Process for the separation of c{hd 4 {b acetylenic hydrocarbons from gas streams

Claim 2

IN THE PROCESS FOR THE SEPARATION OF A DIACETYLENE AND VINYLACETYLENE FROM A HYDROCARBON PYROLSIS GAS THAT CONTAINS FROM 1 TO 10 MOLE PERCENT OF SAID COMPOUNDS WHEREIN SAID HYDROCARBON PYROLYSIS GAS IS PASSED THROUGH A BED OF ACTIVATED CARBON UNTIL THE SURFACE OF THE CARBON IS SATURATED WITH ADSORBED C4 ACETYLENIC HYDROCARBONS AND A STREAM OF INERT GAS IS PASSED THROUGH THE BED OF SATURATED ACTIVATED CARBON THEREBY DESORBING SAID ACETYLENIC HYDROCARBONS AND FORMING A GAS STREAM THAT CONTAINS ABOUT 30 TO 50 MOLE PERCENT OF C4 ACETYLENIC HYDROCARBONS IN SAID INERT GAS, THE IMPROVEMENT THAT COMPRISES SATURATING THE SURFACE OF THE ACTIVATED CARBON WITH AN INERT, NON-EXPLOSIVE COMPOUND THAT HAS CARBON ADSORPTION CHARACTERISTICS SIMILAR TO THOSE OF DIACETYLENE AND VINYLACETYLENE AND THEREAFTER COOLING SAID ACTIVATED CARBON BEFORE THE HYDROCARBON PYROLYSIS GAS IS PASSED INTO THE BED OF ACTIVATED CARBON.

Claim 3

In the process for the separation of diacetylene and vinylacetylene from a hydrocarbon pyrolysis gas that contains from 1 to 10 mole percent of said compounds wherein said hydrocarbon pyrolysis gas is passed through a bed of activated carbon until the surface of the carbon is saturated with adsorbed C4 acetylenic hydrocarbons and a stream of inert gas is passed through the bed of saturated activated carbon thereby desorbing said acetylenic hydrocarbons and forming a gas stream that contains about 30 to 50 mole percent of C4 acetylenic hydrocarbons in said inert gas, the improvement that comprises saturating the surface of the activated carbon with an inert, non-explosive compound that has carbon adsorption characteristics similar to those of diacetylene and vinylacetylene and thereafter cooling said activated carbon before the hydrocarbon pyrolysis gas is passed into the bed of activated carbon.

Claim 4

In the process for the separation of diacetylene and vinylacetylene from a hydrocarbon pyrolysis gas that contains from 1 to 10 mole percent of said compounds wherein said hydrocarbon pyrolysis gas is passed through a bed of activated carbon until the surface of the carbon is saturated with adsorbed C4 acetylenic hydrocarbons and a stream of inert gas is passed through the bed of saturated activated carbon thereby desorbing said acetylenic hydrocarbons and forming a gas stream that contains about 30 to 50 mole percent of C4 acetylenic hydrocarbons in said inert gas, the improvement that comprises saturating the surface of the activated carbon with an inert, non-explosive compound that has carbon adsorption characteristics similar to those of diacetylene and vinylacetylene and thereafter cooling said activated carbon before the hydrocarbon pyrolysis gas is passed into the bed of activated carbon.

Claim 5

The process of claim 1 wherein the inert, non-explosive compound with which the activated carbon is presaturated is n-butane.

Claim 6

The process of claim 1 wherein the activated carbon is presaturated by treatment with a gas stream that contains 1 to 5% of n-butane in nitrogen and cooled to a temperature in the range of about 25* to 60*C. before it is contacted with the hydrocarbon pyrolysis gas.

Claim 7

The process of claim 3 wherein the presaturated activated carbon is cooled to 30* to 40*C. before it is contacted with the hydrocarbon pyrolysis gas.

Claim 8

The process of claim 1 wherein the activated carbon is presaturated by adding liquid n-butane to it, allowing the n-butane to evaporate, and cooling the n-butane-saturated carbon to a temperature in the range of about 25* to 60*C. before it is contacted with the hydrocarbon pyrolysis gas.

Claim 9

The process of claim 1 wherein the activated carbon is presaturated by adding liquid n-butane to the carbon, allowing the n-butane to evaporate, cooling the treated carbon to a temperature in the range of about 25* to 60*C., adding additional liquid n-butane to the carbon, allowing the added n-butane to evaporate, and cooling the n-butane-saturated carbon to 30* to 40*C. before it is contacted with the hydrocarbon pyrolysis gas.

Claim 10

The process of claim 1 wherein the hydrocarbon pyrolysis gas is mixed with about 30 percent to 70 percent of its weight of an inert, non-explosive gas that has carbon adsorption characteristics similar to those of diacetylene and vinylacetylene and the resulting gas mixture is passed into the bed of presaturated carbon.

Claim 11

The process of claim 7 wherein the hydrocarbon pyrolysis gas is mixed with about 45 percent to 60 percent of its weight of n-butane.

Claim 12

In the process for the separation of acetylenic hydrocarbons having 3 or 4 carbon atoms from a pyrolysis gas stream that contains from 1 to 10 mole percent of said compounds wherein (a) said hydrocarbon pyrolysis gas is passed into a first bed of activated carbon and the gas leaving the first bed is passed into a second bed of activated carbon until the surface of the carbon in the first bed is saturated with diacetylene and vinylacetylene and the surface of the carbon in the second bed is saturated with methylacetylene and allene and (b) a stream of inert gas is passed through each of said beds of saturated activated carbon thereby desorbing said acetylenic hydrocarbons and forming gas streams that contain about 30 to 50 mole percent of the acetylenic hydrocarbons in said inert gas, the improvement that comprises saturating the surface of the activated carbon in the first bed of activated carbon with an inert, non-explosive gas that has carbon adsorption characteristics similar to those of diacetylene and vinylacetylene and thereafter cooling said activated carbon before the hydrocarbon pyrolysis gas is passed into the beds of activated carbon.

Claim 13

In the process for the separation of acetylenic hydrocarbons having 3 or 4 carbon atoms from a pyrolysis gas stream that contains from 1 to 10 mole percent of said compounds wherein (a) said hydrocarbon pyrolysis gas is passed into a first bed of activated carbon and the gas leaving the first bed is passed into a second bed of activated carbon until the surface of the carbon in the first bed is saturated with diacetylene and vinylacetylene and the surface of the carbon in the second bed is saturated with methylacetylene and allene and (b) a stream of inert gas is passed through each of said beds of saturated activated carbon thereby desorbing said acetylenic hydrocarbons and forming gas streams that contain about 30 to 50 mole percent of the acetylenic hydrocarbons in said inert gas, the improvement that comprises saturating the surface of the activated carbon in the first bed of activated carbon with an inert, non-explosive gas that has carbon adsorption characteristics similar to those of diacetylene and vinylacetylene and thereafter cooling said activated carbon before the hydrocarbon pyrolysis gas is passed into the beds of activated carbon.

Claim 14

The process of claim 9 wherein the surface of the activated carbon in the first bed of activated carbon is presaturated with n-butane.

Claim 15

The process of claim 9 wherein the activated carbon in the first bed of activated carbon is presaturated by adding liquid n-butane to it, allowing the n-butane to evaporate, and cooling the n-butane-saturated carbon to a temperature in the range of about 25* to 60*C. before it is contacted with the hydrocarbon pyrolysis gas.

Claim 16

The process of claim 9 wherein the hydrocarbon pyrolysis gas is mixed with about 30 percent to 70 percent of its weight of an inert, non-explosive gas that has carbon adsorption characteristics similar to those of the C4 acetylenic hydrocarbons and the resulting gas mixture is passed into the first bed of presaturated activated carbon.

Claim 17

The process of claim 12 wherein the hydrocarbon pyrolysis gas is mixed with about 45 percent to 60 percent of its weight of said inert, non-explosive gas.