The overall objective of this project is to develop a working prototype of a two-part affinity-based membrane separation process for recovering hydrocarbons, and separating organics, from produced water. This effort is focused on produced waters originating from the Greater Green River Basin (GGRB) in Wyoming. Achieving the overall objective will be done in two tasks. Task 2 focuses on the optimization of the separation characteristics of the superhydrophobic/oleophilic and superhydrophilic/oleophobic membranes to achieve high flux/selectivity for Benzene Toluene Ethylbenzene Xylene (BTEX)/oil. This optimization will be based on existing data and membrane synthesis methodologies for such membranes. Computational Fluid Dynamics (CFD) modeling will be combined with experimentation to design the membrane spacers and channel geometry for the prototypes to be constructed in Task 3. As part of Task 3, the research team will execute a techno economic assessment of the implementation of the proposed membrane process in the GGRB. This will include economic benefits from resource (BTEX/oil) recovery, water savings, and reduced treatment costs.
University of Wyoming, Laramie, WY 82071
H2O Systems, Houston, TX 77027
Triton Water Midstream LLC., Edmond, OK 73034
Produced water generally refers to a mixture of formation water and hydraulic fracturing fluids (if used) that return to the surface during the extraction of oil and natural gas resources. Domestically, approximately 21 billion barrels (bbls) of produced water is generated each year, with specific production volumes and qualities varying greatly as a function of site specific characteristics. In 2012, Wyoming ranked as the fourth highest generator of produced water in the U.S, accounting for 10% of the total volume generated. In the context of being the third most arid state in the U.S., the value of water reuse becomes obvious. Produced water reuse and resource recovery in any form requires some level of treatment to remove particulates, residual (free, dispersed) hydrocarbons, organics, and salts. The level of treatment depends on the requirements of the reuse — or resource recovery — application. Typical produced water management systems in Wyoming employ reinjection and/or surface impoundments for disposal. Complicating treatment efforts are the relatively high concentration of organics (natural and synthetic), dispersed/free hydrocarbons, BTEX (benzene, toluene, ethylbenzene and xylene) compounds, biologicals, salts, and minerals. Hydrocarbons (dispersed/dissolved crude oils) and BTEX compounds, as well as synthetic organics, present economic and environmental concerns. The former represents lost revenue, while the latter results in negative environmental impacts like emissions from surface impoundments. Additional concerns arise in the form of performance impacts on downstream filtration and desalination systems, which has played an important role in hindering water reuse and resource extraction from produced water.
Expanding produced water treatment and reuse requires that costs associated with treatment, and recovery of resources contained therein, be reduced to be competitive with reinjection or pit evaporation. The proposed project addresses both areas using nanostructured membranes that take advantage of interfacial chemistry principles to reduce fouling during water filtration and selectively permeate BTEX/oil during resource recovery. As such, this technology improves water quality for reuse (or further treatment) and produces a revenue stream via additional hydrocarbon recovery. In the GGRB, as well as other basins that use pit evaporation as a management method, BTEX compounds pose air emission concerns. Their recovery, therefore, is expected to reduce management costs via reductions in emissions. The importance of this project lies in its ability to generate a prototype process that may be immediately integrated into existing systems in the GGRB and simultaneously improve the economics and viability of produced water management and reduce the environmental footprint of existing pit storage systems.
This project has ended and the final report will be available under “Additional Information” once completed.