electrochemical production of biodiesel using carbon quantum dots and mixture of homo-heterogeneous catalyst

Abstract: the scarcity of known petroleum reserves will make renewable energy resources more attractive. the most feasible way to meet this growing demand is by utilizing alternative fuels. biodiesel is defined as the monoalkyl esters of vegetable oils or animal fats. biodiesel is the best candidate for diesel fuels in diesel engines. the biggest advantage that biodiesel has over gasoline and petroleum diesel is its environmental friendliness. biodiesel burns similar to petroleum diesel as it concerns regulated pollutants. on the other hand, biodiesel probably has better efficiency than gasoline. the major economic factor to consider for input costs of biodiesel production is the feedstock, which is about 80% of the total operating cost. the high price of biodiesel is in large part due to the high price of the feedstock [1]. problem of high price of biodiesel production solved by electrochemical methods that reduces the cost of heat required for the reaction and the cost of washing due to the high amounts of sodium hydroxide in the conventional methods [2]. this research introduces inexpensive way of production biodiesel using the electrolysis methods with graphite electrodes modified with carbon quantum dots (cqds) in the presence of zeolite and in alkaline medium. low applied potential (4v) with less time of production have been used for the synthesis of biodiesel from cooking oil as a sustainable feedstock throw out the transesterification method. the effects of methanol/cooking oil ratio and the mixture of zeolite clinoptilolite and sodium hydroxide concentration as a catalyst on biodiesel conversion were carefully investigated. the optimum condition for the appropriate transesterification conditions were: sodium hydroxide as homogeneous catalyst (1 wt%) and zeolite clinoptilolite as heterogeneous catalyst (1 wt%) with optimum solvent (methanol) to oil volume ratios (1:6) and water (1.8 wt%). the obtained product was studied by uv-visible spectroscopy in the range of 200-400 nm wavelength to ensure the synthesis of biodiesel. the results showed that due to the characteristics of the graphite electrode, there was no voltage drop or reduction in reaction rate and the temperature from the beginning to the end of the reaction, which ultimately leads to the production of biodiesel with 99.36% efficiency during 30 min with the minimum amount of glycerol and soap as byproducts.