Patent ID: 7569736

Claim:
A process for production of a monopentaerythritol of high purity, said process comprising subjecting formaldehyde to reaction with acetaldehyde in an aqueous medium at a formaldehyde to acetaldehyde molar ratio of 5-10 to 1 and in the presence of a strong basic hydroxide and subsequently neutralizing the obtained reaction mixture, wherein said obtained reaction mixture is evaporated yielding a dryness of 50-70% by weight and is subsequently cooled, whereby formed pentaerythritol crystals are separated and recovered and subsequently dissolved in an aqueous mother liquor comprising pentaerythritol having a dryness of 35-55% by weight, said solution being treated in a purification step yielding monopentaerythritol of high purity crystallized at a temperature of 40-90° C., the obtained monopentaerythritol crystals being separated and recovered from remaining method liquor and said remaining mother liquor being re-circulated to said purification step.