Design and fabrication of smooth periodic constriction reactor to biodiesel production from waste cooking oil

Abstract

Recently, due to decreasing fossil energy reserves, research on renewable energy production has become necessary. Biodiesel is an alternative renewable energy to gas oil fuel. The study aims to design and evaluate some smooth periodic constriction (SPC) reactor parameters for biodiesel production from waste oil. Using the Reynolds-average Navier-Stokes equations, dimensions of the constriction area, expansion area and length of each bubble were found to be 2, 5 and 13 mm, respectively. It is observed that increasing the reactor length increases the conversion percentage. After increasing the reactor length from 1 to 2 m, the conversion percentage rises from 40% to 60%. The methyl ester content increases with increasing velocity from 1 to 2.3 m/s. Increasing the molar ratio from 4:1 to 6:1 increases the methyl ester content from 51% to 60%. The optimization points of velocity, reactor length and molar ratio were 2.28 m/s, 2.75 m and 6.54, respectively. Results show that the SPC needs to be combined with another method to increase yield and meet 96% methyl ester content according to standard. Finally, the SPC can be suggested to mix two or more liquids in a continuous process.