Heterogeneous Acid Hydrolysis of Native Cellulose Fibers

1956 ◽  
Vol 48 (7) ◽  
pp. 1183-1189 ◽  
Author(s):  
E. A. Immergut ◽  
B. G. Rånby
Keyword(s):  
Acid Hydrolysis ◽  
Cellulose Fibers ◽  
Native Cellulose ◽  
Hydrolysis Of

scholarly journals Zhurkov’s Stress-Driven Fracture as a Driving Force of the Microcrystalline Cellulose Formation

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2952
Author(s):  
Sergey V. Stovbun ◽  
Mariya G. Mikhaleva ◽  
Aleksey A. Skoblin ◽  
Sergey V. Usachev ◽  
Sergey N. Nikolsky ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Driving Force ◽  
Food Industry ◽  
Thermal Destruction ◽  
Chemical Conversion ◽  
Cellulose Fibers ◽  
Point Of View ◽  
Pure Product ◽  
Hydrolysis Of

Microcrystalline cellulose (MCC) is a chemically pure product of cellulose mechano-chemical conversion. It is a white powder composed of the short fragments of the plant cells widely used in the modern food industry and pharmaceutics. The acid hydrolysis of the bleached lignin-free cellulose raw is the main and necessary stage of MCC production. For this reason, the acid hydrolysis is generally accepted to be the driving force of the fragmentation of the initial cellulose fibers into MCC particles. However, the low sensibility of the MCC properties to repeating the hydrolysis forces doubting this point of view. The sharp, cleave-looking edges of the MCC particles suggesting the initial cellulose fibers were fractured; hence the hydrolysis made them brittle. Zhurkov showed that mechanical stress decreases the activation energy of the polymer fracture, which correlates with the elevated enthalpy of the MCC thermal destruction compared to the initial cellulose.

Anaerobic Treatment of Pulp Mill Effluents

1991 ◽  
Vol 24 (7) ◽  
pp. 203-206 ◽  
Author(s):  
M. K. Korczak ◽  
S. Koziarski ◽  
B. Komorowska
Keyword(s):  
Acid Hydrolysis ◽  
Pulp Mill ◽  
Cellulose Fibers ◽  
Anaerobic Treatment ◽  
High Molecular Mass ◽  
Cod Removal ◽  
Cellulose Production ◽  
Methane Generation ◽  
Pulp Mill Effluents ◽  
Hydrolysis Of

A laboratory-scale study on the anaerobic treatment of selected pulp mill streams was carried out in a collaboration between the Research Institute for Environmental Protection and Designing Office of Water and Waste Disposal. Anaerobic treatment of effluents from acid hydrolysis of wood from sulfate cellulose production, and effluents from the sulfite cellulose fibers washing was investigated. The results indicated 80% COD removal and the average methane generation was found to be 340 Ncm3/gCOD removed in case of highly polluted (COD = 63 kgO2/m3) acid hydrolysis effluents. The waste from cellulose washing contained, beside sugars, alsorefractory compounds, such as high-molecular-mass lignin derivatives, resins and tannins. According to that, only 20-30% COD removal was obtained and the methane generation was 270-360 Ncm3/g COD removed.

The Shape and Size Distribution of Crystalline Nanoparticles Prepared by Acid Hydrolysis of Native Cellulose

2008 ◽  
Vol 9 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Samira Elazzouzi-Hafraoui ◽  
Yoshiharu Nishiyama ◽  
Jean-Luc Putaux ◽  
Laurent Heux ◽  
Frédéric Dubreuil ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Size Distribution ◽  
Native Cellulose ◽  
Hydrolysis Of ◽  
Shape And Size

scholarly journals FUNCTIONAL MATERIALS FROM PAPER WASTES. I. FROM WASTE NEWSPRINT PAPER AND CARDBOARD TO HIGH-GRADE CELLULOSE FIBERS

2018 ◽  
pp. 27-35
Author(s):  
Александра (Aleksandra) Михайловна (Mikhailovna) Михаилиди (Mikhailidi) ◽  
Вадим (Vadim) Иванович (Ivanovich) Маркин (Markin) ◽  
Нина (Nina) Ефимовна (Efimovna) Котельникова (Kotel'nikova) ◽  
Shahriar Karim Saurov
Keyword(s):  
Methylene Blue ◽  
Acid Hydrolysis ◽  
Alkali Treatment ◽  
Functional Materials ◽  
Renewable Resource ◽  
Cellulose Fibers ◽  
High Grade ◽  
Cellulose I ◽  
Powder Cellulose ◽  
Hydrolysis Of

Utilization of paper wastes as renewable resource of lignocellulosic constituents has the opportunity to promote a cleaner environment and to prepare valuable materials. This paper describes our study on an isolation of low-fiber powder cellulose from two grades of wastes as feedstocks: waste newsprint paper and cardboard wrapper through recycling including a thermal defibration, an alkali treatment with a solution of NaOH with a concentration from 0.03 to 1.00 М, a bleaching with a solution of Н2О2 with a concentration from 0.8 to 2.6 М followed with an acid hydrolysis of the pretreated species with a solution of HNO3 of 1.5 and 3.0 M. An impact of the pretreatment on sizes of fibers was evaluated with a stereoscopic microscopy. The powder celluloses obtained as a result of the acid hydrolysis exhibited the structure of cellulose I revealed with a WAXS method and were of a high-grade purity, according to EDXA. Sorption capacities of the powder celluloses from the waste cardboard and newsprint towards a dye methylene blue were 6.67 mg∙g-1 and 8.75 mg∙g-1 correspondingly.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

Deinking of recycled paper by coupling of the enzyme endo-β-1,4-D-glucanasa and the cellulose, and by using a laboratory flotation column

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2669-2678
Author(s):  
Jeovani González P. ◽  
Ramiro Escudero G
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Paper Industry ◽  
Computational Simulation ◽  
Cellulose Fibers ◽  
Residual Water ◽  
Chemical Reagent ◽  
Recycled Paper ◽  
Flotation Column ◽  
Hydrolysis Of

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.

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