Screening and Evaluation of Biocatalysts from Plant Sources for Trans-esterification Stage of Biodiesel Production

The production of biocatalysts using alternative, cheap and easily accessible plant sources which have the potential of increasing the environmental friendliness of the biodiesel process, was investigated. Four common plant species (Elaeis guineensis, Cocos nucifera, Carica papaya and Musa paradisiaca) were investigated. Freshly harvested parts of these species were weighed, dried and burnt to ash. The ash samples were subjected to metal analysis by Atomic Absorption Spectrophotometry (AAS) first as raw ash (5 g of sieved ash for each sample), then as ash leachate (10 mL each). Potash was determined for each sample by evaporating the ash leachate at 60°C with subsequent drying at 110°C. E. guineensis fruit bunch recorded the highest ash value of 5.65 kg while the least value of 0.76 kg was observed in M. paradisiaca. Potash content increased from 30.67% in E. guineensis frond to 53.47% in M. paradisiaca. The highest potassium composition in ash of 47650.20 mg kg-1 was observed in M. paradisiaca while the least value of 4815.2 mg kg-1 was recorded in the frond E. guineensis (oil palm). The following potassium concentrations were recorded in the leachate in decreasing order: M. paradisiaca (4388.37 mg L-1), C. nucifera (3662.51 mg L-1), E. guineensis bunch (3557.25 mg L-1), C. papaya (2781.17 mg L-1) and E. guineensis frond (665.56 mg L-1). Pb and Fe were below equipment detection limits in the samples analyzed. The study established that these species are good sources of biocatalysts usable in the trans-esterification stage of biodiesel production. It also provides an alternative platform for the management of plant waste arising from these species.