Biodiesel synthesis in micromixer with static elements

[Display omitted] •Study of biodiesel synthesis in micromixer with static elements are evaluated.•The presence of static elements optimized the fluid mixing and reaction.•The highest mixing was noticed for a Reynolds number of 100.•Experimentally the higher ethyl esters percentage was 99.53%.•Microreactors are a viable option to produce biodiesel. The biodiesel synthesis intensification can be performed using microdevices. The present research investigated numerical and experimentally the transesterification of sunflower oil with ethanol and sodium hydroxide catalyst in microchannel reactors with static elements. In the numerical study, two micromixer designs (Length=35mm; Width=1500μm, Height=200μm) were evaluated: T-micromixer (micromixer without static elements) and MSE (micromixer with static elements). The mixing of fluids was analyzed for a range of Reynolds number of 0.1–100. The oil conversion was investigated for a range of operating conditions: temperature (25–75°C), ethanol/oil molar ratio (6–12) and catalyst concentration (0.75–1.25%). Similar conditions were experimentally tested in microchannels with static elements (Length=411mm) made of polydimethylsiloxane (PDMS). The MSE showed superior performance of mixing index and oil conversion. The highest mixing was noticed for a Reynolds number of 100. The optimum oil conversion (91.53%) was observed numerically at conditions of 75°C, ethanol/oil molar ratio of 9 and catalyst concentration of 1%. The MSE showed experimentally the highest ethyl esters percentage (99.53%) at 50°C, ethanol/oil molar ratio of 9 and catalyst concentration of 1%, for a residence time of approximately 12s. The use of static elements in micromixer enhanced the biodiesel synthesis.