Abstract A magnetic catalyst with composition ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3 was synthesized by a combustion reaction on a pilot-scale and applied in the conversion of residual oil into biodiesel by simultaneous transesterification and esterification reactions (TES). For that, statistical analysis of the factors that influence the process (catalyst concentration, alcoholic route, and temperature) was evaluated by 23 factorial experimental design. The ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3 magnetic catalyst was characterized in terms of the structure, morphology, magnetic, TPD-NH3 acidity analysis and catalytic properties. The results indicate the formation of a catalyst with a surface area of 52.9 m2g−1, and density of the sample was 4.8 g/cm3 which is consisted of a mixture of the phases containing 55.87% Fe2O3, 36.96% Ni0.5Zn0.5Fe2O4, and 7.16% ZnO. The magnetic characterization indicated that the synthesized catalyst is ferromagnetic with magnetization 6.12 emu/g and coercive field of 5.3 G. In the TES reactions, the residual oil was active showing conversion to 96.16% ethyl esters and with a long useful life maintaining sustained activity after two consecutive reuse cycles with the conversion of 95.27%, 93.07% and 76.93%, respectively. The experimental design was significant and presented a 95% reliability level. The statistical analysis identified (+1) and (−1) as higher and lower level variables, respectively. The amount of catalyst used was equal to 5%, at 200 °C in methyl alcohol (alcoholic route). In summary, a new catalyst composed of a mixture of magnetically active phases was developed and successfully applied in biodiesel’s synthesis from residual oil. Undoubtedly these results have a positive and significant impact on the environment and to society as a whole.

中文翻译：

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燃烧反应中试合成ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3磁性催化剂及其在渣油生物柴油生产工艺中的应用

摘要 通过中试燃烧反应合成了一种组成为ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3的磁性催化剂，并将其应用于通过同步酯交换和酯化反应（TES）将渣油转化为生物柴油。为此，通过 23 个因子实验设计对影响该过程的因素（催化剂浓度、酒精路线和温度）进行了统计分析。对ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3磁性催化剂的结构、形貌、磁性、TPD-NH3酸度分析和催化性能进行了表征。结果表明形成了表面积为 52.9 m2g-1 的催化剂，样品的密度为 4.8 g/cm3，由含有 55.87% Fe2O3、36.96% Ni0.5Zn0.5Fe2O4、36.96% Ni0.5Zn0.5Fe2O4、和 7.16% 氧化锌。磁性表征表明合成的催化剂是铁磁性的，磁化强度为 6.12 emu/g，矫顽力为 5.3 G。在 TES 反应中，残油是活跃的，转化为 96.16% 的乙酯，使用寿命长，保持持续活性。连续两次重复使用，转化率分别为 95.27%、93.07% 和 76.93%。实验设计是显着的，并呈现出 95% 的可靠性水平。统计分析分别将 (+1) 和 (-1) 确定为较高和较低水平的变量。所用催化剂的量等于 5%，在 200 °C 的甲醇中（醇路线）。总之，开发了一种由磁性活性相混合物组成的新型催化剂，并成功应用于渣油合成生物柴油。