Acetic acid production from the hydrothermal transformation of organics in waste liquid crystal display panels

The widespread usage of liquid crystal display (LCD) has led to a large quantity of waste LCD panels, causing serious harm to environment and human health due to toxic substances they contain. Existing literature on this topic mainly deals with recovery of indium and glass from waste LCD panels while the recycling of organics is often neglected. Organics in waste LCD panels are generally treated by incineration and pyrolysis while both can bring about secondary pollution. In this study, the hydrothermal method, an efficient and environment-friendly way, was adopted to treat waste LCD panels with aim of recycling waste organics. Quality and quantity of liquid product (acetic acid) were determined by gas chromatography mass spectrometry and high performance liquid chromatography. Investigated factors included reaction time, temperature, pH value and oxidant supply. The highest yield of acetic acid was 44.91% under the following conditions: a temperature of 300 degrees C, a reaction time of 5 min, 3 mL of water, and a pH of 10. Additionally, the mechanism of acetic acid production was analyzed. (C) 2015 Elsevier Ltd. All rights reserved.