scholarly journals Efficient Hydrolysis of Chitin in a Deep Eutectic Solvent Synergism for Production of Chitin Nanocrystals

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 869 ◽  
Author(s):  
Shu Hong ◽  
Yang Yuan ◽  
Kaitao Zhang ◽  
Hailan Lian ◽  
Henrikki Liimatainen
Keyword(s):  
Deep Eutectic Solvent ◽  
Average Diameter ◽  
Molar Ratio ◽  
High Yield ◽  
Mass Ratio ◽  
Synthesis Conditions ◽  
Chloride Hexahydrate ◽  
Low Energy Consumption ◽  
Ferric Chloride Hexahydrate ◽  
Hydrolysis Of

A deep eutectic solvent (DES) derived from ferric chloride hexahydrate and betaine chloride (molar ratio of 1:1) was used as hydrolytic media for production of chitin nanocrystals (ChNCs) with a high yield (up to 88.5%). The synergistic effect of Lewis acid and released Brønsted acid from betaine hydrochloride enabled the efficient hydrolysis of chitin for production of ChNCs coupled with ultrasonication with low energy consumption. The obtained ChNCs were with an average diameter of 10 nm and length of 268 nm, and a crystallinity of 89.2% with optimal synthesis conditions (at 100 °C for 1 h with chitin-to-DES mass ratio of 1:20). The ChNCs were further investigated as efficient emulsion stabilizers, and they resulted in stable o/w emulsions even at a high oil content of 50% with a low ChNC dosage of 1 mg/g. Therefore, a potential approach based on a DES on the production of chitin-based nanoparticles as emulsifiers is introduced.

scholarly journals Continuous Integrated Process of Biodiesel Production and Purification—The End of the Conventional Two-Stage Batch Process?

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 403
Author(s):  
Matea Bačić ◽  
Anabela Ljubić ◽  
Martin Gojun ◽  
Anita Šalić ◽  
Ana Jurinjak Tušek ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Deep Eutectic Solvent ◽  
International Standards ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Process Conditions ◽  
Integrated Process ◽  
Free Glycerol ◽  
Mass Ratio ◽  
Glycerol Content

In this research, optimization of the integrated biodiesel production process composed of transesterification of edible sunflower oil, catalyzed by commercial lipase, with simultaneous extraction of glycerol from the reaction mixture was performed. Deep eutectic solvents (DESs) were used in this integrated process as the reaction and extraction media. For two systems, choline chloride:glycerol (ChCl:Gly) and choline chloride:ethylene glycol (ChCl:EG), respectively, the optimal water content, mass ratio of the phase containing the mixture of reactants (oil and methanol) with an enzyme and a DES phase (mass ratio of phases), and the molar ratio of deep eutectic solvent constituents were determined using response surface methodology (RSM). Experiments performed with ChCl:Gly resulted in a higher biodiesel yield and higher glycerol extraction efficiency, namely, a mass ratio of phases of 1:1, a mass fraction of water of 6.6%, and a molar ratio of the ChCl:Gly of 1:3.5 were determined to be the optimal process conditions. When the reaction was performed in a batch reactor under the optimal conditions, the process resulted in a 43.54 ± 0.2% yield and 99.54 ± 0.19% glycerol extraction efficiency (t = 2 h). Unfortunately, the free glycerol content was higher than the one defined by international standards (wG > 0.02%); therefore, the process was performed in a microsystem to enhance the mass transfer. Gaining the same yield and free glycerol content below the standards (wG = 0.0019 ± 0.003%), the microsystem proved to be a good direction for future process optimization.

Effect of acidity on the properties of silica-aluminas synthesized by sol-gel method

2020 ◽  
Vol 63 (7) ◽  
pp. 126-132
Author(s):  
Lyubov V. Furda ◽  
◽  
Evgenia A. Tarasenko ◽  
Sofya N. Dudina ◽  
Olga E. Lebedeva ◽  
...  
Keyword(s):  
Surface Area ◽  
Sol Gel ◽  
Molar Ratio ◽  
Active Centers ◽  
Indicator Method ◽  
Synthesis Conditions ◽  
Alkaline Conditions ◽  
Acidic Conditions ◽  
Amphoteric Properties ◽  
Hydrolysis Of

In the present work amorphous silica-aluminas were synthesized by the coprecipitation method during the hydrolysis of an alcohol solution of tetraethoxysilane (with a tetraethoxysilane: alcohol mass ratio of 1: 1) and 6% aqueous solution of aluminum nitrate at pH values of 1, 3, and 10. The Si/Al molar ratio for all synthesized samples were 4.72 (± 0.29). The amorphous character of the investigated materials was confirmed by X-ray phase analysis. According to the results of scanning electron microscopy, it was found that the resulting powders have particles with a size of 1-20 μm. It was shown that the conditions of synthesis affected the specific surface area and porosity of the materials under study. By the method of low-temperature adsorption-thermodesorption of nitrogen it was established that silica-aluminas obtained under acidic conditions were microporous materials. For the sample obtained under alkaline conditions (pH = 10), the contribution of macropores is very significant. A decrease in surface area is observed as the pH of the synthesis increases. The Hammett indicator method was used to identify and quantify surface centers of different acidity. All studied silica-aluminas are characterized by the presence of both Brønsted basic (pKax from 7 to 12.8) and acidic (pKax from 0 to 7) centers, and Lewis basic (pKax from -4.4 to 0) with a pronounced maximum at pKax = 1.02. It was found that the synthesis conditions had a significant effect on the concentration of active centers. The values of the Hammett function are practically the same for the 3 studied silica-aluminas and describe the studied samples as materials of medium acidity. The variety of Lewis and Brønsted centers on the surface indicates the amphoteric properties of the materials under study. This gives the samples the properties of polyfunctional sorbents and catalysts.

scholarly journals An alkaline deep eutectic solvent based on potassium carbonate and glycerol as pretreatment for the isolation of cellulose nanocrystals from empty fruit bunch

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1154-1170
Author(s):  
Pei Gie Gan ◽  
Sung Ting Sam ◽  
Muhammad Faiq Abdullah ◽  
Mohd Firdaus Omar ◽  
Lian See Tan
Keyword(s):  
Acid Hydrolysis ◽  
Potassium Carbonate ◽  
Cellulose Nanocrystals ◽  
Deep Eutectic Solvent ◽  
Average Diameter ◽  
Processing Parameters ◽  
Molar Ratio ◽  
Composition Analysis ◽  
Empty Fruit Bunch ◽  
Box Behnken Design

Cellulose nanocrystals (CNC) were successfully isolated from oil palm empty fruit bunch (EFB) using sulphuric acid hydrolysis preceded by alkaline deep eutectic solvent (DES) pretreatment and bleaching. In this study, an alkaline DES consisting of potassium carbonate and glycerol (molar ratio of 1:7) was used as the pretreatment solvent to promote the dissolution of lignin and hemicellulose. The processing parameters of acid hydrolysis were optimized using Box-Behnken Design. The results showed that the yield of CNC was 37.1%, under the optimal conditions of 60.0 wt% acid concentration at 46.1 °C for 58.5 min. The field emission scanning electron microscopy (FESEM), chemical composition analysis, and Fourier transform infrared (FTIR) results indicated that unwanted impurities, such as hemicellulose and lignin, were efficiently eliminated from the raw EFB fibers by DES pretreatment and bleaching. The average diameter of CNC was less than 10 nm. The raw EFB fiber, treated cellulose, and CNC showed crystallinities of 38.7%, 51.2%, and 65.3%, respectively. The CNC had lower thermal stability, which was ascribed to the sulphate group present on the CNC surface.

Iron carbide and nitride via a flexible route: synthesis, structure and magnetic properties

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21670-21674 ◽  
Author(s):  
Peng Zhang ◽  
Xiaobai Wang ◽  
Wei Wang ◽  
Xiang Lei ◽  
Hua Yang
Keyword(s):  
Magnetic Properties ◽  
Ferric Chloride ◽  
Iron Carbide ◽  
Molar Ratio ◽  
Chloride Hexahydrate ◽  
Ferric Chloride Hexahydrate

Fe4N and Fe3C have been controllably synthesized by adjusting the molar ratio of hexamethylenetetramine to ferric chloride hexahydrate.

An efficient procedure for the TEMPO-catalyzed oxidation of alcohols to aldehydes and ketones using ferric chloride hexahydrate as terminal oxidant

2008 ◽  
Vol 86 (7) ◽  
pp. 720-725 ◽  
Author(s):  
R Senthil Kumar ◽  
K Karthikeyan ◽  
Paramasivan T Perumal
Keyword(s):  
Ferric Chloride ◽  
High Yield ◽  
Efficient Procedure ◽  
Chloride Hexahydrate ◽  
Oxidation Of Alcohols ◽  
Aldehydes And Ketones ◽  
Ferric Chloride Hexahydrate ◽  
Catalyzed Oxidation

A simple, efficient procedure for the oxidation of alcohols by catalytic 2,2,6,6-tetramethyl-piperidyl-1-oxy (TEMPO) was developed using FeCl3·6H2O as the terminal oxidant. The reaction gives high yield of the corresponding aldehydes and ketones with no over oxidation to the acid.Key words: oxidation, TEMPO, FeCl3·6H2O.

Synthesis of Magnesium Oxychloride Nanowhisker by Microemulsion Method

2012 ◽  
Vol 535-537 ◽  
pp. 357-361
Author(s):  
Lin Qing Qin ◽  
Chuang Bin Wang ◽  
Zhi Yang Qin
Keyword(s):  
Magnesium Chloride ◽  
Average Diameter ◽  
Soft Template ◽  
Ammonium Bromide ◽  
Mass Ratio ◽  
Microemulsion Method ◽  
Transmission Electron ◽  
Chloride Hexahydrate ◽  
Magnesium Oxychloride ◽  
Cetyltrimethyl Ammonium

Magnesium oxychloride (MOC,5Mg(OH)2•MgCl2•8H2O,phase 5) nanowhiskers were synthesized via a reverse microemulsion method by suing cetyltrimethyl ammonium bromide (CTAB)/n-butanol (C4H10O)/cyclohexane (C6H12)/water as soft-template. Aqueous solution of magnesium chloride (MgCl2) and MgO powder were suing as reactants. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Results indicated that MOC nanowhiskers can be obtained when the mass ratio of MgO, magnesium chloride hexahydrate and water is 1:1:0.64. The aspect ratio of MOC nanowhisker is more than 100 with an average diameter of 50-90 nm. The influence of size of MgO particles and mass ratio of MgCl2 solution to CTAB on morphology of whiskers was investigated. The growth mechanism of the MOC nanowhisker was also supposed in this study.

Alkylation of enolate anions with dimethyl 3-bromo-2-ethoxypropenylphosphonate. A convergent cyclopentenone annulation method

1982 ◽  
Vol 60 (9) ◽  
pp. 1114-1121 ◽  
Author(s):  
Edward Piers ◽  
Brian Abeysekera
Keyword(s):  
Acid Hydrolysis ◽  
Ferric Chloride ◽  
Sodium Hydride ◽  
Enol Ether ◽  
Mild Acid Hydrolysis ◽  
Chloride Hexahydrate ◽  
Ferric Chloride Hexahydrate ◽  
Allylic Bromide ◽  
Hydrolysis Of ◽  
Mild Acid

A new, convergent synthesis of 2-cyclopenten-1 -ones is reported. Treatment of dimethyl 2-oxopropylphosphonate (21) with excess triethyl orthoformate in the presence of ferric chloride hexahydrate provides the enol ether 22, which upon allylic bromination with N-bromosuccinimide yields the allylic bromide 19. Alkylation of the ketones 24–28 with 19, followed by mild acid hydrolysis of the resultant products 29–33, affords the diketo phosphonates 34–38. When the latter substances are treated with sodium hydride in dimethoxyethane, the corresponding 2-cyclopenten-1 -ones 40–44 are formed in good yields.

Efficient Micromixing for Continuous Biodiesel Production from Jatropha Oil

2018 ◽  
Vol 9 (1) ◽  
pp. 133-139
Author(s):  
Waleed S. Mohammed ◽  
Ahmed H. El-Shazly ◽  
Marwa F. Elkady ◽  
Masahiro Ohshima
Keyword(s):  
Methyl Esters ◽  
Continuous Process ◽  
Sol Gel ◽  
Average Diameter ◽  
Biodiesel Production ◽  
High Mass ◽  
Molar Ratio ◽  
Jatropha Oil ◽  
Energy Deficiency ◽  
Gel Preparation

Introduction: The utilization of biodiesel as an alternative fuel is turning out to be progressively famous these days because of worldwide energy deficiency. The enthusiasm for utilizing Jatropha as a non-edible oil feedstock is quickly developing. The performance of the base catalyzed methanolysis reaction could be improved by a continuous process through a microreactor in view of the high mass transfer coefficient of this technique. Materials & Methods: Nanozirconium tungstovanadate, which was synthetized using sol-gel preparation method, was utilized in a complementary step for biodiesel production process. The prepared material has an average diameter of 0.066 &µm. Results: First, the NaOH catalyzed methanolysis of Jatropha oil was investigated in a continuous microreactor, and the efficient mixing over different mixers and its impact on the biodiesel yield were studied under varied conditions. Second, the effect of adding the nanocatalyst as a second stage was investigated. Conclusion: The maximum percentage of produced methyl esters from Jatropha oil was 98.1% using a methanol/Jatropha oil molar ratio of 11 within 94 s using 1% NaOH at 60 &°C. The same maximum conversion ratio was recorded with the nanocatalyst via only 0.3% NaOH.

scholarly journals Generation of highly amenable cellulose-Iβ via selective delignification of rice straw using a reusable cyclic ether-assisted deep eutectic solvent system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chiranjeevi Thulluri ◽  
Ravi Balasubramaniam ◽  
Harshad Ravindra Velankar
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Deep Eutectic Solvent ◽  
Solvent System ◽  
Cyclic Ether ◽  
Cellulolytic Enzymes ◽  
Ammonium Bromide ◽  
Selective Delignification ◽  
Cellulose Iβ ◽  
Hydrolysis Of

AbstractCellulolytic enzymes can readily access the cellulosic component of lignocellulosic biomass after the removal of lignin during biomass pretreatment. The enzymatic hydrolysis of cellulose is necessary for generating monomeric sugars, which are then fermented into ethanol. In our study, a combination of a deep eutectic (DE) mixture (of 2-aminoethanol and tetra-n-butyl ammonium bromide) and a cyclic ether (tetrahydrofuran) was used for selective delignification of rice straw (RS) under mild conditions (100 °C). Pretreatment with DE-THF solvent system caused ~ 46% delignification whereas cellulose (~ 91%) and hemicellulose (~ 67%) recoveries remained higher. The new solvent system could be reused upto 10 subsequent cycles with the same effectivity. Interestingly, the DE-THF pretreated cellulose showed remarkable enzymatic hydrolysability, despite an increase in its crystallinity to 72.3%. Contrary to conventional pretreatments, we report for the first time that the enzymatic hydrolysis of pretreated cellulose is enhanced by the removal of lignin during DE-THF pretreatment, notwithstanding an increase in its crystallinity. The current study paves way for the development of newer strategies for biomass depolymerization with DES based solvents.

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