Verification for the optimum orifice plate for hydrodynamic cavitation biodiesel reactor

Abstract

This research article presents the verification testfor the optimum orifice plate configuration for hydrodynamic
cavitation biodiesel reactor.The total area of orifice per overall pipe area (β ) variesin the ranges of 0 - 0.12, while
the orifice holes diameter are between 2 - 5 mm. The number of holes is varied depending on the β value. The raw material used in this study is the wasted cooking oil having free fatty acid of 2.7 %. Methanol of 20 % v/v and the
catalyst concentration of 1% w/w of potassium hydroxyl are used. The inlet pressure of the orifice plate is fixed at
4.5 bars and the initial temperature is 45 oC. The reactiontimeis 60 minutes in each test. The sample is collected
every 5 minutes to analyze for the percentage of methyl ester by the NMR analyzer. From results, the increase of
β enhances the higher percentage of methyl ester conversion, due to the higher flow area and hence the higher
reaction rate. Moreover, at the same β range, orifice plate which has more number of holes will provide better
reaction rate. The optimum orifice plate for 96.5 % methyl ester according to the commercial standard is the 15
holesof 2 mm. diameter, with 15 minutes of reaction time.