Optimization of Batch Reactive Distillation Process: Production of Lactic Acid

摘要

Lactic acid is widely used as a raw material for the production of biodegradablernpolymers, food, chemical and pharmaceutical industries. The global market for lacticrnacid is set to reach 259 thousand metric tons by year 2012.rnIn this work, the performance of batch reactive distillation is evaluated to produce lacticrnacid by hydrolysis reaction of methyl lactate. Minimum time optimisation problem isrndeveloped incorporating a process model within gPROMS software for range lactic acidrnpurity (from 80 % to 99 %) and the amount of product. For a given column thernminimum operation time configuration is obtained by optimising the reflux ratio profile.rnThe lactic acid being heaviest in the reaction mixture, reflux ratio policy plays anrnimportant role in removing the light product methanol from the system while ensuringrnthe presence of both reactants in the reaction zone to maximise the conversion to lacticrnacid. Also unlike esterification reaction, total reflux operation is demanded at the end ofrnthe operation in the hydrolysis reaction to purify lactic acid to about 99 % by removingrnthe remaining reactants from the reboiler.