Effect of Water on the Ethanolysis of Waste Cooking Soybean Oil Using a Tin(II) Chloride Catalyst

Abstract

Biodiesel production from cheap lipid raw materials is economically welcome, but a high free fatty acids (FFA) content makes it incompatible with traditional alkaline catalysts. Although liquid mineral acids are alternatively used, serious drawbacks such as high corrosiveness and large effluent generation, as well as the impossibility of catalyst reuse compromises its application. Contrarily, solid acid catalysts appear to be an attractive option; however, the water present or generated during FFA esterification provokes the leaching and deactivation of these catalysts. Thus, in this work we have evaluated the use of tin chloride SnCl 2 , which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, on FFA ethanolysis using waste cooking oil samples (WCO). Additionally, the main kinetic parameters of the reactions were assessed. Compared to pTSA (p-toluenesulfonic-acid), a catalyst also evaluated, SnCl 2 efficiently promoted FFA ethanolysis even in the presence of high amounts of water (ca. 0.1-5.0% w/w). Moreover, the homogeneous SnCl 2 catalyst was easily recovered and reused successively, without loss of activity.

Application of Multivariate Analysis in Mid‐Infrared Spectroscopy as a Tool for the Evaluation of Waste Frying Oil Blends

“…With a global focus on environmental awareness and increasing demands for energy, the concept of producing fuels from renewable resources that are environmentally acceptable has garnered significant attention in the research community. Biodiesel derived from vegetable oils or animal fats can be considered an alternative fuel source to fossil-based diesel [1,2]. Biodiesel can be produced from a large variety of renewable lipid sources and has traditionally been obtained by alcoholysis of vegetable oils in the presence of an alkaline catalyst, methanol and heat.…”

Tin-Catalyzed Esterification and Transesterification Reactions: A Review

“…On the other hand, in general Lewis acid catalysts are few tolerant to water; in addition, there is few works about this aspect in the literature. However, investigating the same effect in SnCl 2 -catalyzed waste cooking soybean oil esterification reactions, da Silva and coworkers [23] verified that tin chloride was much more water tolerant than H 3 PW 12 O 40 catalyst ( Figure 8).…”

Valorization of Wastes for Biodiesel Production: The Brazilian Case

“…This situation leads to the use of solid catalysts that also show some problems found in the reactive process like the leaching and deactivation of the catalyst in the presence of water during the reaction of esterification of FFA. Considering all this information, in a study of 2011, Silva et al [18] evaluated the catalytic activity of tin chloride, SnCl 2 , which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, in FFA ethanolysis using waste cooking oil samples (WCO) obtaining success reaching high conversions of FFA into FAEE (fatty acid ethyl esters) in almost all catalytic runs; even when compared to pTSA(p-toluenesulfonic acid), the SnCl2 catalyst efficiently promoted FFA ethanolysis in the presence of high water concentrations (ca. 5.0% w/w).…”