Thermal degradation kinetics of waste printed circuit boards

Abstract

A large quantity of electronic waste, (e-waste) is generated due to a short lifespan of communication and other devices and introduction of the newly smart gadgets making limited use and generating e-waste at an alarming rate. To resolve this emerging e-waste problem, one has to thermally depolymerise in an inert atmosphere. The thermal degradation of printed circuit boards PCBs was investigated using a simultaneous thermogravimetric analyzer in the temperature range of 350–1200K. Pyrolysis experiments were carried out on PCB samples at six different heating rates of 5, 10, 20, 30, 40 and 50K/min. A unique model was developed in this study, it showed that the apparent activation energy for the upper range (Ea1, 130–97kJ/mol) was always higher than the apparent activation energy (Ea2, 97–75kJ/mol) of the lower range. The results of this study will be useful in the development of pyrolytic/incineration systems for plastic waste from any electronic component. The products from the pyrolysis of PCBs can be utilized as feedstocks in the petrochemical industry, as potential fuels—either gaseous or liquids and as non-combustible materials for filler in the cement and brick industries.