Cellulosic bioethanol production from empty fruit bunches by locally produced cellulase /
Production of bioethanol from oil palm empty fruit bunches (EFB) using locally produced cellulase is among the ways of reducing environmental pollution and consumption of crude oil. This study uses three sequential steps in the production of bioethanol using EFB, which include pretreatment, enzymati...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur: Kulliyyah of Engineering,International Islamic University Malaysia,
2012
|
| Subjects: | |
| Online Access: | http://studentrepo.iium.edu.my/handle/123456789/4394 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Production of bioethanol from oil palm empty fruit bunches (EFB) using locally produced cellulase is among the ways of reducing environmental pollution and consumption of crude oil. This study uses three sequential steps in the production of bioethanol using EFB, which include pretreatment, enzymatic hydrolysis and fermentation process. Sodium hydroxide (NaOH) was used during the pretreatment process to remove lignin and to make the enzymes more accessible for conversion of carbohydrate polymers into fermentable sugars. The amounts of lignin, cellulose, hemicellulose and ash after pretreatment process were 22.09% (w/w), 51.45% (w/w), 22% (w/w) and 2.7% (w/w), respectively. Enzyme hydrolysis resulted in the highest production of reducing sugar of 16.97g/l or 424.25g/kg EFB under the optimized conditions of 4.0% (w/v) substrate concentration, enzyme dosage of 6% (v/v) and agitation of 243 rpm. The result indicates that more than 50% (w/w) of reducing sugar was released from the hydrolysis process because the total sugar content in the EFB was 734.5g/kg of EFB. The reducing sugar obtained from the hydrolysis process was then used for fermentation process to obtain bioethanol. Compatibility studies based on bioethanol production showed that Aspergillus niger and Saccharomyces cerevisae were compatible with each other and their combined effects led to the highest bioethanol concentration of 6.4g/l and yield of 0.38g/g. In order to obtain the maximum amount of bioethanol, screening of important media constituents and process conditions was conducted using Plackett Burman design. Among the parameters tested, pH, temperature, inoculum size, KH2P04, MgS04.7H20, peptone showed positive effects on bioethanol production while yeast extract, malt extract, KCl, agitation and urea were influencing the production negatively. Although agitation appeared to have negative effects but it was considered in one-factor-at-atime (OFAT) experiments to determine the possible optimum level. Two factors (pH and agitation) were considered in OFAT and it was found that the possible pH range for fermentation was between 4 and 6, while agitation was 100 rpm and above. The highest bioethanol obtained after optimization of fermentation process using face centered central composite design (FCCCD) was 7.4g/l (0.74%, w/v) with yield of 0.43g/g based on the agitation of 150 rpm, pH of 5.5 and 0.3% (w/v) of KH2P04. Although, the concentration of bioethanol obtained in this study during the fermentation process was low due to the low amount of reducing sugar (16.97g/l) present in EFB, however the amount of reducing sugar could be directly related to the product formation, which influences the yield and productivity values. |
|---|---|
| Item Description: | Abstracts in English and Arabic. " A dissertation submitted in fulfilment of the requirement for the degree of Master of Science (Biotechnology Engineering)."--On title page. |
| Physical Description: | xvii, 129 leaves : illustrations ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 109-118). |