Abstract Non-condensable pyrolysis gas is a suitable source of hydrocarbons for energy applications. The purpose of this study was to develop a catalytic process for selective decomposition of unsaturated hydrocarbons in the pyrolysis gas as these species compromise the operation of gas engines, gas turbines and fuel cells. The effect of different calcium supports, namely CaCO 3 , Ca(OH) 2 , CaO and their mixtures, on the performance of Ni-based catalytic sorbents during the decomposition of hydrocarbons and HCl sorption from non-condensable pyrolysis gas of mixed plastics was investigated. The plastic mixture containing low density polyethylene (40%), polypropylene (40%), polystyrene (10%) and polyvinyl chloride (10%) was initially pyrolyzed at 600 °C producing condensable oils and non-condensable gases. The non-condensable gases were further treated in a subsequent reactor at 700 °C in the presence of catalytic sorbents. All catalytic sorbents were effective for HCl sorption, decreasing the HCl concentration in the gas stream below detectable levels. However, the choice of calcium support had a substantial effect on the catalytic decomposition of hydrocarbons and the properties of produced carbon deposits. CaCO 3 , Ca(OH) 2 and their mixture at 1:1 ratio by mass loaded with Ni showed higher catalytic activity towards the decomposition of hydrocarbons compared to CaO and a mixture containing CaO, CaCO 3 and Ca(OH) 2 at 1:1:1 ratio by mass. Furthermore, carbon deposits produced on the surface of Ni supported on CaCO 3 , Ca(OH) 2 and their mixture contained multi-walled carbon nanotubes, whereas carbon deposits produced on Ni supported on CaO and the mixture containing CaO had non-filamentous morphology. The observed results can be attributed to the low BET specific surface areas and pore volumes of CaO-containing catalytic sorbents which could limit the dispersion of Ni resulting in low catalytic activity.

中文翻译：

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塑料中不可冷凝热解气的催化加工：钙载体对镍催化烃分解和 HCl 吸附的影响

摘要 不可冷凝的热解气是能源应用的合适碳氢化合物来源。本研究的目的是开发一种催化过程，用于选择性分解热解气中的不饱和烃，因为这些物质会影响燃气发动机、燃气轮机和燃料电池的运行。研究了不同钙载体，即CaCO 3 、Ca(OH) 2 、CaO及其混合物对Ni基催化吸附剂在烃分解过程中的性能和混合塑料不凝性热解气中HCl吸附的影响. 含有低密度聚乙烯 (40%)、聚丙烯 (40%)、聚苯乙烯 (10%) 和聚氯乙烯 (10%) 的塑料混合物最初在 600 °C 下热解，产生可冷凝油和不可冷凝气体。在催化吸附剂的存在下，在随后的反应器中在 700°C 下进一步处理不可冷凝的气体。所有催化吸附剂都对 HCl 吸附有效，将气流中的 HCl 浓度降低到可检测水平以下。然而，钙载体的选择对碳氢化合物的催化分解和产生的积碳的性质有重大影响。CaCO 3 、Ca(OH) 2 和它们以质量比为 1:1 的负载有 Ni 的混合物与 CaO 和含有 1: CaO、CaCO 3 和 Ca(OH) 2 的混合物相比，对烃类的分解表现出更高的催化活性： 1:1 质量比。此外，负载在CaCO 3 、Ca(OH) 2 及其混合物上的Ni表面产生的碳沉积物含有多壁碳纳米管，而在负载在 CaO 上的 Ni 上产生的碳沉积物和含有 CaO 的混合物具有非丝状形态。观察到的结果可归因于低 BET 比表面积和含 CaO 催化吸附剂的孔体积，这可能会限制 Ni 的分散，导致催化活性低。