PROCESS FOR THE CRYSTALLISATION OF A WATER-SOLUBLE COMPOUND

摘要

A process for the crystallisation of a water-soluble compound is disclosed. The process comprises (a) providing, in a crystallisation vessel, a solution of the water-soluble compound in a mixture of water and a solvent in which the water-soluble compound has a lower solubility than in water; (b) passing vapour phase of the mixture through a sorption zone containing a water vapour sorbent to selectively adsorb water from the vapour phase; (c) recycling a part of the vapour phase to the crystallisation vessel or withdrawing vapour phase depleted in water from the process and adding solvent to the crystallisation vessel; (d) allowing solid crystals of the water-soluble compound to precipitate from the solution; and (e) discharging precipitated solid crystals of the water-soluble compound from the crystallisation vessel and discharging a solution of non-crystallised water-soluble compound in water-solvent mixture from the crystallisation vessel.

主权项

1. A process for crystallisation of a water-soluble compound from a solution, comprising:
(a) providing, in a crystallisation vessel, a solution of the water-soluble compound in a mixture of water and a solvent, wherein the water-soluble compound has a lower solubility in the solvent than in water; (b) passing vapour phase of the mixture through a sorption zone containing a water vapour sorbent to selectively adsorb water from the vapour phase to obtain a vapour phase depleted in water and enriched in the solvent and water-saturated water vapour sorbent; (c) enriching the mixture in the crystallisation vessel in solvent by (i) recycling at least part of the vapour phase depleted in water and enriched in the solvent to the crystallisation vessel or (ii) withdrawing vapour phase depleted in water from the process and adding solvent from an external source to the crystallisation vessel; (d) allowing solid crystals of the water-soluble compound to precipitate from the solution in the crystallisation vessel at a crystallisation temperature; and (e) discharging precipitated solid crystals of the water-soluble compound from the crystallisation vessel and discharging a solution of non-crystallised water-soluble compound in water-solvent mixture from the crystallisation vessel.