A Study on High Temperature Pyrolysis Mechanism of Polyethylene

초록

Although the waste incineration has been recognized as a principle tool for mass treatment of various wastes, it may deteriorate air quality considerably by emitting various hazardous air pollutants. Therefore, the modern incinerator s are usually equipped with complex air pollution control devices consisting of acid gas scrubbers, particulate and dioxine control devices. The air pollution control devices are both expensive and difficult to operate and maintain. Therefore, the pyrolysis emerges as a new solution replacing oxidation based incineration because it produces much less air pollutants. However, the success of pyrolysis based incinerators depends on selection of pyrolysis conditions which keep pyrolysis rates reasonably high and produce desirable pyrolysis products. Many of the previous experiments focused only on experimental determination of pyrolysis rates using Thermogravimetry(TGA). In the present study, a pyrolysis reactor was developed to generate high temperature flow condition with the temperatures ranging from 600-900K. The pyrolysis reactor consists of a pre-heater, pyrolysis chamber and pyrolysis product collector. The pre-heater electrically heats the inlet gas of the given compositions to th prescribed pyrolysis temperature. The pyrolysis chamber to compensate any heat loss from the chamber to th ambient. Finally, the pyrolysis collector separates out liquid pyrolysis products for subsequent analysis and the gaseous pyrolysis products are measured for their chemical compositions. The present experiment aims at determining pyrolysis rates and pyrolysis product distributions as a function of pyrolysis temperatures. A special attention was paid to derive pyrolysis mechanism for some of polymers and subsequent dissociation of pyrolysis products. The final goal of the present study is to derive a pyrolysis conditions in which the final pyrolysis products are not-quenchable gaseous fuels containing reasonably high heat content.