Glycerol-enriched heterogeneous catalyst for biodiesel production from soybean oil and waste frying oil

Abstract

In the present work, biodiesel production using a glycerol enriched heterogeneous catalyst was studied. For that purpose, the catalyst performance at different glycerol concentrations and reaction conditions (under ambient atmosphere) was evaluated and two triglyceride sources were used. The most active catalyst was produced using CaO, glycerol and methanol at a mass ratio of 1:1.6:13.4, respectively. By per-forming the transesterification reaction under ambient atmosphere during 2 h at 333 K, using 0.4 wt.% of catalyst and 7:1 methanol to oil molar ratio, a good quality product was obtained (EN 14214) using both soybean oil and waste frying oil. The catalyst could be re-used during four cycles and could also be pre-pared by using ethanol instead of methanol (with differences <4% on product conversion). The glycerol by-product, being rich in calcium soaps, might additionally be used for the enrichment of animal diets. The present process allowed the production of biodiesel from different triglyceride sources using a very active heterogeneous catalyst at competitive reaction conditions compared to the homogeneous process and also enabled a two-way recycling of the glycerol by-product.

Enhancing Biodiesel Production Using Green Glycerol-Enriched Calcium Oxide Catalyst: An Optimization Study

“…The use of appropriate amount of glycerol for its adequate interaction with CaO is of high importance as confirmed also in the previous report that concluded the deactivation of catalyst because of availability of surplus amount of glycerol in the reaction mixture during its by-production during the methanolysis reaction [34]. Also, Ferrero et al [21] reported that glycerol dosage higher than the optimum amount resulted in decreasing of biodiesel yield. This study investigated the impact of different glycerol dosage (5, 10 and 15 wt% of CaO wt.)…”

“…This strategy ensured the elimination of even a minor possibility for the generation of catalytic methoxide species, and generated only glycerol-enriched CaO catalytic material. Previous studies have reported the formation of glycerol-enriched CaO species in the presence [21,22,32] and absence [18,27] of methanol. Understanding the reaction between CaO and methanol that results in the formation of calcium methoxide as reported by Kawashima et al [33] and well-known poisoning phenomenon of CaO because of atmospheric CO 2 and H 2 O, this study used an alternative method for the preparation of only glycerol-enriched CaO species in the presence of oil.…”

“…CaDg has been described as a chemically stable heterogeneous catalyst, weakly basic in nature and not prone for deactivation by the hydration/carbonation reaction when exposed to the surrounding air [19,20]. CaDg has been also described as glycerol-enriched CaO [21,22]. Considering the above-mentioned advantages of CaDg over CaO, Kouzu et al [19] and López Granados et al [23] have recommended to transform CaO to CaDg compound prior to its application for biodiesel production.…”

“…The synthesized catalyst was used to assist the methanolysis reaction between refined Jatropha curcas oil containing extremely low FFAs content. Additionally, the catalytic activity of CaDg have been tested for biodiesel production from few lipid feedstocks such as, soybean oil [21,26,27], sunflower oil [28], castor oil [29] and waste cooking oil [30]. Looking at the novel catalytic proficiency of glycerol-enriched CaO, the reports focused on its utilization for biodiesel production are extremely low in comparison with those of neat CaO catalyst.…”

Catalyst Activity of Solid Acid Catalyst Derived From Agricultural Biomass for Biodiesel Production From Waste Cooking Oil

“…According to the stoichiometric equation, three moles of methanol is required to react with triglyceride and produced three moles of FAME and glycerol as the by-product [4]. Transesterification has been widely used to convert numerous oils into biodiesel including soybean oil [5], palm oil [6], sunflower oil [7], jatropha oil [8], and waste cooking oil (WCO) [9]. However, high cost of vegetable oil feedstock is the main concern for biodiesel production.…”