Process for the rectification of mixtures of high-boiling air-and/or temperature-sensitive useful products

摘要

According to the invention, a process for the rectification of mixtures of high-boiling air- and/or temperature-sensitive substances which require a high separation efficiency is proposed, in particular a process for the working-up of a VE- or VEA-containing product stream. The process is characterized in particular in that, in a first purification stage, low-boiling products and unspecified isomers of the useful product are separated from the product stream virtually without loss of useful product and that, in a second purification stage, the useful product is removed in a stream having a purity of 97% by weight and a further stream having a purity of 92% by weight. A preferred embodiment of the process serves for working up VEA, in which the loss of useful product in the first purification stage is less than 5%, based on that amount of VEA in the feed which is added to the purification stage per unit time. Furthermore, the first purification stage may comprise a rectification column (1), from the top (Ia) of which the low-boiling products and the unspecified isomers of VEA are taken off, a stream containing the useful product in purified form being taken off at the side (15) and/or at the bottom (Ib) of the column (1).