283733 Conceptual Design of a Tubular Coil Reactor for Biodiesel Production
The continuous production of biodiesel is aimed to be performed in a tubular reactor. The transesterification reaction of vegetable oil was carried out with methanol and potassium hydroxide as catalyst. Tubular reactors are commonly used for relatively fast reactions, however the alkaline transesterification of vegetable oils requires at least 30 minutes to reach a high oil conversion, and it is rather performed in tank reactors, either in batch or continuous modes. To reduce the space needed for the reactor, a coil tubular reactor was conceptualized. Simulation tools used in this work are essential for chemical engineers to perform innovative designs for the chemical industry. In this context, a biodiesel reactor was simulated and optimized. The first stage in this work was an experimental design to determine the best reaction conditions at which the vegetable oil could be effectively transformed into methyl esters. Optimization was performed by Taguchi method and using the response surface methodology. The results taken from here were the methanol to oil molar ratio and the amount of catalyst that maximized the yield of methyl esters. In a second stage the kinetic parameters of the transesterification reactions were estimated with Marquardt algorithm, i.e. the activation energy and the pre-exponential factors for each reaction considered. Thirdly, a simulation of the tubular reactor was performed in ASPEN Plus as a plug flow reactor. From here, the size of the reactor was calculated. The transport phenomena were then evaluated by a multiphysics simulation. A prototype of the reactor was finally build. The reactor shows a very good performance for a production of 60 L of biodiesel in one hour. More innovative solutions could be given at industrial scale by following this methodology.