Raney nickel is extensively used as a catalyst in the hydrogenation of vegetable oils. However, it deactivates over time and is known as a spent nickel catalyst, which is potentially hazardous to the environment. By contrasting different approaches, a straightforward and original strategy for regenerating spent nickel catalyst was developed by comparing various methods. The fresh, spent nickel catalyst, and treated catalyst samples were characterized using X-ray diffraction, Fourier transform infrared, atomic absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and color scheme analyses. The results showed that the catalyst deactivation was primarily due to oil deposition over the active sites, agglomeration of catalyst, and entrainment of nickel during hydrogenation. Using n-hexane as the solvent with a spent nickel catalyst-to-solvent ratio of 1:12 (g/mL), a 65 °C temperature, and a two-hour extraction time, ultrasonication-assisted solvent extraction of spent nickel catalyst proved to be the most effective and efficient process for regeneration.

中文翻译：

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植物油多相加氢过程中失活雷尼镍催化剂的有效再生

雷尼镍广泛用作植物油加氢的催化剂。然而，它会随着时间的推移而失活，被称为废镍催化剂，对环境有潜在危害。通过对比不同的方法，通过比较各种方法，开发了一种直接且原始的废镍催化剂再生策略。使用 X 射线衍射、傅里叶变换红外、原子吸收光谱、扫描电子显微镜、能量色散 X 射线光谱和配色方案分析对新鲜、废镍催化剂和处理过的催化剂样品进行表征。结果表明，催化剂失活的主要原因是活性位点上的油沉积、催化剂的团聚以及加氢过程中镍的夹带。以正己烷为溶剂，废镍催化剂与溶剂比为1:12（g/mL），温度65 ℃，萃取时间2 h，超声辅助溶剂萃取废镍催化剂。事实证明这是最有效、最高效的再生过程。