Numerical Analysis of Flow in Microchannels Using The Finite Element Method
Congress: PDPETRO
ABSTRACT:
Biofuels have gained significant popularity as they are a clean and renewable energy source when compared to conventional fossil fuels. Biodiesel is produced from monoalkyl esters derived from vegetable oils, animal fats or other materials composed mainly of triglycerols. In addition to several other important applications, biodiesel is predominantly used as a vehicle fuel, where it is blended with conventional petroleum-derived diesel. Microreactor technology, an essential method for process intensification, offers numerous potential advantages for process industries. Two-phase reactions with mass transfer limitations can be effectively conducted on a small scale in a slow-flow two-phase microreactor. In this type of reactor, alternating and uniform segments (slugs) of the two- phase reaction mixture exhibit areas of mass transfer between phases and well-defined flow patterns. The circulations within these slugs are not completely understood and require systematic numerical analyzes and the development of advanced mathematical models for better understanding and optimization. Furthermore, the application of microreactors can lead to greater energy efficiency and waste reduction in biofuel production. These compact reactors allow for more precise control of reaction conditions, which can result in higher quality products and more sustainable processes. The objective of this work is to study the behavior of two-phase flow through a capillary microreactor for the production of biodiesel, using the homogeneous flow model, where the two phases move at equal speeds and increasing the mixing level, thus being able to be treated as if were a single phase. A computational fluid dynamics (CFD) approach is then used to numerically simulate this type of flow in quadrilateral unstructured meshes. The flows are modeled by the incompressible two-dimensional Navier-Stokes equations, written using the current-vorticity function formulation, which are approximated by the Finite Element Method. The Python programming language was used to develop the computational code. After checking the code, characteristic flows in microchannels were analyzed, comparing the numerical results with experimental results from the literature. Good results were found with this methodology.