A process for purification of a crude product stream recovered from the production of acrylic acid by an aldolisation reaction is disclosed. The product stream comprises acrylic acid, formaldehyde, water, non-condensable vapours and optionally heavy by-products. The process comprises: providing the crude product stream in the vapour phase to a first separation column operated at a temperature and pressure to form an intermediate overhead stream comprising water, formaldehyde and methanol; and passing said intermediate overhead stream to a formaldehyde separation column operated at a temperature and pressure to enable a stream having a higher formaldehyde concentration than the formaldehyde concentration in the intermediate overhead stream to be formed and recovered from at or near the bottom of the formaldehyde separation column as a formaldehyde enriched stream.

A method of obtaining ketones from a fermentation process may include collecting an off-gas and a fermented broth from a fermenter, transferring the off-gas from the fermenter to a ketone recuperation module and the fermented broth to a fluid separating module, and isolating the ketones from both the off-gas and the fermented broth. The off-gas and the fermented broth may both comprise a ketone.

A method of obtaining ketones from a fermentation process may include collecting an off-gas and a fermented broth from a fermenter, transferring the off-gas from the fermenter to a ketone recuperation module and the fermented broth to a fluid separating module, and isolating the ketones from both the off-gas and the fermented broth. The off-gas and the fermented broth may both comprise a ketone.

The present invention relates to a method for producing vanillin, including the steps of: (A) distilling a solution containing crude vanillin and an aliphatic dicarboxylic acid dialkyl ester to obtain a vanillin solution; and (B) subjecting the vanillin solution to anti-solvent crystallization. The method for producing vanillin according to the present invention enables production of high-purity vanillin with industrially sufficient efficiency without use of a special apparatus.

The present invention relates to a method for producing vanillin, including the steps of: (A) distilling a solution containing crude vanillin and an aliphatic dicarboxylic acid dialkyl ester to obtain a vanillin solution; and (B) subjecting the vanillin solution to anti-solvent crystallization. The method for producing vanillin according to the present invention enables production of high-purity vanillin with industrially sufficient efficiency without use of a special apparatus.

The present invention relates to a method for producing vanillin, including the steps of: (A) distilling a solution containing crude vanillin and an aliphatic dicarboxylic acid dialkyl ester to obtain a vanillin solution; and (B) subjecting the vanillin solution to anti-solvent crystallization. The method for producing vanillin according to the present invention enables production of high-purity vanillin with industrially sufficient efficiency without use of a special apparatus.

The present invention relates to a method for producing vanillin, including the steps of: (A) distilling a solution containing crude vanillin and an aliphatic dicarboxylic acid dialkyl ester to obtain a vanillin solution; and (B) subjecting the vanillin solution to anti-solvent crystallization. The method for producing vanillin according to the present invention enables production of high-purity vanillin with industrially sufficient efficiency without use of a special apparatus.

A method for producing dimethylolbutanal, the method including: (A) distilling a raw material comprising dimethylolbutanal (DMB) in a distillation column; (B) separating the distilled raw material in the distillation column into a low boiling point component, dimethylolbutanal, and a high boiling point component; and (C) refluxing a portion or all of the high boiling point component to the distillation column by heating the portion or all of the high boiling point component, in which the dimethylolbutanal is separated from a side cut of the distillation column.

A method for producing dimethylolbutanal, the method including: (A) distilling a raw material comprising dimethylolbutanal (DMB) in a distillation column; (B) separating the distilled raw material in the distillation column into a low boiling point component, dimethylolbutanal, and a high boiling point component; and (C) refluxing a portion or all of the high boiling point component to the distillation column by heating the portion or all of the high boiling point component, in which the dimethylolbutanal is separated from a side cut of the distillation column.

Liquid-liquid extraction and distillation of a liquid feedstock of at least ethanol, water, acetaldehyde and at least one hydrocarbon-based impurity with a boiling point of between 20 C. and 100 C. at atmospheric pressure, or which generates, with at least one of the compounds of the liquid feedstock and/or with the organic extraction solvent and/or with the aqueous back-washing solvent, an azeotrope and a partition coefficient of between 0.1 and 5 at any point in a back-washing (BW) column of the extraction section, by (a) a liquid-liquid extraction step a washing (W) column, a back-washing (BW) column and at least one injection (F2) of a cut withdrawn in step b), located in the top half of the back-washing column, (b) a distillation of an aldehyde and ethanol separation producing at least one aldehyde-rich effluent, one ethanol-rich effluent and one water-rich effluent.