Multistage process for the production of bioethanol from almond shell. (July 2016)

• Record Type: Journal Article
• Authors: Kacem, Imen; Koubaa, Mohamed; Maktouf, Sameh; Chaari, Fatma; Najar, Taha; Chaabouni, Moncef; Ettis, Nadia; Ellouz Chaabouni, Semia
• Is Part Of: Bioresource technology. Volume 211(2016)
• Page Start: 154
• Page End: 163
• Publication Date: 2016-07
• Subjects: Almond shell -- Pre-treatment -- Saccharification -- Laccase -- Bioethanol; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.03.057
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Almond shell was pretreated by NaOH and dilute sulfuric acid. Enzymatic saccharification was optimized using a hybrid design. Laccase was used to detoxify the enzymatic hydrolysate. Ethanol yield increased from 30% to 84% by laccase treatment. Abstract: This work describes the feasibility of using almond shell as feedstock for bioethanol production. A pre-treatment step was carried out using 4% NaOH for 60 min at 121 °C followed by 1% sulfuric acid for 60 min at 121 °C. Enzymatic saccharification of the pre-treated almond shell was performed using Penicillium occitanis enzymes. The process was optimized using a hybrid design with four parameters including the incubation time, temperature, enzyme loads, and polyethylene glycol (PEG) concentration. The optimum hydrolysis conditions led to a sugar yield of 13.5%. A detoxification step of the enzymatic hydrolysate was carried out at pH 5 using 1 U/ml of laccase enzyme produced by Polyporus ciliatus . Fermenting efficiency of the hydrolysates was greatly improved by laccase treatment, increasing the ethanol yield from 30% to 84%. These results demonstrated the efficiency of using almond shell as a promising source for bioethanol production.