Biodiesel, which is derived from oil/fat by transesterification with alcohol, has attracted considerable
attention over the past decades due to its ability to subsidise fossil fuel derived energy as a renewable
and carbon neutral fuel. Several approaches for biodiesel fuel production have been developed, among
which transesterification using a catalyst gives high yields of methyl ester. This method has therefore
been widely utilized for biodiesel production in a number of countries. In this study, a Downflow Liquid
Contactor Reactor (DLCR) has been used for the liquideliquid transesterification reaction of sunflower oil
with alcohol with extraordinary results. The reactor provides great potential for chemical reactions,
which are normally limited by mass transfer and possesses a number of distinctive advantages over
conventional multiphase reactors. Inside the reactor a high velocity liquid jet stream is produced which
generates powerful shear and energy, causing vigorous agitation in the upper part of the reactor. The
high mixing intensity in the DLCR enabled the manufacture of biodiesel to European Standard EN14214
(ester content 96.5%) in 2.5 min at 40 C with 0.43 wt.% alkali catalyst and alcohol to oil molar ratio of 4.5
to 1.0. The separation of FAME from glycerol is done by gravity settling only without water washing. The
effect of the alcohol type (methanol, ethanol) on biodiesel yield was also investigated. The process offers
the advantage of continuous large scale production with limited reactor volume.