Journal of Oil Palm Research Vol. 30 (4) December 2018, p. 642-654

OPTIMISATION OF PROCESS CONDITIONS FOR ETHANOL PRODUCTION FROM ENZYMATICALLY SACCHARIFIED EMPTY FRUIT BUNCH USING RESPONSE SURFACE METHODOLOGY (RSM)

SOH KHEANG LOH*; MOHD ASYRAF KASSIM** and NURUL ADELA BUKHARI*

DOI: https://doi.org/10.21894/jopr.2018.0045
Published Online: 18 October 2018
ABSTRACT

Oil palm empty fruit bunch (EFB), being one of the lignocellulosic biomass forms generated from the palm oil milling process, has high contents of cellulose and hemicelluloses for bioethanol production. However, the conversion routes so far remain challenging and optimisation is necessary. This article aims at optimising the fermentable process variables in the production of bioethanol from EFB using response surface methodology (RSM). The EFB was firstly pre-treated with mild NaOH, then hydrolysed using diluted H2SO4 to extract mainly xylose and subjected to enzymatic saccharification for glucose recovery prior to fermenting the sugars with Saccharomyces cerevisiae. A Central Composite Design (CCD) was used to optimise the three independent variables involved i.e. pH, temperature and agitation rate. The RSM data subjected to analysis of variance (ANOVA) and a second-order polynomial model revealed the optimised conditions: pH 4, 30°C, 150 rpm and 72 hr in batch fermentation. The validation experiment under these conditions gave a maximum bioethanol yield of 0.66 g g-1 glucose, which was very close to the predicted value (0.56 g g-1). These results confirmed that the model was adequate and reliable to optimise bioethanol production from the enzymatically hydrolysed EFB.

KEYWORDS:


* Malaysian Palm Oil Board, 6 Persiaran Institusi, Bandar Baru Bangi, 43000 Kajang, Selangor, Malaysia.
E-mail: lohsk@mpob.gov.my

** School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia.