Title: Corrosion inhibitor for aqueous ammonia absorption system

Abstract

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Inventors:

Phillips, Benjamin A ^[1]; Whitlow, Eugene P ^[2]

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+ Show Inventor Affiliations

1. Benton Harbor, MI
2. St. Joseph, MI

Issue Date:

1998-09-22

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

OSTI Identifier:

871853

Patent Number(s):

5811026

Application Number:

08/696,789

Assignee:

Phillips Engineering Company (St. Joseph, MI)

Patent Classifications (CPCs):

C - CHEMISTRY C09 - DYES C09K - MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

C - CHEMISTRY C23 - COATING METALLIC MATERIAL C23F - NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE

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C - CHEMISTRY C09 - DYES C09K - MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

C09K5/047 - {for absorption-type refrigeration systems}

C - CHEMISTRY C23 - COATING METALLIC MATERIAL C23F - NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE

C23F11/06 - in markedly alkaline liquids

F - MECHANICAL ENGINEERING F25 - REFRIGERATION OR COOLING F25B - REFRIGERATION MACHINES, PLANTS OR SYSTEMS

F25B15/04 - the refrigerant being ammonia evaporated from aqueous solution {
F25B47/003 - {for preventing corrosion}

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02A - TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

Y02A30/27 - Relating to heating, ventilation or air conditioning [HVAC] technologies

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02B - CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

Y02B30/62 - Absorption based systems

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02P - CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

Y02P20/10 - General improvement of production processes causing greenhouse gases [GHG] emissions

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DOE Contract Number:  

15X-17497C

Resource Type:

Patent

Country of Publication:

United States

Language:

English

Subject:

corrosion; inhibitor; aqueous; ammonia; absorption; method; inhibiting; formation; hydrogen; improving; water; refrigeration; air; conditioning; heat; pump; maintaining; hydroxyl; concentration; fluid; selected; range; anaerobic; conditions; temperatures; 425; degree; maintained; introducing; amount; effective; produce; corresponding; normality; relative; content; ranging; 015; 25; fluids; carbon; steel; resulting; solutions; strong; base; specified; buffer; selected range; air conditioning; absorption refrigeration; heat pump; aqueous solution; aqueous solutions; carbon steel; amount effective; anaerobic conditions; strong base; water content; inhibiting corrosion; resulting hydrogen; aerobic conditions; /252/62/210/422/