Increase in Fermentable Sugars of Olive Tree Pruning Biomass for Bioethanol Production: Application of an Experimental Design for Optimization of Alkaline Pretreatment

Olive Tree Pruning (OTP) biomass can be considered a suitable source of fermentable sugars for the production of second-generation bioethanol. The present study proposes a remarkable alternative for the valorization of olive tree pruning residues. OTP biomass was processed using a sequential calcium hydroxide pretreatment/enzymatic hydrolysis. A 24–1 half fractional factorial design was adopted for the screening of process variables and a central composite design was used for the optimization stage. Temperature and lime loading resulted statistically significant. The following optimal conditions were obtained: 0.01 g of Ca(OH)2/g of dry material, 20 g of H2O/g of dry material at 160 °C for 2 h. The mathematical model that governs this alkaline pretreatment was obtained with a 76% adjusted determination coefficient, which means that it is a good representation of the process. Under optimal operating conditions, 13% of the cellulose and 88% of the hemicellulose was solubilized. Moreover, the fermentable sugar content increased 1800% compared with the initial conditions, obtaining 240 g of glucose per kg of OTP residue. The fermentable sugars obtained after the calcium hydroxide pretreatment and enzymatic hydrolysis of OTP biomass yielded 2.8 g of ethanol/100 g of raw material.

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Organosolv pretreatment of olive tree biomass for fermentable sugars

Holzforschung ◽

10.1515/hf.2011.030 ◽

2011 ◽

Vol 65 (2) ◽

Cited By ~ 24

Author(s):

Manuel J. Díaz ◽

Wouter J.J. Huijgen ◽

Ron R. van der Laan ◽

Johannes H. Reith ◽

Cristóbal Cara ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Aqueous Ethanol ◽

Sugar Content ◽

Olive Tree ◽

Main Process ◽

Organosolv Pretreatment ◽

Ethanol Content ◽

Mediterranean Countries ◽

Hydrolysis Of ◽

Tree Pruning

Abstract Olive tree pruning biomass is one of the main agricultural residues available in Mediterranean countries and is currently lacking commercial applications. To take advantage of its sugar content, a pretreatment is necessary to enhance enzyme accessibility of the cellulose fraction of the residue. This paper describes for the first time the use of organosolv pretreatment in this regard. The main process variables such as pretreatment temperature, residence time, and solvent composition (aqueous ethanol) are studied. Results show that organosolv pretreatment causes delignification and hydrolysis of hemicelluloses and improves the enzymatic digestibility of olive tree pruning biomass. A higher pretreatment severity and ethanol content of the solvent were found to increase delignification (up to 64% at 66% w/w aqueous ethanol, 210°C, 60 min). By contrast, xylan hydrolysis was promoted by a lower ethanol content (maximum 92%). The highest enzymatic hydrolysis yield (90% of the structural glucan present in the raw material) has been obtained after pretreatment with 43% w/w aqueous ethanol at 210°C for 15 min. Organosolv pretreatment was found to be the most effective pretreatment for enzymatic hydrolysis of olive tree pruning biomass.

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Tequilana weber Agave Bagasse Enzymatic Hydrolysis for the Production of Fermentable Sugars: Oxidative-Alkaline Pretreatment and Kinetic Modeling

BioEnergy Research ◽

10.1007/s12155-016-9757-8 ◽

2016 ◽

Vol 9 (4) ◽

pp. 998-1004 ◽

Cited By ~ 14

Author(s):

Ulises Velázquez-Valadez ◽

Juan Carlos Farías-Sánchez ◽

Alfonso Vargas-Santillán ◽

Agustín Jaime Castro-Montoya

Keyword(s):

Enzymatic Hydrolysis ◽

Kinetic Modeling ◽

Alkaline Pretreatment ◽

Fermentable Sugars

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Techno-economic feasibility of bioethanol production via biorefinery of olive tree prunings (OTP): optimization of the pretreatment stage

Holzforschung ◽

10.1515/hf-2018-0096 ◽

2018 ◽

Vol 73 (1) ◽

pp. 3-13 ◽

Cited By ~ 9

Author(s):

Juan C. Solarte-Toro ◽

Juan M. Romero-García ◽

Ana Susmozas ◽

Encarnación Ruiz ◽

Eulogio Castro ◽

...

Keyword(s):

Olive Tree ◽

Economic Feasibility ◽

Operating Conditions ◽

Raw Material ◽

Dilute Acid Pretreatment ◽

Bioethanol Production ◽

Optimal Conditions ◽

Dilute Acid ◽

Acid Pretreatment ◽

Tree Pruning

Abstract The aim of this work was to evaluate the economic feasibility of the bioethanol production (BEP) based on olive tree pruning (OTP) as a biomass feedstock with optimization of the dilute acid pretreatment in focus. For this, the BEP was simulated taking into account the influence of the operating conditions of the pretreatment stage. Then, the techno-economic results were analyzed by means of the response surface methodology (RSM). The results show that lowest price of BE was 1.94 USD l−1 with a yield of 174.12 l t−1 OTP under optimal conditions. As a conclusion, the raw material cost has a strong influence in the economic feasibility of the BEP from OTP. The inclusion of other processing lines into the process would improve the process economy.

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Effect of Steam Explosion Pretreatment on Sugar Production by Enzymatic Hydrolysis of Olive Tree Pruning

Energy Procedia ◽

10.1016/j.egypro.2015.12.069 ◽

2015 ◽

Vol 81 ◽

pp. 146-154 ◽

Cited By ~ 5

Author(s):

Marco Barbanera ◽

Cinzia Buratti ◽

Franco Cotana ◽

Daniele Foschini ◽

Elisa Lascaro

Keyword(s):

Enzymatic Hydrolysis ◽

Steam Explosion ◽

Olive Tree ◽

Sugar Production ◽

Steam Explosion Pretreatment ◽

Hydrolysis Of ◽

Tree Pruning

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Torrefaction of olive tree pruning: Effect of operating conditions on solid product properties

Fuel ◽

10.1016/j.fuel.2017.04.007 ◽

2017 ◽

Vol 202 ◽

pp. 109-117 ◽

Cited By ~ 49

Author(s):

M.A. Martín-Lara ◽

A. Ronda ◽

M.C. Zamora ◽

M. Calero

Keyword(s):

Olive Tree ◽

Operating Conditions ◽

Solid Product ◽

Tree Pruning

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Optimization of peroxide-alkaline pretreatment and enzymatic hydrolysis of barley straw (Hordeum vulgare L.) to produce fermentable sugars using a Box–Behnken design

Biomass Conversion and Biorefinery ◽

10.1007/s13399-020-00853-4 ◽

2020 ◽

Cited By ~ 1

Author(s):

N. Ibarra-Díaz ◽

J. F. Castañón-Rodríguez ◽

J. Gómez-Rodríguez ◽

M. G. Aguilar-Uscanga

Keyword(s):

Hordeum Vulgare ◽

Enzymatic Hydrolysis ◽

Alkaline Pretreatment ◽

Barley Straw ◽

Fermentable Sugars ◽

Hordeum Vulgare L ◽

Box Behnken Design ◽

Hydrolysis Of

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Integration of Subcritical Water and Enzymatic Hydrolysis to Obtain Fermentable Sugars and Second-Generation Ethanol from Sugarcane Straw

BioEnergy Research ◽

10.1007/s12155-021-10274-4 ◽

2021 ◽

Author(s):

T. C. G. Oliveira ◽

M. A. Interlandi ◽

K. E. Hanlon ◽

P. C. Torres-Mayanga ◽

M. A. C. Silvello ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Second Generation ◽

Subcritical Water ◽

Fermentable Sugars ◽

Sugarcane Straw ◽

Second Generation Ethanol

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Analytical Characterization of Water-Soluble Constituents in Olive-Derived By-Products

Foods ◽

10.3390/foods10061299 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1299

Author(s):

Pablo Doménech ◽

Aleta Duque ◽

Isabel Higueras ◽

José Luis Fernández ◽

Paloma Manzanares

Keyword(s):

Olive Tree ◽

Mediterranean Area ◽

Water Soluble ◽

Olive Pomace ◽

Olive Leaves ◽

Olive Stone ◽

Olive Trees ◽

Tree Pruning ◽

By Products

Olive trees constitute one of the largest agroindustries in the Mediterranean area, and their cultivation generates a diverse pool of biomass by-products such as olive tree pruning (OTP), olive leaves (OL), olive stone (OS), and extracted olive pomace (EOP). These lignocellulosic materials have varying compositions and potential utilization strategies within a biorefinery context. The aim of this work was to carry out an integral analysis of the aqueous extractives fraction of these biomasses. Several analytical methods were applied in order to fully characterize this fraction to varying extents: a mass closure of >80% was reached for EOP, >76% for OTP, >65% for OS, and >52% for OL. Among the compounds detected, xylooligosaccharides, mannitol, 3,4-dihydroxyphenylglycol, and hydroxytyrosol were noted as potential enhancers of the valorization of said by-products. The extraction of these compounds is expected to be more favorable for OTP, OL, and EOP, given their high extractives content, and is compatible with other utilization strategies such as the bioconversion of the lignocellulosic fraction into biofuels and bioproducts.

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Production of Microfibrillated Cellulose from Fast-Growing Poplar and Olive Tree Pruning by Physical Pretreatment

Applied Sciences ◽

10.3390/app11146445 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6445

Author(s):

David Ibarra ◽

Raquel Martín-Sampedro ◽

Bernd Wicklein ◽

Úrsula Fillat ◽

María E. Eugenio

Keyword(s):

Negative Impact ◽

Raw Materials ◽

Olive Tree ◽

Barrier Properties ◽

Microfibrillated Cellulose ◽

Mechanical Resistance ◽

Fast Growing ◽

Wide Range ◽

Pfi Refining ◽

Tree Pruning

Motivated by the negative impact of fossil fuel consumption on the environment, the need arises to produce materials and energy from renewable sources. Cellulose, the main biopolymer on Earth, plays a key role in this context, serving as a platform for the development of biofuels, chemicals and novel materials. Among the latter, micro- and nanocellulose have been receiving increasing attention in the last few years. Their many attractive properties, i.e., thermal stability, high mechanical resistance, barrier properties, lightweight, optical transparency and ease of chemical modification, allow their use in a wide range of applications, such as paper or polymer reinforcement, packaging, construction, membranes, bioplastics, bioengineering, optics and electronics. In view of the increasing demand for traditional wood pulp (e.g., obtained from eucalypt, birch, pine, spruce) for micro/nanocellulose production, dedicated crops and agricultural residues can be interesting as raw materials for this purpose. This work aims at achieving microfibrillated cellulose production from fast-growing poplar and olive tree pruning using physical pretreatment (PFI refining) before the microfibrillation stage. Both raw materials yielded microfibrillated cellulose with similar properties to that obtained from a commercial industrial eucalypt pulp, producing films with high mechanical properties and low wettability. According to these properties, different applications for cellulose microfibers suspensions and films are discussed.

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