(24e) Process Intensification of the Conversion of Waste Cooking Oil to Fame Using a T- Microreactor

Fatty Acid Methyl Ester (FAME) or biodiesel is considered as an environment-friendly fuel because of its unique properties: it is non-toxic, biodegradable, and produces less greenhouse gas emissions in comparison to fossil fuels [1]. Generally, esters are produced by mechanical stirring via transesterification process in which the fatty acids (oil) is converted into ester by reacting it with alcohol in the presence of a catalyst. However, mechanical stirring has a low efficiency in overcoming the mass transfer limitation between the oil and alcohol phases resulting in lower reaction rates and higher capital production costs [2]. Recently, intensification technologies have been investigated for ester production in order to overcome this issue. Many researchers have employed different intensification processes such as the utilization of microfluidic devices, microwave, ultrasonic, and hydrodynamic cavitation reactors[3][4]. These technologies have been utilized to minimize the limitations in mass transfer between the oil and alcohol. Reducing the mass transfer resistance results in a significant reduction of the overall reaction time which significantly reduces the consumption of energy compared to the mechanical stirring process [5].

Microreactors have been extensively used for liquid-liquid multiphase systems to reduce the mass and heat transfer limitation because of the high interfacial area achieved between the phases. Ester production is almost 15 times faster in a microreactor compared to the conventional method. Numerous flow patterns, such as drop flow, slug flow, and parallel flow have been reported in the literature on ester production by using microreactors from different feedstock of virgin oil [6].

In this work, we present a study on the production of esters from waste cooking oil. In particular, we study the impact of various process parameters such as oil-to-methanol ratio, catalysts concentration, and residence time on the conversion of FAME. We specifically look at the challenges of using waste cooking oil instead of virgin oil during the transesterification process in the microreactor. To our best knowledge, there is no research available on ester production in microreactors using waste cooking oil as a feedstock.

References:

[1] Balat M. Potential alternatives to edible oils for biodiesel production – A review of current work. Energy Convers Manag 2011;52:1479–92. doi:https://doi.org/10.1016/j.enconman.2010.10.011.

[2] Marchetti JM. A summary of the available technologies for biodiesel production based on a comparison of different feedstock’s properties. Process Saf Environ Prot 2012;90:157–63. doi:10.1016/j.psep.2011.06.010.

[3] Azcan N, Danisman A. Microwave assisted transesterification of rapeseed oil 2008;87:1781–8. doi:10.1016/j.fuel.2007.12.004.

[4] Gholami A, Hajinezhad A, Pourfayaz F, Ahmadi MH. The effect of hydrodynamic and ultrasonic cavitation on biodiesel production: An exergy analysis approach. Energy 2018;160:478–89. doi:10.1016/j.energy.2018.07.008.

[5] Chuah LF, Klemeš JJ, Yusup S, Bokhari A, Akbar MM. A review of cleaner intensification technologies in biodiesel production. J Clean Prod 2017;146:181–93. doi:10.1016/j.jclepro.2016.05.017.

[6] Enrique L-G, Enrique O-N, Alejandro M-C, Krishna DPN. Process Intensification of Biodiesel production using a Tubular Micro-Reactor (TMR): Experimental and Numerical Assessment. Chem Eng Commun 2017;204:467–75.