Recovery of trimethylolpropane

Claim 1

A PROCESS FOR THE RECOVERY OF HIGH PURITY TRIMETHYLOLPROPANE FROM AN AQUEOUS REACTION LIQUOR CONTAINING IN SOLUTION TRIMETHYLOPROPANE AND IMPURITIES INCLUDING METAL FORMATE AND POLYHYDRIC BY-PRODUCTS PRODUCED BY CONDENSATION OF N-BUTYRALDEHYDE AND FORMALDEHYDE IN AN AQUEOUS MEDIUM CONTAINING AN ALKALINE CONDENSATION CATALYST, THE PROCESS COMPRISING EXTRACTING SUCH A REACTION LIQUOR WITH WATER IMMISCIBLE SOLVENT SELECTED FROM THE GROUP CONSISTING OF N-BUTYL ALCOHOL AND AMYL ALCOHOL TO FORM A SOLVENT EXTRACT CONTAINING TRIMETHYLOPROPANE, METAL FORMATE AND POLYHYDRIC BY-PRODUCTS, SEPARATING THE SOLVENT EXTRACT FROM THE STRIPPED LIQUOR, RE-EXTRACTING THE SOLVENT EXTRACT WITH WATER TO FORM AN AQUEOUS RE-EXTRACT CONTAINING RE-EXTRACTED TRIMETHYLOLPROPANE CONTAMINATED WITH METAL FORMATE AND POLYHYRIC BY-PRODUCTS, SEPARATING THE AQUEOUS RE-EXTRACT FROM THE STRIPPED SOLVENT, THEREAFTER THE RE-EXTRACTED CONTAMINATED TRIMETHYLOLPROPANE WITH METHANOL AND A MINERAL ACID TO HYDROLYZE POLYHYDRIC BY-PRODUCTS, THEREAFTER CONTACTING AN AQUEOUS SOLUTION OF THE METHANOL-ACID TREATED TRIMETHYLOLPROPANE WHILE DISSOLVED IN WATER WITH BASIC ANION EXCHANGE RESIN AND ACIDIC CATION EXCHANGE RESIN TO REMOVE METAL SALT FROM THE SOLUTION.