Continuous Hydrosonic Reactor for Methyl Esters Production Process from Low Free Fatty Acid Oil Using 3D-Printed Rotor

Abstract

The continuous methyl ester production process was studied using a hydrosonic reactor to determine the relationship between the rotor speed and the purity of methyl ester with TLC/FID technique. The hydrosonic reactor consisted of three main parts: a rotor, a stator, and a motor. The key part is a 3D-printed rotor; the dimensions were 60 mm in outer diameter, 50 mm in length. The rotating 3D-printed rotor was driven and axially rotated inside the stator by shaft, and 400 kW electric motor was used to blend the mixtures. The dimensions of stator were 70 mm inner diameter and 70 mm length, and 5 mm thickness. The gap distance between the rotor and stator was fixed at 10 mm. The hole on the surface of rotor was circular shape (80 holes of 6 mm diameter) and designed radically throughout the axis. The ratio of diameter to depth of the circular hole was 1.0. In the preliminary experiment, the location and dimension of holes were fixed, and 3D-printed rotor speed was varied at 1000, 2000 and 4000 rpm under the condition of 23 vol.% methanol, 10 g KOH/L and 37 L/hr RPO flow rate at 60°C. The results showed that methyl ester purification reached 93.920 wt.%, 95.325 wt.%, 96.700 wt.%, and 97.333 wt.% at 1000, 2000, 3000, and 4000 rpm of rotor speed. Therefore, over 90 wt.% of methyl esters can be produced from RPO by using rotor-stator type of hydrodynamic cavitation.