TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The rotation rate of the magnetic field is at least 3000 revolution per minute (rpm). The individual magnetostrictive pieces of material are small cylindrical iron bodies. The alternating rotary magnetic field produces acoustic resonance in the active centre of the reaction zone. The reaction zone is divided by several perforated baffles, spaced to promote the resonance. The magnetic field strength in the reaction zone is 0.1 Tesla. The catalyst is an alkali metal hydroxide which is first dissolved into the methanol and the solution then mixed with the vegetable oil and the mixture thus formed is emulsified prior to entering the reaction chamber. EXAMPLE - Biodiesel was prepared in reaction zone as follows: A feedstock for conversion to biodiesel was rape seed oil. The dissolution was controlled in order to provide a solution of potassium hydroxide (8 wt.%) in methanol. The potassium hydroxide solution in methanol and feed oil were then emulsified on a continuous basis at a weight ratio of 122 kg of the potassium hydroxide in methanol solution per 1000 kg of the rape seed oil. The flow through the reaction chamber was 5 tonnes per hour of emulsion. During its passage through the reactor chamber, the emulsion was subjected to intense agitation as a result of the application of the rotating magnetic field by units of coils. The length of the reaction chamber under the influence of the magnetic field was 670 mm, the inner diameter of the chamber being 100 mm. The reactor chamber was tuned to operate as a resonant cavity. The speed of sound in the emulsion was around 2000 metres per second, the generation of an acoustic standing wave having a wavelength of around 166 mm and a fundamental frequency of around 12 KHz was achieved. Measurement showed that there was a certain amount of 24 KHz and higher harmonics were achieved. The chamber included, located captive in each of the sections, magnetorestrictive components (600 g) in the form of iron cylinders of length 15 mm and diameter 1 mm. The power consumption during continuous operation was 3-4 Kilowatt hours per tonne of biodiesel produced.