Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose

In this study, the potential of OPF as a lignocellulosic feedstock to produce fermentable sugars using two-stage dilute-acid hydrolysis was assessed. The proximate analysis revealed that OPF fibre was composed of 32.93% cellulose,29.91% hemicellulose and 19.53% lignin. This study focused on the hydr...

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Main Author: Nekoui, Soheil
Format: Thesis
Language:English
Published: 2014
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/64165/1/FK%202014%20109IR.pdf
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spelling my-upm-ir.641652018-05-30T08:16:35Z Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose 2014-10 Nekoui, Soheil In this study, the potential of OPF as a lignocellulosic feedstock to produce fermentable sugars using two-stage dilute-acid hydrolysis was assessed. The proximate analysis revealed that OPF fibre was composed of 32.93% cellulose,29.91% hemicellulose and 19.53% lignin. This study focused on the hydrolysis of cellulose fraction of OPF into glucose in the second-stage of two-stage dilute acid hydrolysis. The second stage reactions were carried out above 150 °C. Four parameters that affect the yield of glucose, namely acid concentration, reaction temperature, reaction time and liquid to solid ratio were investigated. The batch reactions were carried out under different operating conditions as proposed by the experimental design generated by the Response Surface Methodology (RSM). The RSM was used to determine the optimum point for the second stage dilute acid hydrolysis process. In the first stage of dilute acid hydrolysis 4.33 g/L (33% yields) glucose was recovered. From the second stage hydrolysis, at optimum condition of 150 °C temperature, 6 % sulphuric acid concentration, 62 min of reaction time and a liquid/solid ratio of 28:1, the glucose yield was 4.48 g/L (34%). The amount of generated inhibitor (HMF and furfural) was 0.22 g/l. The total glucose yield from both stages of the two-stage hydrolysis process under optimum conditions was 67%. The kinetics study on the formation of glucose from dilute acid hydrolysis of OPF revealed that the reaction was a first order irreversible reaction. Based on the values of rate constants, it was found that the rate of formation of glucose (k1) was more dominant than the rate of degradation (k2). The activation energy values at the optimum acid concentration of 6% were 85.733 kJ/mol for glucose formation and 123.238 kJ/mol for glucose degradation. The n value for glucose formation at 150 °C was 0.647 while for glucose degradation was at 0.487. The findings of this study suggest that the glucose yield can be increased while the inhibitor formation can be decreased by increase in acid concentration and decrease in reaction temperature. Oil palm Subject: Subject: Glucose Hydrolysis 2014-10 Thesis http://psasir.upm.edu.my/id/eprint/64165/ http://psasir.upm.edu.my/id/eprint/64165/1/FK%202014%20109IR.pdf text en public masters Universiti Putra Malaysia Oil palm Subject: Subject: Glucose Hydrolysis
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Oil palm Subject: Subject:
Glucose
Hydrolysis
spellingShingle Oil palm Subject: Subject:
Glucose
Hydrolysis
Nekoui, Soheil
Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
description In this study, the potential of OPF as a lignocellulosic feedstock to produce fermentable sugars using two-stage dilute-acid hydrolysis was assessed. The proximate analysis revealed that OPF fibre was composed of 32.93% cellulose,29.91% hemicellulose and 19.53% lignin. This study focused on the hydrolysis of cellulose fraction of OPF into glucose in the second-stage of two-stage dilute acid hydrolysis. The second stage reactions were carried out above 150 °C. Four parameters that affect the yield of glucose, namely acid concentration, reaction temperature, reaction time and liquid to solid ratio were investigated. The batch reactions were carried out under different operating conditions as proposed by the experimental design generated by the Response Surface Methodology (RSM). The RSM was used to determine the optimum point for the second stage dilute acid hydrolysis process. In the first stage of dilute acid hydrolysis 4.33 g/L (33% yields) glucose was recovered. From the second stage hydrolysis, at optimum condition of 150 °C temperature, 6 % sulphuric acid concentration, 62 min of reaction time and a liquid/solid ratio of 28:1, the glucose yield was 4.48 g/L (34%). The amount of generated inhibitor (HMF and furfural) was 0.22 g/l. The total glucose yield from both stages of the two-stage hydrolysis process under optimum conditions was 67%. The kinetics study on the formation of glucose from dilute acid hydrolysis of OPF revealed that the reaction was a first order irreversible reaction. Based on the values of rate constants, it was found that the rate of formation of glucose (k1) was more dominant than the rate of degradation (k2). The activation energy values at the optimum acid concentration of 6% were 85.733 kJ/mol for glucose formation and 123.238 kJ/mol for glucose degradation. The n value for glucose formation at 150 °C was 0.647 while for glucose degradation was at 0.487. The findings of this study suggest that the glucose yield can be increased while the inhibitor formation can be decreased by increase in acid concentration and decrease in reaction temperature.
format Thesis
qualification_level Master's degree
author Nekoui, Soheil
author_facet Nekoui, Soheil
author_sort Nekoui, Soheil
title Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
title_short Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
title_full Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
title_fullStr Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
title_full_unstemmed Optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
title_sort optimisation of second stage dilute acid hydrolysis of oil palm fronds into glucose
granting_institution Universiti Putra Malaysia
publishDate 2014
url http://psasir.upm.edu.my/id/eprint/64165/1/FK%202014%20109IR.pdf
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