Use of Empty Fruit Bunches from the Oil Palm for bioethanol production: A thorough comparison between dilute acid and dilute alkali pretreatment

Published Date
May 2014, Vol.159:355–364, doi:10.1016/j.biortech.2014.02.122

Author 

S. Chiesa ^,

E. Gnansounou

Bioenergy and Energy Planning Research Group (BPE), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

Received 11 December 2013. Revised 18 February 2014. Accepted 26 February 2014. Available online 7 March 2014. 

Highlights

• Oil palm Empty Fruit Bunches shown as good candidates for bioethanol production.
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  Two pretreatment techniques compared (acid/alkali): the first option is superior.
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  Optimized dilute acid treatment (≈161 °C, 10 min, 1.5% acid): 85% glucose yield.
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  Alkali treatment is seriously hampered by high lignin content of the feedstock.
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  Fate of the different components of biomass monitored during each treatment.

Abstract

In the present work, two pretreatment techniques using either dilute acid (H₂SO₄) or dilute alkali (NaOH) have been compared for producing bioethanol from Empty Fruit Bunches (EFBs) from oil palm tree, a relevant feedstock for tropical countries. Treatments’ performances under different conditions have been assessed and statistically optimized with respect to the response upon standardized enzymatic saccharification. The dilute acid treatment performed at optimal conditions (161.5 °C, 9.44 min and 1.51% acid loading) gave 85.5% glucose yield, comparable to those of other commonly investigated feedstocks. Besides, the possibility of using fibers instead of finely ground biomass may be of economic interest. Oppositely, treatment with dilute alkali has shown lower performances under the conditions explored, most likely given the relatively significant lignin content, suggesting that the use of stronger alkali regime (with the associated drawbacks) is unavoidable to improve the performance of this treatment.

Keywords

Lignocellulosic bioethanol

Oil Palm Empty Fruit Bunches (EFBs)

Dilute sulfuric acid treatment

Dilute sodium hydroxide pretreatment

Surface response analysis

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  Corresponding author. Present address: Station de recherche Agroscope Liebefeld-Posieux ALP, Rte de la Tioleyre 4, Case postale 64, CH-1725 Posieux, Switzerland. Tel.: +41 (0)26 407 71 11; fax: +41 (0)26 407 73 00.
  
  

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