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.

scholarly journals Production of Cellulosic Ethanol from Enzymatically Hydrolysed Wheat Straws

2020 ◽  
Vol 10 (21) ◽  
pp. 7638
Author(s):  
Vasile-Florin Ursachi ◽  
Gheorghe Gutt
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Cellulosic Ethanol ◽  
Raw Material ◽  
High Yield ◽  
Liquid Ratio ◽  
Hydrolysis Process ◽  
Pretreatment Conditions ◽  
Pretreated Wheat Straw ◽  
First Time

The aim of this study is to find the optimal pretreatment conditions and hydrolysis in order to obtain a high yield of bioethanol from wheat straw. The pretreatments were performed with different concentrations of sulphuric acid 1, 2 and 3% (v/v), and were followed by an enzymatic hydrolysis that was performed by varying the solid-to-liquid ratio (1/20, 1/25 and 1/30 g/mL) and the enzyme dose (30/30 µL/g, 60/60 µL/g and 90/90 µL/g Viscozyme® L/Celluclast® 1.5 L). This mix of enzymes was used for the first time in the hydrolysis process of wheat straws which was previously pretreated with dilute sulfuric acid. Scanning electron microscopy indicated significant differences in the structural composition of the samples because of the pretreatment with H2SO4 at different concentrations, and ATR-FTIR analysis highlighted the changes in the chemical composition in the pretreated wheat straw as compared to the untreated one. HPLC-RID was used to identify and quantify the carbohydrates content resulted from enzymatic hydrolysis to evaluate the potential of using wheat straws as a raw material for production of cellulosic ethanol in Romania. The highest degradation of lignocellulosic material was obtained in the case of pretreatment with 3% H2SO4 (v/v), a solid-to-liquid ratio of 1/30 and an enzyme dose of 90/90 µL/g. Simultaneous saccharification and fermentation were performed using Saccharomyces cerevisiae yeast, and for monitoring the fermentation process a BlueSens equipment was used provided with ethanol, O2 and CO2 cap sensors mounted on the fermentation flasks. The highest concentration of bioethanol was obtained after 48 h of fermentation and it reached 1.20% (v/v).

scholarly journals Toward Biochemical Conversion of Lignocellulose On-Farm: Pretreatment and Hydrolysis of Corn Stover in Situ

2017 ◽  
Vol 60 (4) ◽  
pp. 1025-1033
Author(s):  
Alicia A. Modenbach ◽  
Sue E. Nokes ◽  
Michael D. Montross ◽  
Barbara L. Knutson
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Conversion Efficiency ◽  
High Solids ◽  
Cellulose Conversion ◽  
Biochemical Conversion ◽  
High Solids Loading ◽  
Combined Pretreatment ◽  
Pretreatment Conditions ◽  
On Farm

Abstract. High-solids lignocellulosic pretreatment using NaOH followed by high-solids enzymatic hydrolysis was evaluated for an on-farm biochemical conversion process. Increasing the solids loadings for these processes has the potential for increasing glucose concentrations and downstream ethanol production; however, sequential processing at high-solids loading similar to an on-farm cellulose conversion system has not been studied. This research quantified the effects of high-solids pretreatment with NaOH and subsequent high-solids enzymatic hydrolysis on cellulose conversion. As expected, conversion efficiency was reduced; however, the highest glucose concentration (40.2 g L-1), and therefore the highest potential ethanol concentration, resulted from the high-solids combined pretreatment and hydrolysis. Increasing the enzyme dosage improved cellulose conversion from 9.6% to 36.8% when high-solids loadings were used in both unit operations; however, increasing NaOH loading and pretreatment time did not increase the conversion efficiency. The enzyme-to-substrate ratio had a larger impact on cellulose conversion than the NaOH pretreatment conditions studied, resulting in recommendations for an on-farm bioconversion system. Keywords: Corn stover, Enzymatic hydrolysis, Enzyme loading, High solids, Low solids, Sodium hydroxide.

Application of a microassay method to study enzymatic hydrolysis of pretreated wheat straw

2010 ◽  
Vol 85 (9) ◽  
pp. 1291-1297 ◽  
Author(s):  
Pablo Alvira ◽  
María José Negro ◽  
Felicia Sáez ◽  
Mercedes Ballesteros
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Pretreated Wheat Straw ◽  
Hydrolysis Of

scholarly journals Optimization of alkali pretreatment of wheat straw to be used as substrate for biofuels production  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 537-542 ◽  
Author(s):  
K. Jaisamut ◽  
L. Paulová ◽  
P. Patáková ◽  
M. Rychtera ◽  
K. Melzoch
Keyword(s):  
Response Surface Methodology ◽  
Enzymatic Hydrolysis ◽  
Sodium Hydroxide ◽  
Wheat Straw ◽  
Response Surface ◽  
Fermentable Sugars ◽  
Alkali Pretreatment ◽  
The Media ◽  
Pretreatment Conditions ◽  
Expert Designer

Alkali pretreatment of wheat straw was optimized by response surface methodology to maximize yields of fermentable sugars in subsequent enzymatic hydrolysis and to remove maximum lignin in order to improve rheological attributes of the media. The effects of pretreatment conditions on biomass properties were studied using the Expert Designer software. Concentration of sodium hydroxide and temperature were the factors most affecting pretreatment efficiency. At the optimum (80°C, 39 min, 0.18 g NaOH and 0.06 g lime per g of raw biomass), 93.1 ± 1.0% conversion of cellulose to glucose after enzymatic hydrolysis and 80.3 ± 1.2% yield of monosaccharides (glucose plus xylose and arabinose) from cellulose and hemicellulose of wheat straw were achieved.

Ethanol Production From Steam-Explosion Pretreated Wheat Straw

2006 ◽  
Vol 130 (1-3) ◽  
pp. 496-508 ◽  
Author(s):  
Ignacio Ballesteros ◽  
Ma José Negro ◽  
Jose Miguel Oliva ◽  
Araceli Cabanas ◽  
Paloma Manzanares ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Wheat Straw ◽  
Steam Explosion ◽  
Pretreated Wheat Straw

scholarly journals Production of Carbohydrates from Cardoon Pre-Treated by Acid-Catalyzed Steam Explosion and Enzymatic Hydrolysis

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4288 ◽  
Author(s):  
Alessandro Bertini ◽  
Mattia Gelosia ◽  
Gianluca Cavalaglio ◽  
Marco Barbanera ◽  
Tommaso Giannoni ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Steam Explosion ◽  
Degradation Products ◽  
Liquid Fraction ◽  
Raw Material ◽  
Total Carbohydrate ◽  
Carbohydrate Degradation ◽  
Acid Catalyzed ◽  
Pre Treatment

Cardoon (Cynara cardunculus) is a promising crop from which to obtain oilseeds and lignocellulosic biomass. Acid-catalyzed steam explosion is a thermochemical process that can efficiently pre-treat lignocellulosic biomass. The drawback is the production of a high number of carbohydrate degradation products in the liquid fraction that could inhibit microbial growth. In this work, the lignocellulosic biomass of cardoon, gathered from a dedicated field, were used as the raw material for the production of fermentable monosaccharides by employing acid-catalyzed steam explosion. The raw material was pre-soaked with a dilute 1% (w/w) sulfuric acid solution and then subjected to steam explosion under three different severity conditions. The recovered slurry was separated into solid and liquid fractions, which were individually characterized to determine total carbohydrate and inhibitor concentrations. The slurry and the washed solid fraction underwent enzymatic hydrolysis to release glucose and pentose monosaccharides. By conducting the pre-treatment at 175 °C for 35 min and hydrolyzing the obtained slurry, a yield of 33.17 g of monosaccharides/100 g of cardoon was achieved. At the same conditions, 4.39 g of inhibitors/100 g of cardoon were produced.

scholarly journals Reduction of surface area of lignin improves enzymatic hydrolysis of cellulose from hydrothermally pretreated wheat straw

RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36591-36596 ◽  
Author(s):  
M. H. Sipponen ◽  
V. Pihlajaniemi ◽  
O. Pastinen ◽  
S. Laakso
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Surface Area ◽  
Lignin Content ◽  
Cellulose Conversion ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Pretreated Wheat Straw ◽  
Hydrolysis Of

24 h enzymatic hydrolysis (15 FPU g−1) of solid residues from wheat straw autohydrolysis. Cellulose conversion as a function of lignin content (left) or lignin surface area (right) in solid residues.

scholarly journals Implementation of Auto-Hydrolysis Process for the Recovery of Antioxidants and Cellulose from Wheat Straw

2020 ◽  
Vol 10 (17) ◽  
pp. 6112 ◽  
Author(s):  
Andrea Bassani ◽  
Cecilia Fiorentini ◽  
Vellingiri Vadivel ◽  
Alessandro Moncalvo ◽  
Giorgia Spigno
Keyword(s):  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Degradation Products ◽  
Cost Effective ◽  
Point Of View ◽  
Full Potential ◽  
Cellulose Yield ◽  
Whole Process ◽  
Hydrolysis Process ◽  
Environmentally Friendly Process

Wheat straw is an easily affordable, cost-effective and natural source of antioxidants and cellulose, but its full potential is not yet utilized. In the present investigation, an auto-hydrolytic process was applied to recover both antioxidant phenolic compounds and cellulose from wheat straw. Two three-step acid/alkaline fractionation processes were applied differing for the first step: a conventional mild acid hydrolysis or an auto-hydrolysis. The liquors from the first step were analyzed for the recovery of antioxidants, while the final residues from the whole process were analyzed for cellulose yield and purity. The auto-hydrolysis process led to a higher yield in antioxidants but also in sugars (glucose and xylose) and sugar degradation products (5-HMF, 5-MF, furfural) than the acid hydrolysis process. The overall cellulose recovery (about 45% g/100 gcellulose wheat straw dm) and purity was comparable in the two processes; therefore, the auto-hydrolysis-based process could be recommended as a potentially more environmentally friendly process to recover antioxidants and cellulose from wheat straw for different applications. Finally, a first study on the optimization of hydrolysis step was provided from the point of view of improving the cellulose yield, monitoring the sugars release during both the acid hydrolysis and the auto-hydrolysis process.

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