Membrane distillation (MD) is an emerging membrane technology with great potential for treatment of hypersaline wastewater generated by unconventional (shale) oil and gas reservoirs. However, the low energy efficiency of this technology makes the operating cost of MD systems relatively high, especially in the absence of waste heat. There are several MD configurations with inherent advantages and disadvantages and varying performance. As such, there is a need for thermo-economic optimization of MD systems in a systematic manner to assess their economic performance. We present an optimization framework to model and compare the performance of six MD configurations (DCMD, AGMD, PGMD, CGMD, SGMD, and VMD) in continuous recirculation mode for treatment of hypersaline wastewater. The optimization results show that AGMD with small gap size operated at low stream Reynolds number outperforms all other configurations with treatment cost of 4.57 US $/m³ of feed. However, restricting the system design to more practically relevant operating conditions, such as higher Reynolds number and larger gap size, diminishes the cost superiority of AGMD over other configurations. We also observed that treatment cost using PGMD configuration approaches those of CGMD and DCMD, particularly when modules with small gaps are used.

膜蒸馏（MD）是一种新兴的膜技术，在处理非常规（页岩）油气藏产生的高盐废水方面具有巨大潜力。然而，该技术的低能效使得MD系统的运行成本相对较高，尤其是在没有余热的情况下。有几种 MD 配置具有固有的优点和缺点以及不同的性能。因此，需要以系统的方式对 MD 系统进行热经济优化，以评估其经济性能。我们提出了一个优化框架来模拟和比较六种 MD 配置（DCMD、AGMD、PGMD、CGMD、SGMD 和 VMD）在连续再循环模式下处理高盐废水的性能。³饲料。然而，将系统设计限制在更实际相关的操作条件下，例如更高的雷诺数和更大的间隙尺寸，会降低 AGMD 相对于其他配置的成本优势。我们还观察到使用 PGMD 配置的处理成本接近 CGMD 和 DCMD，特别是在使用具有小间隙的模块时。