{"title":"Acetalization of glycerol with benzaldehyde to synthesize 1,3-PDO via terminal hydroxyl group protection: An experimental and kinetic study","authors":"Mohammad Khan , Mohd Moiz Khan","doi":"10.1016/j.scca.2025.100062","DOIUrl":null,"url":null,"abstract":"<div><div>The conversion of waste glycerol from biodiesel production into high-value-added chemicals is vital for promoting sustainable development within the Bio-Circular-Green Economy framework. The acetalization of glycerol with benzaldehyde was investigated using Amberlyst 15 as a catalyst. The resulting benzylidene acetals underwent dehydration and hydrogenolysis to synthesize 1,3-propanediol (1,3-PDO) through terminal hydroxyl group protection. Glycerol conversion reached 100%, yielding 47.8% of 5-membered and 51.3% of 6-membered acetals. Amberlyst 15 exhibited excellent activity and stability over five reuse cycles, ensuring a clean reaction without catalyst deactivation. However, higher catalyst loading, elevated temperatures, and increased mole ratios led to undesired side products, such as methyl-2-hydroxy-3-phenylpropanoate. The optimal conditions for synthesizing benzylidene acetals were determined to be a 1:1 molar ratio, 353 K, 5 wt.% catalyst, and 800 rpm stirring speed. Despite this, the new route was ineffective for 1,3-PDO synthesis. The overall reaction sequence was established, and the mechanism was effectively explained using a pseudo-homogeneous kinetic model.</div></div>","PeriodicalId":101195,"journal":{"name":"Sustainable Chemistry for Climate Action","volume":"6 ","pages":"Article 100062"},"PeriodicalIF":0.0000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sustainable Chemistry for Climate Action","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772826925000070","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The conversion of waste glycerol from biodiesel production into high-value-added chemicals is vital for promoting sustainable development within the Bio-Circular-Green Economy framework. The acetalization of glycerol with benzaldehyde was investigated using Amberlyst 15 as a catalyst. The resulting benzylidene acetals underwent dehydration and hydrogenolysis to synthesize 1,3-propanediol (1,3-PDO) through terminal hydroxyl group protection. Glycerol conversion reached 100%, yielding 47.8% of 5-membered and 51.3% of 6-membered acetals. Amberlyst 15 exhibited excellent activity and stability over five reuse cycles, ensuring a clean reaction without catalyst deactivation. However, higher catalyst loading, elevated temperatures, and increased mole ratios led to undesired side products, such as methyl-2-hydroxy-3-phenylpropanoate. The optimal conditions for synthesizing benzylidene acetals were determined to be a 1:1 molar ratio, 353 K, 5 wt.% catalyst, and 800 rpm stirring speed. Despite this, the new route was ineffective for 1,3-PDO synthesis. The overall reaction sequence was established, and the mechanism was effectively explained using a pseudo-homogeneous kinetic model.