Abstract
Over the years several efforts have been geared towards the exploitation of Biodiesel owing to the world’s crude oil reserve depletion coupled with the consumption rate, increase in greenhouse effect, and its scarcities. This has lifted issues related to its conservation and eco-friendliness which brought about renewed interest in the use of bio-based substances. This research work was targeted at synthesizing chitosan and using it as a heterogeneous catalyst for the conversion of water melon seed oil to biodiesel; this heterogeneous catalyst is promising for the transesterification reactions of vegetable oils due to its economic benefits. More so, it is environmentally benign and can be operated in continuous processes (reused) unlike homogeneous catalysts. Chitosan was prepared from the deacetylation of chitin sourced from fish scale, from which 62.18% and 17.82% were obtained as their percentage yield respectively. The catalyst was then used in the transesterification reaction of water melon seed oil with methanol. The effects of reaction time (45 to 105 min), methanol/fatty acid molar ratio (1.5:1 to 7.5:1), reaction temperature (55 to 70°C), and catalyst concentration (0.25 to 1.25 wt%) on the biodiesel production were studied. From the response surface model result, it was found that the highest yield (94 %) was obtained at 60 °C with 1 wt% catalyzed for 90 mins and molar ratio of 6:1 which was at a high concentration of catalyst (1 wt%), while the lowest result was obtained at lower concentration of the catalyst (0.25 wt%). Based on the results obtained from the characterization of this biodiesel and comparing it with the relevant standard, it proved that chitosan maintained sustainable activity and shows a good quality of being used as a heterogeneous catalyst.

Key words: Biodiesel, Chitosan, Deacetylation, Transesterification