scholarly journals Steam explosion of wood particles from fibreboard and particle board with indirect control by enzymatic hydrolysis

2019 ◽  
Vol 12 (2) ◽  
pp. 185-191
Author(s):  
Andrej Pažitný
Keyword(s):  
Enzymatic Hydrolysis ◽  
Steam Explosion ◽  
Lignocellulosic Materials ◽  
Particle Board ◽  
Severity Factor ◽  
Cellulose Accessibility ◽  
Indirect Control ◽  
Commercial Enzymes ◽  
Wood Particles ◽  
Pretreatment Conditions

Abstract Pretreatment of particles obtained from lignocellulosic materials by steam explosion with indirect control by enzymatic hydrolysis has been studied. The dendromass pretreatment model has been applied for recycled fibreboard and particle board based on softwood. Their structure and chemical composition partly predetermine these lignocellulosic materials consisting of a mixture of spruce and fir particles also for bioethanol production. Optimum steam explosion temperature of 205 °C was determined based on the concentration of total monosaccharides — glucose, xylose and arabinose, among all experimentally prepared hydrolysates. This corresponds to basic conditions for fine disintegration of biomass to lignocellulosic structure with good holocellulose accessibility. Particles obtained from fibreboard and particle board primarily consisting of softwood without steam explosion pretreatment provide relatively low cellulose accessibility for commercial enzymes activity while monosaccharides concentration is partly reduced because of torrefaction at high temperatures. The concentration of monosaccharides in hydrolysates was determined for original sample and each steam explosion temperature. Based on the steam explosion conditions, the effect of severity factors was investigated to find optimum pretreatment conditions to increase accessibility of softwood cellulose and hemicelluloses. The identified optimum severity factor RO = 4.09 matches the optimum steam explosion temperature of 205 °C and the residence time of 10 minutes.

scholarly journals Effects on Lignin Redistribution in Eucalyptus globulus Fibres Pre-Treated by Steam Explosion: A Microscale Study to Cellulose Accessibility

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Eucalyptus Globulus ◽  
Steam Explosion ◽  
Laser Scanning ◽  
Structural Changes ◽  
Micro Particles ◽  
Cellulose Accessibility ◽  
Ft Ir ◽  
Enzymatic Accessibility ◽  
Physical And Chemical

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.

Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Fokko Schütt ◽  
Jürgen Puls ◽  
Bodo Saake
Keyword(s):  
Enzymatic Hydrolysis ◽  
Raw Material ◽  
Steam Pretreatment ◽  
Alkaline Extraction ◽  
Poplar Wood ◽  
Steam Refining ◽  
Severity Factor ◽  
Short Rotation ◽  
Pretreatment Conditions ◽  
Hydrolysis Of

Abstract Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.

scholarly journals Steam Explosion Pretreatment of Beechwood. Part 1: Comparison of the Enzymatic Hydrolysis of Washed Solids and Whole Pretreatment Slurry at Different Solid Loadings

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3653 ◽  
Author(s):  
Robert Balan ◽  
Andrzej Antczak ◽  
Simone Brethauer ◽  
Tomasz Zielenkiewicz ◽  
Michael H. Studer
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Steam Explosion ◽  
Optimization Procedure ◽  
Reaction Conditions ◽  
Steam Explosion Pretreatment ◽  
Pretreatment Temperature ◽  
Pretreatment Conditions ◽  
Whole Slurry ◽  
Hydrolysis Of

Steam explosion is a well-known process to pretreat lignocellulosic biomass in order to enhance sugar yields in enzymatic hydrolysis, but pretreatment conditions have to be optimized individually for each material. In this study, we investigated how the results of a pretreatment optimization procedure are influenced by the chosen reaction conditions in the enzymatic hydrolysis. Beechwood was pretreated by steam explosion and the resulting biomass was subjected to enzymatic hydrolysis at glucan loadings of 1% and 5% employing either washed solids or the whole pretreatment slurry. For enzymatic hydrolysis in both reaction modes at a glucan loading of 1%, the glucose yields markedly increased with increasing severity and with increasing pretreatment temperature at identical severities and maximal values were reached at a pretreatment temperature of 230 °C. However, the optimal severity was 5.0 for washed solids enzymatic hydrolysis, but only 4.75 for whole slurry enzymatic hydrolysis. When the glucan loading was increased to 5%, glucose yields hardly increased for pretreatment temperatures between 210 and 230 °C at a given severity, and a pretreatment temperature of 220 °C was sufficient under these conditions. Consequently, it is important to precisely choose the desired conditions of the enzymatic hydrolysis reaction, when aiming to optimize the pretreatment conditions for a certain biomass.

Combined steam-explosion toward vacuum and dilute-acid spraying of wheat straw. Impact of severity factor on enzymatic hydrolysis

2015 ◽  
Vol 78 ◽  
pp. 516-526 ◽  
Author(s):  
Maache-Rezzoug Zoulikha ◽  
Maugard Thierry ◽  
Zhao Jean-Michel Qiuyu ◽  
Armelle Nouviaire ◽  
Rezzoug Sid-Ahmed
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Steam Explosion ◽  
Dilute Acid ◽  
Severity Factor

scholarly journals Steam Explosion Pretreatment of Beechwood. Part 2: Quantification of Cellulase Inhibitors and Their Effect on Avicel Hydrolysis

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3638
Author(s):  
Simone Brethauer ◽  
Andrzej Antczak ◽  
Robert Balan ◽  
Tomasz Zielenkiewicz ◽  
Michael H. Studer
Keyword(s):  
Acetic Acid ◽  
Enzymatic Hydrolysis ◽  
Steam Explosion ◽  
Biomass Pretreatment ◽  
Reaction Conditions ◽  
Steam Explosion Pretreatment ◽  
Wide Range ◽  
Pretreatment Conditions ◽  
Whole Slurry ◽  
Hydrolysis Of

Biomass pretreatment is a mandatory step for the biochemical conversion of lignocellulose to chemicals. During pretreatment, soluble compounds are released into the prehydrolyzate that inhibit the enzymatic hydrolysis step. In this work, we investigated how the reaction conditions in steam explosion pretreatment of beechwood (severity: 3.0–5.25; temperature: 160–230 °C) influence the resulting amounts of different inhibitors. Furthermore, we quantified the extent of enzyme inhibition during enzymatic hydrolysis of Avicel in the presence of the prehydrolyzates. The amounts of phenolics, HMF, acetic acid and formic acid increased with increasing pretreatment severities and maximal quantities of 21.6, 8.3, 43.7 and 10.9 mg/gbeechwood, respectively, were measured at the highest severity. In contrast, the furfural concentration peaked at a temperature of 200 °C and a severity of 4.75. The presence of the prehydrolyzates in enzymatic hydrolysis of Avicel lowered the glucose yields by 5–26%. Mainly, the amount of phenolics and xylose and xylooligomers contributed to the reduced yield. As the maximal amounts of these two inhibitors can be found at different conditions, a wide range of pretreatment severities led to severely inhibiting prehydrolyzates. This study may provide guidelines when choosing optimal pretreatment conditions for whole slurry enzymatic hydrolysis.

scholarly journals Sugars Production from Municipal Forestry and Greening Wastes Pretreated by an Integrated Steam Explosion-Based Process

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4432 ◽  
Author(s):  
Maria José Negro ◽  
Cristina Álvarez ◽  
Pablo Doménech ◽  
Raquel Iglesias ◽  
Ignacio Ballesteros
Keyword(s):  
Enzymatic Hydrolysis ◽  
Steam Explosion ◽  
Dilute Acid ◽  
Waste Streams ◽  
Enzyme Loading ◽  
Glucose Yield ◽  
Resource Sustainability ◽  
Solids Loading ◽  
Biological Conversion ◽  
Pretreatment Conditions

Increasing awareness of resource sustainability and waste management has led to the search for solutions while promoting circular economy principles. Among all kinds of lignocellulosic biomass available, one with growing interest is municipal forestry and greening waste (MFGW). MFGW makes up an important part of waste streams of municipal solid waste and is a potential feedstock for biological conversion in a lignocellulosic biorefinery. This work studied the fermentable sugars production from MFGW after steam explosion (SE) pretreatment combined with other pretreatments such as dilute acid, organosolv, and metal salts. A range of pretreatment conditions was evaluated according to different parameters: sugars recovery, degradation product generation, and enzymatic hydrolysis yield. At selected pretreatment conditions (diluted acid plus SE, 195 °C, 10 min, and 60 mg H2SO4/g MFGW), 77% of potential sugars content in MFGW was obtained. The effect of solids loading and enzyme dose on glucose release and glucose yield on enzymatic hydrolysis were also determined. Up to 70% of the main sugars in the MFGW were recovered for the coupled pretreatment and enzymatic hydrolysis (45 FPU/g glucan enzyme loading and 20% dry matter solid consistency), resulting in 80 g/L glucose that could be further utilized for ethanol production.

scholarly journals Comparison of the susceptibility of two hardwood species, Mimosa scabrella Benth and Eucalyptus viminalis labill, to steam explosion and enzymatic hydrolysis

2000 ◽  
Vol 43 (2) ◽  
pp. 195-206 ◽  
Author(s):  
L. P. Ramos ◽  
S. T. Carpes ◽  
F. T. Silva ◽  
J. L. M. Ganter
Keyword(s):  
Enzymatic Hydrolysis ◽  
Acid Hydrolysis ◽  
Steam Explosion ◽  
Acid Catalyst ◽  
Water Soluble ◽  
Steam Treatment ◽  
Eucalyptus Viminalis ◽  
Hardwood Species ◽  
Pretreatment Conditions ◽  
By Products

Steam explosion of two hardwood species was carried out with and without addition of sulfuric acid (H2SO4 0.5%, p/v) as a pretreatment catalyst. In general, wood chips of Eucalyptus viminalis Labill were shown to be more amenable to pretreatment than chips derived from bolds of Mimosa scabrella Benth (bracatinga). This was apparent from all pretreatment parameters tested including the overall recovery yields of pretreated fractions, carbohydrates (pentoses and hexoses) recovered as water-solubles, yield of dehydration by-products and lignin susceptibility to acid hydrolysis. There was no evidence for complete deacetylation of both wood species during pretreatment and lignin appeared to undergo extensive acid hydrolysis at higher pretreatment severities. Steam treatment at 205ºC for 5 min without addition of an acid catalyst was shown to be uncapable of removing the hemicellulose component from bracatinga chips, as determined by chemical analysis of the steam-treated water-insoluble fractions. Nearly 30% of the hemicellulose (xylan) found in bracatinga remained unhydrolysed after pretreatment, whereas more than 90% of this component could be removed from eucalypt chips under the same pretreatment conditions. Likewise, pretreatment of eucalypt chips resulted in a more extensive solubilization of glucans (cellulose) by acid hydrolysis. Addition of dilute H2SO4 as a pretreatment catalyst generally increased the recovery yield of fermentable sugars in the water-soluble fractions and this effect was more pronounced for the pretreatment of bracatinga chips. Steam-treated substrates produced from bracatinga were also less accessible to enzymatic hydrolysis than those produced from eucalypt chips, regardless of the use of an acid catalyst.

scholarly journals STUDY ON THE CAPABILITY OF BIO-BUTANOL SYNTHESIS FROM SUGARCANE BAGASSE

2011 ◽  
Vol 14 (3) ◽  
pp. 87-96
Author(s):  
Quyen Huynh ◽  
Tuan Dinh Phan
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Steam Explosion ◽  
Cellulose Hydrolysis ◽  
Clostridium Beijerinckii ◽  
Main Concern ◽  
Cellulose Content ◽  
Glucose Yield ◽  
Cellulose Accessibility ◽  
Acetone Butanol Ethanol

The main concern in converting sugarcane bagasse to bio-butanol fuel is the conversion of the polysaccharides by enzymatic breakdown into monosaccharides. This study focused on the use of steam explosion as a pretreatment method. Steam explosion treatment of biomass had been previously used to increase cellulose accessibility [1,3,5,6,8,9]. Following steam explosion pretreatment, sugarcane bagasse was subjected to enzymatic hydrolysis employing the Acremonium Cellulase as the reactant. The sugars released by enzymatic hydrolysis were further fermented by Clostridium Beijerinckii. Raw sugarcane bagasse was found to have the polysaccharides content of 56.24%. The fiber loss during the steam explosion treatment was high, up to 67.11%. Steam explosion treatment on sugarcane bagasse increased the enzymatic hydrolysis capability of cellulose. After steam explosion treatment at temperature of 224oC for 2 minutes, the cellulose hydrolysis conversion efficiency could reach 98.04% by applying Acremonium Cellulase for 72 hours. It has been stated that steam explosion was suitable to improve cellulose content and consequently improve fermentable glucose yield from enzymatic hydrolysis while drastically reducing hemicellulose content of the fibers. Butanol has been successfully produced from the sugarcane bagasse hydrolysate in acetone-butanol-ethanol (ABE) process applying C. Beijerinckii.

scholarly journals Steam Explosion for Wheat Straw Pretreatment for Sugars Production

Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Pablo Alvira ◽  
María José Negro ◽  
Ignacio Ballesteros ◽  
Alberto González ◽  
Mercedes Ballesteros
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Steam Explosion ◽  
Large Scale ◽  
Degradation Products ◽  
Transport Sector ◽  
High Solids Loading ◽  
Hydrolysis Process ◽  
Pretreatment Conditions ◽  
Pretreated Wheat Straw

AbstractDevelopment of biofuels such as lignocellulosic ethanol represents a sustainable alternative in the transport sector. Wheat straw is a promising feedstock for bioethanol production in Europe due to its large production and high carbohydrates content. In a process to produce cellulosic ethanol, previous to the enzymatic hydrolysis to obtain fermentable sugars and the subsequent fermentation, a pretreatment step to break down the recalcitrance of lignocellulose fiber is essential. In this work, a range of steam explosion pretreatment conditions were evaluated according to different parameters: sugars recovery, degradation products generation, and enzymatic hydrolysis yields. Moreover, the enzymatic hydrolysis process was also studied at high substrate loadings, since operating at high solids loading is crucial for large scale development of ethanol production. Pretreatment at 200°C - 10 min resulted in higher enzymatic hydrolysis yield (91.7%) and overall glucose yields (35.4 g glucose/100 g wheat straw) but also higher production of toxic compound. In turn, the characteristics of the pretreated wheat straw at lower severity (Log R0=3.65) correspond to 190°C and 10 min, with minimal sugars degradation and toxics formation indicated a great potential for maximizing total sugars production by using optimal enzyme combinations including accessory enzymes in the enzymatic hydrolysis step.

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