Biodiesel production in microreactor | Department of Chemical Engineering

Biodiesel production in microreactor

In past few decades, the consumption of petroleum fuels has increased at alarming rates which may lead to depletion of our fuel reserves. The increased use of petroleum fuels has also escalated the emissions of greenhouse gases in the atmosphere. Hence, the need to develop potential alternative renewable bio-fuels is growing persistently. Biodiesel, a renewable and environment-friendly fuel has emerged as one of the most investigated bio-fuel with a goal to decrease our reliance on petroleum fuels and reduce environmental pollution. But the main barriers to the commercialisation of biodiesel are high operating cost and energy requirements, long residence time and limited conversion due to equilibrium limitations. Several types of research on the production of biodiesel have focused on the implementation of micro-reactor technology to provide a solution for these issues. Attributed to the small diffusion distances and large surface area to volume ratio in microreactors, heat, and mass transfer are significantly intensified, thus resulting in higher conversions in shorter residence times. Compared to conventional processes, biodiesel can be produced 10 to 100 times faster in a microreactor. Also, the requirements of high energy in the mixing of reactants, ample floor space and standing time for the separation of products are eliminated using microreactors. However, for microreactors with small channel dimensions of up to 1 mm the throughput remains a challenge. In the proposed project we aim to design a parallel microchannel reactor using the splitting distributor for production of biodiesel using non-edible oils. The application of splitting distributor would increase the overall throughput. Besides, the effects of distributor design, channel aspect ratio and operating parameters (temperature, residence time, alcohol to oil molar ratio, catalyst type and concentration) on the biodiesel yield will be studied. The results from the proposed work would substantially be useful to develop a pilot scale microreactor module for production of biodiesel.

In the current project, we aim at the production of biodiesel using parallel microchannel reactor.  The choice of material for fabrication of microreactor depends on some factors like the type of catalyst used, reaction temperature and compatibility with feedstock oil. The microchannel reactor comprising of parallel microchannels for biodiesel production process will be fabricated on the stainless plate for acid catalysed transesterification of feedstock with high FFA content which is performed at high temperatures. For low FFA content feedstock and low reaction temperatures, transparent channels made up of Quartz, FEP (fluorinated ethylene propylene), PDMS (polydimethylsiloxane), PTFE (polytetrafluoroethylene) will be used to study hydrodynamics and flow patterns observed during biodiesel production. The selection of catalyst type depends on the FFA content of the oil. For oils with FFA content higher than 1% by weight, an acidic catalyst, i.e. H2SO4 will be used whereas for oils with lower FFA content an alkali catalyst, i.e. KOH or NaOH will be used.


Assistant Professor