PROCESS FOR RECOVERING NATURAL GAS LIQUIDS FROM NATURAL GAS PRODUCED IN REMOTE LOCATIONS
Disclosed is a method to reduce the environmental impact of flaring a natural gas feedstream by removing and recovering some or all natural gas liquids (NGLs) ( 29 ) from the natural gas feedstream ( 3 ) prior to flaring ( 100 ). One embodiment of the present method provides for the use of a regenerable adsorbent media to remove the NGLs from the natural gas which can be regenerated by a microwave heating system. Said regeneration step may be operated as a batch process, a semi-continuous process, or a continuous process.
1 . A method for separating and recovering some or all natural gas liquids (NGLs): ethane, propane, butane, pentane, or heavier hydrocarbons from a natural gas feedstream forming a methane-rich natural gas supply and then flaring said methane-rich natural gas supply, wherein the NGLs are separated from the natural gas feedstream by means of a NGLs separation unit, wherein the NGLs separation unit comprises:
(i) an adsorption unit comprising an adsorption bed comprising an adsorbent media which adsorbs NGLs to form a loaded adsorbent media
and
(ii) a regeneration unit comprising a means to regenerate loaded adsorbent media by causing the release of adsorbed NGLs from the loaded adsorbing media and forming regenerated adsorbent media
wherein the method comprises the steps of:
(a) passing the natural gas feedstream through the adsorption unit generating the adsorbent loaded with NGLs and a methane-rich natural gas supply,
(b) transporting the adsorbent loaded with NGLs from the adsorption unit to the regeneration unit,
(c) regenerating the adsorbent loaded with NGLs by releasing the adsorbed NGLs from the loaded adsorbing media and forming regenerated adsorbent media
(d) transporting the regenerated adsorbent media back to the adsorption unit for reuse,
(e) recovering the released NGLs,
and
(f) flaring the methane-rich natural gas supply.
2 . The method of claim 1 wherein the natural gas feedstream is from an oil well, a gas well, or a condensate well.
3 . The method of claim 1 wherein the adsorption media is silica gel, alumina, silica-alumina, zeolites, activated carbon, polymer supported silver chloride, copper-containing resins, porous cross-linked polymeric adsorbents, pyrolized macroporous polymers, or mixtures thereof.
4 . The method of claim 1 wherein the adsorption media is a porous cross-linked polymeric adsorbent, a pyrolized macroporous polymer, or mixtures thereof.
5 . The method of claim 1 wherein the loaded adsorption media is regenerated by means of reduced pressure over the media, heating the media, or a combination of reduced pressure and heating.
6 . The method of claim 1 wherein the loaded adsorption media is regenerated by a microwave heating system.
7 . The method of claim 1 wherein the regeneration step is operated as a batch process, a semi-continuous process, or as a continuous process.
8 . The method of claim 1 wherein the recovered NGLs are stored and/or transported by truck, rail, or ship individually or as a mixture of gases (e.g., as C 2 , C 3 , C 4 , C 5 , etc.) or liquefied individually or as a mixture of liquids.