Membrane distillation is a thermal-driven separation process that utilizes a porous hydrophobic membrane to separate liquid streams based on the differences in vapor pressure. In this process, a feed solution is heated to generate vapor, which passes through the membrane pores, leaving behind the concentrated solution. The vapor is then condensed on the other side of the membrane, resulting in purified water or other desired product. Membrane distillation has been used in various applications, such as desalination, wastewater treatment, and concentration of liquid products. It offers advantages such as high separation efficiency, low energy consumption, and the ability to treat complex feed solutions. However, challenges such as membrane fouling and scaling need to be addressed for optimal performance.