Title: Optimisation of pressed pericarp fibre delignification for glucose recovery using response surface methodology

Authors: Kiew Ling Hii; Mat Don Mashitah

Addresses: School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang, Malaysia ' School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Seri Ampangan, 14300 Nibong Tebal, Penang, Malaysia

Abstract: In this study, pressed pericarp fibres (PPFs) were subjected to chemical pretreatment for bioconversion of lignocellulosic biomass to fermentable sugars. The effectiveness and comparison between pretreatments using acid (HCl) and alkaline (NaOH) to reduce the lignin content was studied. Alkali pretreatment showed better lignin removal than acid pretreatment. Subsequent experiments were then carried out using a statistical design of experiments (DoE) for the optimisation of PPF delignification. The effect of NaOH concentration, incubation time and temperature were chosen as the independent variables, while the percentage of lignin removal as the response. The response surface methodology (RSM) coupled with central composite design (CCD) were used to develop the models to correlate the effect of process variables to the response. Temperature was identified by the analysis of variance (ANOVA) to be the most significant factor on the delignification of PPF. The optimum operating conditions for the process delignification of PPF (54% of lignin removal) were at 5.96% (w/v) of NaOH, 118.02°C and time for 4.92 hours. Three sets of experiments were carried out in order to validate the simulated model and the results were in agreement with the simulated values with an average error of ±1.29.

Keywords: pressed pericarp fibres; PPFs; PPF delignification; chemical pretreatment; lignin removal; central composite design; CCD; optimisation; glucose recovery; response surface methodology; RSM; bioconversion; lignocellulosic biomass; lignocellulose; sodium hydroxide; NaOH concentration; incubation time; temperature; ANOVA.

DOI: 10.1504/IJEE.2014.062157

International Journal of Environmental Engineering, 2014 Vol.6 No.2, pp.220 - 238

Accepted: 24 Jul 2012
Published online: 31 May 2014 *

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