| Pyrolysis, as a new technique to recycle waste printed circuit boards (PCB), makes the organic fractions of PCB convert to flammable gas and oil which are high-quality energy sources, also leads to the effective seperation of metallic and glassfibre fractions of PCB. Pyrolysis technique achieves the aim of environment- friendly, resource reclamation of PCB. However, the scarce of basic information prevents the large-scale equipment development process; furthermore baffles the application and popularization to recycling PCB with pyrolysis technique. Aiming at these questions, two typical kinds of PCB, called FR4 and Teflon PCB, were chosen as experimental materials and the following studies had been done in the paper:Pyrolysis characteristics of two kinds of PCB were investigated with the thermo- gravimetric analyser (TGA) with N2and basic parameters such as the pyrolysis initial and final temperature, the temperature at the maximum pyrolysis rate, thermogravi- metric loss were obtained. The influence of heating rate on the pyrolysis characteristic parameters was studied also. The influence of effective factors of heating rate, particle size, and pyrolysis final temperature on the pyrolysis residue morphology was inves- tigated in detail. The results showed that: the pyrolysis temperatures of 500℃for FR4 PCB and of 700℃for Teflon PCB in engineering design not only ensure the complete decomposition of organic component, but also effective seperation of metallic compo- nent and glassfibre component. Also, the temperature at the maximum pyrolysis rate appeared at the range of 320~360℃for FR4 and of 560~620℃for Teflon PCB. Therefore, the longer residence time at the temperature zone of the feedstocks can be considered in engineering design.The method based on CAI-temperature integral approximation and Levenberg- Marquardt nonlinear regression was carried out to calculate the kinetic parameters of two kinds of PCB respectively and corresponding kinetic models were established. The models were in good agreement with the experimental ones at different heating rate. The effect of the original waste PCB with different pyrolysis time or temperature in process could be estimated based on the models, which could effectively direct and optimize design of pyrolysis reactor. Pyrolysis gas, liquid, solid products of two kinds of PCB was collected using self-designed fixed-bed pyrolysis experimental device and was analyzed qualitatively with the test methods of GC-MS, FT-IR and SEM. For FR4 PCB, bromide exsited mainly in pyrolysis gas and gas products mainly consisted of CO, CO2, propylene, 2-methacrylate, bromomethane, and a small amount of acetone, C1-C3 halogenation alkyls. The pyrolysis gas could be reclaimed as fules after debromide treatment. Pyrolysis liquid products consisted of 8.333% water and 91.667% oil component.The oil component contained high concentrations of benzene, phenol, alkyl benzene and alkyl phenols, which caloric value was up to 30000kJ/kg and could be reclaimed as fuels.For Teflon PCB, pyrolysis gas contained high concentration of octafluoro- cyclobutane and low concentration of small molecular fluorocarbon-hydrogen compounds. The solid products of two kinds of PCB contained glassfibre and metals. The plated sheet metal after pyrolysis treatment contain copper, nickel, gold and a little carbon; non-plated metal contained copper and carbon attached on the metals.Energy consumption was analyzed on the treatment of PCB by pyrolysis technology. Pyrolysis reaction heat was 19.692MJ/kg for FR4 PCB and 11.374MJ/kg for Teflon PCB respectively.For FR4, caloric value of pyrolysis oil was about 1/4 of pyrolysis reaction heat value, which was not enough to support the pyrolysis process of FR4 PCB.
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