scholarly journals Ethanol Production from Waste of Cassava Processing

2018 ◽  
Vol 8 (11) ◽  
pp. 2158 ◽  
Author(s):  
Daiana Martinez ◽  
Armin Feiden ◽  
Reinaldo Bariccatti ◽  
Katya de Freitas Zara

Cassava processing produces by-products such as brown bark, between bark, disposal, bran, fiber and bagasse. Cassava bagasse is characterized as a source of starch that can be converted into sugars to obtain biofuels. The objective of this work was to produce ethanol from this cassava processing residue and to evaluate its contribution potential in the Brazilian energy matrix. Cassava processing residues were obtained from four different starch manufacturers in Brazil. Analysis of the chemical compositions of these samples provided the content of starch, sugar, crude grease, moisture, ash and also their pH values. For the ethanol process, the samples were submitted to enzymatic hydrolysis using the alpha-amylase and amyloglucosidases enzymes, followed by fermentation and distillation. The samples showed high starch indices, approximately 64% on average. The average yield of ethanol obtained was 30% after treatment of the sample like this. Considering the estimated volume of cassava bagasse in Brazil, it is possible to produce an average of 789 million cubic meters per bagasse, replacing about 24% of the first generation ethanol. Cassava bagasse can be considered an interesting biomass for the production of biofuels, contributing to the expansion of the energy matrix.

Author(s):  
D. Mikulski ◽  
G. Kłosowski

AbstractThe possibility of using waste distillery stillage (first-generation technology) after dilute acid pretreatment, as a medium for the preparation of beet molasses mash, for ethanol production according to the simultaneous saccharification and fermentation (SSF) technology, was assessed. The combination of lignocellulosic hydrolysates made from acid-pretreated stillage with sugar-rich beet molasses is an effective way of utilizing the first-generation ethanol production by-products in the second-generation ethanol production technology. It was demonstrated that the final ethanol concentration could be as high as 90 g/L. The process yield was over 94% of the theoretical yield when the molasses was diluted using acid-pretreated maize distillery stillage. An attempt to increase the pool of fermentable sugars by using cellulases to hydrolyze cellulose failed due to product inhibition in the fermentation medium with a high glucose concentration. A more than threefold increase in the concentration of ethyl acetate (even up to 924.4±11.8 mg/L) was observed in the distillates obtained from the media incubated with cellulases. The use of beet molasses combined with the hydrolysate of pretreated distillery stillage also changed the concentration of other volatile by-products. An increase in the concentration of aldehydes (mainly acetaldehyde to a concentration of above 1500 mg/L), methanol, 1-propanol, and 1-butanol was observed, while the concentration of higher alcohols (isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol) decreased. Interestingly, the use of cellulases in fermentation media from molasses and stillage hydrolysates resulted in an average fourfold increase in the concentration of this ester to a maximum level of 924.4±11.8 mg/L. Hydrolysates made from acid-pretreated distillery stillage, combined with sugar-rich beet molasses to boost the efficiency of the conversion process, can be successfully used in the production of second-generation fuel ethanol. However, further optimization of the cellulose enzymatic hydrolysis process is required for efficient use of the raw material.


2021 ◽  
Vol 51 (11) ◽  
Author(s):  
Camila da Silva Turini ◽  
Roberta Martins Nogueira ◽  
Evaldo Martins Pires ◽  
Juliana da Silva Agostini

ABSTRACT: Over post-harvest steps of rice, from pre-cleaning to processing, a large amount of by-product is generated. Some of these by-products, due to their high starch and fiber content can be used in ethanol production. The objective was to evaluate the effect of enzymatic hydrolysis conditions on the production of reducing sugars, from pre-cleaning residue and type III paddy rice, as well as the effect of the pre-treatment of its fibers, targeting the use of these residues in ethanol fuel production. The proximate analysis was performed, followed by the pre-treatment of samples. Enzymatic hydrolysis was conducted in two ways: using one enzyme at a time or applying them simultaneously. The starch content was 41.18 and 53.41%; the fibers were 30.44 and 23.39%, of which 6.53 and 4.41% were lignin, for the pre-cleaning residue and paddy rice, respectively. Alkaline pre-treatment reduce lignin content by 47.94 and 18.23% for the pre-cleaning residue and type III paddy rice, respectively. Hydrolysis efficiency was 22.61 and 15.32% for the cellulase enzyme, and 82.18 and 87.07% for the amylolytic enzymes in the pre-cleaning residue and type III paddy rice, respectively. The hydrolysis with the separated enzymes presented higher reducing sugar yields. Therefore, the pre-cleaning residue and type III paddy rice can be used for ethanol production by its enzymatic hydrolysis, aiming to add value and to increase the sustainability of the rice production chain.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 782
Author(s):  
Karina Juhnevica-Radenkova ◽  
Jorens Kviesis ◽  
Diego A. Moreno ◽  
Dalija Seglina ◽  
Fernando Vallejo ◽  
...  

Historically Triticum aestívum L. and Secale cereále L. are widely used in the production of bakery products. From the total volume of grain cultivated, roughly 85% is used for the manufacturing of flour, while the remaining part is discarded or utilized rather inefficiently. The limited value attached to bran is associated with their structural complexity, i.e., the presence of cellulose, hemicellulose, and lignin, which makes this material suitable mostly as a feed supplement, while in food production its use presents a challenge. To valorize these materials to food and pharmaceutical applications, additional pre-treatment is required. In the present study, an effective, sustainable, and eco-friendly approach to ferulic acid (FA) production was demonstrated through the biorefining process accomplished by non-starch polysaccharides degrading enzymes. Up to 11.3 and 8.6 g kg−1 of FA was released from rye and wheat bran upon 24 h enzymatic hydrolysis with multi-enzyme complex Viscozyme® L, respectively.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1186
Author(s):  
Fidel Toldrá ◽  
Leticia Mora

Foods and their industry by-products constitute very good sources of bioactive peptides, which can be naturally generated during processing but are also extensively produced through enzymatic hydrolysis, microbial fermentation, and even during gastrointestinal digestion in the human body [...]


2015 ◽  
Vol 12 (S316) ◽  
pp. 294-301
Author(s):  
Richard Wünsch ◽  
Jan Palouš ◽  
Guillermo Tenorio-Tagle ◽  
Casiana Muñoz-Tuñón ◽  
Soňa Ehlerová

AbstractMassive stars in young massive clusters insert tremendous amounts of mass and energy into their surroundings in the form of stellar winds and supernova ejecta. Mutual shock-shock collisions lead to formation of hot gas, filling the volume of the cluster. The pressure of this gas then drives a powerful cluster wind. However, it has been shown that if the cluster is massive and dense enough, it can evolve in the so–called bimodal regime, in which the hot gas inside the cluster becomes thermally unstable and forms dense clumps which are trapped inside the cluster by its gravity. We will review works on the bimodal regime and discuss the implications for the formation of subsequent stellar generations. The mass accumulates inside the cluster and as soon as a high enough column density is reached, the interior of the clumps becomes self-shielded against the ionising radiation of stars and the clumps collapse and form new stars. The second stellar generation will be enriched by products of stellar evolution from the first generation, and will be concentrated near the cluster center.


ALCHEMY ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 24
Author(s):  
Dewi Yuliani ◽  
Khoirul Achmad Julianto ◽  
Akyunul Jannah

<p class="BodyAbstract">Rice bran is one among many agricultural by-products containing ~50-60 wt.% of carbohydrate. The carbohydrate is a prominent sugar source for bioethanol production. The objective of this research was to study bioethanol production from rice bran by acid and enzymatic treatment. The variations of acid used were dilute hydrochloric acid and sulphuric acid, while variations of enzyme used were amylolytic and cellulolytic enzyme. Ethanol production of acid-hydrolyzed rice bran was 24.95±1.61% (v/v) by hydrochloric acid and 29.57±2.04% (v/v) by sulphuric acid. Ethanol produced by enzymatic hydrolysis was quite low i.e. 6.7±0.04%, and 8.86±0.29% (v/v) for amylolytic and cellulolytic hydrolysate, respectively.</p><p class="BodyAbstract"> </p><p>Keywords: Bioethanol, rice bran, acid hydrolysis, enzymatic hydrolysis</p>


2021 ◽  
Vol 8 ◽  
Author(s):  
Analía Rodríguez ◽  
Patricia Lema ◽  
María Inés Bessio ◽  
Guillermo Moyna ◽  
Cristina Olivaro ◽  
...  

The effect on color of the initial pH employed in dulce de leche (DL) production was evaluated through physicochemical and spectroscopical characterization of the melanoidins formed in the process. Melanoidins originated at pH values of 6.5, 7.0, and 7.5, and they were released by the enzymatic hydrolysis of the protein backbone and purified by gel filtration. They showed a significant degree of polydispersity, in general, with molecular weights (MWs) below 1,800 Da. DL produced at a higher pH released melanoidins with higher average MW after the enzymatic hydrolysis. They also presented darker colors (dE*ab, C*), more closely resembling those typical of the commercial product. Analysis of the fractions isolated by gel filtration using HPLC-DAD and multinuclear NMR showed an heterogeneous and complex composition. Even though structurally related, the 1H NMR spectra of melanoidins showed a higher degree of aromaticity at higher pH values. In conclusion, the pH employed in DL production affects the amount and structure of the colored products originated by MR reactions, and thus the color of the final product.


2013 ◽  
Vol 11 (3) ◽  
pp. 465-472 ◽  
Author(s):  
Kamilla M. S. Hansen ◽  
Hans-Jørgen Albrechtsen ◽  
Henrik R. Andersen

In order to identify the optimal pH range for chlorinated swimming pools, the formation of trihalomethanes, haloacetonitriles and trichloramine was investigated in the pH-range 6.5–7.5 in batch experiments. An artificial body fluid analogue was used to simulate bather load as the precursor for by-products. The chlorine-to-precursor ratio used in the batch experiments influenced the amounts of by-products formed, but regardless of the ratio the same trends in the effect of pH were observed. Trihalomethane formation was reduced by decreasing pH, but haloacetonitrile and trichloramine formation increased. To evaluate the significance of the increase and decrease of the investigated organic by-products at the different pH values, the genotoxicity was calculated based on literature values. The calculated genotoxicity was approximately at the same level in the pH range 6.8–7.5 and increased when pH was 6.7 or lower. An optimal pH range for by-products formation in swimming pools was identified at pH 7.0–7.2. In the wider pH range (pH 6.8–7.5), the effect on by-product formation was negligible. Swimming pools should never be maintained at lower pH than 6.8 since formation of both haloacetonitriles and trichloramine increase significantly below this value.


Sign in / Sign up

Export Citation Format

Share Document