, about 0.05 to about 5 wt. % sulfur.

Claim 9

A process as defined in claim 1 wherein a halogen additive is also introduced into the reforming zone in an amount sufficient to result in a mole ratio of water entering the zone to halogen entering the zone of about 10:1 to about 100:1.

Claim 10

A process as defined in claim 1 wherein at least a portion of the water or water-producing substance introduced into said zone is an oxygen-containing organic compound which is commingled with said gasoline fraction prior to introducing same into the reforming zone.

Claim 11

A process as defined in claim 1 wherein at least a portion of water or a water-producing substance introduced into said zone is water which is admixed with said hydrogen stream prior to introduction of same into the zone.

Claim 12

A process as defined in claim 1 wherein at least a portion of the water or water-producing substance introduced into the reforming zone is a C2 to C8 alcohol.

Claim 13

A process as defined in claim 1 wherein the total amount of water or water-producing substance introduced into said zone is about 25 wt. ppm. of the gasoline fraction.

Claim 14

In a process for reforming a gasoline fraction wherein the gasoline fraction and a hydrogen stream are contacted in a reforming zone maintained at reforming conditions, with a catalyst comprising a combination of a platinum group component, a tin component and a halogen component with a porous carrier material, in which catalyst the components are present therein in amounts, calculated on an elemental basis, corresponding to about 0.01 to 2 wt. percent platinum group metal, about 0.01 to about 5 wt. percent tin and about 0.1 to about 3.5 wt. percent halogen, in which catalyst the tin component is uniformly dispersed throughout the porous carrier material in a particle size of less than about 100 Angstroms in maximum dimension, in which catalyst substantially all of the platinum group component is present as an elemental metal and substantially all of the tin component is present in an oxidation state above that of the elemental metal, in which process said contacting is performed with no water addition and with the reforming zone maintained substantially free of water or water-producing substances and in which process the initial activity and selectivity characteristics of said catalyst are observed to decay at an accelerated rate after an initial period corresponding to about 0.5 to about 15 barrels of gasoline fraction charged per pound of catalyst, the improvement which comprises continuously introducing water or a water-producing substance into the reforming zone after said initial period in an amount corresponding to about 10 to about 50 wt. ppm. of the gasoline fraction, calculated on the basis of equivalent water, thereby sharply improving the activity and selectivity characteristics of said catalyst.

Claim 15

An improved process as defined in claim 15 wherein a halogen or halogen-containing compound is continuously introduced into the reforming zone after the initial period in an amount sufficient to result in a mole ratio of water entering the zone to halogen entering the zone selected from the range of 10:1 to about 100:1.

Claim 16

An improved process as defined in claim 15 wherein at least a portion of the water or water-producing substance introduced into said zone is a C2 to C8 alcohol.