scholarly journals Effects of operational conditions on auto-catalyzed and sulfuric-acid-catalyzed hydrothermal pretreatment of sugarcane bagasse at different severity factor

2021 ◽  
Vol 159 ◽  
pp. 113077
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Sulfuric Acid ◽  
Sugarcane Bagasse ◽  
Hydrothermal Pretreatment ◽  
Severity Factor ◽  
Operational Conditions ◽  
Acid Catalyzed

scholarly journals Hydrothermal Pretreatment of Wheat Straw: Effects of Temperature and Acidity on Byproduct Formation and Inhibition of Enzymatic Hydrolysis and Ethanolic Fermentation

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 487
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Mass Spectrometry ◽  
Sulfuric Acid ◽  
Wheat Straw ◽  
High Performance ◽  
Enzymatic Saccharification ◽  
Hydrothermal Pretreatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzymatic Digestibility ◽  
Acid Catalyzed ◽  
Pretreatment Conditions

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.

scholarly journals Fractionation and characterization of lignin from sugarcane bagasse using a sulfuric acid catalyzed solvothermal process

RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 26773-26784
Author(s):  
Saksit Imman ◽  
Punjarat Khongchamnan ◽  
Wanwitoo Wanmolee ◽  
Navadol Laosiripojana ◽  
Torpong Kreetachat ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sugarcane Bagasse ◽  
Solvothermal Process ◽  
Global Sustainability ◽  
Lignocellulosic Residue ◽  
Acid Catalyzed

Conversion of lignocellulosic residue to bioenergy and biofuel is a promising platform for global sustainability.

scholarly journals Hydrothermal Pretreatment of Water-Extracted and Aqueous Ethanol-Extracted Quinoa Stalks for Enzymatic Saccharification of Cellulose

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4102
Author(s):  
Cristhian Carrasco ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Sulfuric Acid ◽  
Aqueous Ethanol ◽  
Enzymatic Saccharification ◽  
Product Formation ◽  
Hydrothermal Pretreatment ◽  
Raw Material ◽  
Water Mixture ◽  
Acid Catalyzed ◽  
Preliminary Extraction ◽  
Hydrolysis Of

Auto-catalyzed hydrothermal pretreatment (A-HTP) and sulfuric-acid-catalyzed hydrothermal pretreatment (SA-HTP) were applied to quinoa stalks in order to reduce their recalcitrance towards enzymatic saccharification. Prior to pretreatment, quinoa stalks were extracted with either water or a 50:50 (v/v) ethanol–water mixture for removing saponins. Extraction with water or aqueous ethanol, respectively, led to removal of 52 and 75% (w/w) of the saponins contained in the raw material. Preliminary extraction of quinoa stalks allowed for a lower overall severity during pretreatment, and it led to an increase of glucan recovery in the pretreated solids (above 90%) compared with that of non-extracted quinoa stalks (73–74%). Furthermore, preliminary extraction resulted in enhanced hydrolysis of hemicelluloses and lower by-product formation during pretreatment. The enhancement of hemicelluloses hydrolysis by pre-extraction was more noticeable for SA-HTP than for A-HTP. As a result of the pretreatment, glucan susceptibility towards enzymatic hydrolysis was remarkably improved, and the overall conversion values were higher for the pre-extracted materials (up to 83%) than for the non-extracted ones (64–69%). Higher overall conversion was achieved for the aqueous ethanol-extracted quinoa stalks (72–83%) than for the water-extracted material (65–74%).

scholarly journals Fractionation and characterization of lignin from sugarcane bagasse using a sulfuric acid catalyzed solvothermal process

2020 ◽  
Author(s):  
Saksit Imman ◽  
Punjarat Khongchamnan ◽  
Wanwitoo Wanmolee ◽  
Navadol Laosiripojana ◽  
Torpong Kreetachat ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sugarcane Bagasse ◽  
Organic Phase ◽  
Solid Phase ◽  
Value Added ◽  
Solvothermal Process ◽  
Organosolv Lignin ◽  
Lignin Recovery ◽  
Cross Links ◽  
Acid Catalyzed

Abstract Background: Conversion of lignocellulosic residue to bioenergy and biofuel is a promising platform for global sustainability. Fractionation is an initial step for isolating lignocellulosic components for subsequent valorization. The aim of this research is to develop the solvothermal fractionation of sugarcane bagasse to produce high purity lignin. Physio-chemical structure of isolated lignin from this process was determined.Results: In this study, a central composite design-based response surface methodology (RSM) was used to optimize an acid promoter for isolating lignin from sugarcane bagasse using a solvothermal fractionation process. The reaction was carried out with sulfuric acid, in the concentration of 0.01-0.02 M and a reaction temperature of 180-200°C for 30-90 min. The optimal conditions for the experiment were obtained at the acid concentration of 0.02 M with a temperature of 180ºC for 90 min in methyl isobutyl ketone (MIBK)/methanol/water (35%:25%:40% v/v%). The results showed that 87.1% of lignin recovery was conducted in the organic phase, while 88.0% of lignin removal was done in the solid phase. Furthermore, the change in the physico-chemical characteristics of solid residue and lignin recovery was recorded using various techniques. A GPC analysis of recovered lignin from the organic fraction showed a low average Mw/Mn (1374/785 g/mol) and lower polydispersity index (1.75) compared to commercial organosolv lignin. The maximum lignin degradation temperatures of recovered lignin and commercial organosolv lignin were estimated to be 310°C and 334°C, which can point to potential relationships with the degradation of β-O-4 cross-links. The results indicated that recovered lignin is mostly cross-linked by the β-O-4 cross-links.Conclusions: The development of sulfuric acid catalyzed solvothermal process in this study provides the efficient extraction of high-value organosolv lignin from sugarcane bagasse and the production of recovered lignin in organic phase with low contamination from other contents. The lignin characteristic data can contribute to the development of lignin valorization in value-added applications.

Antiaminic agents derived from thieno[2,3-c]-2-benzothiepin: 4-(1-Methyl-4-piperidylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin and some related compounds

1983 ◽  
Vol 48 (2) ◽  
pp. 623-641 ◽  
Author(s):  
Zdeněk Polívka ◽  
Miroslav Rajšner ◽  
Jan Metyš ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Sulfuric Acid ◽  
Title Compound ◽  
Amino Alcohol ◽  
Hydrogen Sulfate ◽  
Geometric Isomers ◽  
Pure Alcohol ◽  
Acid Catalyzed ◽  
Anticataleptic Activity ◽  
Related Compounds

In the reaction of thieno[2,3c]-2-benzothiepin-4(9H)-one (VI) with 1-methyl-4-piperidylmagnesium chloride 7-(1-methyl-4-piperidyl)thieno[2,3-c]-2-benzothiepin-4(9H)-one (VIII) is formed in addition to the expected amino alcohol VII. The title compound I was obtained by the acid catalyzed dehydration of the pure alcohol VII. Compound I (pipethiadene) has outstanding antihistamine, antiserotonin, antireserpine and anticataleptic activity and was recommended to clinical trials as a potential antimigraine agent. For pharmacokinetic and metabolic studies there were prepared the NC2H3 analogue of pipethiadene IV and further, as potential metabolites, the demethyl analogue III, S-oxide X, demethyl S-oxide XI, N-oxide XIII and N,S-dioxide XIV. The Witting reaction of the ketone VI with 3-dimethylaminopropylidenetriphenylphosphorane resulted in a mixture of geometric isomers of 4-(3-dimethylamino-propylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin with the strongly predominating Z-isomer XVI which was isolated from the mixture by crystallization of the hydrogen maleate. The mixture with the predominating Z-isomer XVI was converted by the treatment with 80% sulfuric acid and dilution with water to a mixture with the predominating E-isomer XV (dithiadene) which was isolated by crystallization of the hydrogen sulfate. Some further new thieno[2,3-c]-2-benzothiepin derivatives were synthesized as potential intermediates.

scholarly journals Effect of severity factor on the hydrothermal pretreatment of sugarcane straw

2019 ◽  
Vol 275 ◽  
pp. 321-327 ◽  
Author(s):  
Gustavo Batista ◽  
Renata B.A. Souza ◽  
Bruna Pratto ◽  
Martha S.R. dos Santos-Rocha ◽  
Antonio J.G. Cruz
Keyword(s):  
Hydrothermal Pretreatment ◽  
Severity Factor ◽  
Sugarcane Straw
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