PHD-Department of Chemistry

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Browsing PHD-Department of Chemistry by Subject "Algae Biofuel Blends"

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    Synthesis of (R)-1-Methyl-4-(1-Methylethenyl) Cyclohexene Multifunctional Derivatives and their Effects on Jatropha Curcas and Algae Biofuel Blends
    (Kenyatta University, 2020-10) Kahindo, John M.
    There is a growing increase in biofuel consumption around the world. Currently there is a desire to enhance biodiesel and biodiesel blends properties by use of multifunctional additives. This project sought to evaluate the miscibility of fatty acid ethyl ester blends from algae and Jatropha curcas L. oils and also synthesise hydrogenated and oxygenated derivatives of d-limonene as potential additives. Sampling of citrus peels was done from Milly Fruit Processors and Kongowea Mombasa. Algae were from Shimoni in Kwale, Shelly beach Mombasa, Jamvi la Wageni Mtongwe Likoni, English point Mombasa. J. curcas seeds were from contracted farmers in Shimba hills, Kwale County. Extraction of citrus oil containing d-limonene was done by use of hexane and liquid / Sc CO2. Catalytic synthesis of hydrogenated and oxygenated limonene derivatives was done using palladium on alumina Pd/Al2O3 and palladium on hydrotalcite Pd/HT respectively. Algae and jatropha seeds were dried, blended and extracted using hexane. The algae and citrus biomass were saccharified then fermented to obtain bioethanol.The algae and jatropha oils were transesterified using bioethanol, blended to form JAB then 2 – 10 % limonene and derivatives added to 20% JAB to form JABLA. GC-MS and FTIR spectrophotometers were used for characterisation. Determination of physicochemical and fuel properties was done using standard methods. Antimicrobial assay of JAB20 and JABLA was done using paper disc diffusion method. The properties of JAB and JABLA were then compared with those of diesel fuel and standard B100 biodiesel. The yield of orange oil was 5.748±0.719 %w/w using hexane. Pd composition of Pd/Al2O3 and Pd/HT was confirmed using XRF spectrometry to be 5% and 4.74% respectively. Characterisation showed that the oxidation products were mainly endo- and exo-epoxides, dihydrocarveol, carveol and carvone and hydrogenated products p-menthene, cis-p-menthane, trans-p-menthane, (S)-1-methylene-4-(1-methylethyl)cyclohexane and (R)-1-methylene-4-(1-methylethyl)cyclohexane. Bioethanol from citrus biomass was 9.42±1.031 % v/w. Algae oil produced 57-62% FAEE and J. curcas oil 63-70% FAEE. Characterisation of the ethyl esters showed mainly dodecanoic acid, tetradecanoic acid, pentadecanoic acid and hexadecanoic acid ethyl esters from algae oil and hexadecanoic acid, octadecanoic acid and 9z-octadecenoic acid ethyl esters from jatropha oil. JAB 5-20% was miscible, physicochemical and fuel characteristics showed that there was significant effect on the J. curcas FAEE calorific value, kinematic viscosity, pour point and cloud point with p < 0.05. The 2-8 % d-limonene additive showed effect on properties of JAB20 density, calorific value, kinematic viscosity, flash point, cetane index, pour point and cloud point with p< 0.05 except for CFPP with a p = 0.215. For 2-8 % hydrogenated d-limonene additive showed effect on density, calorific value, kinematic viscosity, flash point, cetane index, pour point and cloud point p< 0.05. The 2-8 % oxygenated d-limonene additive had effect on density, cetane index and pour point p < 0.05 according to data obtained using STATA/SE 13.0 and Xlstat at 95% confidence level two -tailed. JABLA showed no significant difference in fuel properties with petroleum diesel and standard B100 biodiesel p=0.110. The 8% oxygenated d-limonene also showed Pseudomonas aeroginosa growth inhibition of 23.20 ± 0.80 mm and Candida albicans growth inhibition of 25.30± 0.30 mm. From the findings the additives have beneficial effect on physicochemical and fuel properties of J. curcas and R. grande biofuel blend for increased sustainability and longer shelf life hence potential additives to the biofuels.