Acetone Soluble Cellulose Acetate From Oil Palm Empty Fruit Bunches (OPEFB) Via A One Step Heterogeneous Process For Membrane Applications
| dc.contributor.author | Fauzi | |
| dc.date.accessioned | 2016-06-21T01:57:10Z | |
| dc.date.available | 2016-06-21T01:57:10Z | |
| dc.date.issued | 2015-08 | |
| dc.description.abstract | Cellulose acetates (CA) are normally produced by reaction of cellulose with an excess of acetic anhydride in the presence of sulfuric acid catalyst in a two step process of acetylation, followed by hydrolysis. It would be of economic significance if the hydrolysis step could be reduced or totally eliminated. In this research, acetone soluble CA of DS 2.52 has been successfully synthesized from oil palm empty fruit bunches (OPEFB) without the need of the hydrolysis step via a heterogeneous acetylation of cellulose using a combination of sodium bisulfate and sulfuric acid as catalysts. This has been only made possible by using a mathematical model of the heterogeneous acetylation process of OPEFB cellulose by varying the reaction time and acetic anhydride/cellulose ratio (R). From the obtained model, R = 4.4 and a reaction time of 1.5 hours with a DS of 2.52 were determined as the optimum conditions of the acetylation process. The model has been verified by experimental data and gave less than 2.5 % error, indicating cellulose acetate can be produced without the necessity of the hydrolysis step with proper reaction conditions. Evidence of acetylation was provided by FTIR analysis with the appearance of peaks in OPEFB-CA such as those at 1753, 1384, and 1240 cm-1 corresponding to carbonyl C=O stretching of ester, C-H in -O(C=O)-CH3 and C-O stretching of acetyl groups in the FTIR spectrum. 1HNMR analysis showed that among the three OH groups of OPEFB cellulose, the distribution of the acetyl moiety shows a preference at the C6 position, followed by C2 and C3. XRD analysis show broad peaks at 2θ = 13° and 2θ = 17° indicate a significant reduction in crystallinity in OPEFB-CA, which is further supported by DSC studies where it is estimated that the crystallinity of OPEFB-CA is only 6.41%. The OPEFB-CA films exhibited good mechanical properties where the tensile strength and Young’s modulus of the OPEFB-CA are higher than the commercial CA. The obtained OPEFB-CA of DS 2.52 was then used as a substrate for the preparation of a porous asymmetric membrane coated with polyvinyl alcohol (PVA) to form a composite of OPEFB-CA/PVA membrane. This membrane composite of OPEFB-CA/PVA gave a good performance when applied in the pervaporation of ethanol/water mixture giving a high flux but rather low selectivity. To improve the performance of the membrane, glutaraldehyde (GA), a crosslinking agent was added to the OPEFB-CA/PVA composite resulting in an increase in selectivity from 14.7 at 90 % feed concentration to 119.2 at 99 % feed concentration. In an attempt to demonstrate that this crosslinked membrane (OPEFB-CA/PVA/GA) can be used in a larger degree of the pervaporation process, a scale up calculation has been carried out through simulation. The simulation result showed that the pervaporation system using OPEFB-CA/PVA/GA composite membrane can purify aqueous ethanol up to 99.9 %. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/2144 | |
| dc.subject | Acetone Soluble Cellulose Acetate From Oil Palm Empty Fruit Bunches (Opefb) | en_US |
| dc.subject | Oil Palm | en_US |
| dc.title | Acetone Soluble Cellulose Acetate From Oil Palm Empty Fruit Bunches (OPEFB) Via A One Step Heterogeneous Process For Membrane Applications | en_US |
| dc.type | Thesis | en_US |
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