Lactic acid production from waste liquid crystal display polarizer under hydrothermal reaction conditions

Lactic acid production from waste liquid crystal display polarizer was carried out in batch reactors under the conditions of reaction temperature 250-375 ℃,reaction time 1-11 min and oxidant(30% volume fraction of H2O2) dosage 0-1.0 mL.The effect of reaction temperature,time and oxidant volume on the yield of lactic acid was investigated.The results indicated that the reaction temperature and time had certain effect on lactic acid production.The yield of lactic acid was increased at first and then declined with the increasing of reaction temperature and time.The yield of lactic acid could be as high as 17% under the optimum reaction temperature of 350 ℃ and reaction time of 5 min.Adding oxidant could significantly increase the yield of lactic acid.When the dosage of oxidant was 0.6 mL,the yield of lactic acid was increased to 21% under the optimum hydrothermal reaction conditions.