Biomass processing into ethanol: pretreatment, enzymatic hydrolysis, fermentation, rheology, and mixing

2017 ◽  
Vol 6 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Bohdan Volynets ◽  
Farhad Ein-Mozaffari ◽  
Yaser Dahman

AbstractAlternate energy resources need to be developed to amend for depleting fossil fuel reserves. Lignocellulosic biomass is a globally available renewable feedstock that contains a rich sugar platform that can be converted into bioethanol through appropriate processing. The key steps of the process, pretreatment, enzymatic hydrolysis, and fermentation, have undergone considerable amount of research and development over the past decades nearing the process to commercialization. In order for the commercialization to be successful, the process needs to be operated at high dry matter content of biomass, especially in the enzymatic hydrolysis stage that influences ethanol concentration in the final fermentation broth. Biomass becomes a thick paste with challenging rheology for mixing to be effective. As the biomass consistency increases, yield stress increases which limits efficiency of mixing with conventional stirred tanks. The purpose of this review is to provide features and perspectives on processing of biomass into ethanol. Emphasis is placed on rheology and mixing of biomass in the enzymatic hydrolysis step as one of the forefront issues in the field.

2018 ◽  
Vol 250 ◽  
pp. 191-196 ◽  
Author(s):  
Federico Battista ◽  
Mélanie Gomez Almendros ◽  
Romain Rousset ◽  
Serge Boivineau ◽  
Pierre-Antoine Bouillon

2021 ◽  
Vol 32 ◽  
pp. 03005
Author(s):  
O. N. Vetrova ◽  
O. Y. Eremina ◽  
N. V. Seregina ◽  
N. V. Shuldeshova

The article presents the results of a study of the enzymatic hydrolysis of barley malt sprouts by cellulolytic enzymes. The influence of the process parameters (temperature, substrate concentration, concentration of the enzyme preparation, duration of the process) on the output of dry substances in the hydrolysate is shown. The results of the experiments were presented by a mathematical model of the process and graphically-in the form of surface projections reflecting the mutual influence of each possible pair of factors on the dry matter content in the hydrolysate. It is found that all the studied factors have an effect on the accumulation of dry substances in the hydrolysate. As a result of optimization the parameters of the enzymatic hydrolysis process, the following parameter values were obtained: temperature - 50 ˚С, duration of enzymatic hydrolysis-89 min, substrate concentration - 0.37 (hydromodule 1:10), concentration of the enzyme preparation - 0.05 %.


2021 ◽  
Vol 38 (1) ◽  
pp. 86-96
Author(s):  
Lesvy Ramos ◽  
José Edmundo Apráez ◽  
Kris Stephany Cortes ◽  
José Julián Apráez

The search for forages with high biomass production and high nutritional content has made it possible to find food alternatives that, due to their nutritional benefits and resistance to adverse environmental factors, are the best option for herbivores. With the knowledge of farmers, producers and the experience of researchers, 12 species most frequently used in animal feeding were selected, identified and classified in the University's PSO herbarium of the University of Nariño. These were phenologically, nutritionally and antinutritionally characterized. Of these species, four belonged to the Asteraceae family; the Fabaceae, Adoxaceae and Malvaceae families were represented by two species; the Salicaceae and Cucurbitaceae families were represented by one and were propagated in nursery. In the nutritional composition, the Retamo (Genista monspessulana) stood out for its high dry matter content with 34.2%. Unlike the Chauchilla (Cyclanthera brachystachya), with 8.79%, the Sauco (Sambucus peruviana) had a higher content of protein 25.93%, followed by Abutilon (Abutilon pictum) with 23.42%. Chauchilla (Cyclanthera brachystachya) had the highest crude fiber content, with 21.59%, NDF of 38.06%, and FDA 27.23%. Tannins were the most common secondary metabolites in the species evaluated with moderate or low levels; sterols were present at low levels, and saponins and alkaloids yielded negative values.


2021 ◽  
pp. 11-15
Author(s):  
N. G. Baybakova ◽  
G. V. Varivoda

Relevance. The study of the collection is one of the main sources of replenishing the source material for the breeding process. The presence of the necessary genetic traits can speed up the breeding process. Therefore, at the Bykovskaya melon breeding experimental station, the genetic diversity of melon plants is assessed and promising samples are selected for use in breeding.Materials and methods. The object of research was samples of table watermelon with an unconventional color of the pulp. The aim of the work is to study and isolate the source material of watermelon for use in the breeding process to create new varieties and hybrids of melon crops. In the course of the study, 12 varieties of table watermelon were identified from 33 varieties of the collection nursery, which are sources of economically valuable traits. The selection was carried out according to the yield, the rate of entry into fruiting, taste, color of the pulp.Results. In the course of the research, the obtained samples of table watermelon with an unconventional color of the pulp were evaluated according to a set of economic characteristics in comparison with the standards: Zenith and Sinchevsky. The analysis of the tested samples made it possible to identify 12 samples by economically valuable traits: 3 samples by early maturity and taste: White sugar lump, White wonder, Golden revenge F1; 7 samples with a high dry matter content, in terms of yield and large fruit: Moon and stars yellowflesh, Sweet Siberian, Orangeglo, Daisy, Clay county yellow meat, Mountain sweet yellow, Tendergold; 2 samples for color and pulp consistency: Early moon beane Bakerlneek, Tenderweet orange. The selected samples meet the modern requirements of the industrial melon growing industry, resistant to stress factors of the environment, good taste and consumer properties.Findings. The obtained experimental data will be used to create a genetic collection of watermelon according to the traits that determine the economic value of the gene pool for further use in the breeding process. 


1982 ◽  
Vol 98 (3) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. Woolford ◽  
K. K. Bolsen ◽  
Lesley A. Peartt

SUMMARYAs a result of the treatment of made whole-crop barley silage with antimicrobial agents which are specifically inhibitory to fungi or bacteria, it was shown that the subsequent aerobic deterioration was essentially caused by yeasts. These microorganisms were instrumental in the rise in pH, the increase in temperature and the loss of dry matter observed. The filamentous fungi, like one group of bacteria (the streptomycetes), apparently had no part in the process. Bacteria, such as the lactobacilli and particularly proteolytic bacteria, may have had a role in the terminal stages of deterioration, although it was considered more likely that the yeasts again were involved.The whole-crop wheat silage employed in this work was stable in air, a factor attributed to the combined antimicrobial effects of butyric acid present and the relatively high dry-matter content.


1968 ◽  
Vol 22 (3) ◽  
pp. 515-526 ◽  
Author(s):  
M. J. Manners ◽  
D. E. Kidder

1. Polyethylene glycol (PEG) of high molecular weight, used as a dietary marker, did not distribute uniformly in the water present in a high-casein diet as did glucose, a low-molecular-weight substance.2. This distribution effect also occurred with the contents of the stomach and, to a smaller extent, with the contents of the first quarter of the small intestine of piglets given such a diet.


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