Recovering Secondary REE Value from Spent Oil Refinery Catalysts Using Biogenic Organic Acids
Recovering Secondary REE Value from Spent Oil Refinery Catalysts Using Biogenic Organic Acids
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DOI：
10.3390/catal10091090
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发表时间：
2020-09-01
期刊：
影响因子：
3.9
通讯作者：
Okibe, Naoko
中科院分区：
文献类型：
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作者：
Dewi, Melisa Pramesti;Petrus, Himawan Tri Bayu Murti;Okibe, Naoko
炼油工业产生的废催化剂被认为是有价金属的重要二次来源。特别地，废流化催化裂化（FCC）催化剂代表稀土元素（RE）的潜在来源。本研究的目的是利用废FCC催化剂作为镧的第二来源，通过使用在优化的真菌发酵条件下产生的替代有机酸浸出剂。第一次化学浸出试验表明，柠檬酸（>100 mM）是一种与常规无机酸（1 M）相当的替代浸出剂，并且La溶解行为随不同类型的有机酸而显著变化。初始真菌发酵条件（例如，接种物水平、底物浓度、pH）在很大程度上影响所得的生物酸组成，并且为了几乎仅发酵柠檬酸（类似于130mM）同时控制不需要的草酸的产生，其操作是可能的。实际的生物酸（直接使用无细胞的废培养基）和人工重构的生物酸（化学试剂的混合物）的性能几乎相同，在5%的纸浆密度下实现了类似于74%的最终La溶解。总的来说，有机酸的微生物发酵可能成为一种有前途的方法，以提供一种有效的和环境友好的替代浸出剂，用于从废FCC催化剂废物中清除REE。
Spent catalysts produced by oil refinery industries are regarded as an important secondary source for valuable metals. In particular, spent fluid catalytic cracking (FCC) catalysts represent a potential source for rare earth elements (REEs). This study aimed to exploit the leachability of spent FCC catalysts as a secondary source for La, by using an alternative organic acid lixiviant produced under optimized fungal fermentation conditions. The first chemical leaching tests revealed that citric acid (>100 mM) is a comparable alternative lixiviant to conventional inorganic acids (1 M) and that the La dissolution behavior changed significantly with different types of organic acids. The initial fungal fermentation conditions (e.g., inoculum level, substrate concentration, pH) largely affected the resultant biogenic acid composition, and its manipulation was possible in order to almost solely ferment citric acid (similar to 130 mM) while controlling the production of unwanted oxalic acid. The performance of actual biogenic acids (direct use of cell-free spent media) and artificially reconstituted biogenic acids (a mixture of chemical reagents) was nearly identical, achieving a final La dissolution of similar to 74% at a pulp density of 5%. Overall, the microbiological fermentation of organic acids could become a promising approach to supply an efficient and environmentally benign alternative lixiviant for REE scavenging from spent FCC catalyst wastes.