Catalytic Acetalization: An Efficient Strategy for High-Value Utilization of Biodiesel-Derived Glycerol

Abstract

Abstract:In this study, an efficient process for high value utilization of biodiesel-derived glycerol was proposed via a simple reaction of acetalization catalyzed by novel catalysts of ester sulfate-functionalized ionic liquids (ILs). The relationship between the IL structure and its catalytic activity was investigated. The effects of reaction conditions, and the substrate adaptability, were also carefully studied. The results demonstrate that ester sulfate-functionalized IL shows excellent catalytic activity on the acetalization of glycerol with aldehyde (ketone). Under the optimized condition, 87% glycerol conversion was obtained with 99% acetal selectivity when glycerol was condensed with cyclohexanone. In particular, 29% of product consists of six-membered compound, an important fine chemical and an excellent precursor in organic chemistry, because of the significant steric-hindrance effect of IL catalyst. Furthermore, the IL catalyst shows good recyclability where insignificant activity loss was exhibited even after six runs.

A Review on the Catalytic Acetalization of Bio-renewable Glycerol to Fuel Additives

“…The drawback of this system was its very long reaction time (21–36 h). Generally, the reaction of glycerol with aldehydes/ketones is conducted under homogenous Lewis catalysts (Ruiz et al, 2010 ) or mineral acids such as HF, HCl, H 3 PO 4 , H 2 SO 4 , and p-toluenesulfonic acid (pTSA) to form solketal (1,2-isopropylidene glycerol, 2,2-dimethyl-1, or 3-dioxolane-4-methanol) (Sato et al, 2008 ; Coleman and Blankenship, 2010 ; Suriyapradilok and Kitiyanan, 2011 ; Nanda et al, 2014a ; Sun et al, 2017 ). The first generation of studies was stopped more than half a century ago due to the economic barriers.…”

Acetalization Catalysts for Synthesis of Valuable Oxygenated Fuel Additives from Glycerol

“…In [17], the authors used sulfonic ILs in the acetalization reaction of cyclohexanone and glycerin. They showed that the sample [MeSO 3 bmim][MeSO 4 ] is capable of achieving glycerol conversion of up to 86% (Table 3), with a selectivity for six-membered acetal of 28%.…”

“…To produce value-added chemical compounds, oxidation, dehydration, acetylation, and ammoxidation can be used. Of special interest are the acetalization reactions of glycerol from biodiesel processes into various oxygenated fuel additives [16][17][18]. A literature review was conducted to identify the number of articles published in the journals indexed in Web of Science and Scopus using a basic search for the articles containing information about the formation of acetals or ketals from glycerol.…”

Recent Development of Heterogeneous Catalysis in the Transesterification of Glycerol to Glycerol Carbonate

“…Traditional chemical syntheses are the most widely used methods in the large-scale preparation of glycerol carbonate directly from glycerol. With glycerol used as starting material, glycerol carbonate is obtained via chemical processes, such as carbonation with carbon dioxide [26][27][28] or carbon monoxide in the presence of oxidants [29,30], trans-carbonation with phosgene [21] or urea and its derivatives [31][32][33][34][35], and transesterification with simple carbonate esters (Figure 3) [15][16][17][18][19][20]. Transesterification of glycerol has significant advantages over other methodologies in the following aspects: (1) avoiding the employment and release of poisonous gases and toxic reagents; (2) higher activity and selectivity; (3) shorter reaction time and higher conversion; (4) free of solvent and simple separation of catalyst; and (5) environmentally friendly and intrinsically safe.…”