Natural Rocks–Heterogeneous Catalysts for Oil Transesterification in Biodiesel Synthesis

Abstract

Some of the more recent methods to produce biodiesel are based on heterogeneous catalysis, which has the advantage of easy separation of catalyst from the final product. In this paper, the heterogeneous transesterification of rapeseed oil with methanol is studied. The aim of this work was to investigate the possibilities of using natural catalysts in biodiesel synthesis and to determine the optimal conditions for this process. After the evaluation of catalytic effectiveness of rocks containing calcium and magnesium carbonates, it was determined that dolomite is the most effective catalyst in heterogeneous biodiesel synthesis. The optimal conditions of dolomite preparation are the following: heating at 850 °C for 5 h. The rapeseed oil transesterification was optimized by the application response surface methodology. Optimal conditions for the production of rapeseed methyl esters using dolomite as catalyst are the following: molar ratio of methanol to rapeseed oil of 11.94:1, reaction temperature of 64 °C, dolomite content of 6 wt%, reaction time of 5 h.

Rapeseed Oil Transesterification Using 1-Butanol and Eggshell as a Catalyst

“…Before transesterification tests, is important to prepare the catalyst. Gaide and colleagues [15] studied dolomite as a catalyst for ester synthesis. The optimum fraction size of dolomite was obtained as 0.315-0.1 mm, and the most suitable calcination temperature was 850 • C for 4 h. For the research, snail shells were prepared under the same conditions.…”

“…Calcium oxide, both pure and in mixtures with other metals or their oxides, is used as a heterogeneous alkaline catalyst in biodiesel synthesis [13,14]. Scientists are conducting research to find calcium-rich wastes that can be used as catalysts for oil transesterification [15][16][17]. Large amounts of CaO are found in eggshells, shells of snails, molluscs, crabs, shrimps, and animal bones [18].…”

Possibility of Using Commercial Hydrated Lime as a Catalyst for Rapeseed Oil Methanolysis

“…The observed yield trend is similar to that of methanolysis of soybean oil using hydrated lime [27], where the authors reported that no conversion was achieved at a transesterification temperature of 25°C, while FAME yields were increasing (2, 19, 57 and 100%) with higher reaction temperatures (35, 45, 55 and 60°C). Although the higher temperature is necessary for increasing the reaction rate, conducting methanolysis at temperatures well above the boiling point of alcohol results in higher energy consumption, leads to alcohol loss by evaporation [76], and can accelerate triglyceride saponification [77], which will reduce the yield of biodiesel.…”

Experimental Investigation of the Mechanical and Thermal Behavior of a PT6A-61A Engine Using Mixtures of JETA-1 and Biodiesel

“…A type of fuel that provides high energy efficiency and boosts alternative productive chains. Biodiesel is indeed a renewable fuel that is obtained through oil transesterifications in homogeneous [5] and heterogeneous catalysis media [6]. The chemical process uses different feedstocks [7] like palm [8], Jatropha [9], algae, and palmist kernel oil [10], and reaches typical conversion efficiencies of around 99% having a high selectivity.…”

“…Regulatory policies in the use of aviation fuels establish maximum and minimum limits of partial substitution of JETA-1 in aeronautic operations [4]. These ranges allow fostering productive chains for biofuels obtained from biomass, especially in developing countries [5,6,22,23]. This is specially written in the series of compromises under the United Nations Framework Convention on Climate Change (UNFCCC) and the established guidelines by the Intergovernmental Panel on Climate Change (IPCC) [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”