Patent ID: 6043392
Filing Date: 2000-03-28
Classification: C07C,C12P

Abstract:
A process for recovering low-boiling acids from a concentrated solution of calcium salts of the acids comprisingcontacting a concentrated solution of calcium salt of low-boiling acids with a low-molecular-weight tertiary amine and carbon dioxide,forming calcium carbonate precipitate and a liquid solution containing low-molecular-weight tertiary amine/acid complex,washing the calcium carbonate precipitate with water to remove residual low-molecular-weight tertiary amine,replacing the low-molecular weight tertiary amine in the amine/acid complex with a high-molecular weight tertiary amine by an exchange reaction, andthermally breaking the high-molecular-weight tertiary amine/acid complex and allowing the nonvolatile high-molecular-weight tertiary amine to separate from the volatile low-boiling acid.