Effect of Rhizoclonium grande Saturated Fatty Acid Ethyl Esters on Physicochemical and Fuel Properties of Jatropha curcas Biofuel

Aims: The effect of Rhizoclonium grande saturated fatty acid ethyl esters on physicochemical and fuel properties of Jatropha curcas biofuel was assessed.

Study Design: Probability and purposeful sampling methods were employed. Randomized block design comprising of three blocks, Rhizoclonium grande and Jatropha curcas oils, the ethyl esters and their blends. Each sample from a block was subjected to several treatments with three replications per treatment.

Place and Duration of Study: the Technical University of Mombasa, Jomo Kenyatta University of Agriculture and Technology, Government Chemist and Kenya Pipeline Laboratories in Mombasa between February 2012 and September 2014.

Methodology: Algae was collected from Shimoni in Kwale, Shelly beach, Jamvi la Wageni in Likoni and English point in Mombasa to obtain algae oil. J. curcas seeds were collected from Shimba hills, Kwale. Transesterification of J. curcas and Rhizoclonium grande oil was carried out separately followed by GC-MS characterisation of the ethyl esters. Ethyl esters from J. curcas oils (JOFAEE) were blended with algae oil FAEE (5-25%) to obtain JAB. Physico-chemical and fuel properties of JAB were assessed. Statistical analysis was done using STATA/SE 13.0 at 95% confidence level (P<0.05) two-tailed.

Results: Rhizoclonium grande produced 6.72 - 10.46 % v/w oil. From GC-MS analysis the algae oil fatty acid esters contained pentadecanoic acid ethyl ester, dodecanoic acid ethyl ester, tetradecanoic acid ethyl ester and hexadecanoic acid ethyl ester. There was an observed significant difference in calorific value (P=0.03), kinematic viscosity (P=0.001), pour point (P=0.001) and cloud point (P=0.001) between JO FAEE and JAB samples attributed to the presence of algae oil saturated FAEE. The JAB showed no significant difference in fuel properties with standard biodiesel B100 (P>0.05).

Conclusion: From the findings, the physicochemical and fuel properties of biofuel from J. curcas can be improved by the use of saturated FAEE from R. grande for sustainability.