Abstract The objective of this paper was to study the glycerol etherification with ethanol in a fixed bed reactor catalyzed by Amberlyst 15. We analyzed through a four factor central composite design the influence of independent process variables including pressure (7–103 MPa), temperature (180–290 °C), ethanol/glycerol molar ratio (4–30/1) and amount of catalyst (0–0.95 g). Special interest was taken in evaluating the effect of pressure, since this reaction mixture can be one or two phase depending on this variable. The results showed that for this system it is not necessary to keep all the reaction mixture in just one phase to obtain good results in terms of glycerol conversions and ether yields. For the glycerol conversion, a maximum of 97% was obtained and the optimum conditions were temperature (269 °C), ethanol/glycerol molar ratio (12:1), catalyst amount (0.78 g) and pressure (2.5 MPa). In terms of ether yield, the optimization study using canonical analysis predicted the following optimal levels were predicted: pressure (7.1 MPa), temperature (242 °C), ethanol/glycerol molar ratio of (22:1) and catalyst amount (0.63 g). Under these operating conditions, the experimental value for ether yield obtained was 69%, confirming the result predicted by the optimization study. These results indicated that the equations were effective in describing the actual experimental data. Reaction conditions in which glycerol-ethanol form two phase mixtures still presented excellent results on the responses.

中文翻译：

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不同压力下固定床反应器中甘油与乙醇的醚化反应优化

摘要 本文的目的是研究在 Amberlyst 15 催化的固定床反应器中甘油与乙醇的醚化反应。我们通过四因素中心复合设计分析了独立工艺变量的影响，包括压力（7-103 MPa）、温度（ 180–290 °C)、乙醇/甘油摩尔比 (4–30/1) 和催化剂量 (0–0.95 g)。对评估压力的影响特别感兴趣，因为该反应混合物可以是一相或两相，具体取决于该变量。结果表明，对于该系统，没有必要将所有反应混合物仅保持在一相中以获得甘油转化率和醚产率方面的良好结果。对于甘油转化率，最高可达 97%，最佳条件是温度 (269 °C)、乙醇/甘油摩尔比 (12:1)、催化剂量 (0.78 g) 和压力 (2.5 MPa)。在醚产率方面，使用经典分析的优化研究预测了以下最佳水平：压力 (7.1 MPa)、温度 (242 °C)、乙醇/甘油摩尔比 (22:1) 和催化剂用量 (0.63 g ）。在这些操作条件下，获得的醚收率的实验值为 69%，证实了优化研究预测的结果。这些结果表明这些方程在描述实际实验数据方面是有效的。甘油-乙醇形成两相混合物的反应条件仍然显示出极好的响应结果。温度 (242 °C)、乙醇/甘油摩尔比 (22:1) 和催化剂量 (0.63 g)。在这些操作条件下，获得的醚收率的实验值为 69%，证实了优化研究预测的结果。这些结果表明这些方程在描述实际实验数据方面是有效的。甘油-乙醇形成两相混合物的反应条件仍然显示出极好的响应结果。温度 (242 °C)、乙醇/甘油摩尔比 (22:1) 和催化剂量 (0.63 g)。在这些操作条件下，获得的醚收率的实验值为 69%，证实了优化研究预测的结果。这些结果表明这些方程在描述实际实验数据方面是有效的。甘油-乙醇形成两相混合物的反应条件仍然显示出极好的响应结果。