Method for producing high concentration aqueous HF solutions

A process for separation of HF from its mixture with a liquid fluorocarbon organic process stream, comprising the steps of:

• (a) a liquid fluorocarbon organic mixture containing HF is mixed with an aqueous HF solution and then subjected to phase separation into a liquid organic phase and a liquid aqueous phase;
• (b) the liquid organic phase, having most of its HF content extracted, is isolated;
• (c) the liquid aqueous phase comprises an HF solution which may contains up to about 500 ppm of dissolved organic, is sent to a multi-stage falling film exchanger where it separates the solution into (1) an overhead gas phase containing 86% wt. HF and (2) a bottom aqueous solution containing 39% wt. HF,
• (d) the 39% wt. HF solution is recycled to extract more HF from the incoming liquid fluorocarbon organic process stream, and the overhead gas is sent to a multi-stage absorber where water or steam is introduced to form a 50% wt. HF aqueous solution which is then isolated;
• and
• (e) wherein the vapor leaving the multistage absorber is recycled to step (a) to extract its HF content.