Year Established: 2019 Start Date: 2019-03-01 End Date: 2020-02-29
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,001
Principal Investigators: Seok-Jhin Kim
Abstract: Problem: The costs of treating produced water (PW) typically outweigh the costs of injection, and as a result 91% of PW in the United States in 2012 was disposed of via reinjection. The resulting expansion of oil and gas production and water intensity of hydraulic fracturing methods has increased both the demand for new water supplies and the generation of PW. Recent studies have determined that underground injection of PW induces seismic activity. Oil and gas production in Oklahoma consumes in excess of 60 million m3 of water per year for secondary recovery and 16 million m3 per year for well completion, while simultaneously generating over 120 million m3 per year of PW. The majority of the PW in Oklahoma is disposed of by deep well injection, but recent studies have determined that this induces seismicity. Alternative approaches are needed for PW management. PW could be a valuable resource for the energy and agricultural sectors during periods of limited water availability, if more economical approaches to improve water quality existed. There is a critical need to identify alternative approaches for management of PW throughout Oklahoma and the United States. Objectives: The team proposes to combine a membrane desalination system with solar thermal energy that is abundantly available and a viable alternative to fossil fuels. A solar evaporation technology is ideally suited for a pretreatment step that saves energy and minimize the membrane fouling. The overall goal of the proposed research is to develop novel, energy-efficient solar-energy-combined membrane processes for treating PW to levels suitable for reuse. The primary research objectives of the proposed investigation are to: (1) Design chemical pretreatment process (Dr. Lampert), (2) Develop solar evaporation and condensation network (Dr. Mcllroy), (3) Synthesize ceramic membranes for desalination and organics rejection (Dr. Kim and Dr. Aichele) Methods: (1) The first objective will be accomplished through designing chemical pretreatment process (primary water treatment and chemical softening) to reduce suspended solids, bacterial contamination, and concentration of potential scale-forming components before solar evaporation treatment. (2) The second objective will be performed by developing a high efficiency solar evaporator system that removes solids and significantly reduces the salinity prior to the final membrane desalination/solvent treatment. The evaporator system can be computer controlled to follow the sun, further ensuring maximum light collection and evaporation. A benchtop design exists and readily scaled up to handle larger volumes. (3) The third objective will be realized by developing novel controlled-pore membranes applied to synthetic water solutions and real PW. Thin membranes composed of macroporous ceramic support will be developed for treating water after solar evaporation.