stripping distillation

Distillation includes a distillation section and a stripping section, whereas gas stripping involves only the stripping section

This post was last edited by Blue Flame on 2016-12-5 at 11:23. Stripping is a physical process that uses a gas medium to disrupt the original gas-liquid equilibrium and establish a new one, thereby causing a certain component in the solution to desorb due to the reduced partial pressure, and thus achieving the purpose of separating substances. For example, A is a liquid and B is a gas; B dissolves in A to reach a gas-liquid equilibrium, with the gas phase being dominated by B. When a gas-phase stripping agent C is added, the partial pressures of both A and B in the gas phase decrease, thereby disrupting the gas-liquid equilibrium. Both A and B diffuse into the gas phase, but since B dominates the gas phase, a new equilibrium is established, resulting in a large amount of B diffusing into the gas phase and thus achieving gas-liquid separation. Distillation makes use of the differences in the volatility of various components within a mixture. Through the recirculation of the liquid and gas phases, the gas and liquid phases come into contact with each other in multiple stages in opposite directions. Driven by thermal energy and governed by phase equilibrium principles, the more volatile components (light components) are continuously transferred from the liquid phase to the gas phase, while the less volatile components move from the gas phase to the liquid phase, thereby enabling the continuous separation of the mixture. This process is known as distillation. In this process, heat transfer and mass transfer occur simultaneously, which falls under mass transfer process control. As can be seen from the principle, stripping results in an uncertain composition of the product obtained at the top of the tower; that is, the quality requirements are relatively low ； And the quality requirements for the product at the bottom of the tower are fixed. Distillation, on the other hand, keeps the composition of the products at the top and bottom of the tower constant.