Apparatus for producing lactic acid

Abstract

An apparatus for producing lactic acid according to the invention comprises a reactor carrying out: subjecting glycerin to a hydrothermal reaction under an alkaline condition, supplying an alkaline solution comprising glycerin; and continuously producing lactic acid, wherein glycerin is subjected to a hydrothermal reaction under an alkaline condition at a temperature in the range of 150 to 400° C. and under pressure equal to or more than the saturated vapor pressure at the temperature. The glycerin produced from plant fats, animal fats or the like or pure product synthesized chemically or a discharge containing glycerin generated at the production of diesel fuel oil from fats, in which the fats are subjected to a transesterification with alcohol in the presence of an alkali catalyst in order to obtain fatty acid ester is preferably used as a starting material.

1 . An apparatus for producing lactic acid, wherein the apparatus comprises a reactor carrying out: subjecting glycerin to a hydrothermal reaction under an alkaline condition, supplying an alkaline solution comprising glycerin; and continuously producing lactic acid. 
     
     
         2 . The apparatus for continuously producing lactic acid according to  claim 1 , wherein the reactor carries out the hydrothermal reaction at a temperature in a range of 150 to 400° C. and at a pressure equal to or more than a saturated vapor pressure at the reaction temperature, wherein water maintains a liquid phase state. 
     
     
         3 . The apparatus for producing lactic acid according to  claim 1 , wherein the apparatus further comprises a gas-liquid separator that separates an alkaline solution comprising lactic acid from a hydrogen gas generated in the reactor. 
     
     
         4 . The apparatus for producing lactic acid according to  claim 1 , wherein the apparatus further comprises an electrodialysis unit comprising a bipolar membrane that separates an alkaline solution comprising lactic acid into a solution comprising lactic acid and an alkaline solution. 
     
     
         5 . The apparatus for producing lactic acid according to  claim 1 , wherein the apparatus further comprises a calcium crystallizer that separates an alkaline solution comprising lactic from the gas-liquid separator into a solid of calcium lactate and an alkaline solution according to a crystallization process. 
     
     
         6 . The apparatus for producing lactic acid according to  claim 1 , wherein the apparatus further comprises a high-pressure pump, a heat exchanger, and a valve for controlling a pressure and a tank for storing a raw material.