Propane and propylene are important hydrocarbon substances in petrochemical industry. Due to their close boiling points, separation is challenging. Distillation is a common method to achieve effective separation of propane-propylene.

Distillation is an operation that uses the difference in volatility of each component in a mixture to achieve separation. In the propane-propylene system, the relative volatility of propylene is slightly higher than that of propane. The distillation tower is the key equipment to achieve this process. It mainly consists of a distillation section and a stripping section.

In the distillation section, the rising steam from the bottom of the tower is fully contacted with the liquid refluxed from the top of the tower on the tower plate. The propylene content in the rising steam is relatively high because propylene is more volatile. When the steam contacts the cooler reflux liquid, the propylene part in the steam will be condensed, and the propane part in the reflux liquid will be vaporized. This process is repeated, so that the purity of propylene in the rising steam gradually increases and enriches toward the top of the tower.

In the stripping section, the situation is the opposite. The reflux liquid from the top of the tower flows down along the tower plate and meets the rising steam at the bottom of the tower. Since propane is relatively difficult to volatilize, the propane content in the liquid phase gradually increases during this process and is enriched at the bottom of the tower. The reboiler at the bottom of the tower provides heat to partially vaporize the liquid at the bottom of the tower, providing an upward steam flow for the distillation process.

The entire distillation process requires precise control of operating parameters such as temperature, pressure, and reflux ratio. Temperature and pressure affect the relative volatility of propane and propylene, and a suitable reflux ratio can ensure the separation effect. Through the fine regulation of these parameters, the Propane-Propylene (PP) Splitter can effectively separate propane and propylene to obtain high-purity propane and propylene products, meeting the different production needs of the petrochemical industry for these two substances.