Synthesis of biodiesel in continuous flow packed with ion exchange kenaf fiber
Biodiesel has become increasingly attractive to be explore further for its environmental benefits such as renewable, bio-degradable, non-flammable, non-toxic, and sulfur-free. The most common biodiesel technologies employ homogenous catalysts to induce the reaction between alcohol and the triglyc...
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Format: | Thesis |
Language: | English |
Published: |
2020
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Subjects: | |
Online Access: | http://psasir.upm.edu.my/id/eprint/106340/1/NUR%20HARYANI%20BINTI%20ZABARUDDIN%20-%20IR.pdf http://psasir.upm.edu.my/id/eprint/106340/ |
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Institution: | Universiti Putra Malaysia |
Language: | English |
Summary: | Biodiesel has become increasingly attractive to be explore further for its environmental
benefits such as renewable, bio-degradable, non-flammable, non-toxic, and sulfur-free.
The most common biodiesel technologies employ homogenous catalysts to induce the
reaction between alcohol and the triglycerides during transesterification. Although the
transesterification reaction of triglycerides with alcohols using homogeneous catalyst is
well known and practiced on a commercial scale, there is plenty of scope to improve this
process. There is an approach that involves the use of heterogeneous catalysts that could
be packed in a packed-bed reactor, and this would enable a continuous process to be
developed. Recent progresses in the development of heterogeneous catalysts have been
the generation of ion exchanger to improve transesterification. Previous studies have
reported the application of anion exchange catalyst that derived from synthetic materials
for production of biodiesel. However, removal of spent catalyst is a problem as it falls
under the category of non-biodegradable wastes. The discovery of a novel low cost and
environment friendly catalyst is an attractive option for their utilization and safe disposal.
This study aims to investigate the use of kenaf fiber in the preparation of anion exchange
catalyst used in transesterification. The fabrication of an anion exchange kenaf catalyst
involved three steps: delignification of kenaf fiber, pre-irradiation induced emulsion graft
polymerization of kenaf fiber and quaternary amination. The objective of this work was
to develop a continuous system using an anion exchange kenaf catalyst and to evaluate
the performance of this plant-based catalyst to produce biodiesel in a packed bed reactor.
The transesterification of refined palm oil with ethanol in the presence of a ananion
exchange kenaf catalyst was carried out. A single tubular flow reactors system in the
concurrent up-flow configuration was built in the laboratory scale.The effect of the
process parameters such as molar ratio ethanol to refined palm oil, packed bed height and
volumetric flow rate on the triglycerides conversion and FAEE (fatty acid ethyl ester)
yields were investigated.
Screening design using full factorial were conducted to find the important factors and to
identify the optimum range of the yield. The optimum range was between 95 - 97%
conversion within a reaction ethanol to oil ratio 40:1 - 60:1, packed bed height of 4 cm –
12 cm and volumetric flow rate of 0.3 - 0.5 mL min-1. The response surface methodology
(RSM) based on the central composite design (CCD) was used to optimize the process.
The optimization were conducted around the optimum range established by the full
factorial design. The optimum conditions for transesterification of refined palm oil to
fatty acid ethyl ester were obtained at 9.81 cm packed bed height, 50:1 ethanol to oil
molar ratio and volumetric flow rate of 0.38 ml min-1. At these optimum conditions, the
FAEE yield was 96.74 %, which is well within the yield of 97.29 % as predicted by the
model. Although it was shown that high conversions can be achieved over extended time
on stream, it was clear that the catalyst was losing its activity. Measurements also showed
that during a regeneration experiment, kenaf fiber was dissolved in the solvent and
leaching of the catalyst active sites which resulted in poor catalyst reusability. Based on
the results obtained, anion exchange kenaf catalyst exhibited good performance for the
transesterification of refined palm oil with ethanol to produce FAEEs in packed bed
reactors. |
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