Natural gas processing technology is now quite mature, and many technologies can be used on different occasions to meet different processing needs. This chapter reviews the three current supersonic separator structures and introduces the profile design equations for the various components in the currently common supersonic separators, such as the Laval nozzle, swirl generator, drainage section, and diffuser. The current natural gas processing technologies are introduced. Their pros and cons are outlined, and the benefits of using supersonic separators are highlighted. The theory behind condensation and liquefaction in supersonic separators is explained. Additionally, the economic and environmental impacts of using supersonic separators in natural gas processing are analyzed. Using supersonic separators in natural gas processing offers several advantages, such as reduced emissions, no chemical usage, high resource utilization, and lower noise and vibration levels.