Comparative Study on Kinetic Parameters for Tranesterification of Pongamia and Cotton Seed Oil

Abstract: Tranesterification of pongamia and cotton seed oil were performed at various experimental conditions such as temperature, molar ratio, catalyst concentration, reaction time and stirring speed. Maximum yield of around 85 % was obtained for pongamia and cotton seed oil at optimum conditions of temperature (338 K), molar ratio of methanol to oil (6:1), cation exchange resin catalyst (1.5 wt. %), stirring speed (10 Hz) and reaction time of 3 h. Kinetics of tranesterified pongamia and cotton seed oil were studied using Arrhenius plot. In excess of methanol, the transesterification reaction follows pseudo-first order reaction. The activation energies of pongamia and cotton seed oil were found to be 41570 and 23694.9 J/mol respectively. Kinetic study revealed that cotton seed oil is best suited for the maximum yield of biodiesel production

Biodiesel production from marine cyanobacteria cultured in plate and tubular photobioreactors

262-268Carbon (neutral) based renewable liquid biofuels are alternative to petroleum derived transport fuels that contribute to global warming and are of a limited availability. Microalgae based biofuels are considered as promising source of energy. <i style="mso-bidi-font-style: normal">Lyngbya sp. and Synechococcus sp. were studied for the possibility of biodiesel production in different media such as ASNIII, sea water enrichment medium and BG11. The sea water enrichment medium was found superior in enhancing the growth rate of these microalgae. Nitrogen depletion has less effect in total chlorophyll <i style="mso-bidi-font-style: normal">a content, at the same time the lipid content was increased in both Lyngbya sp. and <i style="mso-bidi-font-style: normal">Synechococcus sp. by 1.4 and 1.2 % respectively. Increase in salinity from 0.5-1.0 M also showed an increase in the lipid content to 2.0 and 0.8 % in these strains; but a salinity of 1.5 M has a total inhibitory effect in the growth. The total biomass yield was comparatively higher in tubular LED photobioreactor than the fluorescent flat plated photobioreactor. Lipid extraction was obtained maximum at 60 ºC in 1:10 sample: solvent ratio. GC-MS analysis of biodiesel showed high content of polyunsaturated fatty acids (PUFA; 4.86 %) than saturated fatty acid (SFA; 4.10 %). Biodiesel production was found maximum in Synechococcus sp. than Lyngbya sp. The viscosity of the biodiesel was closely related to conventional diesel. The results strongly suggest that marine microalgae could be used as a renewable energy source for biodiesel production