scholarly journals Catalytic Reduction of Wood Kikar (Acacia albida) by Acetosolv and Organosolv Pulping with Organic acids

Author(s):  
Akhtar Shareef ◽  
Mohammad Tahir ◽  
Shahid Bhutto ◽  
Nisha Khan

Kikar wood (Acacia albida) of particle size 0.315-1.00 mm was subjected to acetosolv andorganosolv pulping catalyzed by strong acid like HCl. The selective condition for pulping is 95%, 0.25%catalyst (HCl) solid/liquor ratio (S/L) 1:12.5 for 180 mins, for acetic acid, 80%, 0.2% catalyst (HCl), S/L1:12.5 for 120 min, for formic acid, 85%, 0.2% catalyst (HCl), S/L 1:12.5 for 180 min for propionic acid,giving residues impurities but the a-cellulose and klason lignin 58.5% and 24.1% in Kikar wood. Theoptimum delignification was achieved by the acetic acid as compared to other organic acids.

2007 ◽  
Vol 544-545 ◽  
pp. 797-800
Author(s):  
Kun Ho Song ◽  
Byoung Moon Kim ◽  
Jeong Eun Kim ◽  
Kwang Rae Lee

The nano-size PbTiO3 particles were prepared by sol-gel method and the effects of processing variables such as concentration of sol solution, catalyst, concentration of catalyst, calcination temperature and calcination process on particle size of PbTiO3 were analyzed. The condition for preparation of sol solution from the precursor is very critical to the size of PbTiO3 particle. At certain experimental conditions, the particles of 129nm, 213nm and 343nm were obtained. However, the particle size of commercialized PbTiO3 powder was 5㎛(5,000nm). The prepared nano-size PbTiO3 powder adsorbed more acetic acid and formic acid than the commercialized one; 1.5 times for acetic acid and 1.2 times for formic acid. Formic acid was preferentially adsorbed than acetic acid.


2021 ◽  
Vol 41 (1) ◽  
pp. 60-67
Author(s):  
E. K. Ndelekwute ◽  
H. O. Uzegbu ◽  
K. U. Amaefule ◽  
C. O. Okereke ◽  
B. I. Umoh

A Six week study was carried out to investigate effect of different organic acids (OAs) fed through drinking water on carcass yield and internal organs weight of broiler chickens. The OAs were acetic acid (AA) butyric acid (BA), citric acid (CA) and formic acid (FA). One hundred and fifty (150) day old AborAcre-plus chicks were used. There were five treatments. Treatment 1 which served as control (CON) consumed water with no organic acid, while treatments 2,3, 4 and5 respectively were offered drinking water treated with 0.25% acetic acid (AA), butyric acid (BA), citric acid (CA) and formic acid (FA). Each treatment was replicated three times each having 10 birds arranged in completely randomized design (CRD). Feed and water were offered ad libitum. Results showed that dressed carcass weight and breast weight were improved by all the organic acids. While only AA positively influenced the thigh weight, all the OAs drinking water fed resulted to smaller drumstick compared to the CON. Feeding of AA, BA and FA through drinking water increased (PSO.05) deposition of abdominal fat. Weight of pancreas, small intestine, caecum and large intestine was significantly (P<0.05) higher in CON. The gall bladder was significantly (P<0.05) bigger in all the OA groups. Conclusively, OAs could be fed through the drinking water for improved percentage carcass yield, breast meat and larger gall bladder and invariably bile volume


2010 ◽  
Vol 10 (2) ◽  
pp. 3937-3974 ◽  
Author(s):  
S. R. Tong ◽  
L. Y. Wu ◽  
M. F. Ge ◽  
W. G. Wang ◽  
Z. F. Pu

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.


2015 ◽  
Vol 55 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Tarek Abd El-Ghafar El-Shahawy

AbstractLife cannot exist without water. Appropriate management of water, from the water’s source to its utilization, is necessary to sustain life. Aquatic weeds pose a serious threat to aquatic environments and related eco-environments. Short- and long-term planning to control aquatic weeds is extremely important. Water hyacinth,Eichhornia crassipes(Mart.) Solms, is one of the world’s worst pests with a bad reputation as an invasive weed. In this study we are seeking the possibility of using certain chemicals with a natural background, for controlling water hyacinth since there is a delicate balance that needs to be taken into account when using herbicides in water. Five compounds, namely: acetic acid, citric acid, formic acid, and propionic acid, in three concentrations (10, 15, and 20%) were applied (i.e. as a foliar application under wire-house conditions) and compared with the use of the herbicide glyphosate (1.8 kg ∙ ha−1). All of the five compounds performed well in the control of the water hyacinth. As expected, the efficacy increased as the concentration was increased from 10 to 20%. With formic and propionic acids, the plants died earlier than when the other acids or the herbicide glyphosate, were used. Acetic acid came after formic and propionic acids in terms of efficacy. Citric acid ranked last. Formic acid/propionic acid mixtures showed superior activity in suppressing water hyacinth growth especially at the rate of (8 : 2) at the different examined concentrations (3 or 5 or 10%) compared to the formic acid/acetic acid mixtures. Using the formic acid/propionic acid mixture (8 : 2; at 3%) in the open field, provided good control and confirmed the viability of these chemicals in the effective control of water hyacinth. Eventually, these chemical treatments could be used on water for controlling water hyacinth. In the future, these chemicals could probably replace the traditional herbicides widely used in this regard. These chemicals are perceived as environmentally benign for their rapid degradation to carbon dioxide and water. For maximum efficiency thorough coverage especially in bright sunlight is essential.


2010 ◽  
Vol 10 (16) ◽  
pp. 7561-7574 ◽  
Author(s):  
S. R. Tong ◽  
L. Y. Wu ◽  
M. F. Ge ◽  
W. G. Wang ◽  
Z. F. Pu

Abstract. A study of the atmospheric heterogeneous reactions of formic acid, acetic acid, and propionic acid on 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 or (2.37±0.30) ×10−7, (5.00±0.69)×10−3 or (5.99±0.78)×10−7, and (3.04±0.63)×10−3 or (3.03±0.52)×10−7, respectively (using geometric or BET surface area). Furthermore, the effect of varying relative humidity (RH) on these 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 acid solvation, particle surface hydroxylation, and competition for reactive sites. On the basis of the results of experimental simulation, the mechanism of heterogeneous reaction of α-Al2O3 with carboxylic acids at ambient RH was discussed. The loss of atmospheric monocarboxylic acids due to reactive uptake on available mineral dust particles may be competitive with homogeneous loss pathways, especially in dusty urban and desertified environments.


1983 ◽  
Vol 38 (12) ◽  
pp. 1400-1401 ◽  
Author(s):  
R. Haase ◽  
H.-J. Jansen ◽  
B. Winter

Abstract For the binary liquid systems formic acid + acetic acid, formic acid + propionic acid, and acetic acid + propionic acid, we give the results of new calorimetric measurements of the molar excess enthalpy H̄E at 25 °C, 30 °C, 40 °C, and 60°C, covering the entire range of compositions. H̄E is always positive, increases linearly with the temperature, and is slightly asymmetric with respect to the mole fraction x. The composition at the maximum of the function H̄E(x) is independent of the temperature.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rou Cao ◽  
Xinlu Liu ◽  
Jianming Guo ◽  
Yong Xu

Abstract Background Methods to produce XOS have been intensively investigated, including enzymatic hydrolysis, steam explosion, and acid hydrolysis. Acid hydrolysis is currently the most widely used method to produce XOS due to its advantages of fewer processing steps, stronger raw material adaptability, higher yield, and better reproducibility. Especially, organic acids such as acetic acid, formic acid and xylonic acid work better as compared with mineral acids. However, the catalytic mechanism of different organic acids has been little studied. In this paper, four different organic acids, including formic acid, glycolic acid, lactic acid, and acetic acid were selected to compare their hydrolytic effects. Results Using pKa values as the benchmark, the yield of xylo-oligosaccharide (XOS) increased with the increasing value of pKa. The yield of XOS was 37% when hydrolyzed by 5% acetic acid (pKa = 4.75) at 170 ℃ for 20 min. Combined severity (CS), a parameter associated with temperature and reaction time was proposed, was proposed to evaluate the hydrolysis effect. The results of CS were consistent with that of pKa values on both the yield of XOS and the inhibitor. Conclusion The results based on pKa values and combined severity, a parameter associated with temperature and reaction time, concluded that acetic acid is a preferred catalyst. Combining the techno-economic analysis and environmental benefits, acetic acid hydrolysis process has lower factory production costs, and it is also an important metabolite and a carbon source for wastewater anaerobic biological treatment. In conclusion, production of xylo-oligosaccharides by acetic acid is an inexpensive, environment-friendly, and sustainable processing technique.


2021 ◽  
Author(s):  
Rou Cao ◽  
Xinlu Liu ◽  
Jianming Guo ◽  
Yong Xu

Abstract Background: Methods to produce XOS have been intensively investigated, including enzymatic hydrolysis, steam explosion, and acid hydrolysis. Acid hydrolysis is currently the most widely used method to produce XOS due to its advantages of fewer processing steps, stronger raw material adaptability, higher yield, and better reproducibility. Especially, organic acids such as acetic acid, formic acid and xylonic acid work better as compared with mineral acids. However, the catalytic mechanism of different organic acids has been little studied. In this paper, four different organic acids, including formic acid, glycolic acid, lactic acid, and acetic acid were selected to compare their hydrolytic effects.Results: Using pKa values as the benchmark, the yield of xylo-oligosaccharide (XOS) increased with the increasing value of pKa. The yield of XOS was 37% when hydrolyzed by 5% acetic acid (pKa=4.75) at 170℃ for 20 min. Combined severity (CS), a parameter associated with temperature and reaction time was proposed, was proposed to evaluate the hydrolysis effect. The results of CS were consistent with that of pKa values on both the yield of XOS and the inhibitor.Conclusion: The results based on pKa values and combined severity, a parameter associated with temperature and reaction time, concluded that acetic acid is a preferred catalyst. Combining the techno-economic analysis and environmental benefits, acetic acid hydrolysis process has lower factory production costs, and it is also an important metabolite and a carbon source for wastewater anaerobic biological treatment. In conclusion, production of xylo-oligosaccharides by acetic acid is an inexpensive, environment-friendly, and sustainable processing technique.


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