Economic assessment of a multistage surface-heated vacuum membrane distillation process for the treatment of hypersaline produced water

Here, the treatment and disposal of hypersaline produced water remains a challenge, particularly for oil and gas producers in the Permian basin where production wells generate significant amounts of wastewater, and the traditional method of injecting wastewater into disposal wells is coming under increasing scrutiny. Here we investigate the viability of using solar energy to power a multi-stage, surface heated, vacuum membrane distillation (SHVMD) with energy recovery to treat hypersaline produced wastewater from Midland, Texas. Membrane distillation is a process that can desalinate waters with high total dissolved solids concentration, and when incorporated into a system with surface heating and energy recovery can achieve high water recovery rates. Model results show that a 6-stage SHVMD system with a 54.4 % water recovery rate and a gained output ratio (GOR) of 3.28 has the potential to be economically viable when used to treat hypersaline produced water in the Permian basin. Assuming energy costs of $\$0.03$/kWh_thermal and $\$0.12$kWh_electric, we estimate a project net present value (NPV) of $\$225,525$ and an internal rate of return (IRR) of 13.5 % when an air cooled condensor is used to cool the distillate and a NPV of $\$570,791$ and IRR of 24.52 % when a liquid coooling source is available.. Authors: Heeley, Michael B. [University of Michigan, Ann Arbor, MI (United States); UCLA]; Liu, Yiming [University of California, Los Angeles, CA (United States)]; Wang, Jingbo [University of California, Los Angeles, CA (United States)]; Municchi, Federico [Colorado School of Mines, Golden, CO (United States)]; Lou, Jincheng [Colorado School of Mines, Golden, CO (United States)]. DOE Contract: EE0008391. Subjects: 29 ENERGY PLANNING, POLICY, AND ECONOMY; Brine; Economic assessment; Membrane distillation; Multi-stage distillation; Surface heating; Water recovery