Experimental and mathematical optimization of the peroxide delignification of larch in the presence of MnSO4 catalyst

2020 ◽  
Vol 20 (1) ◽  
pp. 67-75
Author(s):  
I. G. Sudakova ◽  
N. V. Garyntseva ◽  
A. I. Chudina ◽  
B. N. Kuznetsov
Keyword(s):  
Mathematical Optimization ◽  
Single Step ◽  
High Yield ◽  
Optimal Conditions ◽  
Optimal Parameters ◽  
Mathematical Methods ◽  
Catalytic Method ◽  
Mild Conditions ◽  
Xrd Studies ◽  
Peroxide Delignification

Experimental and mathematical methods were used to obtain the optimal parameters of peroxide delignification of larch in the presence of MnSO4 catalyst, which provide a high yield of cellulose (44.3 wt.%) with a low content of residual lignin: temperature 100 °C, content of H2O2 6 wt.%, CH3COOH 25 wt.%, hydromodulus 15, and duration 3 h. The cellulose produced under optimal conditions had the following chemical composition: cellulose 92.7 wt.%, lignin 0.6 wt.%, and hemicellulose 5.7 wt.%. IR spectroscopy and XRD studies revealed that the structure of cellulose produced from larch is similar to that of industrial microcrystalline cellulose. The proposed catalytic method allows obtaining larch-derived cellulose with a minimum content of lignin under mild conditions in a single step with a high yield, crystallinity 0.8 and crystallite size 3.0 nm.

REGULARITIES OF THE PROCESS OF PINE WOOD PEROXIDE DELIGNIFICATION IN THE PRESENCE OF SULFURIC ACID CATALYST

2018 ◽  
pp. 63-71 ◽  
Author(s):  
Ирина (Irina) Геннадьевна (Gennad'yevna) Судакова (Sudakova) ◽  
Наталья (Natal'ya) Викторовна (Viktorovna) Гарынцева (Garyntseva) ◽  
Анна (Anna) Ильинична (Il’inichna) Чудина (Chudina) ◽  
Борис (Boris) Николаевич (Nikolaevich) Кузнецов (Kuznetsov)
Keyword(s):  
Microcrystalline Cellulose ◽  
Acid Catalyst ◽  
Raw Material ◽  
High Yield ◽  
Catalytic Method ◽  
Pine Wood ◽  
Temperature Range ◽  
Multi Stage ◽  
Hydrolysis Of Cellulose ◽  
Peroxide Delignification

The known methods to obtain microcrystalline cellulose (MCC) from wood raw material is multi-stage and it is based on the integration of environmentally hazardous processes of pulping, bleaching and acid hydrolysis of cellulose amorphous part. The paper describes a one-stage catalytic method to obtain microcrystalline cellulose from pine wood based on peroxide delignification in acetic acid-water in the presence of a catalyst H2SO4. The optimal parameters of the process of pine wood peroxide delignification in the presence of 2% H2SO4 catalyst were determined by experimental and numerical methods: temperature – 100 °C, concentration H2O2 – 5 wt.%, CH3COOH – 25 wt.%, LWR 15, duration – 4 h. They provide a high yield of cellulose (45.2 wt.%) with a low content of residual lignin (1.0 wt%).The kinetic study of pine wood peroxide delignification at the temperature range 70-100 ºC was accomplished. The delignification process is described satisfactory by the first order equation in all temperature range. The rate constants vary between 0.08·10-4 and 2.15·10-4 s-1 and the activation energy is 90 kJmol-1. It was established by FTIR and XRD methods, that the cellulose, obtained from pine wood has the composition and structure similar to the commercial microcrystalline cellulose.

scholarly journals MATHEMATICAL OPTIMIZATION OF THE PROCESS OF BIRCH WOOD XYLAN SULFATION BY SULFAMIC ACID IN N, N-DIMETHYLFORMAMIDE MEDIUM

2021 ◽  
pp. 87-94
Author(s):  
Aleksandr Sergeyevich Kazachenko ◽  
Vladimir Aleksandrovich Levdansky ◽  
Aleksandr Vladimirovich Levdansky ◽  
Boris Nikolayevich Kuznetsov
Keyword(s):  
Nmr Spectroscopy ◽  
Mathematical Optimization ◽  
Sulfamic Acid ◽  
13C Nmr Spectroscopy ◽  
Sulphur Content ◽  
Effect Of Temperature ◽  
High Yield ◽  
Birch Wood ◽  
Optimal Conditions ◽  
Birch Wood Xylan

The effect of temperature and duration of sulfation of birch wood xylan by sulfamic acid in N, N-dimethylformamide (DMF) medium in the presence of urea on the yield of sulfated xylan and on the sulphur content was studied. By mathematical optimization, the sulfation conditions have been established allowing to achieve a high yield of the obtained xylan sulfates with a high sulphur content. Under optimal sulfation conditions: temperature 100±3 °C, duration 1.5 hours, the yield of sulfated xylan reaches to 63% mas. and the content of sulfur – 17.6% mas. The presence of sulfate groups in sulfated xylan samples obtained under optimal conditions was confirmed by elemental analysis and FTIR and 13C NMR spectroscopy.

Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain

1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Culture Media ◽  
Biological Fluids ◽  
Single Step ◽  
High Yield ◽  
Step Method ◽  
Commercial Preparation ◽  
E Coli ◽  
Tissue Culture Media

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.

Application of Poly(Vinylbenzyltrimethylammonium Tribromide) Resin as an Efficient Polymeric Catalyst in the Acetalization and Diacetylation of Benzaldehydes

2020 ◽  
Vol 17 ◽  
Author(s):  
Zubiao Zheng ◽  
Bingbing Han ◽  
Junjun Hu ◽  
Xianwei Li
Keyword(s):  
High Efficiency ◽  
Optimal Conditions ◽  
Mild Conditions ◽  
Polymeric Catalyst

: The applications of a new supported tribromide reagent (poly(vinylbenzyltrimethylammonium tribromide) resin) were reported. This supported tribromide resin was used as a catalyst in the acetalization and diacetylation of benzaldehydes under mild conditions with high efficiency. The effects of solvents, amount of the supported tribromide resin on the reactions were investigated. Under the optimal conditions, most of acetal and 1,1-diacetates of benzaldehydes were selectively obtained in excellent yields.

Eco-Friendly Synthesis of Sulphonic Acid Oxime Esters Catalyzed by 2-(1H-Benzotriazole-1-yl)-1,1,3,3-Tetramethyluronium Tetrafluoroborate

2014 ◽  
Vol 525 ◽  
pp. 93-96
Author(s):  
Wei Shi ◽  
Ji Ming Zhang ◽  
Jian Hua Zhou ◽  
Jian Hua Zhou ◽  
Song Song Ding
Keyword(s):  
High Selectivity ◽  
Sulphonic Acid ◽  
Present Approach ◽  
High Yield ◽  
Facile Synthesis ◽  
Reaction Duration ◽  
Mild Conditions ◽  
Environmental Friendly

Herein we describle a facile synthesis of sulphonic acid oxime esters in acetonitrile from the corresponding sulphonic acids and oximes catalyzed by the environmental friendly 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) in the presence of triethylamine (TEA) under mild conditions. The present approach offers the advantages of a clean reaction, simple methodology, employing readily available catalyst, short reaction duration, high selectivity and high yield.

Regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole

2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Zheng Li ◽  
Tianpeng Li ◽  
Rugang Fu ◽  
Jingya Yang
Keyword(s):  
Transition Metal ◽  
Michael Addition ◽  
Potassium Acetate ◽  
High Yield ◽  
Metal Free ◽  
Mild Conditions

AbstractThe regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole catalyzed by potassium acetate is described. A series of 3-(benzotriazol-1-yl)-1,5-diarylpent-4-en-1-ones were efficiently synthesized under mild conditions. This protocol has advantages of transition-metal free catalyst, high yield and high regioselectivity.

scholarly journals High yield accelerated reactions in nonvolatile microthin films: chemical derivatization for analysis of single-cell intracellular fluid

2018 ◽  
Vol 9 (40) ◽  
pp. 7779-7786 ◽  
Author(s):  
Zhenwei Wei ◽  
Xiaochao Zhang ◽  
Jinyu Wang ◽  
Sichun Zhang ◽  
Xinrong Zhang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Single Cell ◽  
Individual Cell ◽  
High Yield ◽  
Chemical Derivatization ◽  
Intracellular Fluid ◽  
Mild Conditions ◽  
Successful Analysis ◽  
Trace Components

The identification of trace components from an individual cell can require derivatization under mild conditions for successful analysis by mass spectrometry (MS).

scholarly journals Green Preparation of High Yield Fluorescent Graphene Quantum Dots from Coal-Tar-Pitch by Mild Oxidation

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 844 ◽  
Author(s):  
Quanrun Liu ◽  
Jingjie Zhang ◽  
He He ◽  
Guangxu Huang ◽  
Baolin Xing ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Coal Tar ◽  
Graphene Quantum Dots ◽  
High Yield ◽  
Coal Tar Pitch ◽  
Narrow Size Distribution ◽  
Material Source ◽  
Graphene Layers ◽  
Mild Conditions ◽  
Simple Strategy

Coal tar pitch (CTP), a by-product of coking industry, has a unique molecule structure comprising an aromatic nucleus and several side chains bonding on this graphene-like nucleus, which is very similar to the structure of graphene quantum dots (GQDs). Based on this perception, we develop a facile approach to convert CTP to GQDs only by oxidation with hydrogen peroxide under mild conditions. One to three graphene layers, monodisperse GQDs with a narrow size distribution of 1.7 ± 0.4 nm, are obtained at high yield (more than 80 wt. %) from CTP. The as-produced GQDs are highly soluble and strongly fluorescent in aqueous solution. This simple strategy provides a feasible route towards the commercial synthesis of GQDs for its cheap material source, green reagent, mild condition, and high yield.

scholarly journals A Photochemical Strategy for Carbon Isotope Exchange with CO2

2020 ◽  
Author(s):  
Victor Babin ◽  
Alex Talbot ◽  
Alexandre Labiche ◽  
Gianluca Destro ◽  
Antonio Del Vecchio ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Isotope Exchange ◽  
Thermal Conditions ◽  
Single Step ◽  
Structural Modifications ◽  
Mild Conditions ◽  
Stark Contrast ◽  
Acetic Acids

A novel photocatalytic approach for carbon isotope exchange is reported. Utilizing [<sup>13</sup>C]CO<sub>2</sub> as primary C1 sources, this protocol allows the insertion of the desired carbon isotope into phenyl acetic acids without the need of structural modifications or pre-functionalization, in one single step. The exceptionally mild conditions required for this traceless transformation are in stark contrast with previous methods requiring the use of harsh thermal conditions.

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