Solvent Extraction

Fact Sheet - Solvent Extraction

Intro to Produced Water
Technology Descriptions
Fed & State Regulations
Technology Identification

Other fact sheets describe several physical and chemical separation methods that remove oil and other organics from water. These technologies are able to remove most of the dissolved and dispersed oil, but typically they have difficulty removing the dissolved oil and organics. This fact sheet describes solvent extraction - a technology that has successfully removed dissolved oil and organic fractions.

  Schematic of MPPE process
Schematic of MPPE process; Source: VWS MPP Systems B.V.

Meijer and Kuijvenhoven (2002) describe Macro Porous Polymer Extraction (MPPE) - a fluid extraction technology that removes dissolved organics from offshore produced water. The MPPE process takes place in the pores of polymer particles. Water contaminated with hydrocarbons is passed through a column packed with porous polymer beads, which contain a proprietary extraction liquid that readily removes dissolved oil and organics from produced water. Due to their heightened affinity for the extraction liquid, hydrocarbons are removed. The purified water can be reused or discharged. Periodical in situ regeneration makes use of low-pressure steam to strip the hydrocarbons of the extraction liquid. The stripped hydrocarbons are condensed and then separated from the water phase by gravity. The resulting, almost 100% pure hydrocarbon phase, is recovered, removed from the system, and readied for subsequent use, reuse, or disposal. Meanwhile, the condensed aqueous phase is recycled within the system.

  Electron microscope photo of the pore structure of the MPP
Electron microscope photo of the pore structure of the MPP; Source: VWS MPP Systems B.V.

The figure shows a schematic of the MPPE process.

The photo shows an electron micrograph of the pore structure of the polymers. The application of two columns allows for continuous operation and simultaneous extraction and regeneration. A typical cycle combines one hour of extraction and one hour of regeneration.

MPPE has a good track record for reducing organic constituents to low levels (Grini et al. 2003). Produced water treatment data (Meijer et al. 2004) show >99% removal of BTEX and PAHs, and >95% removal of aliphatics of chain lengths < C20. Removals were less effective for aliphatics of chain lengths >C20.

Akzo Nobel, undated, "MPPE for Removing Dissolved and Dispersed Hydrocarbons from Offshore Produced Water."

Grini, P.G., C. Clausen, and H. Torvik, 2003, "Field Trials with Extraction Based Produced Water Purification Technologies," presented at the 1st NEL Produced Water Workshop, Aberdeen, Scotland, March 26-27.

Meijer, D.T., and C.A.T. Kuijvenhoven, 2002, "Field-Proven Removal of Dissolved Hydrocarbons from Offshore Produced Water by the Macro Porous Polymer-Extraction Technology," presented at the 12th Produced Water Seminar, Houston, TX, Jan. 16-18.

Meijer, D.T., C. Kuijvenhoven, and H. Karup, 2004, "Results from the Latest MPPE Field Trials at NAM and Total Installations," presented at the 2nd NEL Produced Water Workshop, Aberdeen, Scotland, Apr. 21-22.