High local pressure and temperature can be generated by the sudden collapse of cavities which contributed to minimising the mass transfer between methanol and rubber seed oil phase in an acid esterification pretreatment process. The reaction is carried out in a 50 L/batch pilot scale reactor with an induced pressure of 1-3.5 bar around the orifice plate to generate the cavitational field. The double diaphragm pump is the key component to dissipate the energy in the hydrodynamic cavitation process. Four orifice plates with the various designs were studied for hydrodynamic cavitation process. In this regard, cavitation number effect, concentration effect and relative esterified efficiencies for all orifice plates were studied on various upstream pressure. It has been found that the plate with 21 holes of 1mm diameter with an inlet pressure of 3 bar gave a comprehensive result for the relative esterified efficiency of 0.005�10-5J-1. The relative efficiency of hydrodynamic cavitation process is fourfold higher than the mechanical stirring conventional process which makes it energy efficient. The final product from hydrodynamic cavitation process was purified via pilot scale distillation column of 5 L/batch capacity to further commence the transesterification process. The effects of temperature, pressure and packing height on distillation have been studied. The purified product properties such as moisture content, acid value and higher heating value were measured. It was found that purified product can be utilised for transesterification reaction for biodiesel production as a greener fuel. © 2016, AIDIC Servizi S.r.l.