I-Corps: Solar Desalination of Oilfield Produced Water with Nanostructured Gel Materials

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of technology for the desalination of produced water from the energy industry. The energy industry is currently facing increasing environmental and economic pressure with regard to the production of wastewater from its wells. This produced water has a very high total dissolved solids (TDS) concentration, reaching salinities up to ten times that of typical sea water. The U.S. oil and gas industry produces a billion barrels of water annually. The vast majority (more than 90%) of this water is re-injected in geological formations for disposal or enhanced oil recovery. While re-injection is the cheapest disposal method at this time, there are concerns about forming pressure spikes in the drilled neighboring wells and induced seismic activity. In several parts of the U.S. (e.g., California, Texas and New Mexico), oil and gas production regions are located near water-stressed regions. The desalination and use of produced water as a potential source of potable water may provide additional water to these regions. This I-Corps project is based on the development of technology to modify solar evaporation ponds, an existing method for the disposal of produced water for some oil and gas producers. The proposed technology uses two major modifications to these solar still/evaporation ponds: 1) placing hierarchical nanostructured hydrogel materials on top of the feed water to increase the rate of evaporation, and 2) adding a superhydrophobic coating to the glass at the top of the solar still to enhance the rate of droplet departure on the glass surface and move condensed water out of the way from incoming radiation. The proposed approach will use fully passive desalination technology without any moving parts. The low capital and operating costs associated with this approach make it more reliable and economically feasible for small-scale plants at oil and gas well sites, which are often located far away from substantial infrastructure. In addition, the proposed design may ensure zero liquid discharge to eliminate the problem of treating the ultra-high saline water that is typically produced at the end of the desalination process. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.