Process for removal of impurities in alkyl nitrite formation

Claim 2

A process for removing impurities from the gaseous product stream of an alkyl nitrite production zone comprising: (a) contacting at least a portion of the gaseous product stream containing nitric oxide, alkyl nitrite and impurities recovered from an alkyl nitrite production zone, a lower alcohol and oxygen in a reaction zone to produce a recovery stream substantially free of nitric oxide, said oxygen being present in said reaction zone in an amount such that the mole ratio of nitric oxide to oxygen in said reaction zone is in the range of from about 4:1 to about 2:1 and said lower alcohol being present in said reaction zone in an amount such that the mole ratio of nitric oxide to lower alcohol is about 1:1 or less; (b) withdrawing said recovery stream from said reaction zone, said recovery stream containing alkyl nitrite and impurities and being substantially free of nitric oxide; (c) removing at least a portion of the alkyl nitrite from said recovery stream; and (d) purging at least a portion of said recovery stream from which the alkyl nitrite has been removed.

Claim 3

The process of claim 1 wherein said alkyl nitrite is methyl nitrite and said lower alcohol is methanol.

Claim 4

The process of claim 2 wherein the nitric oxide content in said recovery stream is one percent or less.

Claim 5

The process of claim 3 wherein of the nitric oxide contacted, 95 percent or more is converted to methyl nitrite.

Claim 6

The process of claim 4 wherein of the nitric oxide contacted, 99 percent or more is converted to methyl nitrite.

Claim 7

The process of claim 2 wherein a bottoms stream is withdrawn from said reaction zone, said bottoms stream comprising methanol, methyl nitrite and water.

Claim 8

The process of claim 1 wherein alkyl nitrite removed in step (c) is recycled to said alkyl nitrite production zone.

Claim 9

The process of claim 1 wherein said portion of the gaseous product stream is a sufficient amount to prevent the buildup of impurities.

Claim 10

The process of claim 8 wherein said portion is less than about 10 percent of the gaseous product stream.

Claim 11

The process of claim 9 wherein said portion is less than about 4 percent of the gaseous product stream.

Claim 12

The process of claim 10 wherein said portion is about 1 percent of the gaseous product stream.

Claim 13

The process of claim 1 wherein said process is carried out in a continuous manner.

Claim 14

The process of claim 1 wherein said alkyl nitrite is ethyl nitrite and said lower alcohol is ethanol.

Claim 15

A process for removing impurities from the effluent of an alkyl nitrite production zone comprising: (a) contacting at least a portion of the gaseous product stream containing nitric oxide, alkyl nitrite and impurities recovered from an alkyl nitrite production zone, a lower alcohol and oxygen in a reaction zone to produce a recovery stream substantially free of nitric oxide, said oxygen being present in said reaction zone in an amount such that the mole ratio of nitric oxide to oxygen in said reaction zone is in the range of from about 4:1 to about 2:1 and said lower alcohol being present in said reaction zone in an amount such that the mole ratio of nitric oxide to lower alcohol is about 1:1 or less; (b) withdrawing said recovery stream from said reaction zone, said recovery stream containing alkyl nitrite and impurities and being substantially free of nitric oxide; (c) supplying said recovery stream to a scrubbing means; (d) supplying liquid scrubbing agent to said scrubbing means; (e) withdrawing a bottoms stream from said scrubbing means comprising at least a portion of the alkyl nitrite supplied to said scrubbing means together with said scrubbing agent; and (f) withdrawing an overhead stream from said scrubbing means.

Claim 16

A process for removing impurities from the effluent of an alkyl nitrite production zone comprising: (a) contacting at least a portion of the gaseous product stream containing nitric oxide, alkyl nitrite and impurities recovered from an alkyl nitrite production zone, a lower alcohol and oxygen in a reaction zone to produce a recovery stream substantially free of nitric oxide, said oxygen being present in said reaction zone in an amount such that the mole ratio of nitric oxide to oxygen in said reaction zone is in the range of from about 4:1 to about 2:1 and said lower alcohol being present in said reaction zone in an amount such that the mole ratio of nitric oxide to lower alcohol is about 1:1 or less; (b) withdrawing said recovery stream from said reaction zone, said recovery stream containing alkyl nitrite and impurities and being substantially free of nitric oxide; (c) supplying said recovery stream to a scrubbing means; (d) supplying liquid scrubbing agent to said scrubbing means; (e) withdrawing a bottoms stream from said scrubbing means comprising at least a portion of the alkyl nitrite supplied to said scrubbing means together with said scrubbing agent; and (f) withdrawing an overhead stream from said scrubbing means.

Claim 17

The process of claim 14 wherein said liquid scrubbing agent comprises methanol.

Claim 18

The process of claim 14 wherein said overhead stream is discharged to the atmosphere.

Claim 19

The process of claim 14 wherein said bottoms stream is recycled to said alkyl nitrite production zone.

Claim 20

The process of claim 14 wherein said alkyl nitrite is methyl nitrite and said lower alcohol is methanol.

Claim 21

The process of claim 18 wherein the nitric oxide content in said recovery stream is one percent or less.

Claim 22

The process of claim 18 wherein of the nitric oxide contacted, 95 percent or more is converted to methyl nitrite.

Claim 23

The process of claim 18 wherein of the nitric oxide contacted, 99 percent or more is converted to methyl nitrite.

Claim 24

The process of claim 14 wherein said process is carried out in a continuous manner.

Claim 25

A process for removing impurities from a production cycle comprising one or more reactions steps, wherein one of the reaction steps is the production of alkyl nitrite by contacting nitric oxide, oxygen and lower alcohol, comprising: (a) contacting at least a portion of the gaseous product stream containing nitric oxide, alkyl nitrite and impurities recovered from an alkyl nitrite production zone, a lower alcohol and oxygen in a reaction zone to produce a recovery stream substantially free of nitric oxide, said oxygen being present in said reaction zone in an amount such that the mole ratio of nitric oxide to oxygen in said reaction zone is in the range of from about 4:1 to about 2:1 and said lower alcohol being present in said reaction zone in an amount such that the mole ratio of nitric oxide to lower alcohol is about 1:1 or less; (b) withdrawing said recovery stream from said reaction zone, said recovery stream containing alkyl nitrite and impurities and being substantially free of nitric oxide; (c) removing at least a portion of the alkyl nitrite from said recovery stream; and (d) purging at least a portion of said recovery stream from which the alkyl nitrite has been removed.

Claim 26

A process for removing impurities from a production cycle comprising one or more reactions steps, wherein one of the reaction steps is the production of alkyl nitrite by contacting nitric oxide, oxygen and lower alcohol, comprising: (a) contacting at least a portion of the gaseous product stream containing nitric oxide, alkyl nitrite and impurities recovered from an alkyl nitrite production zone, a lower alcohol and oxygen in a reaction zone to produce a recovery stream substantially free of nitric oxide, said oxygen being present in said reaction zone in an amount such that the mole ratio of nitric oxide to oxygen in said reaction zone is in the range of from about 4:1 to about 2:1 and said lower alcohol being present in said reaction zone in an amount such that the mole ratio of nitric oxide to lower alcohol is about 1:1 or less; (b) withdrawing said recovery stream from said reaction zone, said recovery stream containing alkyl nitrite and impurities and being substantially free of nitric oxide; (c) removing at least a portion of the alkyl nitrite from said recovery stream; and (d) purging at least a portion of said recovery stream from which the alkyl nitrite has been removed.

Claim 27

The process of claim 23 wherein said process is carried out in a continuous manner.

Claim 28

The process of claim 23 wherein said alkyl nitrite is methyl nitrite and said lower alcohol is methanol.