The Hydrolysis of Hydrogen Cyanide in Acetic Acid Solutions with Mineral Acids as Catalysts1

1943 ◽  
Vol 65 (8) ◽  
pp. 1479-1482
Author(s):  
Vernon K. Krieble ◽  
Frederick C. Duennebier ◽  
Edward Colton
Keyword(s):  
Acetic Acid ◽  
Hydrogen Cyanide ◽  
Acid Solutions ◽  
Mineral Acids ◽  
Hydrolysis Of

THE HYDROLYSIS OF PROPIONITRILE IN CONCENTRATED SOLUTIONS OF MINERAL ACIDS

1942 ◽  
Vol 20b (8) ◽  
pp. 168-173 ◽  
Author(s):  
J. D. McLean ◽  
B. S. Rabinovitch ◽  
C. A. Winkler
Keyword(s):  
Activation Energy ◽  
Sulphuric Acid ◽  
Acid Concentration ◽  
Rate Increase ◽  
Acid Solutions ◽  
Concentrated Solutions ◽  
Consecutive Reactions ◽  
Mineral Acids ◽  
Hydrolysis Of

The study of the hydrolysis of propionitrile in concentrated acid solutions has been extended to hydrobromic, nitric, and sulphuric acids for a range of acid concentrations. For the system of irreversible, unimolecular consecutive reactions, nitrile [Formula: see text] amide [Formula: see text] acid, [Formula: see text] for all acid concentrations below 4 N. At higher concentrations, k1 and k2 are of the same order, and, in the case of sulphuric acid, k1 becomes [Formula: see text]k2 at concentrations above 20 N. The observed activation energy decreases with increasing acid concentration for all acids. The specific differences in rate increase with acid concentration may be accounted for by the specific variations of A and E for each acid.

Organic material dissolved during oxygen-alkali pulping of hot water extracted birch sawdust

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN
Keyword(s):  
Acetic Acid ◽  
Betula Pendula ◽  
Cooking Time ◽  
Hot Water ◽  
Partial Hydrolysis ◽  
Chemical Pulping ◽  
Black Liquors ◽  
Aliphatic Carboxylic Acids ◽  
Hydrolysis Of ◽  
Cooking Conditions

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

scholarly journals A novel recyclable furoic acid-assisted pretreatment for sugarcane bagasse biorefinery in co-production of xylooligosaccharides and glucose

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lin Dai ◽  
Tian Huang ◽  
Kankan Jiang ◽  
Xin Zhou ◽  
Yong Xu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Production Cost ◽  
Solid Loading ◽  
Fed Batch ◽  
Acid Pretreatment ◽  
Furoic Acid ◽  
Cooling Crystallization ◽  
Mineral Acids ◽  
Hydrolysis Of

Abstract Background Pretreatment is the key step for utilizing lignocellulosic biomass, which can extract cellulose from lignin and disrupt its recalcitrant crystalline structure to allow much more effective enzymatic hydrolysis; and organic acids pretreatment with dual benefic for generating xylooligosaccharides and boosting enzymatic hydrolysis has been widely used in adding values to lignocellulose materials. In this work, furoic acid, a novel recyclable organic acid as catalyst, was employed to pretreat sugarcane bagasse to recover the xylooligosaccharides fraction from hemicellulose and boost the subsequent cellulose saccharification. Results The FA-assisted hydrolysis of sugarcane bagasse using 3% furoic acid at 170 °C for 15 min resulted in the highest xylooligosaccharides yield of 45.6%; subsequently, 83.1 g/L of glucose was harvested by a fed-batch operation with a solid loading of 15%. Overall, a total of 120 g of xylooligosaccharides and 335 g glucose could be collected from 1000 g sugarcane bagasse starting from the furoic acid pretreatment. Furthermore, furoic acid can be easily recovered by cooling crystallization. Conclusion This work put forward a novel furoic acid pretreatment method to convert sugarcane bagasse into xylooligosaccharides and glucose, which provides a strategy that the sugar and nutraceutical industries can be used to reduce the production cost. The developed process showed that the yields of xylooligosaccharides and byproducts were controllable by shortening the reaction time; meanwhile, the recyclability of furoic acid also can potentially reduce the pretreatment cost and potentially replace the traditional mineral acids pretreatment.

Durability of Red Mud Based Geopolymer Paste in Acid Solutions

2016 ◽  
Vol 866 ◽  
pp. 99-105 ◽  
Author(s):  
Smita Singh ◽  
M.U. Aswath ◽  
R.V. Ranganath
Keyword(s):  
Mechanical Properties ◽  
Acetic Acid ◽  
Fly Ash ◽  
Red Mud ◽  
Acetic Acid Solution ◽  
Strength Loss ◽  
Acid Solutions ◽  
Test Results ◽  
Acid Attack ◽  
Geopolymer Paste

The present investigation is on the effect of red mud on the mechanical properties and durability of the geopolymer paste in sulphuric and acetic acid solution. Red mud and fly ash were used to form the geopolymer paste along with the alkalies. The variation of red mud in the paste composition was from 0% to 90%. Cylindrical shaped specimens of 1 inch diameter and 1 inch height were prepared. The specimens were immersed in 5% sulphuric acid and 5% acetic acid for 1, 7, 14, 28, 56 and 84 days and tested for weight loss, visual deformation, strength loss and colour of the solvent, based on the procedure specified by ASTM C 267 – 01. SEM/EDX Tests were performed on the geopolymer specimens. Test results show that initially, the strength of the geopolymer increased upon the addition of red mud. The strength was maximum when the percentage of red mud was 30%. The maximum strength obtained was 38 MPa for the paste containing 30% red mud using 10M alkali solution as against 31.69 MPa, when only fly ash was used. Geopolymer paste containing 30% and 50% red mud showed better resistance to acid attack. The strength loss was minimum for the samples containing 30% red mud in both inorganic and organic acid i.e. sulphuric and acetic acid.

The synthesis of norbornanes with functionalized carbon substituents at a bridgehead. 1-(3-Oxonorborn-1-yl)ethanone and 1-(3-oxonorborn-1-yl)-2-propanone

1992 ◽  
Vol 70 (5) ◽  
pp. 1492-1505 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bromide ◽  
Tertiary Alcohol ◽  
Ethyl Bromoacetate ◽  
Second Molar ◽  
Molar Equivalent ◽  
Acid Lactone ◽  
Basic Hydrolysis ◽  
Hydrolysis Of

Treatment of 2-norobornene-1-carboxylic acid (7) with one equivalent of methyllithium in ether followed by a second molar equivalent after dilution with tetrahydrofuran gave 1-(norborn-2-en-lyl)ethanone (10) and only a trace of the tertiary alcohol 11. Reaction of 7 with formic acid followed by hydrolysis gave a 4:3 mixture of exo-3- and exo-2-hydroxynorbornane-1-carboxylic acid (16 and 17), whereas oxymercuration–demercuration gave only the exo-3-hydroxy isomer 16. Oxidation of 16 and 17 gave 3- and 2-oxonorbornane-1-carboxylic acid (27 and 29), respectively. Oxymercuration–demercuration of 10 gave exclusively 1-(exo-3-hydroxynorborn-1-yl)ethanone (30), which was also prepared by treatment of 16 with methyllithium in analogous fashion to that used for the conversion of 7 to 10. Oxidation of 30 gave 1-(3-oxonorborn-1-yl)ethanone (1). Dehydrobromination of exo-2-bromonorbornane-1-acetic acid and dehydration of 2-hydroxy-norbornane-2-acetic acid derivatives gave 1-(norborn-2-ylidene) acetic acid derivatives to the exclusion of norborn-2-ene-1 -acetic acid derivatives. Treatment of exo-5-acetyloxy-2-norobornanone (52) with ethyl bromoacetate and zinc gave ethyl exo-5-acetyloxy-2-hydroxynorbornane-(exo- and endo-2-acetate (53 and 54). Reaction of 53 with hydrogen bromide gave initially ethyl endo-3-acetyloxy-exo-6-bromonorbornane-1-acetate (59), which was subsequently converted to a mixture of 59 and its exo-3-acetyloxy epimer 61. Catalytic hydrogenation of this mixture gave a mixture of ethyl endo- and exo-3-acetyloxynorbornane-1 -acetate (62 and 63). Basic hydrolysis of this gave a mixture of the corresponding hydroxy acids, 70 and 71; the former was slowly converted to the latter at pH 5. Oxidation of the mixture of 70 and 71 gave 3-oxonorbornane-1-acetic acid (72). Treatment of the mixture with methyllithium as for 16 gave a mixture of 1-(endo- and exo-3-hydroxynorborn-1-yl)-2-propanone (73 and 74), which was oxidized to 1-(3-oxo-norborn-1-yl)-2-propanone (2). Reaction of exo-2-hydroxynorbornane-1-acetic acid lactone (75) with methyllithium in ether gave (1-(exo-2-hydroxynorborn-1-yl)-2-propanone (76), which on oxidation gave the 2-oxo isomer 78 of 2.

scholarly journals REGULATORY MECHANISMS OF CELLULAR RESPIRATION

1950 ◽  
Vol 34 (2) ◽  
pp. 211-224 ◽  
Author(s):  
E. S. Guzman Barron ◽  
Maria Isabel Ardao ◽  
Marion Hearon
Keyword(s):  
Acetic Acid ◽  
Pyruvic Acid ◽  
No Oxidation ◽  
Yeast Cells ◽  
Acid Formation ◽  
Cellular Respiration ◽  
Acid Oxidase ◽  
Acid Solutions ◽  
Fluoroacetic Acid ◽  
A Cell

The rate of the aerobic metabolism of pyruvic acid by bakers' yeast cells is determined mainly by the amount of undissociated acid present. As a consequence, the greatest rate of oxidation was observed at pH 2.8. Oxidation, at a slow rate, started at pH 1.08; at pH 9.4 there was no oxidation at all. The anaerobic metabolism, only a fraction of the aerobic, was observed only in acid solutions. There was none at pH values higher than 3. Pyruvic acid in the presence of oxygen was oxidized directly to acetic acid; in the absence of oxygen it was metabolized mainly by dismutation to lactic and acetic acids, and CO2. Acetic acid formation was demonstrated on oxidation of pyruvic acid at pH 1.91, and on addition of fluoroacetic acid. Succinic acid formation was shown by addition of malonic acid. These metabolic pathways in a cell so rich in carboxylase may be explained by the arrangement of enzymes within the cell, so that carboxylase is at the center, while pyruvic acid oxidase is located at the periphery. Succinic and citric acids were oxidized only in acid solutions up to pH 4. Malic and α-ketoglutaric acids were not oxidized, undoubtedly because of lack of penetration.

Improved synthesis of anti-sesquinorbornene

1984 ◽  
Vol 62 (9) ◽  
pp. 1840-1844 ◽  
Author(s):  
Karl R. Kopecky ◽  
Alan J. Miller
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Lead Tetraacetate ◽  
Carboxyl Group ◽  
Silver Acetate ◽  
Benzenesulfonyl Chloride ◽  
Methoxide Ion ◽  
Hydrolysis Of ◽  
Monomethyl Ester

Treatment of methyl hydrogen decahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a,8a-dicarboxylate with lead tetraacetate in benzene – acetic acid replaces the carboxyl group by an acetoxy group. Hydrolysis of this product with 25% sulfuric acid at 130 °C forms 8a-hydroxydecahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a-carboxylic acid 10. The reaction between 10 and benzenesulfonyl chloride in pyridine containing triethylamine at 95 °C produces anti-sesquinorbornene 1 in 34% yield. In the absence of triethylamine 1 is converted to the hydrochloride. The iodohydroperoxide of 1 is converted by silver acetate at 0 °C to the diketone in a luminescent reaction. The 1,2-dioxetane could not be isolated. Decahydro-1,4:5,8-exo,exo-dimethanonaphthalene-4a,8a-dicarboxylic anhydride is converted slowly by methoxide ion in methanol at 150 °C to the monomethyl ester which then undergoes demethylation. The isomeric exo,endo anhydride undergoes reaction readily with methoxide ion at 80 °C.

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