Methods for pretreatment of lignocellulose raw materials in second-generation bioethanol production Metody wstępnej obróbki surowców lignocelulozowych w procesie produkcji bioetanolu drugiej generacji

2015 ◽  
Vol 1 (4) ◽  
pp. 174-178
Author(s):  
Marta Wilk
Keyword(s):  
Second Generation ◽  
Raw Materials ◽  
Bioethanol Production ◽  
Second Generation Bioethanol

scholarly journals Flocculation Causes Inhibitor Tolerance in Saccharomyces cerevisiae for Second-Generation Bioethanol Production

2014 ◽  
Vol 80 (22) ◽  
pp. 6908-6918 ◽  
Author(s):  
Johan O. Westman ◽  
Valeria Mapelli ◽  
Mohammad J. Taherzadeh ◽  
Carl Johan Franzén
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Second Generation ◽  
Raw Materials ◽  
Defined Medium ◽  
Bioethanol Production ◽  
Dilute Acid ◽  
Fermentation Inhibitors ◽  
Inhibitor Tolerance ◽  
Content Type ◽  
Second Generation Bioethanol

ABSTRACTYeast has long been considered the microorganism of choice for second-generation bioethanol production due to its fermentative capacity and ethanol tolerance. However, tolerance toward inhibitors derived from lignocellulosic materials is still an issue. Flocculating yeast strains often perform relatively well in inhibitory media, but inhibitor tolerance has never been clearly linked to the actual flocculation abilityper se. In this study, variants of the flocculation geneFLO1were transformed into the genome of the nonflocculating laboratory yeast strainSaccharomyces cerevisiaeCEN.PK 113-7D. Three mutants with distinct differences in flocculation properties were isolated and characterized. The degree of flocculation and hydrophobicity of the cells were correlated to the length of the gene variant. The effect of different strength of flocculation on the fermentation performance of the strains was studied in defined medium with or without fermentation inhibitors, as well as in media based on dilute acid spruce hydrolysate. Strong flocculation aided against the readily convertible inhibitor furfural but not against less convertible inhibitors such as carboxylic acids. During fermentation of dilute acid spruce hydrolysate, the most strongly flocculating mutant with dense cell flocs showed significantly faster sugar consumption. The modified strain with the weakest flocculation showed a hexose consumption profile similar to the untransformed strain. These findings may explain why flocculation has evolved as a stress response and can find application in fermentation-based biorefinery processes on lignocellulosic raw materials.

scholarly journals Exploring grape marc as trove for new thermotolerant and inhibitor-tolerant Saccharomyces cerevisiae strains for second-generation bioethanol production

2013 ◽  
Vol 6 (1) ◽  
pp. 168 ◽  
Author(s):  
Lorenzo Favaro ◽  
Marina Basaglia ◽  
Alberto Trento ◽  
Eugéne Van Rensburg ◽  
Maria García-Aparicio ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Second Generation ◽  
Bioethanol Production ◽  
Grape Marc ◽  
Second Generation Bioethanol

scholarly journals Evaluation of polyploid miscanthus lines usage efficiency as a feedstock for bioethanol production

2021 ◽  
Vol 29 ◽  
pp. 13-19
Author(s):  
R. Y. Blume ◽  
O.V. Melnychuk ◽  
S.P. Ozheredov ◽  
D.B. Rakhmetov ◽  
Y.B. Blume
Keyword(s):  
Sweet Sorghum ◽  
Second Generation ◽  
Ethanol Yield ◽  
Bioenergy Crops ◽  
Control Line ◽  
Bioethanol Production ◽  
Second Generation Bioethanol ◽  
Giant Miscanthus ◽  
First And Second Generation ◽  
Bioethanol Yield

Aim. Main aim of this research was the evaluation of theoretical bioethanol yield (per ha) from hexaploid giant miscanthus (Miscanthus х giganteus) and further comparison with conventional triploid form as well as with other bioethanol crops. Methods. Several mathematic functions were determined that describe yearly yield dynamics and equations, which were used in calculations of theoretical bioethanol yield. Results. The theoretical bioethanol yield was evaluated for different hexaploid miscanthus lines. The most productive in terms of ethanol yield were lines 108 and 202, from which potential bioethanol yield was found to be higher than in control line (6451 L/ha) by 10.7 % and 14.2% respectively and can reach 7144 L/ha and 7684 L/ha. Conclusions. It was determined that the most productive lines of polyploid miscanthus (lines 108 and 202) are able to compete with other plant cellulosic feedstocks for second-generation bioethanol production in Ukraine. However, these lines show bioethanol productivity than sweet sorghum, in the case when sweet sorghum is processed for obtainment of both first- and second-generation bioethanol. Keywords: bioenergy crops, biofuels, giant miscanthus, Miscanthus, polyploidy, second-generation bioethanol.

scholarly journals Study of wheat straw delignification in a rotary-pulsation apparatus

2020 ◽  
pp. 103-110
Author(s):  
Larysa Sablii ◽  
Oleksandr Obodovych ◽  
Vitalii Sydorenko ◽  
Tamila Sheyko
Keyword(s):  
Wheat Straw ◽  
Production Technology ◽  
Raw Materials ◽  
Hydrolytic Enzymes ◽  
Bioethanol Production ◽  
Second Generation Bioethanol ◽  
Pulsation Apparatus ◽  
Rotary Pulsation Apparatus ◽  
Solid Water ◽  
Pre Treatment

This paper presents the results of studies of isolation lignin and hemicelluloses efficiency during the pre-treatment of wheat straw for hydrolysis in a rotary-pulsation apparatus. The pre-treatment of lignocellulosic raw materials for hydrolysis is a necessary step in the second-generation bioethanol production technology. The lignocellulose complex is destroyed during this process, and this allows hydrolytic enzymes access to the surface of cellulose fibers. The pre-treatment is the most energy-consuming stage in bioethanol production technology, since it usually occurs at high temperature and pressure for a significant time. One of the ways to improve the efficiency of this process is the use of energy-efficient equipment that allows intensifying heat and mass transfer. An example of such equipment is a rotary-pulsation apparatus, which are effective devices in stirring, homogenization, dispersion technologies, etc. The treatment of wheat straw in a rotary-pulsation apparatus was carried out under atmospheric pressure without external heat supply at solid/water ratios of 1:10 and 1:5 in the presence of alkali. It was determined that the treatment of the water dispersion of straw at ratio of 1:10 due to the energy dissipation during 70 minutes leads to the release of 42 % of lignin and 25.76 % of easily hydrolyzed polysaccharides. Changing the solid / water ratio from 1:10 to 1:5 leads to an increase in the yield of lignin and easily hydrolyzed polysaccharides to 58 and 33.38 %, respectively.

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