Maafa Ibrahim M
Chemical Engineering Department, College of Engineering, Jazan University, Jazan 45142, Saudi Arabia.
Polymers (Basel). 2021 Jan 11;13(2):225. doi: 10.3390/polym13020225.
The manufacturing of polystyrene around the globe has escalated in the past years due to its huge applications in various areas. The perpetual market needs of polystyrene led the polystyrene wastes accretion in the landfill causing environmental deterioration. The soaring need for polystyrene also led to the exhaustion of petroleum, a non-renewable energy source, as polystyrene is a petroleum-derived product. Researchers from around the world have discovered a few techniques to take care of the polystyrene scraps, namely recycling and energy recovery techniques. Nevertheless, there are demerits involved with recycling techniques, such as they call for huge labor expenses in the separation process and cause water pollution, thereby decreasing the process sustainability. Owing to these demerits, the researchers have focused their attention on the energy recovery technique. Since petroleum is the main ingredient of polystyrene synthesis, the restoration of liquid oil from polystyrene via the pyrolysis method is a promising technique as the recovered oil has greater calorific value as compared to commercially available fuel. The present paper surveys the pyrolysis technique for polystyrene and the important process parameters that control the end product, like oil, gas, and char. The chief process parameters that are discussed in this review paper include the type of reactors, temperature, residence time, pressure, catalyst types, type of fluidizing gases, and their flow rate. A more recent technique of utilizing a solvent to perform pyrolysis and the effect of various process conditions on the product yield have been discussed. Apart from this, various outlooks to optimize the liquid oil recovery from polystyrene are also reviewed.
在过去几年中，由于聚苯乙烯在各个领域的大量应用，全球范围内聚苯乙烯的产量不断增加。聚苯乙烯持续的市场需求导致垃圾填埋场中聚苯乙烯废弃物的堆积，造成环境恶化。对聚苯乙烯不断飙升的需求还导致了石油（一种不可再生能源）的枯竭，因为聚苯乙烯是一种石油衍生产品。世界各地的研究人员已经发现了一些处理聚苯乙烯废料的技术，即回收和能量回收技术。然而，回收技术存在缺点，例如在分离过程中需要巨大的劳动力成本并会造成水污染，从而降低了该过程的可持续性。由于这些缺点，研究人员将注意力集中在了能量回收技术上。由于石油是聚苯乙烯合成的主要成分，通过热解方法从聚苯乙烯中还原液态油是一种很有前景的技术，因为回收的油比市售燃料具有更高的热值。本文综述了聚苯乙烯的热解技术以及控制最终产物（如油、气和焦炭）的重要工艺参数。本综述论文中讨论的主要工艺参数包括反应器类型、温度、停留时间、压力、催化剂类型、流化气体类型及其流速。还讨论了一种利用溶剂进行热解的最新技术以及各种工艺条件对产物产率的影响。除此之外，还综述了优化从聚苯乙烯中回收液态油的各种前景。
