Process for making acrylic acid from dextrose

A process for making acrylic acid from dextrose, comprising:

• a. fermenting dextrose in the presence of a biological catalyst to produce a fermentation broth containing lactic acid;
• b. removing solids from the fermentation broth to produce a clarified fermentation broth;
• c. removing lactic acid from the clarified fermentation broth by extraction into an organic solvent;
• d. separating the lactic acid-loaded organic solvent from the fermentation broth remainder after lactic acid has been removed therefrom;
• e. recycling at least a portion of the fermentation broth remainder to the fermentation step;
• f. reacting lactic acid in the lactic acid-loaded solvent with ammonia to provide a crude dehydration feed comprising ammonium lactate;
• g. separating ammonium lactate from organic solvent in the crude dehydration feed to provide a dehydration feed;
• h. carrying out a vapor phase dehydration of ammonium lactate in the dehydration feed to produce a crude acrylic acid product;
• i. purifying the crude acrylic acid product to provide a purified acrylic acid product, by a process including
• a first distillation to remove acetaldehyde and ammonia overhead and provide a bottoms stream comprised predominantly of acrylic acid and propionic acid, and
• a second distillation of the bottoms stream from the first distillation to provide a second distillation overhead stream enriched in acrylic acid and a second distillation bottoms stream enriched in propionic acid;
• and,
• j. further purifying the acrylic acid in the second distillation overhead stream by contacting with an the amphoteric ion exchange resin to separate and elute propionic acid into a raffinate or both melt crystallization and by contacting with an the amphoteric ion exchange resin to separate and elute propionic acid into a raffinate.