Aldol condensation reaction apparatus

An apparatus for an aldol condensation reaction which produces 2-ethylhexenal from n-butyraldehyde by an aldol condensation reaction, the apparatus comprising:

• a continuous stirred tank reactor 10 into which n-butyraldehyde and a catalyst flow,
• a plug flow reactor 20 into which n-butyraldehyde, the catalyst, and a product flow from the continuous stirred tank reactor 10,
• an oil-water separator 30 into which the product and the catalyst flow from the plug flow reactor 20 and which separates the catalyst with an aqueous layer and separates the product with an organic layer, and
• a heat exchanger 40 for transferring heat of the separated product to n-butyraldehyde flowing into the continuous stirred tank reactor 10,
• wherein the catalyst separated as the aqueous layer in the oil-water separator 30 directly flows into the continuous stirred tank reactor 10 and is circulated.