Novel catalyst and process for hydrogenation of unsaturated hydrocarbons

Claim 2

A process for selectively hydrogenating an impurity selected from the group consisting of acetylenic compounds, dienes and mixtures thereof in a feed containing at least one mono-olefin and said impurity, comprising: selectively hydrogenating said impurity in the presence of a catalyst consisting essentially of palladium supported on an alumina support which is substantially crystalline alpha-alumina, said support having been calcined at a temperature of at least 1150° C. and no greater than 1400° C., said palladium being present on said support in an amount effective to catalyze said selective hydrogenation, said catalyst having an average pore radius of from 200 to 2000 Å, with at least 80% of the pores having a pore radius within the range of from 100 to 3000 Å.

Claim 3

The process of claim 1, wherein the palladium is present in an amount of at least 0.1 percent, by weight.

Claim 4

The process of claim 2, wherein the palladium content is no greater than 1 percent by weight.

Claim 5

The process of claim 3, wherein the surface area is no greater than 50 m 2 /g.

Claim 6

The process of claim 4, wherein the support is prepared by calcining a mixture of β-Al 2 O 3 .3H 2 O, α-Al 2 O 3 .H 2 O and amorphous aluminum hydroxide containing from 5% to 35%, by weight, of β-Al 2 O 3 .3H 2 O, said calcining being effected at a temperature of at least 1150° C. and no greater thatn 1400° C.

Claim 7

The process of claim 5, wherein the surface area is from 3 to 30 m 2 /g.

Claim 8

The process of claim 5, wherein the porosity is from 0.2 to 1.0 ml/g.

Claim 9

The process of claim 7, wherein the surface acidity is from 0.002 to 0.05 millimole of pyridine absorbed per gram of catalyst.

Claim 10

The process of claim 8, wherein the palladium is present mainly in the regions of the support which are at least 160 microns below the geometric surface.

Claim 11

The process of claim 9, wherein the palladium is present mainly in the regions of the support which are at least 500 microns below the geometric surface.

Claim 12

The process of claim 5, wherein the selective hydrogenation is effected in a single stage.

Claim 13

The process of claim 11, wherein the liquid hourly space velocity is from 50 to 170 hours -1 .

Claim 14

The process of claim 12, wherein the olefin feed is introduced into the single stage as a liquid.

Claim 15

The process of claim 13, wherein the inlet temperature is from 0° C. to 50° C., the outlet temperature does not exceed 60° C. and the pressure is from 14 to 35 Kg/cm 2 .

Claim 16

The process of claim 13, wherein no more than 5% wt. of the feed is vaporized during the hydrogenation.

Claim 17

The process of claim 13, wherein more than 5% wt. of the feed is vaporized during the hydrogenation.

Claim 18

The process of claim 14 wherein the olefin feed is a propylene feed including methylacetylene and propadiene as impurities.

Claim 19

The process of claim 17, wherein the effluent from the hydrogenation contains no more than 1000 ppm of diene and acetylene impurities.

Claim 20

The process of claim 1, wherein the active palladium surface area is from 20 to 200 m 2 /g and the palladium is in the form of crystallites having an average size of at least 25 Å.

Claim 21

The process of claim 17, wherein the effluent from the hydrogenation contains less than 5 ppm of each of methyl acetylene and propadiene.

Claim 22

A process for selectively hydrogenating an impurity in a propylene feed, said impurity being selected from the group conisting of propadiene, methylacetylene and mixtures thereof comprising: selectively hydrogenating said impurity in the presence of a catalyst consisting essentially of palladium supported on an alumina support which is substantially crystalline alpha alumina, said palladium being present on said support in an amount effective to catalyze said selective hydrogenation, said catalyst having an average pore size of from 200 to 2000 Å, with at least 80% of the pores having a pore radius within the range of from 100 to 3000 Å, said support having been prepared by calcining a mixture of β-Al 2 O 3 .3H 2 O, α-Al 2 O 3 .3H 2 O and amorphous aluminum hydroxide containing from 5% to 35%, by weight, of β-Al 2 O 3 .3H 2 O, said calcining being effected at a temperature of at least 1150° C. and no greater than 1400° C., said catalyst having a surface area of no greater than 50 m 2 /g, said palladium being present mainly in the regions of the support which are at least 60 microns below the geometric surface, said selective hydrogenating being effected at an inlet temperature of from 0° C., to 60° C. and at an outlet temperature which does not exceed 60° C., said propylene feed being introduced to the hydrogenating as a liquid, said hydrogenating producing an effluent containing no more than 1000 ppm of propadiene and methylacetylene impuriities, said hydrogenating of the impurities being 30% to 90% selective to propylene.

Claim 23

A process for selectively hydrogenating an impurity in a propylene feed, said impurity being selected from the group conisting of propadiene, methylacetylene and mixtures thereof comprising: selectively hydrogenating said impurity in the presence of a catalyst consisting essentially of palladium supported on an alumina support which is substantially crystalline alpha alumina, said palladium being present on said support in an amount effective to catalyze said selective hydrogenation, said catalyst having an average pore size of from 200 to 2000 Å, with at least 80% of the pores having a pore radius within the range of from 100 to 3000 Å, said support having been prepared by calcining a mixture of β-Al 2 O 3 .3H 2 O, α-Al 2 O 3 .3H 2 O and amorphous aluminum hydroxide containing from 5% to 35%, by weight, of β-Al 2 O 3 .3H 2 O, said calcining being effected at a temperature of at least 1150° C. and no greater than 1400° C., said catalyst having a surface area of no greater than 50 m 2 /g, said palladium being present mainly in the regions of the support which are at least 60 microns below the geometric surface, said selective hydrogenating being effected at an inlet temperature of from 0° C., to 60° C. and at an outlet temperature which does not exceed 60° C., said propylene feed being introduced to the hydrogenating as a liquid, said hydrogenating producing an effluent containing no more than 1000 ppm of propadiene and methylacetylene impuriities, said hydrogenating of the impurities being 30% to 90% selective to propylene.

Claim 24

The process of cklaim 1 wherein the hydrogenating is effected with a hydrogen to impurity ratio of from 1 to 2.5 moles of hydrogen per mole of impurity.

Claim 25

The process of cklaim 1 wherein the hydrogenating is effected with a hydrogen to impurity ratio of from 1 to 2.5 moles of hydrogen per mole of impurity.

Claim 26

The process of claim 22 wherein the hydrogenating is effected at a pressure of from 14 to 35 kg/cm 2 .

Claim 27

The process of claim 23 wherein the hydrogenating is effected in a single stage.

Claim 28

The process of claim 24 wherein the surface acidity is from 0.002 to 0.05 millimole of pyridine absorbed per gram of catalyst.

Claim 29

The process of claim 25 wherein the surface area is from 3 to 30 m 2 /g.

Claim 30

The process of claim 1 wherein the liquid hourly space velocity is from 50 to 170 hours -1 .