Enzymatic synthesis of biodiesel from Jatropha curcas oil via hydroesterification /
Conventional process of biodiesel production generates toxic and obnoxious contaminants that need to be treated before disposal into the environment. It is thus imperative that an environmental friendly approach can be employed in biodiesel production in order to ensure resource conservation. This s...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur :
Kulliyyah of Engineering, International Islamic University Malaysia,
2014
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | Conventional process of biodiesel production generates toxic and obnoxious contaminants that need to be treated before disposal into the environment. It is thus imperative that an environmental friendly approach can be employed in biodiesel production in order to ensure resource conservation. This study produced biodiesel from Jatropha curcas oil, a non-food material with huge potential for biodiesel industry. The biodiesel was produced by hydroesterification approach utilizing the activity of Candida cylindarcea lipase in the hydrolysis of Jatropha curcas oil to afford free fatty acids (FFAs) (Hydrolysate). The crude Jatropha curcas oil was characterized by determining its physico-chemical properties. The result of the physico-chemical properties showed that acid value of the oil was high (14.6 KOH g-1) thus the utilization of the feedstock in conventional biodiesel synthesis is prone to soap formation which reduces the yield. Candida cylindracea lipase was purified and immobilized on functionalized activated carbon (to enhance the adsorption of the enzyme to the support). Enzyme activity was determined on p-nitrophenylpalmitate (p-NPP) before and after the immobilization. The immobilized capacity of the enzyme was found to be very high (6427.5 U/g). The immobilized enzyme was utilized in the hydrolysis of Jatropha curcas oil. One-factor-at-a-time (OFAT) was employed to determine optimum levels of the three selected parameters (temperature, catalyst loading and agitation) for hydrolysis of the crude Jatropha oil. Face Centered Central Composite Design (FCCCD) by Design Expert software 6.0.8 under response surface methodology (RSM) was used for optimization. Optimized conditions for the parameters as well as the response were determined to be 8% w/w of the immobilized catalyst, 40oC for temperature, 200rpm agitation and 78% FFA production. In the esterification reaction to convert the hydrolysate to biodiesel, optimum level for five parameters (reaction temperature, catalyst loading, agitation, molar ratio of methanol to oil and reaction time) were determined and three parameters were selected for optimization using FCCCD. Optimized parameter were found to be agitation of 400 rpm, reaction temperature of 60oC, methanol to oil molar ratio of 5:1, reaction time of 6hrs and catalyst loading of 4wt. % producing 96% yield and 96% conversion of the hydrolysate. The model hydrolysis and esterification coefficient of determination (R2) being 0.959 and 0.9507 while their adjusted R2 was 0.922 and 0.9063 respectively. Kinetics of esterification was carried out to evaluate activation energy (21.26kJ/mol) and frequency factor (7.55) from a pseudo-first order reaction rate. Numerical optimization solution suggested by the software was carried out for validation of both hydrolysis and esterification reactions. The biodiesel produced was characterized to determine the extent of conformity with specified standards of ASTM D 6751and EN 14214. Biodiesel production from feedstock of high FFA value was thus achieved through environmental friendly approach. |
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| Physical Description: | xx, 172 leaves : ill ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 151-167). |