Tech Team Extracting Power From Dirty Water
Dr. Frank Huang (center) with some of the students working on the pressure retarded osmosis project, which is funded by a five-year grant from N.M. EPSCoR.
Dr. Frank Huang and Vivian Hernandez in the environmental engineering laboratory in Jones Annex on campus.
Vivian Hernandez displays one of the osmosis units that is being developed at New Mexico Tech.
Photos by Thomas Guengerich/New Mexico Tech
Dr. Frank Huang, professor of environmental engineering, leads a team of about 20 professors, researchers, graduate students and undergrads. They have finished the first year of a five-year National Science Foundation grant to develop a process of extracting electricity from brackish produced water produced by the oil-and-gas industry.
Using a process called pressure retarded osmosis, or PRO, the project aims to develop a cost-effective manner of generating power from water containing high concentrations of total dissolved solids, or TDS.
The project is under the aegis of the New Mexico Experimental Program to Stimulate Competitive Research, or EPSCoR.
In simple terms, high-TDS produced water and low-TDS produced water are fed into separate pipes, via filters which remove humus and other particles which can block the membranes. The water is then fed into the membrane system, which consists of hollow fiber membranes. The water in the low-TDS produced water is drawn across the membrane to the high-TDS produced water. The increase in volume creates a pressure which forces the water through the turbine and generates electricity.
The team at New Mexico Tech is designing and fabricating the fiber membranes with off-the-shelf polymers. The workshop will include morning talks, followed by hands-on demonstrations on how to build the membranes.
“Rarely will you find a university that is able to make membranes,” Huang said. “We can develop a process to make membranes that fit our need. The students are excited to put it all together.”
Fabricating the membranes is only half the job. The workshop will also include characterization of the membranes. Attendees will use a portable scanning electron microscope to look at cross-sections of the membranes, a viscometer to see how viscous the polymer dope solution is, as well as determining how hydrophilic or hydrophobic the membranes are using contact angle measurements. They will also test the tensile strength of the membranes to gauge the bursting pressures of the membranes.
Vivian Hernandez, an undergrad in chemical engineering, is learning to make the membranes and assemble them using a centrifugal potting machine. Hundreds – perhaps thousands – of the fiber membranes are assembled in a cylindrical unit, which will serve as the test device.
“It’s been great to be hands-on,” she said. “I’ve learned so much on this project.”
Kelsy Waggaman, an undergrad in environmental engineering, said the project is exciting because of the practical potential.
“The membrane is the key and it's a barrier to increasing the efficiency ofthe technology,” she said. “We need to make a membrane that can handle the environmental factors. We want to make sure the oil and gas operators are excited to use osmotic power technology and that it’s economically beneficial to corporations. There’s so much happening on many levels; this is very exciting research.”
The petroleum industry generates about 28 billion gallons of produced water annually in the state, with 22 billion gallons coming from the oil-rich
The team includes scientists from New Mexico Tech, Eastern New Mexico University, New Mexico State University, Sandia National Laboratory, Los Alamos National Laboratories, Apache Corp. and NASUS Water Technology. Students from Tech, Eastern New Mexico and
Huang said future workshops will provide updates and offer instruction on building workable, scalable modules and further characterization of membranes.
– NMT –
By Thomas Guengerich/