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

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

2020 ◽  
Vol 10 (21) ◽  
pp. 7638
Author(s):  
Vasile-Florin Ursachi ◽  
Gheorghe Gutt

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).


2021 ◽  
Author(s):  
Youshan Sun ◽  
Xuyang Zhang ◽  
Fei Wang ◽  
Meiyan Wang

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.


2011 ◽  
Vol 236-238 ◽  
pp. 1431-1436
Author(s):  
Jing Liu ◽  
Katsuya Nagata

Alkaline sulfite/anthraquinone (AS/AQ) pulping of wheat straw under different conditions was conducted in this study. A transition point of kappa number at approximately 6.5 was observed based on all experimental results. This transition point can be regarded as the phase transfer point in AS/AQ pulping from bulk to residual delignification. Effective delignification without great lost of pulp yield can be achieved before kappa number was below this transition point during AS/AQ pulping of wheat straw. It is found that the ratio of cooking liquid to solid should not be lower than 6, if good mass transfer of chemicals and lignin dissolving is needed. As the ratio of Na2SO3 to NaOH dosage ranged from 0.4 to 2.4, low proportion of Na2SO3 allows effective delignification while no serious degradation of carbohydrate. Moreover, similar to kraft pulping, addition of AQ in the range of 0.05% to 0.25% is useful to remove lignin and protect the carbohydrate during AS/AQ pulping. Finally, although the transition point of kappa number may be changed while different raw material used for same pulping process or different pulping process for same raw materials, it is of interest and important for mill practice.


2011 ◽  
Vol 239-242 ◽  
pp. 102-107
Author(s):  
Jin Bao Li ◽  
Mei Yun Zhang ◽  
Hui Juan Xiu ◽  
Yun Zhang

During the wet PU, PVC synthetic production, MCC could be served as a good micropore and thickening agents, and could obviously enhance the feel and elasticity of synthetic leather, but cotton pulp and wood pulp resources, which were used as raw material commonly to produce MCC for synthetic leather, was limited. In this paper, MCC was prepared with wheat straw pulp through the dilute acid hydrolysis, alkali treatment, enzyme treatment, drying and crushing. This paper focused on the effect of conditions of acid hydrolysis on performance of MCC, and the optimization of process parameters. The morphology, size, crystallinity and thermostability of MCC were characterized by scanning electron microscopy, X-ray diffraction, TGA spectrograph. Wheat Straw MCC could meet the requirements of synthetic leather industry standards for MCC.


2015 ◽  
Vol 17 (3) ◽  
pp. 89-94 ◽  
Author(s):  
Małgorzata Smuga-Kogut ◽  
Arkadiusz D. Wnuk ◽  
Kazimiera Zgórska ◽  
Mariusz S. Kubiak ◽  
Janusz Wojdalski ◽  
...  

Abstract This study proposes a method for the production of ethanol from wheat straw lignocellulose where the raw material is chemically processed before hydrolysis and fermentation. The usefulness of wheat straw delignification was evaluated with the use of a 4:1 mixture of 95% ethanol and 65% HNO3 (V). Chemically processed lignocellulose was subjected to enzymatic hydrolysis to produce reducing sugars, which were converted to ethanol in the process of alcoholic fermentation. Chemical processing damages the molecular structure of wheat straw, thus improving ethanol yield. The removal of lignin from straw improves fermentation by eliminating lignin’s negative influence on the growth and viability of yeast cells. Straw pretreatment facilitates enzymatic hydrolysis by increasing the content of reducing sugars and ethanol per g in comparison with untreated wheat straw.


Author(s):  
Daniel Sulzenbacher ◽  
Denise Atzmüller ◽  
Felix Hawe ◽  
Manuela Richter ◽  
Alvaro Cristobal-Sarramian ◽  
...  

AbstractUsing lignocellulosic raw materials as substrate for biotechnological applications has been a focus of research during the last two decades. They contain sugars, which can be used in industrial fermentation processes, in from of polysaccharides (cellulose, hemicellulose). Wheat straw, one representative of lignocellulosic materials, is sustainably and abundantly available, especially in Europe and North America. However, wheat straw, just like any other lignocellulosic material, needs to be pretreated in one way or the other in order to generate sufficient quantities of monosaccharides. One widely used pretreatment for lignocellulosic material is steam explosion combined with enzymatic hydrolysis. In this study, the effects of steam exploding wheat straw in combination with water are presented. By impregnation with water, saccharide yields from subsequent enzymatic hydrolysis increased from 18.8 to 22.6 g L−1 for glucose and 13.8 to 16.4 g L−1 for xylose, respectively. Moreover, the basic steam explosion parameters residence time and temperature were optimized in ranges from 5 to 20 min and 180–200 °C. This further optimization increased the maximum saccharide yield to 41.2 g L−1 for glucose (200 °C, 15 min) and 18.9 g L−1 for xylose (190 °C, 10 min). Finally, the growth of the intensively investigated biotechnological production host Yarrowia lipolytica on hydrolysates derived from different steam explosion parameters was evaluated. Y. lipolytica grew well in media containing up to 90% wheat straw hydrolysate as sole carbon source, demonstrating the potential as substrate for biotechnological processes.


Author(s):  
V. S. Boltovsky

Plant raw materials are practically an inexhaustible natural resource, since they are constantly renewed in the process of plant photosynthesis, which determines the prospects for their use for industrial processing in various ways, including hydrolytic. The main biopolymer components of plant biomass in terms of their quantitative content are polysaccharides, the hydrolytic processing of which by acidic or enzymatic hydrolysis leads to the formation of monosaccharides and various products obtained from them. This review of scientific literature analyzes theoretical concepts and the current state of research on the development, improvement and prospects for the use of enzymatic hydrolysis of plant raw materials. The efficiency of this process and the composition of the resulting products largely depend on the features of the supramolecular structure of cellulose, the content of hemicelluloses and lignin in the raw material, the balance and activity of the cellulase complex of enzymes. It is shown that the main directions of development and improvement of the processes of enzymatic hydrolysis of plant raw materials at present are the production and use of more effective strains of microorganisms that produce highly active enzymes, the directed creation of complex enzymes (hydrolyzing not only cellulose, but also hemicellulose, as well as destroying lignin), the development of methods for pretreatment of raw materials to increase the reactivity of cellulose and remove lignin and improve the processes of fermentolysis.


2021 ◽  
pp. 309-317
Author(s):  
Leysan Azatovna Mingazova ◽  
Yelena Vyacheslavovna Kryakunova ◽  
Zosia Albertovna Kanarskaya ◽  
Альберт Владимирович Kanarskiy ◽  
Igor' Vadimovich Kruchina-Bogdanov ◽  
...  

The aim of this work is to develop a technology for the preparation of neutral-sulfite liquors formed during the production of fibrous semi-finished products - cellulose from birch wood - for subsequent use as a nutrient medium for the cultivation of microorganisms. Acid hydrolysis was carried out at a temperature of 100 °С at a ratio of a 10% sulfuric acid solution to a liquor sample of 1 : 1. Enzymatic hydrolysis of neutral sulfite liquors was carried out with the enzyme preparations Accellerase XY and Accellerase XC at 50±2 °C and 60±2 °C. The end of hydrolysis was determined by the cessation of the increase in the content of reducing substances (RS) in the hydrolyzate. The original neutral sulphite lye contained 9.4% dry matter, 21.7 g/l of reducing substances, pH 5.3±0.2. It has been shown that as a result of enzymatic hydrolysis, the content of insoluble dry residue in the hydrolyzate decreases to 8.32% and 8.41%, respectively, and during acid hydrolysis – to 7.8%. The content of RS in neutral sulfite lye after acid hydrolysis increases by an average of 3 times, while after enzymatic hydrolysis - a maximum of 2 times. It was found by gas-liquid chromatography that pentoses predominate in the obtained hydrolysates. Microbiological processing of media with a similar carbohydrate composition is possible by a number of strains of microorganisms capable of assimilating pentoses, for example, yeast-like fungi of the Saccharomycetaceae family and bacteria of the Enterobacteriaceae family.


Author(s):  
Lyubov Mikhailovna Esina ◽  
Valeriia Victorovna Bogomolova ◽  
Olga Nikolaevna Krivonos ◽  
Svetlana Leonidovna Chernyavskaya

Pipelines, mechanisms and hydraulic structures laid on the bottom of freshwater bodies are exposed to massive exposure of fouling organisms - mollusks Dreissena polymorpha . Such fouling hinders the equipment operation and increases the corrosion of materials, besides, utilization of mollusks ( Dreissena polymorpha ) requires financial expenditure. Therefore, to solve the problem, dreissena was suggested to be used as a raw material for producing enzymatic hydrolyzate. The data of the mass-size and chemical composition of the raw materials (dreissena flesh) are presented. During the analysis of the model of a 2-factor experiment (the amount of enzyme preparation and the duration of fermentolysis were taken as factors) there was defined the optimal amount of enzyme (bacterial protease - protozyme). The comparative analysis of a control sample (without adding the enzyme) and enzymatic hydrolyzates of dreissena was carried out. There was stated the increase in protein content (3.7-17.8%), in dry matter (7.0-22.7%), amine nitrogen (446.2-158.6 mg/100 g). The periods of the most intensive increase in the degree of hydrolysis (during the first 2 hours of enzymatic hydrolysis by 2.8% and further 3-4 hours by 1.2%), as well as periods of values stabilization (during 2-3 hours and after 4 hours of enzymatic hydrolysis an increase by 0.6% on average). The change in the optical density of hydrolyzate solutions and their TCA-filtrates has been studied, which helped to compare the degree of protein destruction. There has been presented the technological chart of producing enzymatic hydrolyzates from dreissena with following conditions for fermentolysis: temperature 50 ºС, water ratio 1:1, quantity of enzyme protozyme 0.1% to the mass of blanched dreissena with valves, duration 3-4 hours.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 388
Author(s):  
Hamayoun Mahmood ◽  
Saqib Mehmood ◽  
Ahmad Shakeel ◽  
Tanveer Iqbal ◽  
Mohsin Ali Kazmi ◽  
...  

Glycerol pretreatment is a promising method for the environmentally-friendly transformation of lignocellulosic materials into sustainable cellulose-rich raw materials (i.e., biopolymer) to fabricate biocomposites. Here, a comparison of aqueous acidified glycerol (AAG) pretreatment of wheat straw (WS) with alkaline, hot water, and dilute acid pretreatments on the thermal and mechanical characteristics of their fabricated composite board is presented. A comparison of total energy expenditure during WS pretreatment with AAG and other solutions was estimated and a comparative influence of AAG processing on lignocellulosic constituents and thermal stability of WS fiber was studied. Results imply that AAG pretreatment was superior in generating cellulose-rich fiber (CRF) as compared to other pretreatments and enhanced the cellulose contents by 90% compared to raw WS fiber. Flexural strength of acidic (40.50 MPa) and hot water treated WS composite (38.71 MPa) was higher compared to the value of 33.57 MPa for untreated composite, but AAG-treated composites exhibited lower values of flexural strength (22.22 MPa) compared to untreated composite samples. Conversely, AAG pretreatment consumed about 56% lesser energy for each kg of WS processed as compared to other pretreatments. These findings recognize that glycerol pretreatment could be a clean and new pretreatment strategy to convert agricultural waste into high-quality CRF as a sustainable raw material source for engineered biocomposite panels.


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