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US 5,345,004 AGranted
Process for the preparation of 1,3-butylene glycol
AssigneeDaicel Chemical Industries, Ltd.
InventorKazuhisa Nishiguchi
Life of this patent
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Abstract
Disclosed are the improvements of a process for the preparation of 1,3-butylene glycol, in which the generation of by-products can be decreased, resulting in being capable of producing 1,3-butylene glycol having high quality (e.g. an odorless, so-called "cosmetic grade") at a high-yield.
Claims12
A process for the preparation of 1,3-butylene glycol by steps (a), (b) and (c);
- (a) aldol condensation step of acetaldehyde in the presence of an alkali catalyst to obtain a crude reaction solution primarily containing aldoxane, acetaldehyde, water and small amounts of croton aldehyde;
- (b) thermal decomposition step of aldoxane to obtain paraldol while distilling off a distillate containing acetaldehyde, water and small amounts of croton aldehyde from the crude reaction solution;
- (c) hydrogenation step of paraldol to obtain 1,3-butylene glycol in the presence of a catalyst;
- characterized in that a refined acetaldehyde not containing a substantial amount of croton aldehyde is recirculated to step (a) after removal of croton aldehyde from the distillate in step (b).
1 more element
A process for the preparation of 1,3-butylene glycol by steps (a), (b) and (c);
- (a) aldol condensation step of acetaldehyde in the presence of an alkali catalyst to obtain a crude reaction solution primarily containing aldoxane, acetaldehyde, water and small amounts of croton aldehyde;
- (b) thermal decomposition step of aldoxane to obtain paraldol while distilling off a distillate containing acetaldehyde, water and small amounts of croton aldehyde from the crude reaction solution;
- (c) hydrogenation step of paraldol to obtain 1,3-butylene glycol in the presence of a catalyst;
- characterized in that water is charged into the aldoxane decomposition column in step (b).
1 more element
A process for the preparation of 1,3-butylene glycol by steps (a), (b) and (c);
- (a) aldol condensation step of acetaldehyde under the presence of an alkali catalyst to obtain a crude reaction solution primarily containing aldoxane, acetaldehyde, water and small amounts of croton aldehyde;
- (b) thermal decomposition step of aldoxane to obtain paraldol while distilling off a distillate containing acetaldehyde, water and small amounts of croton aldehyde from the crude reaction solution;
- (c) hydrogenation step of paraldol to obtain 1,3-butylene glycol in the presence of a catalyst;
- characterized in that fresh water is charged into the top of a distillation column while removing water after having removed ethanol and butanol from a crude 1,3-butylene glycol solution containing ethanol and butanol obtained in said hydrogenation step (c).
1 more element
Dependencies are inferred from the claim text.