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 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 Calcium peroxide pretreatment to facilitate the delignification and enzymatic hydrolysis of wheat straw

2021 ◽  
Author(s):  
Youshan Sun ◽  
Xuyang Zhang ◽  
Fei Wang ◽  
Meiyan Wang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Complex Structure ◽  
Raw Material ◽  
Liquid Ratio ◽  
Enzymatic Digestibility ◽  
Calcium Peroxide ◽  
Glucose Recovery ◽  
Solid Liquid ◽  
Hydrolysis Of

Abstract Calcium peroxide (CaO2) pretreatment was employed to remove lignin and subsequently facilitate enzymatic digestibility of wheat straw. An optimal condition was obtained at 130°C for 10 min with 0.35 g CaO2/g dried material of wheat straw and a 1:8 solid-liquid ratio. Under this condition, 57.8% of initial lignin, 7.2% of initial glucan, and 30.6% of initial xylan were removed from CaO2 pretreatment, respectively, meanwhile, a glucose recovery of 90.6 % and a xylose recovery of 65.9 % were obtained from the subsequent enzymatic hydrolysis of treated wheat straw, respectively. CaO2 pretreatment was proved to be a very effective method in delignification and improving enzymatic digestibility. Compared to raw material, the complex structure of lignocellulose was drastically disrupted with a wide emergence of scaly bulges and fully exposed microfibers, which still retained in the solid.

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.

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.

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 TECHNOLOGY AND EQUIPMENT FOR PROCESSING ACTIVATED AGRICULTURAL PLANT WASTE INTO BIOETHANOL

2022 ◽  
Vol 16 (4) ◽  
pp. 59-67
Author(s):  
Dmitriy Prosvirnikov ◽  
Denis Tuncev ◽  
Bulat Ziganshin
Keyword(s):  
Enzymatic Hydrolysis ◽  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Raw Materials ◽  
Raw Material ◽  
Pine Wood ◽  
Agricultural Plant ◽  
Plant Waste ◽  
Hydrolysis Temperature ◽  
Reducing Substances

The article is devoted to the development of technology and equipment for the production of bioethanol from agricultural plant waste, activated by the steam explosion method. The value and novelty of research lies in obtaining new data on the effective acidic and enzymatic hydrolysis of activated raw materials, and developing a technology for the conversion of plant raw materials into bioethanol. The studies were carried out on the basis of the Department of Wood Materials Processing of Kazan National Research Technological University (Republic of Tatarstan, Kazan). A pilot plant for the production of bioethanol and the principle of its operation are presented. Pine wood waste and wheat straw (collected in Kukmor region of the Republic of Tatarstan in the period August-September 2021) were used as raw materials. Steam-explosive activation of raw materials was carried out at temperatures of 165 ⁰C and 210 ⁰C for 5 minutes. Acid hydrolysis parameters: H2SO4 concentration - 0.5% and 1.5%, hydromodule 1:15, hydrolysis temperature - 187⁰C, hydrolysis duration - 5 hours. Enzymatic hydrolysis parameters: preparation - Cellulox-A (OOO PO Sibbiopharm, Russia) - 6 and 12 g/kg of raw material, hydrolysis temperature - 45 ⁰C, substrate pH 4.7 (acetate buffer), raw material concentration in the substrate 33 g/l, the duration of hydrolysis is 72 h. Alcoholic fermentation of hydrolysates was carried out at 32-34⁰C using Saccharomyces cerevisiae yeast, fermentation duration 7 h, yeast concentration 25 g/l. The bioethanol yield in % of reducing substances was recalculated after determining the mass yield. It is concluded that the vapor-explosive activation of pine wood at a temperature of 210 ºC makes it possible to obtain by acid hydrolysis and anaerobic fermentation of reducing substances up to 0.26 kg (0.33 l) of ethanol from 1 kg of activated raw materials, and activation of wheat straw at the same temperature allows obtaining up to 0.172 kg (0.218 l) ethanol with 1 kg of activated straw

Fractionation of broom (Cytisus striatus) biomass components via mild sulfite pretreatment and enzymatic hydrolysis

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 118-140
Author(s):  
Tânia P. Gomes ◽  
Vera L. D. Costa ◽  
Álvaro F. C. Vaz ◽  
Rogério M. S. Simões
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
High Performance ◽  
Raw Material ◽  
Maximum Temperature ◽  
Solid Residue ◽  
Reaction Conditions ◽  
Positive Role ◽  
Biomass Components ◽  
Pretreatment Conditions

The potential of broom biomass to produce oligo- and monosaccharides was investigated using mild sulfite pretreatment conditions followed by enzymatic hydrolysis. Both treatments were analyzed via response surface methodology using an experimental central composite rotatable design 24 + star, which explored the following variables: sulfuric acid charge (0% to 3%), sodium sulfite charge (0% to 4%, maximum temperature (150 °C to 190 °C), and time at maximum temperature (0 min to 30 min). Oligo- and monosaccharides in the pretreatment hydrolysates were determined using high performance liquid chromatography. The amount of total extracted xylose, mannose, and galactose ranged from 3.5% to 15.8% of the initial biomass, while the model estimated optimal reaction conditions enabled the extraction of practically all hemicellulose in the raw material. However, the mildest pretreatment reaction conditions, with low temperature and low sulfuric acid charges, provided a hydrolysate where a major part of the extracted polysaccharides remained in oligomer form, enabling their separation by filtration. The cellulose-rich solid residue was submitted to enzymatic hydrolysis using a Novozymes® enzymatic cocktail. The enzymatic hydrolysis was successful, but some polysaccharides remained in the solid residue, mainly composed of lignin. An enzymatic yield of 60% was attained with no added sulfite in the pretreatment at 190 °C, despite the confirmed positive role of sulfur content in the solid residues.

scholarly journals A New and Environmentally Friendly Route for Preparation of Carbon Microspheres from Wheat Straw

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Chen Leishan ◽  
Wang Cunjing ◽  
Miao Yu ◽  
Chen Gairong
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Wheat Straw ◽  
Carbon Materials ◽  
Hydrothermal Carbonization ◽  
Raw Material ◽  
Carbon Microspheres ◽  
Liquid Ratio ◽  
Solid Liquid ◽  
Scanning Electron

The reactions were performed to synthesize carbon materials using wheat straw powder as raw material. The wheat straw powder was first hydrolyzed at the absence of a catalyst at 190°C for 1 h, then the hydrolyzate solution was used as carbon source to prepare carbon materials via hydrothermal carbonization at 180°C in the absence of a catalyst for 8 h. The influence of solid-liquid-ratio of wheat straw to water on the morphology of the product was investigated. The samples were examined by a scanning electron microscope and Fourier transform infrared spectroscopy. The results show that the product was carbon microspheres with a large number of O–H, CHO, and other functional groups, and the diameters of carbon microspheres noticeably depended on the solid-liquid ratio. When the solid-liquid ratio was 1 : 60, the diameters of carbon microspheres were in the range of 100 to 300 nm when the solid-liquid ratio was 1 : 40, carbon microspheres with larger and more uniform diameters mostly about 250 nm were obtained, and when the solid-liquid-ratio was 1 : 20, there were more larger carbon microspheres with diameters about 800 nm in the product and the surface of these carbon microspheres is smoother, whereas; the uniformity of the product deteriorates.

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