Method for the dissolution of amorphous dithiazines
AssigneeConocoPhillips Company
InventorsJay Locklear, David P. Cope
Life of this patent
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Abstract
The invention relates to the dissolution of amorphous dithiazine (a-DTZ) or polythioformaldehyde or other polymeric by-products of the treatment of hydrocarbon products (a-DZT) to remove them from surfaces. These are solids that build up on surfaces of processing plant and are resistant to most chemical treatment. The treatment requires treating the surface with an effective amount of a mercaptan or an amine. Surfactants to keep the dissolved a-DTZ or other components from redepositing elsewhere are also described, as is the use of hydrogen sulfide to add in removal by mercaptans.
Claims20
A method of removing amorphous dithiazine or polythioformaldehyde or polymeric by-products of hydrocarbon sweetening processes (herein an “a-DZT”) from a surface, said method comprising reacting said a-DZT at least partially coating said surface with an effective amount of a mercaptan or an amine to remove at least a portion of said a-DZT, thereby cleaning said surface, wherein said method excludes use of a peroxide.
A method of, removing amorphous dithiazine or polythioformaldehyde or polymeric by-products of hydrocarbon sweetening processes (herein an “a-DZT”) from a surface, said method comprising:
- a) reacting said a-DZT at least partially coating said surface with an effective amount of a mercaptan or an amine in the presence of hydrogen sulfide thereby at least partially removing at least a portion of said a-DZT, thereby cleaning said surface;
- b) wherein a rate of removal of said a-DZT is increased by a factor of 2 or more relative to a rate of removal of said a-DZT with essentially no hydrogen sulfide present.
A method of removing amorphous dithiazine or polythioformaldehyde or polymeric by-products of hydrocarbon sweetening processes (a-DZT) from a surface, wherein said method excludes use of a peroxide, said method comprising reacting said a-DZT at least partially coating said a surface with an effective amount of a mercaptan to remove at least a portion of said a-DZT, thereby cleaning said surface, said mercaptan at a pH of 4-7 and selected from methanethiol;
- ethanethiol;
- 1-propanethiol;
- 2-propanethiol;
- allyl mercaptan;
- butanethiol;
- tert-butyl mercaptan;
- pentanethiol;
- thiophenol;
- dimercaptosuccinic acid;
- thioacetic acid;
- 2-mercaptoethanol;
- dithiothreitol/dithioerythritol (an epimeric pair);
- 2-mercaptoindole;
- furan-2-ylmethanethiol;
- 3-mercaptopropane-1,2-diol;
- 3-mercapto-1-propanesulfonic acid;
- 1-hexadecanethiol;
- pentachlorobenzenethiol or combinations thereof.
A method of removing amorphous dithiazine or polythioformaldehyde or polymeric by-products of hydrocarbon sweetening processes (a-DZT) from a surface, said method comprising reacting said a-DZT on said a surface with an effective amount of an amine at a basic pH to remove at least a portion of said a-DZT from said surface, wherein said amine is selected from a group consisting of alkyl amines, alkyl-hydroxy amines, amino acids, amino saccharides, diamines, triamines, alkyl benzyl amines, methylamine, propylamine, monoethanolamine, isopropanolamine, tris(2-aminoethyl)amine, glucosamine, ethylene diamine, diethanolamine, diisopropanolamine, methyldiethanolamine, triethanolamine, diethylenetriamine, pyrrolidone, triethylamine, 1-methyl-2-pyrrolidinone, monoethanolamine, diethanolamine, methyldiethanolamine, N,N-dimethyl-N-(2-hydroxypropyl)amine, N,N,N′-trimethyl-N′-(2-hydroxypropyl)ethylenediamine, N,N,N′,N″-tetramethyl-N″-(2)-hydroxypropyl) diethylenetriamine, N,N,N′,N″,N″-pentamethyl-N′″-(2-hydroxypropyl)triethylenetetramine, and or combinations thereof.
Dependencies are inferred from the claim text.