Biochemical Conversion of Lignocellulosic Biomass from Date Palm of Phoenix dactylifera L. into Ethanol Production

Yousra Antit,Moktar Hamdi,Sebastián Sánchez,Inmaculada Olivares

doi:10.3390/en14071887

Abstract

Cellulosic fibers from date palm are among the most promising lignocellulose feedstock for biorefinery purposes. The world production is between 1.9 and 2.4 million t/year. Initially, a pretreatment with dilute-sulphuric acid of these fibers was performed using a response surface methodology, with temperature and process time as factors. The aim is to produce bioethanol from young and old fibers from date palm, Phoenix dactylifera L. Optimal thermochemical pretreatment conditions for both fibers palms were 220 °C in hydrothermal conditions (without acid); in these conditions pretreated young fibers presented a maximum content in holocelluloses of 45.18% and old fibers 61.97%. Subsequently, during the enzymatic hydrolysis a maximum yield of total reducing sugars (TRS) was reached, 46.32 g/100 g for pretreated dry young fibers and 48.54 g/100 g for pretreated dry old fibers. After enzymatic saccharification, hydrolysates were fermented by Pachysolen tannophilus (ATCC 32691) to ethanol, reaching yields (YE/TRS) of 37.94 g ethanol/100 g of TRS for young fibers and 35.84 g ethanol/100 g of TRS for old fibers. Globally, considering the full process, in the fermentation of the hydrolysates, a yield (YE) of 10.64 g ethanol/100 g of dry young fibers and 10.88 g ethanol/100 g of dry old fibers was reached.

Highlights

Cellulosic fibers are the byproduct of the date palm tree; it is the fibrous part that covers the trunk of the tree which is bonded to the stipe before the death of a palm frond [2]
This study proves that biofuel yield from date palm waste via fermentation is high, as recent research shows [50]
This research highlights that waste of date palm tree

Summary

Introduction

Cellulosic fibers are the byproduct of the date palm tree; it is the fibrous part that covers the trunk of the tree which is bonded to the stipe before the death of a palm frond [2]. In Tunisia, its annual quantity is about 30,460 t/year [3]. This substrate is used both crude and oxidized as a composite material [4]. This fiber is used to generate heat by combustion as well as for wood production; it is employed as an energy resource for the wood industry [5]

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Conclusion