scholarly journals Bioethanol Production by Enzymatic Hydrolysis from Different Lignocellulosic Sources

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 753
Author(s):  
Katja Vasić ◽  
Željko Knez ◽  
Maja Leitgeb
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Fossil Fuels ◽  
Fermentation Process ◽  
Marine Algae ◽  
Cost Effective ◽  
Agricultural Wastes ◽  
Bioethanol Production ◽  
Renewable Sources ◽  
Alternative Sources

As the need for non-renewable sources such as fossil fuels has increased during the last few decades, the search for sustainable and renewable alternative sources has gained growing interest. Enzymatic hydrolysis in bioethanol production presents an important step, where sugars that are fermented are obtained in the final fermentation process. In the process of enzymatic hydrolysis, more and more new effective enzymes are being researched to ensure a more cost-effective process. There are many different enzyme strategies implemented in hydrolysis protocols, where different lignocellulosic biomass, such as wood feedstocks, different agricultural wastes, and marine algae are being used as substrates for an efficient bioethanol production. This review investigates the very recent enzymatic hydrolysis pathways in bioethanol production from lignocellulosic biomass.

scholarly journals Valorization of Alkaline Peroxide Mechanical Pulp by Metal Chloride-Assisted Hydrotropic Pretreatment for Enzymatic Saccharification and Cellulose Nanofibrillation

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 331 ◽  
Author(s):  
Huiyang Bian ◽  
Xinxing Wu ◽  
Jing Luo ◽  
Yongzhen Qiao ◽  
Guigan Fang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Lignin Content ◽  
Enzymatic Saccharification ◽  
Fiber Surface ◽  
Cost Effective ◽  
Metal Chloride ◽  
Fractionation Process ◽  
Metal Chlorides ◽  
Alkaline Peroxide

Developing economical and sustainable fractionation technology of lignocellulose cell walls is the key to reaping the full benefits of lignocellulosic biomass. This study evaluated the potential of metal chloride-assisted p-toluenesulfonic acid (p-TsOH) hydrolysis at low temperatures and under acid concentration for the co-production of sugars and lignocellulosic nanofibrils (LCNF). The results indicated that three metal chlorides obviously facilitated lignin solubilization, thereby enhancing the enzymatic hydrolysis efficiency and subsequent cellulose nanofibrillation. The CuCl2-assisted hydrotropic pretreatment was most suitable for delignification, resulting in a relatively higher enzymatic hydrolysis efficiency of 53.2%. It was observed that the higher residual lignin absorbed on the fiber surface, which exerted inhibitory effects on the enzymatic hydrolysis, while the lower lignin content substrates resulted in less entangled LCNF with thinner diameters. The metal chloride-assisted rapid and low-temperature fractionation process has a significant potential in achieving the energy-efficient and cost-effective valorization of lignocellulosic biomass.

scholarly journals Bioethanol Production from Enzymatic Hydrolyzates of Pretreated Flaxseed Meals by Baker’s Yeast

2021 ◽  
Author(s):  
SAHELI GHOSAL ◽  
JAYATI BHOWAL
Keyword(s):  
Enzymatic Hydrolysis ◽  
Fermentation Process ◽  
Reducing Sugars ◽  
Reducing Sugar ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Bioethanol Production ◽  
Dilute Acid ◽  
Cellulose Conversion ◽  
Flaxseed Meal

Abstract The present study investigated the usefulness of flaxseed meals as a novel feedstock for the production of bioethanol. The proximate composition of the flaxseed meal was carried out before the pretreatment of the flaxseed meal. In this study, flaxseed meal was pretreated with dilute acid, alkali, and aqueous for disruption of lignocellulosic compounds. The acid pretreated flaxseed meal was used for enzymatic hydrolysis by different enzymes (cellulase, α-amylase, and cellulase combined with α-amylase) for better release of reducing sugar. The cellulose conversion to reducing sugar was significantly higher for acid pretreated flaxseed meals. After enzymatic hydrolysis with cellulase, cellulose conversions to reducing sugars were found to be significantly higher than those of α-amylase and cellulase combined with α-amylase. The bioethanol production was also investigated. The fermentation process was carried out by using baker’s yeast (Saccharomyces cerevisiae) with the acid pretreated flaxseed meal enzymatic hydrolyzate. Maximum ethanol production (0.11 g/l) was achieved from the fermented medium obtained from the acid pretreated flaxseed meal followed by enzymatic hydrolysis by using cellulase enzyme. The structural analysis of bioethanol was also investigated by FTIR.

scholarly journals Mushroom-mediated delignification of agricultural wastes for bio-ethanol production

2021 ◽  
Vol 38 (1) ◽  
pp. 137-145
Author(s):  
A. Ahmed El-Imam ◽  
P. Akoh ◽  
S. Saliman ◽  
E. Ighalo
Keyword(s):  
Pleurotus Ostreatus ◽  
Cost Effective ◽  
Agricultural Wastes ◽  
Bioethanol Production ◽  
Biological Pretreatment ◽  
Lignin Removal ◽  
Cost Effective Method ◽  
Ethanol Yields ◽  
Banana Leaves ◽  
Bioethanol Yield

Biological pretreatment is a cost-effective method of delignifying lignocellulosic biomass, making it less recalcitrant to hydrolysis into fermentable sugars. In this study, selected agricultural wastes were pretreated with mushrooms (Lentinus squarrosulus and Pleurotus ostreatus) to delignify them for bioethanol production. The substrates were supplemented with 0.2 % CaCO3, inoculated with 12 % (w/w) L. squarrosulus and Pleurotus ostreatus spawns and incubated at 25 oC for 21 days. The highest lignin removal and highest bioethanol yield of 77.45 % and 13.98 % were obtained from bean husks pretreated with L. squarrosulus. Similarly, 64.29 % and 60.92 % lignin were removed from the Pleurotus ostreatus-pretreated banana leaves and sawdust, respectively, while 12.08 % and 13.05 % bio-ethanol yields were recorded, respectively. These findings demonstrate that affordable and straightforward mushroom delignification of abundant and cheap biomass can improve hydrolysis outcomes, thus easing bioethanol production.

scholarly journals CELLULOSIC BIOETHANOL PRODUCTION FROM ULVA LACTUCA MACROALGAE

2021 ◽  
Vol 55 (5-6) ◽  
pp. 629-635
Author(s):  
AMINA ALLOUACHE ◽  
AZIZA MAJDA ◽  
AHMED ZAID TOUDERT ◽  
ABDELTIF AMRANE ◽  
MERCEDES BALLESTEROS
Keyword(s):  
Enzymatic Hydrolysis ◽  
Fossil Fuels ◽  
Ethanol Yield ◽  
Lignin Content ◽  
Arable Land ◽  
Ulva Lactuca ◽  
Marine Macroalgae ◽  
Bioethanol Production ◽  
Acid Pretreatment ◽  
Total Glucose

Nowadays, the use of biofuels has become an unavoidable solution to the depletion of fossil fuels and global warming. The controversy over the use of food crops for the production of the first-generation biofuels and deforestation caused by the second-generation ones has forced the transition to the third generation of biofuels, which avoids the use of arable land and edible products, and does not threaten biodiversity. This generation is based on the marine and freshwater biomass, which has the advantages of being abundant or even invasive, easy to cultivate and having a good energetic potential. Bioethanol production from Ulva lactuca, a local marine macroalgae collected from the west coast of Algiers, was examined in this study. Ulva lactuca showed a good energetic potential due to its carbohydrate-rich content: 9.57% of cellulose, 6.9% of hemicellulose and low lignin content of 5.11%. Ethanol was produced following the separate hydrolysis and fermentation process (SHF), preceded by a thermal acid pretreatment at 120 °C during 15 min. Enzymatic hydrolysis was performed using a commercial cellulase (Celluclast 1.5 L), which saccharified the cellulose contained in the green seaweed, releasing about 85.01% of the total glucose, corresponding to 7.21 g/L after 96 h of enzymatic hydrolysis at pH 5 and 45 °C. About 3.52 g/L of ethanol was produced after 48 h of fermentation using Saccharomyces cerevisiae at 30 °C and pH 5, leading to a high ethanol yield of 0.41 g of ethanol/g of glucose.

scholarly journals Production of Bioethanol using Waste Fruits under Acid and Alkali Catalytic Hydrolysis: A Review

2021 ◽  
Vol 34 (1) ◽  
pp. 25-34
Author(s):  
S.J. De Silva ◽  
Udara S.P.R. Arachchige ◽  
A.H.L.R. Nilmini
Keyword(s):  
Fossil Fuels ◽  
Fermentation Process ◽  
Energy Content ◽  
Cost Effective ◽  
Inoculum Size ◽  
High Oxygen Content ◽  
The World ◽  
Fruit Waste ◽  
Gain Energy ◽  
Efficiency Cost

The present world highly depends on petroleum fuels to gain energy for transportation resulting in the vast side of environmental problems such as global warming and air pollution. Due to this, the price of conventional fuel escalating day by day. Accordingly, the world needs renewable, ecologically suitable, cost-effective alternate against fossil fuels. Bioethanol is one of the most usable fuel or fuel additives among the other biofuels. Ingoing qualities of bioethanol such as high-octane number, high oxygen content, and low energy content are revealed that application of bioethanol produced from different types of waste materials feedstock in the transportation and energy sector diminishes environment pollution. It provides a solution for waste management. The world releases a considerable amount of fruits as waste annually. Thereby, fruit waste is the cheapest feedstock to produce bioethanol. Fruit waste such as whole rotten fruits, fruit peels, seeds and other residues consists of cellulose, hemicellulose, lignin, starch and simple sugars. Conversion of cellulose and hemicellulose to ethanol is vital to advance pretreatment and hydrolysis techniques to obtain maximum ethanol content. The production process of bioethanol from fruit waste mainly contains pretreatment; hydrolysis, saccharification, fermentation and ethanol extracting process (distillation) steps. Yeast (S. cerevisiae) is primarily used in the fermentation process because of its high conversion efficiency, cost-effectiveness and feasibility of handling. Considering the optimum configuration for bioethanol production, simultaneous saccharification and fermentation (SSF) is the best commensurate method having maximum bioethanol concentration. The fermentation process could be appreciated through various factors, such as temperature (30-33 ºC), pH of the medium (4-5), time of incubation, feedstock concentration, inoculum size, agitating rate, N sources in the medium to gain high bioethanol concentration.

scholarly journals Enzymatic hydrolysis by Trichoderma reesei of diluted acid-pretreated wastepaper for bioethanol production

2021 ◽  
Author(s):  
Nazia Hossain ◽  
Lee Lai Hoong ◽  
Pranta Barua ◽  
Manzoore Elahi M Soudagar ◽  
Teuku Meurah Indra Mahlia
Keyword(s):  
Enzymatic Hydrolysis ◽  
Trichoderma Reesei ◽  
Glucose Consumption ◽  
Cost Effective ◽  
Static Condition ◽  
Bioethanol Production ◽  
Waste Biomass ◽  
Glucose Content ◽  
Glucose Yield ◽  
Waste Office Paper

Abstract Enzymatic hydrolysis of waste biomass for bioethanol production is considered a traditional, inexpensive, and energy-effective approach decades ago. In the present study, waste office paper was pretreated with diluted sulfuric acid (H2SO4) and hydrolysed with one of the most available and cost-effective enzymes, cellulase from Trichoderma reesei, under submerged static condition. Wastepaper size was reduced to 2cm2, blended with water and dry wet-blended, and pretreated with diluted H2SO4. Among different concentrations (0.5M, 1.0M, 1.5M, 2.0M) of H2SO4, the maximum glucose content was obtained at 2.0M H2SO4 at 90 min reaction time, and glucose yield was 0.11g glucose/g wastepaper. The cut paper, wet-blended, and acid-treated wastepaper was hydrolysed with cellulase enzyme for 2, 4, and 5 consecutive days with 5mg, 10mg, 15mg, and 20mg enzyme loadings. The maximum glucose content was obtained, 9.75g/l after 5 days of enzymatic hydrolysis with 20mg enzyme loading and a glucose yield of a 0.5g glucose/g wastepaper. The wastepaper hydrolysate was further fermented for 6, 8, and 10 hours continuously with Saccharomyces cerevisiae (yeast), and at 10 hours of fermentation, the maximum glucose consumption was 0.18g by yeast. Later, HPLC analysis of the fermented medium presented a strong peak of bioethanol content at 16.12min. Further, the distillation of bioethanol by rotary evaporator presented 0.79ml bioethanol/fermented solution, which indicated the conversion efficiency of 79%.

Evaluation of Catalysts Mordenite and MoO3/Mordenite in the Production of Biodiesel

2019 ◽  
Vol 958 ◽  
pp. 11-16
Author(s):  
Fabiana Medeiros do Nascimento Silva ◽  
Erivaldo Genuíno Lima ◽  
Tellys Lins de Almeida Barbosa ◽  
Meiry Gláucia Freire Rodrigues
Keyword(s):  
Energy Production ◽  
Fossil Fuels ◽  
Methyl Esters ◽  
Developed Countries ◽  
Diesel Oil ◽  
High Energy ◽  
Renewable Sources ◽  
Reliable Source ◽  
Alternative Sources ◽  
Developing And Developed Countries

The world's energy production is generated mainly from fossil fuels, so it is important to develop fuels from renewable sources. Growing caution with the environmental impact imposes restrictions on emissions from the combustion of fossil fuels. With increasing human population and expanding economies in both developing and developed countries, there is an increase in energy consumption and production. The need arises to supply this high energy production with a renewable and reliable source fuel [1]. These facts have stimulated research by alternative sources for the development of renewable fuels. One of the most promising fuels is biodiesel, an alternative to petroleum diesel from high-quality renewable sources, which allows the replacement of fossil diesel oil without modifications to the vehicle's engine [2, 3]. In recent years, methyl esters of fatty acids derived from vegetable oil have gained considerable attention as alternative fuel [4, 5].

Comparative evaluation of free and immobilized cellulase for enzymatic hydrolysis of lignocellulosic biomass for sustainable bioethanol production

Cellulose ◽  
2017 ◽  
Vol 24 (12) ◽  
pp. 5529-5540 ◽  
Author(s):  
Avinash P. Ingle ◽  
Jyoti Rathod ◽  
Raksha Pandit ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Comparative Evaluation ◽  
Bioethanol Production ◽  
Immobilized Cellulase ◽  
Hydrolysis Of

scholarly journals BIOGAS PRODUCTION FROM CO-DIGESTION OF SELECTED AGRICULTURAL WASTES IN NIGERIA

2015 ◽  
Vol 3 (11) ◽  
pp. 7-16
Author(s):  
Sambo ◽  
Etonihu ◽  
A. M. Mohammed
Keyword(s):  
Rice Husk ◽  
Crude Protein ◽  
Fossil Fuels ◽  
Biogas Production ◽  
Mineral Elements ◽  
Gas Production ◽  
Agricultural Wastes ◽  
Banana Peel ◽  
Volatile Solids ◽  
Alternative Sources

The fear of depletion of fossil fuels and their attendant ecological effects and the high cost of renewable energy technology in Nigeria has triggered a need to develop alternative sources of energy, among which is biogas production. A slurry of 1 kg mixture of agro-waste feed stocks (plantain peel/rice husk, PP/RH; banana peel/plantain peel, BP/PP; and banana peel/rice husk, BP/RH) in 1:1 ratio was co-digested in locally fabricated digesters (10 L capacity). The experiment was run for 50 days and assessed for proximate content, biogas generation, organic matter, and mineral content in the digested and undi-gested agro-waste materials. The proximate composition showed that while banana peel had the highest moisture (56%), rice husk was highest in the content of ash (64%), crude protein (6.94%), and volatile solids (20%). The weekly cumulative biogas generation increased from 852.6 cm3 for BP/PP sample to 1049.7 cm3 for PP/RH sample for the 7 weeks at the experimental room temperature range of 29 oC to 35 oC. Sample PP/RH generated the highest volume of gas (biogas, methane, and others) compared to BP/RH and BP/PP samples.  In each case the volume of gas production decreased in week 7 from 271.4 cm3 to 152.0 cm3 (for biogas), 161.4 cm3 to 97.1 cm3 (for methane), and 110.0 cm3 to 54.9 cm3 (for other gases). The nutritional concentrations of the digested and undigested mixture of the waste samples after Atomic Absorption Spectrophotometer (AAS) and Flame Photometry showed that the digested samples had higher contents of the nutritional elements than the undigested samples. The mineral elements ranged from 0.554 mg/g in the undigested rice husk to 18.155 mg/g in the digested banana peel samples. Fermentation of agricultural wastes to generate biogas and sludge with agricultural value offers an al-ternative and efficient method of agricultural wastes and energy management in Nigeria.

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