Formation of Aliphatic Carboxylic Acids during Soda-AQ Pulping of Kenaf Bark

Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 388-394 ◽  
Author(s):  
Z. Feng ◽  
R. Alén ◽  
K. Niemelä
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Dicarboxylic Acids ◽  
Hydroxy Acids ◽  
Hydroxy Carboxylic Acids ◽  
Aliphatic Carboxylic Acids ◽  
Cooking Conditions ◽  
Acetic Acids

Summary The formation of aliphatic carboxylic acids during soda-AQ pulping of kenaf bark was studied. In addition to formic and acetic acids, a variety of hydroxy monocarboxylic and dicarboxylic acids were monitored. The results showed that the formation of hydroxy acids and formic acid significantly depend, in contrast to acetic acid, on the cooking conditions employed. Detailed gas chromatographic studies revealed that the most abundant hydroxy carboxylic acids were glucoisosaccharinic, lactic, glycolic, 3-deoxypentonic, 2-hydroxybutanoic, xyloisosaccharinic, 3,4-dideoxypentonic, 2-hydroxyglutaric, and glucoisosaccharinaric acids. The total amount of aliphatic carboxylic acids corresponded to 12–16% of o.d. kenaf bark.

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.

scholarly journals Computational notes on the electronic properties of carboxylic acid

2020 ◽  
Vol 9 (2) ◽  
pp. 1079-1082
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Electronic Properties ◽  
Carboxylic Acids ◽  
Normal Mode ◽  
Normal Modes ◽  
Carboxyl Groups ◽  
Vibrational Characteristics ◽  
Vibrational Features ◽  
Acetic Acids

The present work describing the electronic properties and vibrational characteristics of carboxylic acids. Acetic acid is chosen as model molecules then optimized at B3LYP/6-31g(d,p) level of theory. The vibrational frequencies were calculated at the same level of theory. Band assignments which were calculated as 18 normal modes were assigned as one compare the normal mode coordinates with original one. Band assignments were described indicating the directions of normal modes in terms the vibrating atoms of the acetic acids. It could be concluded that DFT could be a useful tool for elucidation both the structural and vibrational features of carboxylic acids and then further utilized for assignment of the structures contains carboxyl groups which are known as most reactive structures in chemistry, biology and environment.

scholarly journals Heterogeneous chemistry of monocarboxylic acids on α-Al<sub>2</sub>O<sub>3</sub> at ambient condition

2010 ◽  
Vol 10 (2) ◽  
pp. 3937-3974 ◽  
Author(s):  
S. R. Tong ◽  
L. Y. Wu ◽  
M. F. Ge ◽  
W. G. Wang ◽  
Z. F. Pu
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Propionic Acid ◽  
Ambient Condition ◽  
Heterogeneous Reactions ◽  
Dust Particles ◽  
Monocarboxylic Acids ◽  
Al2o3 Particles ◽  
Α Al2o3

Abstract. A study of the atmospheric heterogeneous reactions of formic acid, acetic acid, and propionic acid on dust particles (α-Al2O3) was performed at ambient condition by using a diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reactor. From the analysis of the spectral features, observations of carboxylates formation provide strong evidence for an efficient reactive uptake process. Comparison of the calculated and experimental vibrational frequencies of adsorbed carboxylates establishes the bridging coordinated structures on the surface. The uptake coefficients of formic acid, acetic acid, and propionic acid on α-Al2O3 particles are (2.07±0.26)×10−3, (5.00±0.69)×10−3, and (3.04±0.63)×10−3, respectively (using geometric area). Besides, the effect of various relative humid (RH) on this heterogeneous reactions was studied. The uptake coefficients of monocarboxylic acids on α-Al2O3 particles increase initially (RH<20%) and then decrease with the increased RH (RH>20%) which was due to the effect of water on carboxylic acids solvation, particles surface hydroxylation, and competition on reactive site. On the basis of the results of experimental simulation, the mechanism of heterogeneous reaction of dust with carboxylic acids at ambient condition was discussed. The loss of atmospheric monocarboxylic acids due to reactive uptake on available mineral dust particles can be competitive with homogeneous loss pathways, especially in dusty urban and desertified environments.

scholarly journals Importance of secondary sources in the atmospheric budgets of formic and acetic acids

2010 ◽  
Vol 10 (10) ◽  
pp. 24435-24497 ◽  
Author(s):  
F. Paulot ◽  
D. Wunch ◽  
J. D. Crounse ◽  
G. C. Toon ◽  
D. B. Millet ◽  
...  
Keyword(s):  
Formic Acid ◽  
Carboxylic Acids ◽  
Transport Model ◽  
Negative Temperature ◽  
Photochemical Oxidation ◽  
Secondary Source ◽  
Chemical Transport Model ◽  
Wet And Dry Deposition ◽  
Secondary Sources ◽  
Acetic Acids

Abstract. We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

INHIBITION OF CATALASE BY CARBOXYLIC ACIDS RELATED TO DISSOCIATION AND ASSOCIATION OF THE APOPROTEIN

1962 ◽  
Vol 40 (1) ◽  
pp. 1327-1334 ◽  
Author(s):  
Michio Itoh ◽  
Yasuharu Nakamura ◽  
Kazuo Shibata
Keyword(s):  
Absorption Spectrum ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Free Acid ◽  
Second Step ◽  
Benzoic Acids ◽  
Reagent Concentration ◽  
Inhibitory Effects ◽  
Different Types ◽  
Aliphatic Carboxylic Acids

The inhibitory effects of aliphatic and aromatic carboxylic acids (formic, acetic, propionic, butyric, benzoic, and salicylic acids) on catalase at pH 7.0 were studied by measuring the catalatic activity as a function of reagent concentration, and the results were correlated with the data obtained simultaneously by spectroscopic and ultracentrifugal analyses. The inhibition by salicylic and benzoic acids proceeds in two steps. In the first step, the activity drops to a certain level, and the sedimentation peak of the native catalase is unaltered. The second step of inhibition is accompanied by the dissociation of the catalase molecule into subunits, and the absorption spectrum is changed greatly. The inhibition by the aliphatic carboxylic acids except formic acid proceeds also in two steps in which the second step of inhibition is accompanied by the association of the catalase molecules. The inhibition by formic acid obeys the mechanism of the combination between heme and the free acid rather than its anion. These different types of inhibitions at neutral pH are discussed in relation to the data obtained previously at acidic pH's.

scholarly journals Alkali consumption of aliphatic carboxylic acids during alkaline pulping of wood and nonwood feedstocks

Holzforschung ◽  
2013 ◽  
Vol 67 (6) ◽  
pp. 643-650 ◽  
Author(s):  
Hannu Pakkanen ◽  
Raimo Alén
Keyword(s):  
Wheat Straw ◽  
Degradation Products ◽  
Dicarboxylic Acids ◽  
Kraft Pulping ◽  
Alkaline Pulping ◽  
Carbohydrate Degradation ◽  
Cooking Temperature ◽  
Alkali Consumption ◽  
Aliphatic Carboxylic Acids ◽  
Acetic Acids

Abstract The carbohydrate degradation products have been examined, which are formed during the conventional kraft pulping of a softwood, hardwoods, bamboo, and wheat straw as well as soda and soda-anthraquinone pulping of wheat straw. The focus was on “volatile” acids such as formic and acetic acids and “nonvolatile” hydroxy monocarboxylic and dicarboxylic acids. The different consumption profiles were obtained for the charged alkali required for the neutralization of these aliphatic acids depending on the feedstock and the cooking method. The relative composition of the acid fraction in the black liquors of softwood and hardwood and nonwood feedstocks showed characteristic variations. However, in the case of wood kraft pulping, the variations in cooking conditions (effective alkali 19–21% and cooking temperature 155–170°C) had no significant effect on the acid composition. The total amount of volatile and hydroxy acids formed during pulping at a typical target κ number level for each feedstock ranged from 78 to 174 kg ton-1 based on o.d. feedstock. It was highest in birch kraft pulping and lowest in wheat soda-anthraquinone pulping.

Gas phase acidities of aliphatic carboxylic acids, based on measurements of proton transfer equilibria

1989 ◽  
Vol 67 (4) ◽  
pp. 611-618 ◽  
Author(s):  
Gary Caldwell ◽  
Richard Renneboog ◽  
Paul Kebarle
Keyword(s):  
Mass Spectrometry ◽  
Proton Transfer ◽  
Gas Phase ◽  
Carboxylic Acids ◽  
Carbon Number ◽  
Reference Compound ◽  
Text Data ◽  
Gas Phase Acidity ◽  
Aliphatic Carboxylic Acids ◽  
Acetic Acids

Measurements of the gas phase proton transfer equilibrium [1]: AH + B− = A− + BH with a pulsed electron high pressure mass spectrometer (PHPMS) lead to [Formula: see text] and [Formula: see text] data. These relative acidities are converted to the absolute acidities [2]: AH = A− + H+bycalibration of the relative [Formula: see text] and [Formula: see text] scale to the known values for [Formula: see text] and [Formula: see text] of a reference compound(HCl). Earlier determinations that included 16 aliphatic AH are extended in the present work and provide data for 47 aliphatic carboxylic acids. These include halogen, OH, CH3O, C2H5O, PhO, and NH2 substituted acetic acids, and halogen substituted, unsaturated, and cyclic RCO2H of higher carbon number. The effects of the various substituents on the gas phase acidity are briefly examined. Keywords: acidities in gas phase, proton transfer equilibria, ion-molecule equilibria, mass spectrometry.

The Distribution of Cigarette Smoke Components between Mainstream and Sidestream Smoke: I. Acidic Components

1983 ◽  
Vol 12 (2) ◽  
Author(s):  
H. Sakuma ◽  
M. Kusama ◽  
S. Munakata ◽  
T. Ohsumi ◽  
S. Sugawara
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Cigarette Smoke ◽  
Sidestream Smoke ◽  
Phenolic Components ◽  
Acidic Components ◽  
Acetic Acids

AbstractYields in sidestream (SS) and mainstream (MS) smokes and sidestream to mainstream distribution ratios (SS/MS) of acidic components were examined for four types of cigarette made from bright, Burley, Turkish and domestic (c.v. Matsukawa) tobacco. Of the acidic components, formic and acetic acids were analysed by GC following n-butyl esterification, and acids other than formic and acetic acids and phenols similarly after trimethylsilylation. In acidic fractions of sidestream and mainstream smokes of four types of cigarettes, major phenolic components were phenol, catechol and hydroquinone, and major acids were formic, acetic, lactic, glycolic and succinic The following compounds gave SS/MS ratios > 1 for all types of cigarettes tested: phenol, cresols, xylenols, guaiacol, formic acid and acetic acid.

INHIBITION OF CATALASE BY CARBOXYLIC ACIDS RELATED TO DISSOCIATION AND ASSOCIATION OF THE APOPROTEIN

1962 ◽  
Vol 40 (10) ◽  
pp. 1327-1334 ◽  
Author(s):  
Michio Itoh ◽  
Yasuharu Nakamura ◽  
Kazuo Shibata
Keyword(s):  
Absorption Spectrum ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Free Acid ◽  
Second Step ◽  
Benzoic Acids ◽  
Reagent Concentration ◽  
Inhibitory Effects ◽  
Different Types ◽  
Aliphatic Carboxylic Acids

The inhibitory effects of aliphatic and aromatic carboxylic acids (formic, acetic, propionic, butyric, benzoic, and salicylic acids) on catalase at pH 7.0 were studied by measuring the catalatic activity as a function of reagent concentration, and the results were correlated with the data obtained simultaneously by spectroscopic and ultracentrifugal analyses. The inhibition by salicylic and benzoic acids proceeds in two steps. In the first step, the activity drops to a certain level, and the sedimentation peak of the native catalase is unaltered. The second step of inhibition is accompanied by the dissociation of the catalase molecule into subunits, and the absorption spectrum is changed greatly. The inhibition by the aliphatic carboxylic acids except formic acid proceeds also in two steps in which the second step of inhibition is accompanied by the association of the catalase molecules. The inhibition by formic acid obeys the mechanism of the combination between heme and the free acid rather than its anion. These different types of inhibitions at neutral pH are discussed in relation to the data obtained previously at acidic pH's.

Sign in / Sign up

Export Citation Format

Share Document