Method and apparatus for removing aromatic hydrocarbons from a gas stream prior to an amine-based gas sweetening process
AssigneeKinder Morgan, Inc.
InventorJonathan E. Thonsgaard
Life of this patent
Estimating the term…
Abstract
A method is provided for the extraction of aromatic hydrocarbons, including benzene, toluene, ethylbenzene, and xylene, collectively known as “BTEX,” in a continuous process utilizing a glycol contactor to cause absorption of the BTEX upstream of an amine-based gas sweetening process. The preferred glycol for BTEX absorption is triethylene glycol. The glycol used in the glycol contactor for BTEX extraction may either be fully regenerated (dry), or wet glycol from a downstream gas dehydration system. The method may be achieved with the use of a number of separate absorber/contactor vessels, or the method may be achieved within one combination vessel.
Claims20
A method for removing aromatic hydrocarbons from a gas stream treated in an amine-based gas sweetening process to prevent the same aromatic hydrocarbons from entering the amine process and becoming a potential emission source, said method comprising the steps of:
- providing a flow of gas containing aromatic hydrocarbons to include BTEX;
- initially treating the flow of gas by passage through a first glycol contactor for absorbing the BTEX;
- and
- then treating the flow of gas by passage through an amine-based gas sweetening process including an amine contactor for gas sweetening to remove acidic gases, and a second glycol contactor for dehydration and further absorption of BTEX.
An apparatus for gas sweetening and removing aromatic hydrocarbons from a gas stream passing through said apparatus from an upstream location to a downstream location, said apparatus comprising:
- a vessel having an upper end and a lower end;
- an upstream glycol contactor section for BTEX absorption placed within said vessel and positioned adjacent said lower end;
- a downstream glycol contactor section for dehydration and further BTEX absorption placed within said vessel and positioned adjacent said upper end;
- an amine contactor section for gas sweetening placed within said vessel and positioned between said upstream glycol contactor and said downstream glycol contactor;
- a glycol bypass line interconnecting said upstream and said downstream glycol contactor sections;
- and
- wherein the gas stream makes countercurrent contact with glycol flowing through said upstream and said downstream glycol contactor sections, and with amine flowing through said amine contactor, said glycol bypass line allowing glycol to flow from said downstream glycol contactor section to said upstream glycol contactor section.
An apparatus for gas sweetening and removing aromatic hydrocarbons from a gas stream passing through said apparatus from an upstream location to a downstream location, said apparatus comprising:
- a vessel for use in treatment of the gas stream containing aromatic hydrocarbons to include BTEX, the gas stream flowing through said vessel from an upstream location to a downstream location;
- an amine contactor in said vessel for gas sweetening to remove acid gases from the gas stream flowing through said amine contactor;
- and
- a first glycol contactor in said vessel at an upstream location from said amine contactor for absorbing BTEX from the gas stream.
Dependencies are inferred from the claim text.