Hot Compressed Water Pretreatment Of Oil Palm Residues To Enhance Glucose Recovery
Loading...
Date
2011-10
Authors
Goh, Chun Sheng
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
This study presents the pretreatment of oil palm residues using hot
compressed water (HCW) to enhance glucose recovery in enzymatic hydrolysis for
the production of second generation bio-ethanol. Oil palm residues chosen in this
work is oil palm fronds (OPF) and empty fruit bunch (EFB). The experiments were
carried out in a batch system using a 10 bar pressurized reactor. Response surface
methodology (RSM) in conjunction with central composite design (CCD) was used
to optimize the response and effect of reaction temperature, reaction time and liquidsolid
ratio on the pretreatment process. Response investigated is glucose recovery for
OPF and EFB respectively. All variables were found to significantly affect the
responses. Composition changes with reaction conditions were studied to provide
supportive data for the justification of experimental response. It was found that
basically cellulose and hemicellulose content decreased with reaction temperature
and reaction time but increased with liquid-solid ratio. Generally lignin shows a
similar trend but it shows a slightly different change at high temperature and long
reaction time, in which re-condensation of lignin occurred and lignin content in the
pulps increased. Digestibility of pulps was also related to the composition, but it
varies from one condition to another. Quadratic polynomial equations were used to
model the responses by multiple regression analysis for OPF and EFB, respectively.
Maximum glucose recovery of OPF and EFB was found to be 83.60 % (176 ºC,
11.16 min, 8.00 mL/g) and 74.80 % (150.00 ºC, 11.86 min, 12.23 mL/g) respectively.
Experimental verification of the optimum conditions gave glucose yields in good
agreement with the estimated values of the models. It was found that OPF and EFB
behaved differently in HCW pretreatment, in terms of composition changes, and
subsequently digestibility and overall glucose yield. Generally, OPF has higher yield
than EFB due to its compositional changes.
Description
Keywords
Hot compressed water pretreatment , oil palm residues to enhance glucose recovery