Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion

This work addresses for the first time the study of olive stone (OS) biomass pretreatment by reactive extrusion technology using NaOH as the chemical agent. It is considered as a first step in the biological conversion process of the carbohydrates contained in the material into bio-based products. O...

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Main Authors: Pablo Doménech, Aleta Duque, Isabel Higueras, Raquel Iglesias, Paloma Manzanares
Format: Article
Language:English
Published: MDPI AG 2020-09-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/13/17/4517
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author Pablo Doménech
Aleta Duque
Isabel Higueras
Raquel Iglesias
Paloma Manzanares
author_facet Pablo Doménech
Aleta Duque
Isabel Higueras
Raquel Iglesias
Paloma Manzanares
author_sort Pablo Doménech
collection DOAJ
description This work addresses for the first time the study of olive stone (OS) biomass pretreatment by reactive extrusion technology using NaOH as the chemical agent. It is considered as a first step in the biological conversion process of the carbohydrates contained in the material into bio-based products. OS is a sub-product of the olive oil extraction process that could be used in a context of a multi-feedstock and multi-product biorefinery encompassing all residues generated around the olive oil production sector. OS biomass is pretreated in a twin-screw extruder at varying temperatures—100, 125 and 150 °C and NaOH/biomass ratios of 5% and 15% (dry weight basis), in order to estimate the effectiveness of the process to favour the release of sugars by enzymatic hydrolysis. The results show that alkaline extrusion is effective in increasing the sugar release from OS biomass compared to the raw material, being necessary to apply conditions of 15% NaOH/biomass ratio and 125 °C to attain the best carbohydrate conversion rates of 55.5% for cellulose and 57.7% for xylan in relation to the maximum theoretical achievable. Under these optimal conditions, 31.57 g of total sugars are obtained from 100 g of raw OS.
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spelling doaj.art-89650136b01a4cf99410ac2c6df8701a2023-11-20T12:07:30ZengMDPI AGEnergies1996-10732020-09-011317451710.3390/en13174517Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline ExtrusionPablo Doménech0Aleta Duque1Isabel Higueras2Raquel Iglesias3Paloma Manzanares4Biofuels Unit, Energy Department—CIEMAT, Avda. Complutense 40, 28040 Madrid, SpainBiofuels Unit, Energy Department—CIEMAT, Avda. Complutense 40, 28040 Madrid, SpainBiofuels Unit, Energy Department—CIEMAT, Avda. Complutense 40, 28040 Madrid, SpainBiofuels Unit, Energy Department—CIEMAT, Avda. Complutense 40, 28040 Madrid, SpainBiofuels Unit, Energy Department—CIEMAT, Avda. Complutense 40, 28040 Madrid, SpainThis work addresses for the first time the study of olive stone (OS) biomass pretreatment by reactive extrusion technology using NaOH as the chemical agent. It is considered as a first step in the biological conversion process of the carbohydrates contained in the material into bio-based products. OS is a sub-product of the olive oil extraction process that could be used in a context of a multi-feedstock and multi-product biorefinery encompassing all residues generated around the olive oil production sector. OS biomass is pretreated in a twin-screw extruder at varying temperatures—100, 125 and 150 °C and NaOH/biomass ratios of 5% and 15% (dry weight basis), in order to estimate the effectiveness of the process to favour the release of sugars by enzymatic hydrolysis. The results show that alkaline extrusion is effective in increasing the sugar release from OS biomass compared to the raw material, being necessary to apply conditions of 15% NaOH/biomass ratio and 125 °C to attain the best carbohydrate conversion rates of 55.5% for cellulose and 57.7% for xylan in relation to the maximum theoretical achievable. Under these optimal conditions, 31.57 g of total sugars are obtained from 100 g of raw OS.https://www.mdpi.com/1996-1073/13/17/4517lignocellulosic biomassextrusionpretreatmentolive oil industrysub-productfermentable sugars
spellingShingle Pablo Doménech
Aleta Duque
Isabel Higueras
Raquel Iglesias
Paloma Manzanares
Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
Energies
lignocellulosic biomass
extrusion
pretreatment
olive oil industry
sub-product
fermentable sugars
title Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
title_full Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
title_fullStr Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
title_full_unstemmed Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
title_short Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion
title_sort biorefinery of the olive tree production of sugars from enzymatic hydrolysis of olive stone pretreated by alkaline extrusion
topic lignocellulosic biomass
extrusion
pretreatment
olive oil industry
sub-product
fermentable sugars
url https://www.mdpi.com/1996-1073/13/17/4517
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