Process, method, and system for removing mercury from fluids

摘要

Trace levels of mercury in a natural gas are removed in a gas processing plant in an amine unit and/or a dehydrator. The mercury removal occurs concurrently with the removal of acid gases in an amine unit, e.g., an absorber or scrubber, with an amine solution containing a complexing agent. The mercury removal can also be carried out concurrently with the removal of water in a glycol dehydrator with the addition of a complexing agent to the glycol solution. Volatile mercury in the natural gas is removed by the complexing agent, forming non-volatile mercury species in the rich amine/glycol solution.

主权项

1. A method for removing a trace amount of mercury in a natural gas feed, comprising:
providing a gas feed containing a first concentration of volatile mercury and acid gases; contacting the gas feed in an absorber with an absorption solution comprising lean amine and a first complexing agent comprising volatile cations selected from ammonium polysulfide, amine polysulfides, and sulfanes, wherein the absorption solution concurrently removes mercury and non-volatile mercury and acid gases from the gas feed; generating a rich amine solution containing acid gases and at least 50% of the volatile mercury in the gas feed as non-volatile mercury and a treated gas stream with a second concentration of acid gases and mercury.