Abstract In this work, the catalytic upgrading of a bio-oil model compound via esterification with ethanol was studied using 12-tungstosilicic acid as the catalyst. The response surface method was used to investigate and optimize the process variables, which include the ethanol to acid molar ratio, catalyst loading, reaction temperature, and reaction time for maximum conversion of the organic acid for esterification under atmospheric conditions. The effect of high He pressure on acid conversion for esterification was also studied. The maximum acid conversion was almost 90%, which can be achieved at reaction temperature of 77 °C, ethanol to acid molar ratio of 5:1, catalyst loading of 4.0% w/w, and reaction time of 8.3 h. Pressurizing the reaction with inert He did not have any effect for acid conversion at this optimum condition and had a slight negative effect under the studied conditions. After upgrading, the esterified products were found to improve the heating value from 17.6 to 23.2 MJ/kg and appeared to enhance fuel properties.

中文翻译：

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杂多酸催化剂酯化生物油模型化合物的工艺变量优化

摘要 在这项工作中，以12-钨硅酸为催化剂，研究了乙醇酯化生物油模型化合物的催化升级。响应面法用于研究和优化工艺变量，包括乙醇与酸的摩尔比、催化剂负载、反应温度和反应时间，以在大气条件下实现酯化有机酸的最大转化率。还研究了高压对酯化酸转化率的影响。在反应温度为 77 ℃、乙醇酸摩尔比为 5:1、催化剂负载量为 4.0% w/w、反应时间为 8.3 h 的条件下，酸转化率最高可达 90%。在此最佳条件下，用惰性 He 对反应进行加压对酸转化率没有任何影响，并且在所研究的条件下有轻微的负面影响。升级后，发现酯化产品的热值从 17.6 MJ/kg 提高到 23.2 MJ/kg，并且似乎提高了燃料性能。