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 Chemical Pretreatments on Residual Cocoa Pod Shell Biomass for Bioethanol Production

Bionatura ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 1490-1500
Author(s):  
Jose F. Alvarez-Barreto ◽  
Fernando Larrea ◽  
Maria C. Pinos C ◽  
Jose Benalcázar ◽  
Daniela Oña ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Reducing Sugars ◽  
Ethanol Yield ◽  
Lignin Content ◽  
Reducing Sugar ◽  
Sugar Concentration ◽  
Biomass Composition ◽  
Future Research ◽  
Bioethanol Production ◽  
Acid Pretreatment

Cocoa pod shell is an essential agricultural residue in Ecuador, and this study addressed its potential valorization for bioethanol production. For this, three types of pretreatments, acid, alkaline, and autohydrolysis, were applied to pod shells from two different cocoa types, national and CCN-51. to remove the lignin. Untreated and treated biomasses were characterized by composition, thermal stability, Fourier transformed infrared spectroscopy (FITR), and scanning electron microscopy (SEM). The treated biomass was then enzymatically hydrolyzed with cellulase. Reducing sugars were quantified after pretreatments and enzymatic hydrolysis, and the pretreatment liquors and the enzymatic hydrolysates were subjected to alcoholic fermentation with Saccharomyces cerevisiae. There were substantial differences in composition between both biomasses, particularly in lignin content, with national cocoa having the lowest values. All pretreatment conditions had significant effects on biomass composition, structure, and thermal properties. After alkaline pretreatment, the biomass presented the highest cellulose and lowest lignin contents, resulting in the highest reducing sugar concentration in the pretreatment liquor. The highest lignin content was found after the acid pretreatment, which resulted in low, reducing sugar concentrations. Autohydrolysis produced similar results as the acid pretreatment; however, it resulted in the highest sugar concentration after enzymatic hydrolysis, while the acid-treated sample had negligible levels. After fermentation, there were no differences in productivity among the pretreatment liquors, but autohydrolysis had the largest ethanol yield. In the hydrolysates, it was also autohydrolysis that resulted in higher productivity and yield. Thus, there is an indication of the formation of inhibitors, both enzymatic activity and ethanol production, in the acid and alkaline pretreatments, and this should be tackled in future research. Nonetheless, given the crucial changes observed in biomass, we believe that cocoa pod shell pretreatment has potential for the generation of reducing sugars that could be further used in different bioprocesses, nor only bioethanol production.

scholarly journals Evaluation of Copper-Contaminated Marginal Land for the Cultivation of Vetiver Grass (Chrysopogon zizanioides) as a Lignocellulosic Feedstock and its Impact on Downstream Bioethanol Production

2019 ◽  
Vol 9 (13) ◽  
pp. 2685 ◽  
Author(s):  
Emily M. Geiger ◽  
Dibyendu Sarkar ◽  
Rupali Datta
Keyword(s):  
Contaminated Soil ◽  
Ethanol Yield ◽  
Dilute Acid Pretreatment ◽  
Cellulose Content ◽  
Bioethanol Production ◽  
Vetiver Grass ◽  
Acid Pretreatment ◽  
Biofuel Feedstock ◽  
Lignocellulosic Feedstock ◽  
The Impact

Metal-contaminated soil could be sustainably used for biofuel feedstock production if the harvested biomass is amenable to bioethanol production. A 60-day greenhouse experiment was performed to evaluate (1) the potential of vetiver grass to phytostabilize soil contaminated with copper (Cu), and (2) the impact of Cu exposure on its lignocellulosic composition and downstream bioethanol production. Dilute acid pretreatment, enzymatic hydrolysis, and fermentation parameters were optimized sequentially for vetiver grass using response surface methodology (RSM). Results indicate that the lignocellulosic composition of vetiver grown on Cu-rich soil was favorably altered with a significant decrease in lignin and increase in hemicellulose and cellulose content. Hydrolysates produced from Cu exposed biomass achieved a significantly greater ethanol yield and volumetric productivity compared to those of the control biomass. Upon pretreatment, the hemicellulosic hydrolysate showed an increase in total sugars per liter by 204.7% of the predicted yield. After fermentation, 110% of the predicted ethanol yield was obtained for the vetiver grown on Cu-contaminated soil. By contrast, for vetiver grown on uncontaminated soil a 62.3% of theoretical ethanol yield was achieved, indicating that vetiver has the potential to serve the dual purpose of phytoremediation and biofuel feedstock generation on contaminated sites.

scholarly journals Evaluation of buriti endocarp as lignocellulosic substrate for second generation ethanol production

2018 ◽  
Author(s):  
Plínio R Rodrigues ◽  
Mateus FL Araújo ◽  
Tamarah L Rocha ◽  
Ronnie Von S Veloso ◽  
Lílian A Pantoja ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Fossil Fuels ◽  
Alcoholic Fermentation ◽  
Lignin Content ◽  
Cellulolytic Enzymes ◽  
Lignocellulosic Substrate ◽  
Acid Pretreatment ◽  
Surface Response Methodology ◽  
Pre Treatment ◽  
Second Generation Ethanol

The production of lignocellulosic ethanol is one of the most promising alternatives to fossil fuels, however, this technology still faces many challenges related to the viability of the alcohol in the market. In this paper the endocarp of buriti fruit was assessed for ethanol production. The whole fruit was characterized physically and chemically and its endocarp submitted to acid and alkaline pre-treatments, which were optimized through the use of surface response methodology for removal of hemicellulose and lignin, respectively. Hemicellulose content was reduced by 88% after acid pretreatment. Alkaline pre-treatment reduced the lignin content in the recovered biomass from 11.8% to 4.2% and increased the concentration of the cellulosic fraction to 88.5%. The pre-treated biomass was saccharified by the action of cellulolytic enzymes and, in the optimized condition, was able to produce 110 g of glucose per L of hydrolyzate. Alcoholic fermentation of the enzymatic hydrolyzate bio-catalized by Saccharomyces cerevisiae resulted in a fermented medium with 4.3% ethanol and YP/S of 0.33.

scholarly journals Bioethanol production from extracted olive pomace: dilute acid hydrolysis

Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Maria C. Fernandes ◽  
Ivone Torrado ◽  
Florbela Carvalheiro ◽  
Vânia Dores ◽  
Vera Guerra ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Acid Hydrolysis ◽  
Lignin Content ◽  
Enzymatic Saccharification ◽  
Size Reduction ◽  
Bioethanol Production ◽  
Olive Pomace ◽  
Dilute Acid ◽  
Dilute Acid Hydrolysis ◽  
Separate Hydrolysis And Fermentation

AbstractResidues from olive oil industry such as Extracted Olive Pomace (EOP) are potential substrates for bioethanol production. In this work, enzymatic hydrolysis of EOP pretreated by dilute acid hydrolysis (DAH) was assessed, and the enzymatic hydrolysis and bioconversion were carried out both by separate hydrolysis and fermentation (SHF) and pre-saccharification followed by simultaneous saccharification and fermentation (PSSF). DAH led to a significant removal hemicellulose, but the subsequent enzymatic treatments showed that the resulting residue was still partially recalcitrant to cellulase hydrolysis. Size reduction and further treatment of EOP-DAH with an alkaline solution were also tested. Alkaline post-treatment allowed a decrease in lignin content, but had little effect on enzymatic saccharification comparing to size reduction. Hence fermentation study was performed with ground EOP-DAH. The PSSF process showed a relatively higher bioethanol fermentation yield (0.46 gg-1) when compared to the SHF process.

Susceptibility of pretreated wood sections of Norway spruce (Picea abies) clones to enzymatic hydrolysis

2012 ◽  
Vol 42 (1) ◽  
pp. 38-46 ◽  
Author(s):  
Yohama Puentes Rodriguez ◽  
Helena Puhakka-Tarvainen ◽  
Ossi Pastinen ◽  
Matti Siika-aho ◽  
Leila Alvila ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Picea Abies ◽  
Norway Spruce ◽  
Wood Density ◽  
Lignin Content ◽  
Trichoderma Viride ◽  
Wood Decay ◽  
Wood Properties ◽  
Acid Pretreatment ◽  
The Relationship

The structure of softwoods, which confers resistance to degradation through hydrolysis and decay, currently limits their use for the production of biofuels. However, since wood is very heterogeneous, it is possible that differences in wood properties within and between trees could differentially affect its processability. In this research, heartwood (inner) and sapwood (outer) from Norway spruce ( Picea abies (L.) Karst.) clones were enzymatically hydrolyzed by Trichoderma viride cellulases after concentrated acid pretreatment. Wood sections with two particle sizes were compared based on their susceptibility to enzymatic hydrolysis, evaluated by assaying the formation of hydrolysis products and measured as reducing sugar yield (RSY). We also studied the relationship between RSY and the susceptibility to Heterobasidion parviporum wood decay and whether these traits are reflected in wood density and yield. Wood from the outer section produced more RSY with higher glucan but lower lignin content than wood from the inner section. Furthermore, susceptibility to enzymatic hydrolysis was positively correlated with H. parviporum wood decay, while both processes were negatively correlated with wood density. Our results revealed the importance of clonal trials for identifying suitable lignocellulosic biomass when considering wood properties and indicate that potential genotypes for the production of biofuels are not necessarily the most productive.

scholarly journals Nitric Acid Pretreatment of Jerusalem Artichoke Stalks for Enzymatic Saccharification and Bioethanol Production

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2153 ◽  
Author(s):  
Urszula Dziekońska-Kubczak ◽  
Joanna Berłowska ◽  
Piotr Dziugan ◽  
Piotr Patelski ◽  
Katarzyna Pielech-Przybylska ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Enzymatic Hydrolysis ◽  
High Efficiency ◽  
Ethanol Yield ◽  
Enzymatic Saccharification ◽  
Jerusalem Artichoke ◽  
Potential Candidate ◽  
Acid Pretreatment ◽  
Glucose Yield ◽  
Theoretical Yield

This paper evaluated the effectiveness of nitric acid pretreatment on the hydrolysis and subsequent fermentation of Jerusalem artichoke stalks (JAS). Jerusalem artichoke is considered a potential candidate for producing bioethanol due to its low soil and climate requirements, and high biomass yield. However, its stalks have a complexed lignocellulosic structure, so appropriate pretreatment is necessary prior to enzymatic hydrolysis, to enhance the amount of sugar that can be obtained. Nitric acid is a promising catalyst for the pretreatment of lignocellulosic biomass due to the high efficiency with which it removes hemicelluloses. Nitric acid was found to be the most effective catalyst of JAS biomass. A higher concentration of glucose and ethanol was achieved after hydrolysis and fermentation of 5% (w/v) HNO3-pretreated JAS, leading to 38.5 g/L of glucose after saccharification, which corresponds to 89% of theoretical enzymatic hydrolysis yield, and 9.5 g/L of ethanol. However, after fermentation there was still a significant amount of glucose in the medium. In comparison to more commonly used acids (H2SO4 and HCl) and alkalis (NaOH and KOH), glucose yield (% of theoretical yield) was approximately 47–74% higher with HNO3. The fermentation of 5% nitric-acid pretreated hydrolysates with the absence of solid residues, led to an increase in ethanol yield by almost 30%, reaching 77–82% of theoretical yield.

scholarly journals Seaweed Bioethanol Production: A Process Selection Review on Hydrolysis and Fermentation

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 99 ◽  
Author(s):  
Felix Offei ◽  
Moses Mensah ◽  
Anders Thygesen ◽  
Francis Kemausuor
Keyword(s):  
Fossil Fuels ◽  
Ethanol Yield ◽  
Process Efficiency ◽  
Bioethanol Production ◽  
Substrate Selection ◽  
Process Selection ◽  
Enzyme Preparations ◽  
Red Seaweeds ◽  
Composition And Structure ◽  
Polysaccharide Composition

The rapid depletion and environmental concerns associated with the use of fossil fuels has led to extensive development of biofuels such as bioethanol from seaweeds. The long-term prospect of seaweed bioethanol production however, depends on the selection of processes in the hydrolysis and fermentation stages due to their limiting effect on ethanol yield. This review explored the factors influencing the hydrolysis and fermentation stages of seaweed bioethanol production with emphasis on process efficiency and sustainable application. Seaweed carbohydrate contents which are most critical for ethanol production substrate selection were 52 ± 6%, 55 ± 12% and 57 ± 13% for green, brown and red seaweeds, respectively. Inhibitor formation and polysaccharide selectivity were found to be the major bottlenecks influencing the efficiency of dilute acid and enzymatic hydrolysis, respectively. Current enzyme preparations used, were developed for starch-based and lignocellulosic biomass but not seaweeds, which differs in polysaccharide composition and structure. Also, the identification of fermenting organisms capable of converting the heterogeneous monomeric sugars in seaweeds is the major factor limiting ethanol yield during the fermentation stage and not the SHF or SSF pathway selection. This has resulted in variations in bioethanol yields, ranging from 0.04 g/g DM to 0.43 g/g DM.

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