Ultrasound assisted interesterification for biodiesel production from palm oil and methyl acetate: Optimization using RSM

Abstract

High energy demand in the industrial world and pollution problems caused by the use of fossil fuels causes the need for the latest innovations that will replace the use of non-renewable energy. One of them is the replacement of diesel fuel with biodiesel. At present biodiesel production uses a transesterification reaction which produces a side product in the form of glycerol. However, the presence of glycerol is considered waste and has no economic value so a separation process is needed. So to eliminate the by-product separation process, a new route is used. This route is called interesterification, using methyl acetate instead of methanol which later produces triacetin as a by-product. Triacetin is recognized as an additive in biodiesel which functions as an anti- knocking in diesel engines. In this research, an interesterification study was carried out by ultrasound and a potassium methoxide catalyst was used to increase the reaction rate and the yield of biodiesel. The operating parameters used include the reactant molar ratio of 1:3; 1:6 and 1:9, catalyst concentration 0.5%; 1.0%; and 1.5%, and reaction times 5, 10, and 15 minutes. The parameter optimization is carried out by the central composite design (CCD) method to reduce the number of experiments needed and also to evaluate various variables and their interactions. The optimal operating conditions are the molar ratio of methyl acetate to palm oil of 8.95, catalyst concentration of 1.44%, and interesterification time of 10.03 minutes can produce the yield of biodiesel of 99.66%.

Effects of Diacetinmonoglycerides and Triacetin on Biodiesel Quality

“…This profile comes from the vegetable oils from which they have been synthesized and is shown in Table 2. As a starting point for this work, the vegetable oils with the largest volumes of global production have been used [2,25,26]. By selecting these oils, a wide range of compositions is also obtained, ranging from a high content of saturated compounds (such as palm), to a high content of polyunsaturated compounds (with two and three double bonds in the molecule, such as those contained in soybeans and sunflower), going through mainly monounsaturated oils (rapeseed).…”

“…In Figure 1, properties such as the density and viscosity of acetylacylglycerides are correlated with the number of acetate groups present in the molecule. [2,25,26]. By selecting these oils, a wide range of compositions is also obtained, ranging from a high content of saturated compounds (such as palm), to a high content of polyunsaturated compounds (with two and three double bonds in the molecule, such as those contained in soybeans and sunflower), going through mainly monounsaturated oils (rapeseed).…”

Optimization and Kinetics Extraction of Natural Dyes from Henna Leaves (Lawsonia inermis L.) with Ultrasonic Assistance

“…Data were analyzed using Design-Expert 11 software by adjusting the second-order polynomial model as in Equation ( 9). Y= β0+β1x1+β2x2+β3x3+β12x1x2+β13x1x3+β23x2x3+β11x12+β22x22+ β33x32 (9) where, Y is the response of the calculated model (yield value). The values x1, x2, and x3 indicate the independent variables.…”

“…Notably, all variables, except for ethanol concentration, exhibit values with a noteworthy impact on the yield response. The ethanol concentration variable, indicated by a p-value exceeding 0.05, suggests a lesser influence on the yield response value [9,10].…”

Interesterification of Glyceryl Trioctanoate Catalyzed by Sulfonic Silica-Based Materials: Insight into the Role of Catalysts on the Reaction Mechanism

“…Working in supercritical conditions or with enzymes as catalysts is not economically feasible from the point of view of industrial application, due to the high operative costs and long reaction time required in the case of enzymatic processes. Interesterification can be carried out in the presence of both basic and acid catalysts, which were tested in homogeneous and heterogeneous phase, either in thermal or ultrasound-assisted conditions [ 29 , 30 , 31 , 32 ]. Homogeneous base-catalyzed interesterification has been mainly studied due to the mild temperature and lower reaction time needed to achieve almost quantitative conversion of triglycerides and high yields of FAAE and triacetin [ 15 , 33 , 34 ].…”