An esterification product
neutralization / water separation apparatus according to an embodiment of the present invention for solving the above problems includes: a
neutralization tank into which an unrefined product mixture containing an
alcohol and an ester compound, a neutralizing agent, and water are introduced to form a neutralized mixture; a water separation tank disposed below the
neutralization tank and separating the neutralized mixture into a floating layer and an aqueous layer; a partition wall extending downward from the ceiling of the water separation tank to form a lower passage in the water separation tank; and a
transfer line for transferring the neutralized mixture from the neutralization tank to the water separation tank, wherein the water separation tank includes a first water separation section into which the neutralized mixture flows from the neutralization tank via the
transfer line; and a second water separation section into which the neutralized mixture flows from the first water separation section via the lower passage, and the first and second water separation sections are separated by the partition wall.