Manufacturing method for lactide using a multitude falling film reactor

摘要

invention is an aqueous solution of lactic acid to 50 ~ 700 torr of pressure and temperature at 80 ~ 120 of evaporation to step 1 , a water content of 1% or less by polymerizing the oligomer in the concentrated lactic acid at a temperature of 190 ~ 205 step 2 , the resulting lactic acid oligomer at a temperature of 5 ~ 100 torr of pressure and 200 ~ 270 both the depolymerization of step 3 relates to a manufacturing method is characterized by performing in the lactide drop tube bundle membrane device . According to the present invention , a viscosity of the liquid phase reaction is greater in the low pressure drop across the membrane tube bundle is distributed evenly to the individual vertical pipe of the apparatus , only 100% standpipe to the inner wall surface and flows down a bundle circumferentially uniform film thickness drop tube applying the device to the whole of the unit process it is possible to continuously producing high yields of lactide . ;