scholarly journals Delignification of unbleached pulp by ternary deep eutectic solvents

2021 ◽  
Vol 10 (1) ◽  
pp. 666-676
Author(s):  
Veronika Majová ◽  
Michal Jablonský ◽  
Marek Lelovský
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Molar Ratios ◽  
The Individual ◽  
Low Solubility ◽  
Unbleached Pulp

Abstract The processing of lignocellulosic materials is very limited because of their low solubility in water and some organic solvents. Fifteen ternary deep eutectic solvents (DESs) were prepared and tested as solvents suitable for delignification of unbleached pulp. The selected ternary DESs are composed of quaternary ammonium salts and amino acids as hydrogen-bond acceptors, and organic acids and polyvalent alcohols as hydrogen bond donors, with molar ratios varying for the individual components. The delignification efficiency is significantly influenced by the degree of penetration of the solvent into the pulp fibre structure. Therefore, the density and viscosity analysis of individual solvents was performed. Unbleached beech pulp with initial kappa number 13.9 was treated with the prepared DESs. The kappa number indicates the residual lignin content or the bleachability of pulp. The efficiency of the solvents ranged from 1.4% to 28.1%. The most suitable for the pretreatment of fibres, based on lignin removal efficiency, were found to be three DESs, in the following order: malonic acid/choline chloride/1,3-propanediol (1:1:3) > choline chloride/acetamide/lactic acid (1:2:3) > choline chloride/urea/lactic acid (1:2:3).

Deep eutectic solvent delignification: Impact of initial lignin

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 7301-7310
Author(s):  
Veronika Majová ◽  
Silvia Horanová ◽  
Andrea Škulcová ◽  
Jozef Šima ◽  
Michal Jablonský
Keyword(s):  
Lactic Acid ◽  
Oxalic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Detailed Understanding

This study aimed to resolve the issue of the lack of detailed understanding of the effect of initial lignin content in hardwood kraft pulps on pulp delignification by deep eutectic solvents. The authors used Kappa number of the concerned pulp, intrinsic viscosity, and selectivity and efficiency of delignification as the parameters of the effect. The pulp (50 g oven dry pulp) was treated with four different DESs systems based on choline chloride with lactic acid (1:9), oxalic acid (1:1), malic acid (1:1), and system alanine:lactic acid (1:9); the results were compared to those reached by oxygen delignification. The results showed that the pulp with a higher initial lignin content had a greater fraction of easily removed lignin fragments.

scholarly journals Choline Chloride Based Natural Deep Eutectic Solvents as Extraction Media for Extracting Phenolic Compounds from Chokeberry (Aronia melanocarpa)

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1619 ◽  
Author(s):  
Maša Islamčević Razboršek ◽  
Milena Ivanović ◽  
Peter Krajnc ◽  
Mitja Kolar
Keyword(s):  
Hydrogen Bond ◽  
Phenolic Compounds ◽  
Choline Chloride ◽  
Dry Weight ◽  
Deep Eutectic Solvents ◽  
Ultrasound Assisted Extraction ◽  
Hydrogen Bond Acceptor ◽  
Mean Values ◽  
Natural Deep Eutectic Solvents ◽  
The Individual

For the isolation of selected phenolic compounds from dried chokeberries, natural deep eutectic solvents (NADESs) were investigated as a green alternative to conventionally used extraction solvents. Four types of NADESs were synthesised, with choline chloride as the hydrogen bond acceptor in combination with different hydrogen bond donors (sugars, organic acid and urea). Ultrasound-assisted extraction was used to improve the extractability of the phenolic compounds and the results were compared to those obtained with 80% methanol as the extraction media. The highest values of total phenols and total flavonoids were found in the extract obtained with choline chloride–fructose NADES (36.15 ± 3.39 mg gallic acid g−1 dry weight (DW) and 4.71 ± 0.33 mg rutin g−1 DW, respectively). The extraction recoveries for the individual phenolic compounds depended strongly on the phenolic compound’s structure, with relative mean values between 70% and 97%.

scholarly journals Integration of Choline Chloride-Based Natural Deep Eutectic Solvents and Macroporous Resin for Green Production of Enriched Oil Palm Flavonoids as Natural Wound Healing Agents

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1802
Author(s):  
Mohamad Shazeli Che Zain ◽  
Jen Xen Yeoh ◽  
Soo Yee Lee ◽  
Adlin Afzan ◽  
Khozirah Shaari
Keyword(s):  
Hydrogen Bond ◽  
Wound Healing ◽  
Oil Palm ◽  
Choline Chloride ◽  
Radical Scavenging ◽  
Deep Eutectic Solvents ◽  
Hydrogen Bond Acceptor ◽  
Molar Ratios ◽  
Natural Deep Eutectic Solvents ◽  
Water Contents

Huge quantities of oil palm (Elaeis guineensis Jacq.) leaves (OPL) are generated as agricultural biomass from oil palm plantations. OPL are known to contain significant amounts of flavonoids. For maximal exploitation of these valuable antioxidant compounds, an innovative and sustainable extraction method employing natural deep eutectic solvents (NaDES) combined with ultrasonic assisted extraction was developed. Various NaDES composed of choline chloride as the hydrogen bond donor (HBD) and 1,2 propanediol (PD), 1,4 butanediol (BD), glycerol (GLY), glucose (GLU), maltose (MAL), and lactic acid (LA) as the hydrogen bond acceptor (HBA) were synthesized. The influence of these compositions, the methods of their synthesis, molar ratios, and water contents on their capacity to extract flavonoids from OPL was evaluated. Based on the results, it was found that methods which incorporate a heating step produced NaDES with the best capacity to extract OPL flavonoids. These thermal methods combined with molar ratios of 1:3 or 1:4 and water contents of 17 to 50% were found to be the optimal conditions for preparing NaDES, specifically when applied to the PD, BD, and GLY NaDES. Subsequently, UHPLC-UV/PDA-MS/MS analysis revealed NaDES extracts recovered by macroporous adsorption resin XAD7HP were able to optimally extract at least twelve luteolin and apigenin derivatives in OPL NaDES extracts prepared from glycerol and 1,4-butanediol demonstrated better and comparable efficiency as aqueous methanol in extracting flavonoids from OPL. The in vitro studies of antioxidant and wound healing properties supported these findings by exhibiting good free radical scavenging, cell proliferation, and migration activities. Additionally, the NaDES extracts also showed non-cytotoxicity effects at 1000 µg/mL and below on 3T3 fibroblast cells. Results of the study showed that NaDES could be a promising eco-friendly green solvent to extract bioactive OPL flavonoids that have great potential for applications as wound healing agents.

scholarly journals Silica Gel Impregnated by Deep Eutectic Solvents for Adsorptive Removal of BTEX from Gas Streams

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1894 ◽  
Author(s):  
Patrycja Makoś ◽  
Edyta Słupek ◽  
Aleksandra Małachowska
Keyword(s):  
Lactic Acid ◽  
Silica Gel ◽  
Choline Chloride ◽  
Specific Interaction ◽  
Chemical Properties ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Gas Streams ◽  
Tetrapropylammonium Bromide ◽  
Sorbent Materials

The paper presents the preparation of new adsorbents based on silica gel (SiO2) impregnated with deep eutectic solvents (DESs) to increase benzene, toluene, ethylbenzene, and p-xylene (BTEX) adsorption efficiency from gas streams. The DESs were synthesized by means of choline chloride, tetrapropylammonium bromide, levulinic acid, lactic acid, and phenol. The physico-chemical properties of new sorbent materials, including surface morphology and structures, as well as porosity, were studied by means of thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller analysis. The effect of DESs type, flow rate, and initial concentration of BTEX were also investigated followed by regeneration and reusability of adsorbents. The results indicate that SiO2 impregnated with tetrapropylammonium bromide and lactic acid in a 1:2 molar ratio have great potential for the removal of BTEX from gas streams. Its adsorption capacity was higher than the pure SiO2 and other developed SiO2-DES adsorbents. This result can be explained by the specific interaction between DESs and BTEX, i.e., hydrogen bonds interaction.

scholarly journals Facilely reducing recalcitrance of lignocellulosic biomass by a newly developed ethylamine-based deep eutectic solvent for biobutanol fermentation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignocellulosic Biomass ◽  
Fossil Fuels ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Specific Yield ◽  
Green Solvents ◽  
Hydrogen Bond Donor ◽  
Total Sugars

Abstract Background Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation. Results Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars as high as 53.5 g L−1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU g−1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g L−1 and 706 g kg−1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g L−1 was achieved with butanol yield of 137 g kg−1 pretreated corncob by Clostridium saccharobutylicum DSM13864. Conclusions Ethylamine and lactic acid-based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.

scholarly journals Review on Carbon Dioxide Absorption by Choline Chloride/Urea Deep Eutectic Solvents

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Rima J. Isaifan ◽  
Abdukarem Amhamed
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Bond ◽  
Ionic Liquids ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Absorption Capacity ◽  
Carbon Dioxide Absorption ◽  
Hydrogen Bond Donor ◽  
Separation Processes ◽  
Hydrogen Bond Acceptor

In the recent past few years, deep eutectic solvents (DESs) were developed sharing similar characteristics to ionic liquids but with more advantageous features related to preparation cost, environmental impact, and efficiency for gas separation processes. Amongst many combinations of DES solvents that have been prepared, reline (choline chloride as the hydrogen bond acceptor mixed with urea as the hydrogen bond donor) was the first DES synthesized and is still the one with the lowest melting point. Choline chloride/urea DES has proven to be a promising solvent as an efficient medium for carbon dioxide capture when compared with amine alone or ionic liquids under the same conditions. This review sheds light on the preparation method, physical and chemical characteristics, and the CO2 absorption capacity of choline chloride/urea DES under different temperatures and pressures reported up to date.

scholarly journals The Effect of Deep Eutectic Solvents as Co-solvent on Organophosphorus Hydrolase Targeting Engineering Enzyme-catalyzed

2020 ◽  
Vol 10 (5) ◽  
pp. 6488-6497
Keyword(s):  
Organic Solvents ◽  
Low Cost ◽  
Choline Chloride ◽  
Molar Fraction ◽  
Enzyme Reaction ◽  
Deep Eutectic Solvents ◽  
Biochemical Properties ◽  
Organophosphorus Hydrolase ◽  
The Stability ◽  
The Individual

Deep eutectic solvents (DESs) are systems formed from one or more compounds in a mixture form, to give a eutectic with a melting point much lower than either of the individual components. DESs have attracted considerable attention as green alternative solvents to conventional solvents because they are not only eco-friendly, non-toxic, and biodegradable organic compounds, but also low cost and easy to produce.and share several features and properties. DESs not only have particular properties in comparison with traditional organic solvents, but also their combination with organic solvents may also show improved and desired properties. In this study, DESs were used as the solvent in buffer containing organophosphorus hydrolase enzyme, in order to optimize the enzyme reaction buffer. Different DESs such as reline (choline chloride 2:1 urea), ethaline (choline chloride 2:1 ethanol) and glyceline (choline chloride 2:1 glycerol) were selected as an adjuvant for OPH enzyme reaction buffer. Biochemical properties, thermal stability and half-life of the OPH enzyme were studied, accordingly. In the reline, a reduction in the activity of the enzyme and in ethaline and glyceline, an increase in the activity and the stability were observed when compared with the buffer. The highest activity and stability in ethaline and glyceline in molar fraction was 0.025 and 0.25, respectively.

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