Corrosion inhibitor

Abstract

The present invention is directed to an aqueous amine resin corrosion inhibitor composition and methods of using the same for inhibiting corrosion in equipment in contact with alkanolamine, hot carbonate solutions, diglyme and / or other solvents and acid gases such as carbon dioxide, hydrogen sulfide or a mixture of the two. The inhibitor preferably relates to compositions useful for inhibiting corrosion in environments in contact with alkanolamine, hot carbonate solutions, diglyme, and / or solvent gas treating systems and acid gases, and more particularly, to an amine resin solution made by reacting sterically hindered amines such as those selected from the group consisting of alkyl diamines, alkyltriamines, amino alcohols and mixtures thereof with aldehydes, aldehyde donors, the reaction product of lower alkanolamines and lower aldehydes, and mixtures thereof. The subject compositions are preferably made by reacting the sterically hindered amines and aldehyde compounds in about a 1:1 molar ratio at a temperature ranging from about 110° F. to 120° F., using a sufficient amount of the sterically hindered amine to produce a reaction product having a pH ranging from about 10.5 to about 12.0.

Description

[0001] The present invention relates to corrosion inhibitors. In a preferred embodiment, the invention relates to a corrosion inhibitor which provides protection against corrosion in alkanolamine, hot carbonate solution, diglyme, and / or other solvent planks used for removal of acid gases, e.g. CO.sub.2, H.sub.2S or mixtures of the two. Specifically, the invention relates to a new aqueous amine resin corrosion inhibitor.BACKGROUND OF INVENTION[0002] General surface corrosion of metals by chemicals dissolved in an electrolyte is a common problem in the operation of industrial processes which utilize amines, alkanol amines, hot carbonate solutions, or diglyme as reactants, products, solvents, etc. For example, it is known that acid gases, such as carbon dioxide and H.sub.2S, can be removed from gaseous feed streams, such as natural gas and synthesis gas, using dilute aqueous solutions of alkanol amines, such as monoethanolamine, diethanolamine, and methyl diethanolamine, and other weak...

AI Technical Summary

Benefits of technology

[0013] In addition, the present invention, according to another embodiment, is directed to a new non-toxic corrosion inhibitor which provides protection against corrosion in alkanolamine, hot carbonate solution, diglyme or other solvent gas treating plants used for the removal of acid gases, such as CO.sub.2, H.sub.2S, or mixtures thereof.

Problems solved by technology

General surface corrosion of metals by chemicals dissolved in an electrolyte is a common problem in the operation of industrial processes which utilize amines, alkanol amines, hot carbonate solutions, or diglyme as reactants, products, solvents, etc.

The presence of acid gases and the resulting necessity for its stripping by gas treatment services inherently results in a corrosion problem.

This problem is particularly acute and / or critical when carbon steels are used in the equipment to save on capital costs over the use of more exotic and expensive metal alloys such as stainless steel.

While the above compositions are effective, they each have various defects which detract from their universal use.

For example, compounds of arsenic, antimony, vanadium and other heavy metals are known to be toxic and their use presents waste disposal problems for the plant operators.

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