Membrane separation techniques are used to separate certain components (protein, fat, water, etc.) in liquid products such as milk and to obtain these components in pure form, and also to remove microorganisms in these liquid products. In addition, these techniques are used to concentrate milk in the dairy industry. In membrane separation, components pass through pores of a certain size and are separated according to molecular weights. The basic principle in separation techniques is based on the fact that the liquid is passed through the pores of the membrane under certain pressure, the desired components (retantat) are kept in the pores and other components (permeate) pass through the membrane. The techniques used are grouped into four main categories: Microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and hyperfiltration (reverse osmosis). Among the advantages of the membrane separation technique are the low electricity consumption, the possibility of use in various areas, and the fact that it does not cause undesired changes in the product characteristics. There are disadvantages such as the cost of initial installation, fouling of the membrane pores, and the membrane cleaning takes a long time.