Abstract Spent hydrodesulphurization (HDS) catalysts generally contain about 20% oil, the presence of which hinders the metallurgical processes for recovering valuable metals. In this study, a new approach was developed to remove oil from spent HDS catalysts by microwave pyrolysis. Firstly, the effects of the pyrolysis temperature and time on removing oil were investigated using microwave and conventional pyrolysis. The results show that removing oil using microwave pyrolysis was superior to using conventional pyrolysis in terms of energy savings, speed, and removal ratio. Under the optimum pyrolysis conditions (700 °C, 30 min, and an inert atmosphere), about 64% and 25% removal of carbon and sulfur, respectively, and 25% weight loss were achieved with the proposed method, while using conventional pyrolysis, only 40% and 18% removal of carbon and sulfur, respectively, and 20% weight loss were achieved. The properties of the raw spent HDS catalysts and pyrolysis products, including their morphologies and elemental states, were investigated using SEM-EDS, XPS, and FTIR. The results of these analyses indicate that the proposed method not only removes oil efficiently, but can also remove elemental carbon from spent catalysts. Finally, the main components of recovered oil and gas were investigated using FTIR, GC–MS, and GC–TCD analyses.

中文翻译：

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使用微波热解法有效去除废加氢脱硫催化剂中的油

摘要 废加氢脱硫 (HDS) 催化剂通常含有约 20% 的油，其存在阻碍了回收有价值金属的冶金过程。在这项研究中，开发了一种通过微波热解从废 HDS 催化剂中去除油的新方法。首先，利用微波和常规热解研究了热解温度和时间对除油的影响。结果表明，微波热解除油在节能、速度和去除率方面均优于常规热解。在最佳热解条件（700 °C、30 min 和惰性气氛）下，所提出的方法分别实现了约 64% 和 25% 的碳和硫去除率以及 25% 的重量损失，而使用常规热解，仅分别实现了 40% 和 18% 的碳和硫去除率以及 20% 的重量损失。使用 SEM-EDS、XPS 和 FTIR 研究了原始废 HDS 催化剂和热解产物的性质，包括它们的形态和元素状态。这些分析的结果表明，所提出的方法不仅可以有效地去除油，而且还可以从废催化剂中去除元素碳。最后，使用 FTIR、GC-MS 和 GC-TCD 分析对回收的油气的主要成分进行了研究。但也可以从废催化剂中去除元素碳。最后，使用 FTIR、GC-MS 和 GC-TCD 分析对回收的油气的主要成分进行了研究。但也可以从废催化剂中去除元素碳。最后，使用 FTIR、GC-MS 和 GC-TCD 分析对回收的油气的主要成分进行了研究。