Alkyl levulinates (ALs) are strategic compounds for the development of sustainable energy transition. In this regard, the direct alcoholysis of fructose and inulin for the selective ethyl levulinate (EL) production was investigated with a One-Factor-At-a-Time (OFAT) approach employing diluted H2SO4 as catalyst to clarify the role of the main reaction parameters (substrate and acid loadings, temperature, reaction time). The OFAT investigation on fructose ethanolysis allowed to reach the EL yield of 91.5 mol%. The inulin ethanolysis was then optimized adopting the multivariate approach based on the Response Surface Methodology (RSM), which highlighted the interplay of the reaction parameters on the selective EL production. This allowed to identify the optimal conditions to reach the highest EL yield (up to 89.3 mol%) and also those which ensured the highest EL concentration, adopting a substrate loading (14 wt%) higher than the majority ones reported in the literature according to the high gravity approach, and the lowest diethyl ether (DEE) by-product yield. The DEE formation is scarcely investigated in the literature, but it can negatively influence the alcoholysis process, thus it was considered in this work. Moreover, the humin solid residue was deeply characterized to envisage its possible applications, under a circular economy perspective.

中文翻译：

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深入研究调整果糖和菊粉合成乙酰丙酸乙酯的反应参数

乙酰丙酸烷基酯 (AL) 是可持续能源转型发展的战略化合物。在这方面，使用稀释 H2SO4 作为催化剂，采用一次单因素 (OFAT) 方法研究了果糖和菊粉的直接醇解选择性乙酰丙酸乙酯 (EL) 生产，以阐明主要反应的作用参数（底物和酸负载、温度、反应时间）。 OFAT 对果糖乙醇分解的研究使 EL 产率达到 91.5 mol%。然后采用基于响应面方法 (RSM) 的多变量方法优化菊粉乙醇分解，该方法强调了反应参数对选择性 EL 生产的相互作用。这使得能够确定达到最高 EL 产率（高达 89.3 mol%）的最佳条件，以及确保最高 EL 浓度的最佳条件，采用比文献中报道的大多数基质负载（14 wt%）更高的基质负载（14 wt%）。高重力方法和最低的乙醚 (DEE) 副产物产率。文献中很少研究 DEE 的形成，但它会对醇解过程产生负面影响，因此在本工作中予以考虑。此外，对胡敏素固体残渣进行了深入的表征，以在循环经济的角度下设想其可能的应用。