Field Evaluation of a Surfactant-Modified Zeolite System for Removal of Organics from Produced Water

Authors: Robert S. Bowman, New Mexico Technological University, Socorro, NM; Enid J. Sullivan, Los Alamos National Laboratory, Los Alamos, NM; and Lynn E. Katz and Kerry A. Kinney, University of Texas, Austin, TX.

Venue: 44th Annual Meeting of the Clay Minerals Society in Santa Fe, NM, June 3–7, 2007 (http://www.clays.org/home/HomeAnnualMeeting.html [external site]).

Abstract: About 2.3 billion cubic meters (600 billion gallons) of wastewater (produced water) is generated each year as a byproduct of oil and gas operations in the continental United States. Disposal of this water represents about 10% of the cost of hydrocarbon production. Inexpensive treatment technologies can lower the cost of disposal and generate higher-quality water for other uses. Surfactant-modified zeolite (SMZ) has been shown to effectively sorb a variety of nonpolar organic compounds from water. SMZ was tested as a medium to remove benzene, toluene, ethylbenzene, and xylenes (BTEX) from produced water generated during extraction of coalbed natural gas. BTEX removal is necessary prior to surface discharge of produced waters or as a pretreatment for reverse osmosis. We demonstrated in laboratory column experiments that BTEX-saturated SMZ is readily regenerated by air sparging. There was no loss in BTEX sorption capacity, and a minor decrease in hydraulic conductivity, after 50 sorption/regeneration cycles. Based upon the laboratory results, a pilot-scale produced-water treatment system was designed and tested at a reinjection facility in the San Juan Basin of New Mexico. The SMZ-based system was designed to treat up to 110 liters (30 gallons) of produced water per hour on a continuous basis by running two SMZ columns in series. The system performed as predicted, based on laboratory results, over repeated feed and regeneration cycles during the month-long operation. The BTEX-laden sparge gases were treated with a vapor-phase bioreactor system, resulting in an emissions-free process.

Related NETL Project: The primary goal of the related NETL project entitled “Long-Term Field Development of a Surfactant-Modified Zeolite/Vapor-Phase Bioreactor System for Treatment of Produced Waters for Power Generation” (DE-FC26-04NT15546) is to conduct a long-term field test of a prototype Surfactant-Modified Zeolite/Vapor-Phase Bioreactor (SMZ/VPB) treatment system for removing dissolved organics from produced water prior to demineralization to produce a water that can be used by utilities or other industrial users.

NETL Project Contacts
NETL - Jesse Garcia (Jesse.Garcia@netl.doe.gov or 918-699-2036)
UT - Lynn Katz (lynnkatz@mail.utexas.edu or 512/ 471-4244)