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US 5,450,892 AGranted
Alkaline scrubber for condensate stripper off-gases
AssigneeAlliedSignal Inc.
InventorWilson T. Gautreaux, Jr.
Life of this patent
Estimating the term…
Abstract
This invention relates to an alkaline scrubber for condensate stripper off-gases. In particular, this invention relates a process for selectively removing hydrogen sulfide and methyl mercaptan from a gas stream containing these compounds and methanol. Such gas streams are commonly generated during pulp and paper production.
Claims18
A process for selectively removing hydrogen sulfide and methyl mercaptan from a gas stream containing and methanol, which comprises:
- (a) passing an alkaline liquid stream having:
- 1) a pH level of at least 12,
- 2) a temperature in the range of 160.degree.-212.degree. F., and
- 3) a sodium hydroxide content at a molar concentration in the range of 1-5, through a scrubber unit having 3 or 4 stages at a flow rate in the range of 5-20 gallons per minute;
- (b) passing said gas stream at a temperature in the range of 212.degree.-280.degree. F. through the scrubber unit in a countercurrent direction to the flow of the alkaline liquid stream, with the molar flow rate of the gas stream at a rate proportional to the alkaline liquid stream at a ratio in the range of 2:1 to 10:1, wherein the gas stream existing the scrubber unit contains 20-30% less methanol than said gas stream entering the scrubber unit, and
- (c) wherein upon exiting the scrubber unit, the gas stream is incinerated.
3 more elements
A process for selectively removing hydrogen sulfide and methyl mercaptan from a gas stream containing hydrogen sulfide, methyl mercaptan, and methanol, which comprises:
- (a) passing an alkaline liquid stream having:
- 1) a pH level of at least 12,
- 2) a temperature in the range of 160.degree.-212.degree. F., and
- 3) a sodium hydroxide content at a molar concentration in the range of 1-5, through a scrubber unit having 3 or 4 stages at a flow rate in the range of 5-20 gallons per minute;
- (b) passing said gas stream at a temperature in the range of 212.degree.-280.degree. F. through the scrubber unit in a co-current direction to the flow of the alkaline liquid stream, with the molar flow rate of the gas stream at a rate proportional to the alkaline liquid stream at a ratio in the range of 2:1 to 10:1, wherein the gas stream existing the scrubber unit contains 20-30% less methanol than said gas stream entering the scrubber unit;
- and
- (c) wherein upon exiting the scrubber unit, the gas stream is incinerated.
4 more elements
Dependencies are inferred from the claim text.