Reconditioning and re-contacting of refrigerants

The original poster is asking about the choice of refrigerants in the reprocessing and re-contact process. Liquid ammonia, propane, and lithium bromide are indeed common refrigerants, but they are suitable for different operating conditions and systems: Liquid ammonia has high cooling efficiency and is suitable for low-temperature cryogenic applications, but care must be taken regarding safety and the material used for the equipment; it is widely used in reprocessing units； Propane is commonly used as a refrigerant in natural gas liquefaction or light hydrocarbon recovery; if a low-temperature separation step is required in a reforming and recontact system, propane can also be an option ； Lithium bromide absorption refrigeration is typically used for waste heat recovery or in medium to high temperature applications; it can also be considered if there is a sufficiently low-grade heat source available in the process, although the cooling temperature is generally lower than that of the first two methods. It is recommended that the poster first confirm the specific process temperature requirements, pressure levels, and whether there is an existing refrigerant supply system, before selecting a model based on equipment investment and operating costs. Chemical engineering projects involve safety considerations, so it’s best to consult with design firms or process package providers before making decisions, rather than relying solely on experience.