Vapour induced phase separation

Vapour induced phase separation (VIPS) - in this process, the polymer solution is exposed to an atmosphere containing a non-solvent, which is absorbed and causes precipitation of the polymer. 

A typical configuration for a methanol carbonylation plant is shown in Fig. 1. The feedstocks (MeOH and CO) are fed to the reactor vessel on a continuous basis. In the initial product separation step, the reaction mixture is passed from the reactor into a flash-tank where the pressure is reduced to induce vapourisation of most of the volatiles. The catalyst remains dissolved in the liquid phase and is recycled back to the reactor vessel. The vapour from the flash-tank is directed into a distillation train which removes methyl iodide, water and heavier by-products (e.g. propionic acid) from the acetic acid product. 

It has been well known for a couple of decades that noncrystalline metallic alloys can be made by vapour- and melt-quenching. Recent results show that an amorphous phase can also be formed directly when a crystalline metallic alloy is subjected to various types of disordering processes. Solid-state amorphization can be induced through a variety of methods including absorption of atomic hydrogen, thermal interdiffusion reaction along the interface separating... 

When chlorine is reacted with organic reactants, specially if nitogen containing compounds or ammonium ions are present, the possible formation of unstable chlorinated compounds should be considered. Any segregation of a separate phase from the bulk liquid is potentially dangerous and should be investigated carefully. The demixion of an unstable liquid phase may induce a high vapour pressure of the unstable product in the gas phase because the gas phase is in equilibrium with the separated unstable liquid. This problem should be considered. 

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