In situ generation of polysulfide ions using elemental sulfur for improved corrosion control, cyanide management, mercury management, arsine management and performance and reliability of acid gas removal equipment
AssigneeExxonMobil Research and Engineering Company
InventorsGordon Bryce McGarvey, Robert J. Falkiner, David R. Slim, Bryan M. Knickerbocker
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Abstract
Methods and systems are provided for the in situ generation of polysulfide ions in a process stream including S2− and/or HS− ions. Methods and systems are also provided to ameliorate corrosion in a process stream containing an acid gas or a scrubbing agent solvent, and abate mercury and cyanide in process streams containing a scrubbing agent solvent.
Claims21
A method for operating an acid gas treatment unit with reduced corrosion comprising:
- (a) contacting an acid gas stream containing H2S with an aqueous alkaline absorbent solution to absorb the H2S into the solution to form a stream including HS− and/or S2− ions;
- (b) contacting the stream containing the HS− and/or S2− ions with elemental sulfur to react the sulfur with the HS− and/or S2− ions to generate polysulfide ions, and
- (c) regenerating the aqueous alkaline absorbent solution to release acid gas components from the solution, while operating with an accumulation of heat stable salts exceeding 3 wt. percent.
A method for treating a gas stream containing acidic components including H2S in an acid gas treatment unit with reduced corrosion, which comprises:
- (i) contacting the acid gas stream with a lean stream of an aqueous amine absorbent solution to absorb the H2S into the solution to form a rich absorbent solution stream including HS− and/or S2− ions;
- (ii) contacting the rich absorbent solution stream containing containing the HS− and/or S2− ions with elemental sulfur to react the sulfur with the HS− and/or S2− ions to generate polysulfide ions, and
- (iii) regenerating the aqueous alkaline absorbent solution to release acid gas components from the solution and form a regenerated stream of lean aqueous amine absorbent while operating with an accumulation of heat stable salts exceeding 3 wt. percent.
Dependencies are inferred from the claim text.