Methods and compounds for removing non-acidic contaminants from hydrocarbon streams
An extraction solvent comprised of one or more ethyleneamines having structure (I), (II), or (III): where R 1 -R 6 can independently be H, C 1 -C 4 linear or branched alkyl, amido (RRNC═O), or hydroxyalkyl, where each R in the amido group independently H or C 1 alkyl, and where x ranges from 1 to 6, may be contacted with a hydrocarbon stream to remove or extract non-acidic contaminants, such as thiophenes, benzothiophenes, alkyl sulfides, alkyl disulfides, mercaptans, aromatics, oxygenates, metals, olefins, and combinations thereof, from the hydrocarbon stream. The extraction solvent may include co-solvents and the hydrocarbon stream may be in gas and/or liquid form.
1. A process for removal of non-acidic contaminants from a hydrocarbon stream comprising the contaminants, the process comprising:
contacting the hydrocarbon stream containing non-acidic contaminants selected from a group consisting of thiophenes, benzothiophenes, alkyl sulfides, alkyl disulfides, mercaptans, aromatics, oxygenates, metals, olefins, and combinations thereof with an extraction solvent comprising one or more ethyleneamines having structure (I), (II), or (III):
where R 1 is H, R 2 -R 6 is, to the extent chemically possible, independently H, C 1 -C 4 linear or branched alkyl, amido (RRNC═O), or hydroxyalkyl, where each R in the amido group is independently H or C 1 alkyl, and where x ranges from 1 to 6; and
upon contacting the hydrocarbon stream with the extraction solvent, a portion of the non-acidic contaminants are removed from the hydrocarbon stream.
2. The process of claim 1 , wherein the ratio of the one or more ethyleneamines to hydrocarbon in the hydrocarbon stream ranges from about 1:10 to about 95:100.
3. The process of claim 1 , wherein the extraction solvent comprises triethylenetriamine or diethylenetriamine.
4. The process of claim 1 , wherein the extraction solvent further comprises a co-solvent selected from a group consisting of water, an alcohol, a glycol, an amide, an ester, an amine different from the ethyleneamine, a quaternary ammonium compound, and combinations thereof.
5. The process of claim 1 , wherein the hydrocarbon stream is selected from the group consisting of a gas stream, a liquid stream, and combinations thereof.
6. The process of claim 1 , wherein the contacting is achieved by an extraction process having a counter-flow design between the hydrocarbon stream and the extraction solvent.
7. The process of claim 1 , wherein the contacting is achieved by injecting the extraction solvent directly into the hydrocarbon stream.
8. The process claim 1 , further comprising creating an immiscible two-phase liquid comprising a contaminant-laden extraction solvent stream and a hydrocarbon stream having a reduced amount of non-acidic contaminants after the hydrocarbon stream is contacted with the extraction solvent.
9. The process of claim 8 , wherein the contaminant-laden extraction solvent stream is separated from the hydrocarbon stream having a reduced amount of non-acidic contaminants using a separation mechanism selected from the group consisting of a knockout drum, a centrifuge, an absorbent material, and combinations thereof thereby giving a separated contaminant-laden extraction solvent stream.
10. The process of claim 9 , further comprising regenerating the separated contaminant-laden extraction solvent stream by passing the contaminant-laden extraction solvent stream through selective filtration media or additional adsorption material thereby removing the contaminants.