Effect of Temperature and Initial Acid Concentration on the Reactive Extraction of Carboxylic Acids

2013 ◽  
Vol 58 (6) ◽  
pp. 1822-1826 ◽  
Author(s):  
Hasan Uslu ◽  
Ş. İsmail Kırbaşlar
Keyword(s):  
Carboxylic Acids ◽  
Acid Concentration ◽  
Reactive Extraction ◽  
Effect Of Temperature

Observations on the Anodic Behavior off Nickel and Chromium: Surface Topography and Temperature Effect

CORROSION ◽  
1966 ◽  
Vol 22 (2) ◽  
pp. 32-38 ◽  
Author(s):  
J. R. MYERS ◽  
W. B. CROW ◽  
F. H. BECK ◽  
R. K. SAXER
Keyword(s):  
Activation Energy ◽  
Surface Topography ◽  
Passive Film ◽  
Acid Concentration ◽  
Passive State ◽  
Effect Of Temperature ◽  
Nickel Surface ◽  
Passive Region ◽  
Potential Region ◽  
Metallographic Examination

Abstract Metallographic examination of anodically polarized nickel and chromium after long-time exposure at selected active, passive and transpassive potentials in H2-saturated, IN H2SO4 at 25 C (77 F) revealed significant differences in surface topography. Etch figures, present only in the trans-passive state, supported the belief that “active patches” are generated in passive films of these metals at potentials more noble than the passive region. The difference in nature of nickel surface in the early trans-passive region and visible oxygen evolution region is discussed. Effect of temperature on passive nickel (i.e., nickel in passive potential region) over the range 25 to 95 C (77 to 203 F) was determined for H2-saturated 0.5, 1, 5 and ION H2SO4 (pH = 0.85 to −1.05). Apparent activation energies for dissolution of passive nickel were determined. Inflection temperature (Ti) above which “active patches” apparently are formed in passive film was dependent on acid concentration according to the expression 1/Ti × 103 = −0.11 pH+ 3.04 over the pH range investigated and was independent of the direction from which the temperature was approached. The change in apparent activation energy (ΔQ) was a function of direction from which the temperature was approached. Measurements in which temperature was increased stepwise showed that ΔQ is related to pH by the expression ΔQ (kg - cal/mole) = 15,4 pH - 4.7 for acid concentrations studied. Because Ti and ΔQ are dependent on acid concentration, Seeger's activation energy for crystallization of a very thin pseudomorphic film and Kramer's exo-electron emission temperature which are independent of concentration cannot be used to explain fully generation of “active patches” in a passive film as proposed by previous investigators.

Equilibrium and Kinetics of Reactive Extraction of Propionic Acid Using Aliquat 336 and Tri-n-Butyl Phosphate in n-Hexanol

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Dr. Kailas L. Wasewar ◽  
Amit Keshav ◽  
Shri Chand
Keyword(s):  
Propionic Acid ◽  
Acid Concentration ◽  
Fermentation Broth ◽  
Reactive Extraction ◽  
Acid Extraction ◽  
Aliquat 336 ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pharmaceutical Industries ◽  
Kinetics Of

Recovery of propionic acid from different sources, like aqueous streams or from fermentation broth, is important in view of its wide usage in food, chemical and pharmaceutical industries. Reactive extraction is an emerging separation technique having numerous advantages like high selectivity and recovery. Effect of acid concentration, extractant concentration, pH, temperature and kinetics are the important steps in the reactive extraction. Equilibrium of propionic acid extraction using tri-n-butyl phosphate (TBP) and Aliquat 336 in n-hexanol respectively was carried out to find the better extractant out of the two for extraction of propionic acid. Aliquat 336 was found to be better than TBP with Ks = 2.2119 m3/kmol, thus indicating good complexation between it and the acid. The kinetics of extraction of the acid using Aliquat 336 in a stirred cell was investigated. The reaction was found to be first order in acid concentration and zero order in Aliquat 336 concentration. The reaction was found to be fast pseudo first order reaction occurring in the diffusion film and was found to be independent of hydrodynamics conditions. Rate constant was evaluated to be 163.398 1/s.

scholarly journals Equilibrium Study on Reactive Extraction of Lactic Acid with Tri-n – Butyl Phosphate in n - Hexane

2013 ◽  
Vol 12 (2) ◽  
pp. 1
Author(s):  
Panut Mulyono ◽  
Anita Pardah
Keyword(s):  
Aqueous Solution ◽  
Lactic Acid ◽  
Ambient Temperature ◽  
Carboxylic Acids ◽  
Distribution Ratio ◽  
Equilibrium Constants ◽  
Reactive Extraction ◽  
Extraction Temperature ◽  
Process Selection ◽  
Initial Concentration

Extraction of carboxylic acids from dilute aqueous solution using traditional solvents such as ketones, alcohols, ethers, and ester is inefficient because the distribution ratio is rather low. Reactive extraction which exploits reversible chemical complexation is an effective separation process for extraction of carboxylic acids from aqueous streams such as fermentation broths and wastewaters. In the extraction process, selection of the solvent is an important aspect to be considered. Considering its solubility in water, cost and availability, tri-n-butyl phosphate (TBP) seems to be an attractive solvent for the extraction of lactic acid from aqueous solution. The purpose of this experiment is to study the equilibrium of the reactive extraction of lactic acid in aqueous solution with TBP in n-hexane. The parameters studied in this experiment were initial concentration of lactic acid in the aqueous phase, TBP concentration in n-hexane phase, and the extraction temperature. The experiments at ambient temperature were carried out using a separatory funnel, while the experiments at other than ambient temperature were carried out using erlenmeyer flask and water bath shaker to adjust the temperature. In this experiment, the initial concentration of lactic acid was varied from 0.1 to 0.5 gmol/dm3. The range of initial TBP concentrations in n-hexane was 0.1 to 1.0 gmol/dm3 and the extraction temperature range was 283 to 313 K. The experimental results showed that the higher the initial concentration of lactic acid in aqueous solution, the higher the distribution ratio for a fixed TBP concentration and extraction temperature. For a fixed initial concentration of lactic acid in aqueous solution and extraction temperature, the distribution ratio of lactic acid is increased by increasing TBP concentration. The overall equilibrium constants (Kpq) for the experiments using TBP concentration ranging from 0.1 to 1.0 gmol/dm3 at the extraction temperature of 293 K are calculated to be 0.0668 to 0.5144. Kpq for the experiments at the temperature ranging from 283 to 313 K at the initial concentration of lactic acid of 0.2 gmol/L are found to be 0.0122 to 0.8856. The Kpq as a function of temperature (T) in K can be expressed as ln Kpq = 10,596/T - 38.08 with sum of square of error of 0.14.

scholarly journals A study on the effect of parameters on lactic acid production from whey

2016 ◽  
Vol 18 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Hamidreza Ghafouri Taleghani ◽  
Ghasem D. Najafpour ◽  
Ali Asghar Ghoreyshi
Keyword(s):  
Lactic Acid ◽  
Acid Concentration ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Dry Weight ◽  
Optimal Growth ◽  
Inoculum Size ◽  
Effect Of Temperature ◽  
Lactic Acid Concentration ◽  
Initial Substrate

Abstract In batch fermentation of whey, selection of suitable species at desired conditions such as substrate, product concentrations, temperature and inoculum size were investigated. Four Lactobacillus species and one Lactococcus species were screened for lactic acid production. Among them L. bulgaricus ATCC 11842 were selected for further studies. The optimal growth of the selected organism for variable size of inocula was examined. The results indicated that inoculum size had insignificant effect on the cell and lactic acid concentration. The effect of temperature was also studied at 32, 37, 42 and 47°C. Results showed that the concentration of cell dry weight increased with increment of temperature from 32 to 42°C. The maximum cell and lactic acid concentration was obtained at 42°C. The effect of initial substrate concentration on lactic acid production was also examined. The optimum initial lactose concentration was found to be 90 g/l.

Application of reactive extraction to recovery of carboxylic acids

2001 ◽  
Vol 6 (6) ◽  
pp. 386-394 ◽  
Author(s):  
Yeon Ki Hong ◽  
Won Hi Hong ◽  
Dong Hoon Han
Keyword(s):  
Carboxylic Acids ◽  
Reactive Extraction
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