Process for removal of arsenic from gases

Claim 2

A process for removing arsine impurities from a gaseous stream or, alternatively, a liquid stream by contacting said stream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide.

Claim 3

A process in accordance with claim 1 wherein said alkaline earth metal oxide is barium oxide.

Claim 4

A process in accordance with claim 1 wherein said gaseous stream is selected from the group consisting of hydrocarbons, industrial gases, fuels, inert gases and industrial effluents.

Claim 5

A process in accordance with claim 3 wherein said gaseous stream is a stream of hydrocarbons.

Claim 6

A process in accordance with claim 3 wherein said gaseous stream is a stream of an inert gas selected from the group consisting of helium, argon and nitrogen.

Claim 7

A process in accordance with claim 1 wherein said arsine has the formula AsR x H 3-x , wherein each R is a hydrocarbyl group having from 1 to 8 carbon atoms and x is either 0, 1 or 2.

Claim 8

A process in accordance with claim 6 wherein at least a portion of said arsine is AsH 3 .

Claim 9

A process in accordance with claim 1 wherein the atomic ratio of said alkaline earth metal to the chromium of said copper chromite in said sorbent material (B) is in the range of from about 1:100 to about 1:2.

Claim 10

A process in accordance with claim 8 wherein said ratio is in the range of 1:10 to 1:4.

Claim 11

A process in accordance with claim 1 wherein said catalytic sorbent has a surface area in the range of from about 10 to about 300M 2 per gram and a pore volume in the range of from about 0.1 to 1.0 cc per gram.

Claim 12

A process in accordance with claim 1 wherein the process conditions are maintained in the following ranges: (a) temperature, from about 50° to about 500° F., (b) pressure, from 0 to about 3,000 psig, and (c) gas hourly space velocity, about 100 to about 4,000 volume per volume catalyst per hour.

Claim 13

A process in accordance with claim 1 wherein said gaseous stream is a hydrocarbon stream selected from the group consisting of hydrocarbons having from 1 to 9 carbon atoms, and mixtures thereof.

Claim 14

A process in accordance with claim 11 wherein the temperature is in the range of from about 100° to about 250° F., the pressure is in the range of from about 10 to about 2000 psig and the gas hourly space velocity is in the range of from about 600 to about 2000 volume per volume catalyst per hour.

Claim 15

A process for the removal of arsine impurities from a gaseous stream selected from the group consisting of hydrocarbons and inert gases comprising the step of contacting said stream with a catalytic sorbent consisting essentially of copper (II) chromite and barium oxide.

Claim 16

A process for the removal of arsine impurities from a gaseous stream selected from the group consisting of hydrocarbons and inert gases comprising the step of contacting said stream with a catalytic sorbent consisting essentially of copper (II) chromite and barium oxide.

Claim 17

A process for treating a hydrocarbon feedstream comprising arsine impurities and olefins, which process comprises the steps of: (a) contacting said feestream first with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide, to substantially reduce the arsine content of said feedstream and to produce an intermediate stream, (b) contacting at least a portion of said intermediate stream with hydrogen and a noble metal hydrogenation catalyst to substantially hydrogenate said olefins present in said intermediate stream, and (c) recovering a hydrogenated hydrocarbon stream.

Claim 18

A process for treating a hydrocarbon feedstream comprising arsine impurities and olefins, which process comprises the steps of: (a) contacting said feestream first with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide, to substantially reduce the arsine content of said feedstream and to produce an intermediate stream, (b) contacting at least a portion of said intermediate stream with hydrogen and a noble metal hydrogenation catalyst to substantially hydrogenate said olefins present in said intermediate stream, and (c) recovering a hydrogenated hydrocarbon stream.

Claim 19

A process in accordance with claim 15 wherein said noble metal catalyst comprises at least one metal selected from the group consisting of palladium and platinum on a solid support.

Claim 20

A process for treating a hydrocarbon feedstream comprising alkanes having from 6 to 9 carbon atoms and containing arsine impurities, said process comprising the steps of: (a) contacting said feestream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said feedstream to produce an intermediate stream, (b) subjecting said intermediate stream to a dehydrogenation or dehydrocyclization process in which said intermediate stream is contacted with a noble metal catalyst, and (c) recovering a hydrocarbon product stream produced in step (b).

Claim 21

A process for treating a hydrocarbon feedstream comprising alkanes having from 6 to 9 carbon atoms and containing arsine impurities, said process comprising the steps of: (a) contacting said feestream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said feedstream to produce an intermediate stream, (b) subjecting said intermediate stream to a dehydrogenation or dehydrocyclization process in which said intermediate stream is contacted with a noble metal catalyst, and (c) recovering a hydrocarbon product stream produced in step (b).

Claim 22

A process for treating a feedstream comprising unsaturated hydrocarbons having from 2 to 8 carbon atoms and containing arsine impurities and H 2 S, said process comprising the steps of: (a) treating said feedstream first to substantially reduce the H 2 S content of said feedstream and to produce an intermediate stream, (b) contacting said intermediate stream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said intermediate stream, and (c) recovering a purified stream of unsaturated hydrocarbons.

Claim 23

A process for treating a feedstream comprising unsaturated hydrocarbons having from 2 to 8 carbon atoms and containing arsine impurities and H 2 S, said process comprising the steps of: (a) treating said feedstream first to substantially reduce the H 2 S content of said feedstream and to produce an intermediate stream, (b) contacting said intermediate stream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said intermediate stream, and (c) recovering a purified stream of unsaturated hydrocarbons.

Claim 24

A process for treating a feedstream comprising unsaturated hydrocarbons having from 2 to 8 carbon atoms and containing arsine impurities, said feedstream being essentially free of acetylenes, which process comprises the step of: (a) contacting said feedstream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said feedstream, thus producing a treated feedstream.

Claim 25

A process for treating a feedstream comprising unsaturated hydrocarbons having from 2 to 8 carbon atoms and containing arsine impurities, said feedstream being essentially free of acetylenes, which process comprises the step of: (a) contacting said feedstream with a sorbent consisting essentially of a material selected from the group consisting of (A) copper (II) chromite and (B) copper (II) chromite promoted by at least one alkaline earth metal oxide to substantially reduce the arsine content of said feedstream, thus producing a treated feedstream.

Claim 26

A process in accordance with claim 19, comprising the further steps of (b) admixing said treated feedstream with a second stream comprising unsaturated hydrocarbons having from 2 to about 8 atoms and containing acetylenic impurities, said second stream being essentially free of arsines, and then (c) contacting at least a portion of said admixture of said treated feedstream and said second stream with hydrogen and a noble metal hydrogenation catalyst to selectively hydrogenate a substantial portion of said acetylenic impurities to olefins.

Claim 27

A process in accordance with claim 1 comprising the additional step of regenerating said sorbent, after it has been saturated with arsenic, by heating said arsenic-saturated sorbent with oxygen so as to convert arsenic to a volatile arsenic oxide and to remove arsenic oxide.