Effects of torrefaction and water washing on the properties and combustion reactivity of various wastes

• Main Authors: Chen, Chia-Yang, Chen, Wei-Hsin, Zulkiflee Lubes, Zul Ilham
• Format: Article
• Published: John Wiley & Sons 2021
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/26963/

On account of increasing waste problems and energy crisis, this study performed waste-to-energy on three kinds of intermediate waste epoxy resins, including the one used for printed circuit board manufacture (WE1), the one from Bisphenol A type epoxy resin (WE2), and the one from purifying process (WE3), using water washing and torrefaction. Biomass and coal were also tested for comparison. The properties, including proximate analysis, elemental analysis, higher heating value (HHV), and combustion characteristics of the feedstocks before/after the pretreatments, were analyzed. Coal and WE3 did not need any pretreatment to be fuel because their HHVs were high already (26.7 and 34.12 MJ/kg, respectively). Torrefaction presented a good modification on fir in that its fixed carbon content increases a lot, resulting in a 42% enhancement in HHV. However, the high thermal resistance of the intermediate waste epoxy resins let them show merely upgrade after torrefaction pretreatment, especially for WE2. After torrefaction, the ash content of it attained 77% that was not suitable as a fuel. On the other hand, water washing displayed good performance on it where its ash content was reduced by over 88% coupled with the 270% increment on HHV. This was attributed to the removal of salt in WE2 during water washing. The TGA/DTG proved that salt inside intermediate waste epoxy resins was diminished after water washing. Furthermore, after water washing, all the combustible contents concentrated at a lower temperature (250 degrees C-500 degrees C) which benefited the real application.