National Engineering Laboratory of Advanced Tire Equipment and Key Materials, Qingdao University of Science and Technology, Qingdao, 266061, Shandong Province, China.
Shandong Key Laboratory of Advanced Manufacturing of Polymer Materials, Qingdao, 266061, Shandong Province, China.
Environ Sci Pollut Res Int. 2023 May;30(25):66665-66682. doi: 10.1007/s11356-023-26999-y. Epub 2023 Apr 26.
At present, disposable plastic products such as plastic packaging are very common in our daily life. These products are extremely easy to cause serious damage to the soil and marine environment due to their short design and service life, difficulties in degradation, or long degradation cycles. Thermochemical method (pyrolysis or catalytic pyrolysis) is an efficient and environmentally friendly way to treat plastic waste. In order to further reduce the energy consumption of plastic pyrolysis and improve the recycling rate of spent fluid catalytic cracking (FCC) catalysts, we adopt the "waste-to-waste" approach to apply the spent FCC catalysts as catalysts in the catalytic pyrolysis of plastics, exploring the pyrolysis characteristics, kinetic parameters, and synergistic effects between different typical plastics (polypropylene, low-density polyethylene, polystyrene). The experimental results show that the spent FCC catalysts used in the catalytic pyrolysis of plastics are beneficial to reduce the overall pyrolysis temperature and activation energy, in which the maximum weight loss temperature decreases by about 12 ℃ and the activation energy decreases by about 13%. The activity of spent FCC catalysts is improved after modification by microwave and ultrasonic, which further improve the catalytic efficiency and reduce the energy consumption of pyrolysis. The co-pyrolysis of mixed plastics is dominated by positive synergistic effect, which is conducive to improving the thermal degradation rate and shortening the pyrolysis time. This study provides relevant theoretical support for the resource application of spent FCC catalysts and "waste-to-waste" treatment of plastic waste.
目前，一次性塑料制品，如塑料包装，在我们的日常生活中非常普遍。由于其设计和使用寿命短、降解困难或降解周期长，这些产品极容易对土壤和海洋环境造成严重破坏。热化学法（热解或催化热解）是处理塑料废物的一种有效且环保的方法。为了进一步降低塑料热解的能耗，提高废流化催化裂化（FCC）催化剂的回收利用率，我们采用“废物利用”的方法，将废 FCC 催化剂用作塑料催化热解的催化剂，探索不同典型塑料（聚丙烯、低密度聚乙烯、聚苯乙烯）的热解特性、动力学参数和协同效应。实验结果表明，在塑料催化热解中使用废 FCC 催化剂有利于降低整体热解温度和活化能，最大失重温度降低约 12℃，活化能降低约 13%。经过微波和超声改性后，废 FCC 催化剂的活性得到提高，进一步提高了催化效率，降低了热解能耗。混合塑料的共热解以正协同效应为主，有利于提高热降解速率，缩短热解时间。本研究为废 FCC 催化剂的资源应用和塑料废物的“废物利用”处理提供了相关的理论支持。
