Treatment of gas streams for removal of acid gases

• US 4,696,803 A
• Filed: 02/13/1986
• Issued: 09/29/1987
• Est. Priority Date: 02/13/1986
• Status: Expired due to Fees

• Current Assignee: Huntsman Petrochemical LLC (Huntsman Corporation)
• Original Assignee: Texaco Incorporated (Chevron Corp.)
• Inventors: Nieh, Edward C. Y.
• Primary Examiner(s): Hart, Charles
• Application Number:
  US06/829,347
• Time in Patent Office: 593 Days
• Field of Search: 55/68, 55/73, 423/228, 423/229
• US Class Current: 423/228
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: C01B 2203/0415 Purification by absorption in liquids
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 3/52 by contacting with liquids; Regeneration of used liquids C01B3/508 takes precedence
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

Improvements are provided in accordance with the present invention by a continuous process for the treating of a gas stream containing acid gas components wherein the gas stream is counter currently contacted in an absorption zone with an aqueous solution of a mixture of N-methyldiethanolamine with N,N-diethyl hydroxylamine to thereby provide for acid gas (e.g., CO₂) absorption.

Claims

1. A method for the purification of a stream of gas comprising a normally gaseous hydrocarbon or synthesis gas contaminated with acid gases which comprises the steps of:

countercurrently contacting said gas stream in an absorption zone with a treating agent to thereby remove a substantial portion of the acid contaminants from said hydrocarbon gas stream by absorption into said treating agent, discharging an at least partially purified hydrocarbon gas stream from said absorption zone, and discharging said treating agent enriched with absorbed acid gas components from said absorption zone, said treating agent consisting essentially of an aqueous solution of from about 40 to about 60 wt. % of N-methyldiethanolamine and from about 5 to about 15 wt. % of N,N-diethyl hydroxylamine.

2. A method as in claim 1, wherein the conditions utilized in said absorption zone include a temperature within the range of about 10°

to about 70°

C. and a pressure of from about atmospheric to about 2000 psig.

3. A method as in claim 1 wherein the sum of the normality of the N-methyldiethanolamine and the normality of the N,N'"'"'-diethyl hydroxylamine in said aqueous solution is about 4 or more.

4. A method for the purification of a stream of gas comprising a normally gaseous hydrocarbon or synthesis gas contaminated with acid gases, including carbon dioxide, which comprises the steps of:

countercurrently contacting said gas stream in an absorption zone with a treating agent to thereby remove a substantial portion of the carbon dioxide contaminants from said hydrcarbon gas stream by absorption into said treating agent, discharging an at least partially purified hydrocarbon gas stream from said absorption zone, and discharging said treating agent enriched with absorbed carbon dioxide from said absorption zone, said treating agent consisting of an aqeouous solution of from about 40 to about 60 wt. % of N-methyldiethanolamine and from about 5 to about 15 wt. % of N,N'"'"'-diethyl hydroxylamine.

5. A method as in claim 4 wherein the sum of the normality of the N-methyldiethanolamine and the normality of the N,N'"'"'-diethyl hydroxylamine in said aqueous solution is about 4 or more.