In here, we present the low-cost production of NaAlO₂–Al₂O₃ catalysts, which exhibit high activity in the transesterification of methyl acetate with glycerol to obtain acetins. The catalyst preparation procedure is based on the spray drying of a colloidal boehmite suspension, supplemented with a sodium aluminate (NaAlO₂) solution using a pilot scale spray drier. Upon subsequent calcination, we obtain spherical micro particles presenting a homogeneous dispersion of sodium aluminate and featuring high basicity. The NaAlO₂ loading has a marked impact on the basicity and textural properties of the final materials. These solids are found to be efficient heterogeneous base catalysts for the upgrading of glycerol (which is essentially a waste) to glycerol acetins (which are important bio-based fuel additives). With 100 mg of the catalyst loaded with 20 wt% of NaAlO₂, a conversion of 96% is obtained after 4 h of reaction at 60 °C (10 mmol of glycerol + 100 mmol of methyl acetate). Importantly, the selectivity for triacetin is as high as 20% (the rest being 50% of diacetin and 30% of monoacetin). The catalysts act strictly in a heterogeneous way and are recyclable upon calcination.

中文翻译：

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通过对NaAlO2和勃姆石悬浮液进行喷雾干燥获得的高碱性固体催化剂，用于将甘油提纯为乙酸甘油酯

在这里，我们介绍了低成本生产的NaAlO ₂ -Al ₂ O ₃催化剂，该催化剂在乙酸甲酯与甘油的酯交换反应中显示出很高的活性，从而制得乙酸甘油酯。催化剂的制备过程是基于使用中试规模的喷雾干燥器对胶态勃姆石悬浮液进行喷雾干燥的过程，该悬浮液中补充了铝酸钠（NaAlO ₂）溶液。在随后的煅烧之后，我们获得了呈现铝酸钠均匀分散并具有高碱度的球形微粒。NaAlO ₂装载量对最终材料的碱度和纹理特性有显着影响。发现这些固体是有效的非均相基础催化剂，用于将甘油（本质上是废物）提质为甘油乙酸酯（它们是重要的生物基燃料添加剂）。在100 mg的催化剂中负载有20 wt％的NaAlO _2时，在60°C下反应4 h（10 mmol甘油+ 100 mmol乙酸甲酯）后，转化率为96％。重要的是，三醋精的选择性高达20％（其余为双醋精的50％和单醋精的30％）。催化剂严格以非均相方式起作用，并且在煅烧时可再循环。