Biodiesel production processes using coconut oil containing a relatively high content of free fatty acids (4.5% w/v and higher) have been characterized using alkali, acid and enzymatic- based catalysts. The use of ethanol (molar ratio of 3:1 of ethanol:triglycerides) instead of methanol was evaluated in all processes. An alkali-based process resulted in rapid conversion of the triglycerides in the coconut oil to esters with an 80% conversion in 5-10 min. However pre-treatment with 0.7% H2SO4 v/v at 50oC for 3 h was required before alkali addition to avoid saponification of the free fatty acids. By comparison, a longer reaction time (50 h) was required for the acid process which also resulted in a lower conversion (67% at 50oC). The use of an acid overcomes the limitations of the alkali process of saponification when high FFA content oils are used, and gave a higher conversion 70% at 75oC after 300 min. By comparison use of an enzymatic (lipase) catalyst (1% w/v) at 50oC resulted in a conversion of 80% in 50 h. The enzyme based process under similar conditions was significantly improved by the use of high frequency sonication which reduced the reaction time to 3 h and achieved a 92% conversion of triglycerides to esters. To further improve the economics of the enzyme process, an initial study showed that the enzyme catalyst was able to be recycled with only a 20% decrease in conversion. The use of the glycerol by-product from the enzyme process as a carbon source for yeast growth resulted in improved kinetics to that for yeast growth on pure glycerol indicating that no inhibitory by-products were produced during the enzyme process. The overall economics of the process, and its sensitivity to key process variables was further analysed using a computer-based model of biodiesel production. It showed that an internal rate of return (IRR) of 30% for a commercial size plant of 4 million litre per annual.