Function of cascade compressors and power consumption optimization in ammonia liquefaction process: a system evaluation with a 6 sigma approach

Ammonia is stored as a liquefied raw material as it is used in the fertilizer and cooling industries. The use of multistage compressors during storage is essential, as the boiling point is very low (-33°C) due to a typical petroleum derivative. Because pressure-temperature optimization with a typical single-stage compressor does not allow ammonia to be stored under atmospheric conditions. The use of condenser and throttling valves used in cooling systems together with multi-stage compressors for storage in atmospheric conditions allows ammonia to be stored in liquid form during storage. In this study, a method has been developed to optimize the energy consumption by calculating the power consumption for the pressure and temperature conditions determined for the liquefaction of anhydrous ammonia, to improve the liquefaction conditions and to minimize the energy consumption.