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

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.

Download Full-text

Structural elucidation of lignins from corncob acid hydrolysis residue by enzymatic mild acidolysis and deep eutectic solvent pretreatment

BioResources ◽

10.15376/biores.15.2.4362-4372 ◽

2020 ◽

Vol 15 (2) ◽

pp. 4362-4372

Author(s):

Na Li ◽

Chao Cao ◽

Lupeng Shao ◽

Chao Wang ◽

Yu Liu ◽

...

Keyword(s):

Acid Hydrolysis ◽

31P Nmr ◽

Structural Characteristics ◽

Choline Chloride ◽

Deep Eutectic Solvent ◽

Gel Permeation Chromatography ◽

Structural Features ◽

Molar Ratio ◽

Efficient Extraction ◽

Hydrolysis Residue

Achieving mild and efficient extraction of high purity lignin from corncob acid hydrolysis residue is essential for efficient lignin application. In this study, enzymatic/mild acidolysis lignin (EMAL) and deep eutectic solvent (DES)-lignin were extracted from corncob acid hydrolysis residue. The structural features of the two lignin fractions were investigated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), and 31P-nuclear magnetic resonance (31P-NMR). The highest DES-lignin yield of 58.8 wt% was achieved at 120 °C with a choline chloride-to-lactic acid (ChCl-to-Lac) molar ratio of 1:10 and a reaction time of 12 h. The FTIR analysis indicated a higher amount of guaiacyl units in EMAL than DES-lignin. Furthermore, condensation and fragmentation occurred simultaneously under DES pretreatment, but the fragmentation reaction was dominant. The structural characteristics investigated will allow for more effective lignin usage.

Download Full-text

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

Nanomaterials ◽

10.3390/nano10050869 ◽

2020 ◽

Vol 10 (5) ◽

pp. 869 ◽

Cited By ~ 2

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.

Download Full-text

Densities and Refractive Indices of Potassium Carbonate -Based Deep Eutectic Solvents with Dual Hydrogen Bond Donors at Several Temperatures (293.15 to 343.15 K)

10.20944/preprints201705.0148.v1 ◽

2017 ◽

Author(s):

Hosein Ghaedi ◽

Muhammad Ayoub ◽

Suriati Sufian ◽

Azmi Mohd Shariff ◽

Bhajan Lal

Keyword(s):

Hydrogen Bond ◽

Refractive Index ◽

Potassium Carbonate ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Molar Ratio ◽

Hydrogen Bond Acceptor ◽

Molar Ratios ◽

Experimental Density ◽

Hydrogen Bond Donors

Deep eutectic solvents (DESs) are known as tunable solvents. It is possible to prepare ternary deep eutectic solvent (TDES) are used for desired purpose by selecting the suitable molar ratio and components of mixture. Therefore, four DESs and two TDESs were prepared in this work. DESs and TDESs were prepared with potassium carbonate (PC) as a hydrogen bond acceptor (HBA) and three hydrogen bond donors (HBDs) such as glycerol (GL), ethylene glycol (EG) and 2-amino-2methyl-1-3-propanediol (AMPD) known as a hindered amine (HA). Binary DESs were PC-GL with molar ratios 1:10 and 1:16 and PC-EG with the same molar ratios. TDES were prepared by adding AMPD in binary DESs such as PC-GL-AMPD 1:16:1 and PC-EG-AMPD 1:10:1. The experimental density and refractive index of all DESs and TDESs were measured at the temperature of 293.15 to 343.15 K with an interval of 5 K. The effect of temperature, molar ratio and alkyl chain length on the properties was investigated. The molar volumes and isobaric thermal expansion were calculated using experimental density data. The experimental refractive index data was used to derive the specific refraction, molar refraction, free molar volume, electronic polarization, polarizability constant and internal pressure at several temperatures.

Download Full-text

Efficient Micromixing for Continuous Biodiesel Production from Jatropha Oil

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681207666170718160304 ◽

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.

Download Full-text

Cellulose Nanocrystals Derived from Textile Waste through Acid Hydrolysis and Oxidation as Reinforcing Agent of Soy Protein Films

10.21748/am20.197 ◽

2020 ◽

Author(s):

Shuting Huang

Keyword(s):

Acid Hydrolysis ◽

Soy Protein ◽

Cellulose Nanocrystals ◽

Protein Films ◽

Textile Waste ◽

Reinforcing Agent

Download Full-text

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

Energies ◽

10.3390/en14020403 ◽

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.

Download Full-text

Paving the Way to Food Grade Analytical Chemistry: Use of a Natural Deep Eutectic Solvent to Determine Total Hydroxytyrosol and Tyrosol in Extra Virgin Olive Oils

Foods ◽

10.3390/foods10030677 ◽

2021 ◽

Vol 10 (3) ◽

pp. 677

Author(s):

Vito Michele Paradiso ◽

Francesco Longobardi ◽

Stefania Fortunato ◽

Pasqua Rotondi ◽

Maria Bellumori ◽

...

Keyword(s):

Analytical Chemistry ◽

Acid Hydrolysis ◽

Virgin Olive Oil ◽

Deep Eutectic Solvent ◽

Spectrophotometric Analysis ◽

Health Claim ◽

Food Grade ◽

Olive Oils ◽

Natural Deep Eutectic Solvent ◽

The Way

Extra virgin olive oil (EVOO) is well known for containing relevant amounts of healthy phenolic compounds. The European Food Safety Authority (EFSA) allowed a health claim for labelling olive oils containing a minimum amount of hydroxytyrosol (OHTyr) and its derivatives, including tyrosol (Tyr). Therefore, harmonized and standardized analytical protocols are required in support of an effective application of the health claim. Acid hydrolysis performed after extraction and before chromatographic analysis has been shown to be a feasible approach. Nevertheless, other fast, green, and easy methods could be useful for on-site screening and monitoring applications. In the present research, a natural deep eutectic solvent (NADES) composed of lactic acid and glucose was used to perform a liquid/liquid extraction on EVOO samples, followed by UV-spectrophotometric analysis. The spectral features of the extracts were related with the content of total OHTyr and Tyr, determined by the acid hydrolysis method. The second derivative of spectra allowed focusing on three single wavelengths (i.e., 299 nm, 290 nm, and 282 nm) significantly related with total OHTyr, total Tyr, and their sum, respectively. In particular, the sum of OHTyr and Tyr could be determined with a root mean square error of prediction of 29.5 mg kg−1, while the limits of quantitation and detection were respectively 11.8 and 4.9 mg kg−1. The proposed method, therefore, represents an easy screening tool, with the use of a green, food-derived solvent, and could be considered as an attempt to pave the way for food grade analytical chemistry.

Download Full-text