当前位置: X-MOL 学术J. Anal. Appl. Pyrol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Catalytic degradation of linear low-density polyethylene over hy-zeolite via pre-degradation method
Journal of Analytical and Applied Pyrolysis ( IF 6 ) Pub Date : 2019-03-01 , DOI: 10.1016/j.jaap.2018.11.025
Ishaka Muhammad , Nura Makwashi , George Manos

Abstract The catalytic degradation of linear low-density (lldPE) polyethylene over HY-zeolite catalyst was studied in a semi-batch reactor. One of the important problems encountered during catalytic pyrolysis of macromolecules is the contact with the catalyst, which is known to affect the product distribution and the quality of the coke formed. A pre-degradation procedure was introduced to achieve efficient contact between the LLDPE macromolecules and the catalyst. The influence of the pre-degradation to the reaction conditions including holding time, temperature, polymer to catalyst ratio and flow rate of carrier gas was examined. Moreover, the pre-degradation results were compared with the results obtained using normal mixing procedure. The results obtained showed that, pre-degradation promotes the liquid fraction by a factor of more than one-fold increase at the expense of the gas fraction and the coke yield. The optimal liquid fraction with pre-degradation was obtained at low reaction temperature and catalyst amount respectively, i.e. high polymer to catalyst ratio, making it economically viable method for the degradation of lldPE. The coke content was analysed using TGA in nitrogen atmosphere to remove the soft coke and then in air isothermally at the final temperature to burn the hard coke. The TGA results of the coked sample show less concentration of coke components on the catalyst using the pre-degradation method as compared to the normal mixing which shows high concentration of coke components especially at low reaction temperature. Moreover, the majority of the coke components produced using the pre-degradation method were soft coke, making it more efficient for the re-usability of the catalyst. The liquid samples collected were analysed using gas chromatography and the products distribution were presented in the form of boiling point distribution curves. The bulk of the liquid products produced were lighter fractions with a peak around the gasoline range.

中文翻译:

预降解法在水沸石上催化降解线性低密度聚乙烯

摘要 在半间歇式反应器中研究了HY-沸石催化剂对线性低密度(lldPE)聚乙烯的催化降解。在大分子催化热解过程中遇到的重要问题之一是与催化剂的接触,已知这会影响产物分布和形成的焦炭的质量。引入预降解程序以实现 LLDPE 大分子与催化剂之间的有效接触。检查了预降解对反应条件的影响,包括保持时间、温度、聚合物与催化剂的比率和载气流量。此外,将预降解结果与使用正常混合程序获得的结果进行比较。得到的结果表明,预降解以气体分数和焦炭收率为代价,将液体分数提高了一倍以上。分别在较低的反应温度和催化剂用量下获得了具有预降解的最佳液体馏分,即高聚合物与催化剂的比例,使其成为一种经济可行的lldPE降解方法。在氮气氛中使用 TGA 分析焦炭含量以去除软焦,然后在最终温度下在空气中等温以燃烧硬焦。结焦样品的 TGA 结果显示,与显示高浓度焦炭组分,尤其是在低反应温度下的正常混合相比,使用预降解方法的催化剂上的焦炭组分浓度较低。而且,使用预降解方法生产的大部分焦炭成分是软焦,这使其更有效地提高了催化剂的可重复使用性。使用气相色谱分析收集的液体样品,产物分布以沸点分布曲线的形式呈现。生产的大部分液体产品是较轻的馏分,峰值在汽油范围附近。
更新日期:2019-03-01
down
wechat
bug