Oil & Natural Gas Projects
Exploration and Production Technologies
Modified Reverse Osmosis System for Treatment of Produced Water
This project was selected in response to DOE's Oil Exploration and Production
solicitation DE-PS26-01NT41048, focus area Effective Environmental Protection.
The goal of the program was to reduce compliance costs and improve environmental
performance by providing lower-cost technologies, and/or provide sound scientific
basis for cost-effective, risk-based regulatory decisions.
The project goal was to develop and fabricate a bentonite clay membrane (cheap
and readily available) and a precipitator unit with either tubular ceramic or
clay membranes to provide a water treatment system that would process produced
water into reusable water, reducing current disposal costs by as much as 90%.
New Mexico Institute of Mining and Technology
Researchers developed some promising synthetic clay membranes, although the
original betonite membranes did not prove successful for salt rejection. The
new membranes developed are being tested further for potential use in gas separation.
The development of a modified reverse osmosis (RO) system such as that proposed
by the project would be a significant breakthrough in the field of water treatment
by decreasing operat-ing costs through the use of a cheap membrane such as the
proposed bentonite clay membrane. Potential uses of the treated and purified
water would be significant.
Disposal of large amounts of produced water is expensive for the oil and gas
industry and potentially dangerous to the environment. RO has been shown in
some studies to be potentially feasible for decontamination of produced waters,
but costs would be prohibitive and existing technology inadequate. Researchers
proposed to develop an inexpensive RO membrane that needs little or no pretreatment,
which would make RO desalination more cost-effective.
The project covered the following tasks:
- Task I: Bench-scale testing and prototype developing. Bench-scale experiments
on clay and ceramic membranes were to lead to numerical design criteria for
membranes to be used to develop a prototype of a modified RO system.
- Task II: Field demonstration of trailer-mounted RO unit consisting of a
prefilter, one or more RO modules, and a tubular membrane precipitation unit.
The originally proposed Task II could not be delivered due to failure of salt
rejection rates using compacted bentonite membranes.
- New Task II: The bench-scale test with the presence of organics, continued
development of the spiral-wound module, and development of the fluidized bioreactor
module to simultaneously remove organic and salt (tested with a ceramic or
clay membrane), which will be utilized in removing bacteria. Several good
results were obtained:
--Synthetic bentonite membranes were developed whose Na+ rejection rate was
com-prable to the compacted membranes tested in the first part of this project.
However, their permability to water was significantly higher than that of
the compacted thick membranes, which made them unsuitable for steady salt
rejection during operations. Fortunately, they are very well adapted to test
--Synthetic zeolite membranes. Unlike the bentonite clay membranes, the zeolite
mem-branes maintained stability and high salt rejection rate even for a highly
saline solution. Actual produced brines from gas and oil fields then were
tested. Preliminary results were favorable for salt rejection and showed that
the dissolved organics-mainly hydrocarbons-did not affect the salt rejection
(though rejection of organics was inconclusive).
--Methane conversion. An -alumina-supported Pt-Co/Na Y catalytic zeolite membrane
was developed and demonstrated for overcoming the two-step limitation of nonoxidation
meth-ane (CH4) conversion to higher hydrocarbons (C2+) and hydrogen (H2).
The project is complete. A new project, Treating Coalbed Methane Produced Water
for Benefi-cial Use by MFI Zeolite Membranes (DE-FC26-04NT15548), carries on
the studies begun in this project. The new project will develop a new technology
of reverse osmosis through molecular sieve zeolite membranes to efficiently
treat for beneficial use coalbed natural gas produced water with high total
dissolved solids. The project will include extensive fundamental investigation
of the RO mechanisms on zeolite membranes. The understanding gained will be
used to improve zeolite membranes, and finally, to subject these improved membranes
to long-term (>1,500 hours) RO operation to study their stability and to
collect experimental data for technical and economic evaluations of the new
Lee, R., and Dong, J., Modified Reverse Osmosis System for Treatment of Produced
Waters, final technical progress report, September 1, 2000-February 28, 2004,
U.S. DOE, Contract No. DE-FC26-00BC15326, June 2004.
Li, L., Dong, J., and Lee, R., Preparation of ?-alumina-supported mesoporous
bentonite mem-branes for reverse osmosis desalination of aqueous solutions,
J. Colloid and Interface Sci., 273 (2004) 540-546.
Li, L., Dong, J., Nenoff, T., and Lee, R.: Reverse osmosis of ionic aqueous
solutions on a MFI zeolite membrane, Desalination, Nov. 5, 2004, V. 170, No.
3, pp. 209-316.
Li, L., Dong, J., Nenoff, T., and Lee, R., Desalination by Reverse Osmosis
Using MFI Zeolite Membranes, J. Membrane Sci., Nov. 1, 2004, V. 243, No.1-2,
Project Start: September 1, 2000
Project End: February 28, 2004
Anticipated DOE Contribution: $916,000
Performer Contribution: $285,642 (24% of total)
NETL - John Ford (firstname.lastname@example.org or 918-699-2061)
NMIMT - Robert Lee (email@example.com or 505-835-5142)
Synthetic zeolite membrane used in reverse osmosis treatment system.