Biofuels have been gaining more space in the global energy sector, with special attention to ethanol, which has shown growing demand. Ethanol is a potential and promising alternative fuel due to the use of abundant renewable sources and its combustion characteristics. From this scenario, this research aimed to optimize ethanol production by a flocculant Saccharomyces cerevisiae CCA008 using cashew apple juice (CAJ) as feedstock. The alcoholic fermentation of CAJ was influenced for all evaluated variables (inoculum and substrate concentration, temperature, and agitation) and statistical models were successfully applied to describe the interaction between these variables and to optimize the operating conditions. The optimum conditions were initial substrate concentration (S0) of 102 g L−1, inoculum concentration (X0) of 5 g L−1, temperature (T) and agitation (Agit) settings at 34 °C and 140 rpm, respectively. Last, but not least, the scale-up of ethanol production was carried out using the predicted optimum operating conditions, the fluid dynamics characteristics and applying the best scale-up criterion (power per unit of volume). The efficiencies of the processes (on bench and pilot-scale) were not significantly different and high efficiencies (96.6–98.2%) were achieved, demonstrating satisfactory results. Moreover, maximum ethanol concentration (Pmax), YP/S and productivity (QP) did not vary significatively when the process was scaled-up. On the pilot-scale, Pmax, YP/S and QP were 49.2 ± 2.2 g L−1, 0.493 ± 0.00 g g−1 and 5.0 ± 0.2 g L−1 h−1, respectively. Therefore, ethanol could be efficiently produced by the fermentation of CAJ using the flocculent yeast S. cerevisiae CCA008 and the process could be easily scaled up.

中文翻译：

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以腰果苹果汁为原料的絮凝酵母乙醇生产的优化和放大

生物燃料在全球能源领域获得了更多空间，尤其是乙醇，其需求不断增长。由于使用丰富的可再生资源及其燃烧特性，乙醇是一种潜在且有前景的替代燃料。在这种情况下，本研究旨在通过使用腰果苹果汁 (CAJ) 作为原料的絮凝剂酿酒酵母 CCA008 优化乙醇生产。CAJ 的酒精发酵受到所有评估变量（接种物和底物浓度、温度和搅拌）的影响，并且成功地应用了统计模型来描述这些变量之间的相互作用并优化操作条件。最佳条件是初始底物浓度 (S0) 为 102 g L-1，接种物浓度 (X0) 为 5 g L-1，温度 (T) 和搅拌 (Agit) 设置分别为 34 °C 和 140 rpm。最后但并非最不重要的是，乙醇生产的放大是使用预测的最佳操作条件、流体动力学特性和应用最佳放大标准（每单位体积的功率）进行的。流程的效率（实验室规模和中试规模）没有显着差异，并且实现了高效率（96.6-98.2%），显示出令人满意的结果。此外，当工艺放大时，最大乙醇浓度 (Pmax)、YP/S 和生产率 (QP) 没有显着变化。在试点规模上，Pmax、YP/S 和 QP 分别为 49.2 ± 2.2 g L-1、0.493 ± 0.00 gg-1 和 5.0 ± 0.2 g L-1 h-1。因此，使用絮状酵母 S 发酵 CAJ 可以有效地生产乙醇。