The plastic waste poly styrene (PS) has been selected for the conversion to value added useful products using pyrolysis. The thermal and catalytic pyrolysis of polystyrene (PS) are investigated at reaction temperature ranging from 500°C to
800°C for 30 min, as an effective way to recycle polystyrene and produce valuable aromatic hydrocarbons benzene, toluene, ethyl benzene and xylene (BTEX). The catalytic pyrolysis is performed using commercial catalyst ZSM-5 which is reused repeatedly twice and further regenerated to evaluate the stability of ZSM-5 for PS pyrolysis with reference to BTEX formation. The maximum liquid yield of 96 wt. % and 86.2 wt. % are obtained at a temperature of 700°C for thermal pyrolysis and catalytic pyrolysis (fresh catalyst/1^st run), respectively. The product analyses show that liquid yield contains substantial amount of BTEX with the increase in temperature for fresh ZSM-5. The BTEX yield is significantly increased for catalytic pyrolysis (fresh catalyst/1^st run) i.e., about 75 wt. % for fresh ZSM-5 in comparison to thermal pyrolysis at a temperature of 700°C. There is very minute change in BTEX yield for the 2^nd and 3^rd run of catalytic pyrolysis using spent catalyst ZSM-5. The maximum aromatic (BTEX) of 23.71 wt. % for fresh ZSM-5 is obtained at the temperature of 700°C. However, spent ZSM-5(3^rd run) produced 20.45 wt. % BTEX at the same temperature. The regenerated ZSM-5 produced only 2 wt. % less BTEX yield in comparison to fresh ZSM-5 at the optimum temperature of 700°C. The gas chromatography and other fuel test have been performed for liquid yield characterisation. The characteristics of product prove that the liquid hydrocarbon has potential to use it as fuel.

中文翻译：

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ZSM-5通过热分解废聚苯乙烯生产轻质芳烃的性能和可重复使用性评估

选择了废塑料聚苯乙烯（PS），可通过热解转化为增值有用产品。研究了聚苯乙烯（PS）在500°C至
800°C反应温度下30分钟的热解和催化热解，这是回收聚苯乙烯并生产有价值的芳烃苯，甲苯，乙苯和二甲苯（BTEX）的有效方法）。使用商业催化剂ZSM-5进行催化热解，将其重复使用两次并进一步再生，以评估BSM形成对ZSM-5进行PS热解的稳定性。最大液体产量为96 wt。％和86.2 wt。％在700°C的温度下进行热裂解和催化裂解（新鲜催化剂/ 1 ^st运行）。产品分析表明，随着温度的升高，新鲜ZSM-5的液体收率中含有大量的BTEX。的BTEX收率用于催化热解（新鲜催化剂/ 1显著增加^第一运行），即，约75wt。与在700°C的温度下热裂解相比，新鲜ZSM-5的％含量。使用废催化剂ZSM-5进行的^第二和^第三次催化热解的BTEX收率变化很小。最大芳烃（BTEX）为23.71 wt。在700°C的温度下获得新鲜ZSM-5的％。然而，用了ZSM-5（3^次运行）产生20.45 wt。％BTEX在相同温度下。再生的ZSM-5仅产生2 wt。在700°C的最佳温度下，与新鲜的ZSM-5相比，BTEX的收率降低了％。已经进行了气相色谱法和其他燃料测试以表征液体产率。产品的特性证明液态烃有潜力将其用作燃料。