金属盐(SO42-/Cl-)固体酸催化剂在污泥制生物柴油中的应用

研究NaHSO₄·H₂O（布朗斯特酸位为主）和AlCl₃·6H₂O（路易斯酸位为主）两类金属盐固体酸催化剂在污泥制取生物柴油过程中的催化性能.结果表明，经过130℃脱水的NaHSO₄·H₂O较AlCl₃·6H₂O表现更为优异，两种催化剂的最优催化条件为催化剂投加量1.2g/10g冷冻干燥污泥、反应温度130℃、反应时间4h.虽然对粗脂肪的酯化率NaHSO₄·H₂O低于AlCl₃·6H₂O，分别为（63.4±2.6）％和（68.9±1.4）％（对应的生物柴油产率分别为9.73%~10.69％和10.80%~11.39％（污泥干基）），但经过GC-MS分析发现NaHSO₄·H₂O催化的生物柴油纯度更高，品质更好；两种催化剂的重复使用性<3~5次.两种催化剂均可实现低成本、高性能且环境友好的催化污泥制备生物柴油.

Application of modified metal salt hydrates containing SO42-/Cl- in the production of biodiesel from sewage sludge

The catalytic performance of two kinds metal salt solid acid catalysts (NaHSO₄·H₂O that mainly were Bronsted acid sites and AlCl₃·6H₂O that mainly were Lewis acid sites) for biodiesel production from sludge was compared. The results showed that NaHSO₄·H₂O dehydrated at 130℃ had better performance than AlCl₃·6H₂O. The optimal catalytic conditions of the two catalysts were as follows:catalyst dosage of 1.2g/10g freeze-drying sludge, reaction temperature of 130℃, reaction time of 4h. The esterification rate of crude fat catalysed by NaHSO₄·H₂O (63.4±2.6)% was lower than that of AlCl₃·6H₂O (68.9±1.4)%, the corresponding biodiesel yields were 9.73%~10.69% and 10.80%~11.39% (sludge dry base). However, the GC-MS analysis showed that the biodiesel catalysed by NaHSO₄·H₂O had higher purity and better quality. The reusability of the two catalysts was <3~5times. Therefore, both of the two catalysts were excellent in biodiesel production from sludge with low cost, high performance and environmental friendliness.