Separation, recovery and upgrading of biomass derived 2,3-butanediol

An integrated solvent free method for separation and recovery of 2,3-butanediol (2,3-BDO) from fermentation broth, said process comprising the steps of:

• a) acetalization of fermentation broth with an aldehyde in the presence of a catalyst forming cyclic acetal;
• wherein the catalyst is selected from the group consisting of aluminum oxide, aluminum phosphate, ZSM-5 with silicon/aluminum, Nafion NR50® and Amberlyst-15®;
• b) isolating 2,3-BDO as phase-separated cyclic acetal;
• wherein the cyclic acetal is dioxolane;
• c) upgrading methyl ethyl ketone (MEK) synthesis by cleavage of dioxolane with a catalyst to form methyl ethyl ketone (MEK) and butanal;
• d) recycling butanal by adding the resulting product of MEK and butanal to the said fermentation broth.

A solvent free method for separation and recovery of 2,3-butanediol (2,3-BDO) from fermentation broth, said process comprising the steps of:

• a) acetalization of fermentation broth with an aldehyde in the presence of a catalyst forming cyclic acetal;
• wherein the catalyst is selected from the group consisting of ZSM-5 with silicon/aluminum, Nafion NR50® and Amberlyst-15®;
• said step (a) conducted at a temperature that is selected from room temperature and about 40° C., for about 3-5 hours;
• a) isolating 2,3-BDO as phase-separated cyclic acetal;
• wherein the cyclic acetal is dioxolane;
• b) transacetalization of phase-separated dioxolane with methanol followed by distillation of acetal, to obtain high purity 2,3-BDO and butyraldehyde dimethyl acetal;
• c) distilling off butyraldehyde dimethyl acetal;
• d) recovering high purity 2,3-BDO;
• e) recycling and reusing the catalyst;
• wherein the catalyst is reactive after about 10 cycles;
• f) upgrading methyl ethyl ketone (MEK) synthesis by cleavage of dioxolane obtained from step (a) with an acid catalyst to form methyl ethyl ketone (MEK) and butanal;
• and
• g) recycling butanal by adding the resulting product of MEK and butanal to the said fermentation broth.