scholarly journals Kinetic Modeling of Essential Oil Extraction by Hydrodistillation of Xylopia aethiopica (Dunal) A. Rich Fruits from Congo-Brazzaville

2021 ◽  
Vol 2 (3) ◽  
pp. 105-110
Author(s):  
Thomas Silou ◽  
Jean Bruno Bassiloua ◽  
Rosalie Kama Niamayoua
Keyword(s):  
Experimental Data ◽  
Essential Oil ◽  
Diffusion Control ◽  
First Order ◽  
Extraction Solvent ◽  
Peleg Model ◽  
Congo Brazzaville ◽  
Kinetics Of ◽  
And Diffusion ◽  
Xylopia Aethiopica

The extraction kinetics of the essential oil of Xylopia aethiopica (Dunal) A. Rich by hydrodistillation was studied for modeling its process and optimizing its yield. The oils obtained, analyzed by GC/MS, consists mainly of pinenes, sabinene, myrenal, terpinene-4-ol, limonene. Experimental data were fitted into first and second order kinetics for a 2-steps extraction, washing and diffusion, of the phenomenological model, according to the hypothesis used. The essential oil which moves inner vegetable cells by diffusion and is extracted at the surface of the particle by washing with an extraction solvent. When the washing step is instantaneous compared to that of diffusion, the mechanism, which is under diffusion control, admits first order. Considering both washing and diffusion steps, kinetic order became 2, in agreement with the Peleg model. The Monod and Langmuir models also fitted experimental data. All these models validated by the experimental data with determination coefficients R2> 0.96 can be used for optimizing the extraction of the essential oil of Xylopia aethiopica (Dunal) A. Rich.

scholarly journals Modeling the kinetics of essential oil hydrodistillation from plant materials

2013 ◽  
Vol 67 (5) ◽  
pp. 843-859 ◽  
Author(s):  
Svetomir Milojevic ◽  
Dragana Radosavljevic ◽  
Vladimir Pavicevic ◽  
Srdjan Pejanovic ◽  
Vlada Veljkovic
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Physical Model ◽  
Steam Distillation ◽  
Sigmoid Function ◽  
Plant Materials ◽  
Operational Conditions ◽  
First Order ◽  
Kinetics Of ◽  
And Diffusion

The present work deals with modeling the kinetics of essential oils extraction from plant materials by water and steam distillation. The experimental data were obtained by studying the hydrodistillation kinetics of essential oil from juniper berries. The literature data on the kinetics of essential oils hydrodistillation from different plant materials were also included into the modeling. A physical model based on simultaneous washing and diffusion of essential oil from plant materials were developed to describe the kinetics of essential oils hydrodistillation, and two other simpler models were derived from this physical model assuming either instantaneous washing followed by diffusion or diffusion with no washing (i.e. the first-order kinetics). The main goal was to compare these models and suggest the optimum ones for water and steam distillation and for different plant materials. All three models described well the experimental kinetic data on water distillation irrespective of the type of distillation equipment and its scale, the type of plant materials and the operational conditions. The most applicable one is the model involving simultaneous washing and diffusion of the essential oil. However, this model was generally inapplicable for steam distillation of essential oils, except for juniper berries. For this hydrodistillation technique, the pseudo first-order model was shown to be the best one. In a few cases, a variation of the essential oil yield with time was observed to be sigmoidal and was modeled by the Boltzmann sigmoid function.

scholarly journals Kinetic Modeling of Essential Oil Hydro-Distillation from Peels of Pomelo (Citrus grandis L.) Fruit Grown in Southern Vietnam

2021 ◽  
Vol 50 (11) ◽  
pp. 3251-3261
Author(s):  
Phat Dao Tan ◽  
Xuan Phong Huynh ◽  
Huynh Cang Mai ◽  
Giang Bach Long ◽  
Van Muoi Nguyen
Keyword(s):  
Essential Oil ◽  
Diffusion Model ◽  
Economic Value ◽  
Extraction Process ◽  
First Order ◽  
First Order Kinetics ◽  
Estimated Parameters ◽  
Wide Range ◽  
Kinetics Of ◽  
And Diffusion

Thorough understanding of kinetics plays a key role in improving existing industrial processes. In this study, we attempted to model the kinetics of the hydro-distillation process that produces essential oil from peels of pomelo (Citrus grandis L.) fruit, which is a product with high economic value and a wide range of applications. We first determined the optimal water-to-material ratio for attaining maximal oil yield. Then, further experimental attempts were carried out at different distillation rates to generate experimental data to fit three kinetic models, namely first-order kinetics model, instantaneous washing, followed by diffusion model and simultaneous washing and diffusion model. Overall, the three models have well described the experimental kinetic data on hydro-distillation (R2> 90%). Of which, the simultaneous washing and diffusion model attaining the R2 of 99.97% was chosen as the most suitable to describe the kinetics of the extraction process. Estimated parameters also shown that the washing stage occurs more rapidly than the later, diffusion stage. GC-MS results showed that the obtained oil sample was characterized by the dominance of the D-Limonene compound (97.873%).

Oxidation of Copper Sulfides in Aqueous Ammonia. III. Kinetic Characteristics

1979 ◽  
Vol 32 (12) ◽  
pp. 2597 ◽  
Author(s):  
AO Filmer ◽  
AJ Parker ◽  
BW Clare ◽  
LGB Wadley
Keyword(s):  
Aqueous Ammonia ◽  
Sulfide Oxidation ◽  
Metal Sulfide ◽  
Diffusion Control ◽  
Sulfate Ions ◽  
Kinetics Of Oxidation ◽  
Copper Sulfides ◽  
Shrinking Core ◽  
Kinetics Of ◽  
And Diffusion

The kinetics of oxidation with oxygen of chalcocite, Cu2S, to CuS in buffered aqueous ammonia at pH 10.5 at 30� can be modeled approximately by a shrinking core of Cu2S within a thickening shell of CuxS (x ≥ 1). The Cu2S core offers partial cathodic protection to the CuxS and diffusion of Cu+ through CuxS controls the rate of reaction. The kinetics of oxidation of covellite, CuS, to Cu2+, sulfur and sulfate ions in the same solvent can be modeled by a shrinking core of CuS surrounded by a shrinking sphere of CuyS (y < 1) which is much less effectively protected cathodically by the CuS core. Oxidation of CuS is subject to mixed chemical and diffusion control. Rates of oxidation of NiS and of CuS, in the presence and absence of tetrachloroethene and ammonium sulfate, show that, whether sulfur is a major oxidation product or not, the presence of sulfur has very little, if any, influence on the rate or mechanism of oxidation. This is contrary to current ideas on metal sulfide oxidation.

Kinetics of Glyphosate Adsorption on Composite Resin from Aqueous Solution

2013 ◽  
Vol 803 ◽  
pp. 157-160
Author(s):  
Zhen Zhen Kong ◽  
Dong Mei Jia ◽  
Su Wen Cui
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Composite Resin ◽  
Order Equation ◽  
Second Order ◽  
First Order ◽  
Basic Resin ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Best Fit

The composite weakly basic resin (D301Fe) was prepared and examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption kinetics of glyphosate from aqueous solution onto composite weakly basic resin (D301Fe) were investigated under different conditions. The experimental data was analyzed using various adsorption kinetic models like pseudo-first order, the pseudo-second order, the Elovich and the parabolic diffusion models to determine the best-fit equation for the adsorption of glyphosate onto D301Fe. The results show that the pseudo-second order equation fitted the experimental data well and its adsorption was chemisorption-controlled.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

Cementation kinetics of copper on a rotating zinc cylinder

1987 ◽  
Vol 52 (5) ◽  
pp. 1204-1210 ◽  
Author(s):  
Vladimír Glaser ◽  
Jan Vídenský ◽  
Miroslav Kužela
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Kinetic Equation ◽  
Rate Equation ◽  
Diffusion Region ◽  
First Order ◽  
Proportionality Constant ◽  
Zinc Surface ◽  
Reaction Proceeds ◽  
Kinetics Of

The authors followed the course of cementation of copper from sulphate solutions on a rotating zinc cylinder. Treatment of experimental data revealed that the coefficient of proportionality in the kinetic equation is not influenced by the Cu layer deposited on the zinc surface and is independent of the concentration of Cu(II) ions, but decreases with increasing concentration of ZnSO4 in solution. The cementation reaction proceeds in the diffusion region and is of the first order with respect to the concentration of Cu(II) ions; the proportionality constant in the rate equation corresponds to the mass transfer coefficient.

Aromatic Plants from “Plateau des Cataractes”: Kinetic modeling of the extraction of leaf essential oils from Curcuma mangga (Valeton and Zijp) acclimatized in Congo-Brazzaville

2021 ◽  
pp. 186-194
Author(s):  
Thomas Silou ◽  
Ernest Bitemou ◽  
Kevin Bikindou ◽  
Aubin Nestor Loumouamoua ◽  
Pierre Chalard
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Phenomenological Approach ◽  
Aromatic Plants ◽  
First Order ◽  
The Many ◽  
The One ◽  
Congo Brazzaville ◽  
Hand Modeling ◽  
Quantitative Importance

Curcuma mangga Val. and Zijp is one of the many underutilized species of the genus Curcuma despite their proven interest as spice to color and enhance the taste of food, on the one hand, and as medicinal plants through essential oils extracted from different parts of the plant, on the other hand. Modeling the extraction in order to optimize the yield of essential oil is a pre requisite for the development of this species used as a spice in Congo-Brazzaville. The experimental results of the extraction of essential oil from the leaves analyzed, according to the phenomenological approach, validate both the kinetic model of the pseudo first order, when the washing step is neglected compared to the diffusion step and that of Peleg corresponding to a desorption in two steps (washing/diffusion). The main constituents of the oil adopt different desorption routes depending on their nature and their quantitative importance in the oil. Simple kinetics have been observed for sesquiterpenes present in relatively large amounts and complex for the monoterpenes in much smaller quantities.

THE KINETICS OF THE FORMATION OF THE MONOSULPHATO COMPLEX OF IRON (III) IN AQUEOUS SOLUTION

1962 ◽  
Vol 40 (9) ◽  
pp. 1836-1845 ◽  
Author(s):  
G. G. Davis ◽  
W. MacF. Smith
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Ionic Strength ◽  
Continuous Flow ◽  
Hydrogen Ions ◽  
Kcal Mole ◽  
Forward Reaction ◽  
First Order ◽  
Kinetics Of Formation ◽  
Kinetics Of

The kinetics of formation of the monosulphato complex of iron (III) has been examined spectrophotometrically using a continuous-flow technique over the range of temperatures 15.6 to 34.5 °C in an aqueous medium of ionic strength 0.5 and a range of concentrations of hydrogen ions 0.05 to 0.30 M. The experimental data may be interpreted on the assumption that the significant reactions are a bimolecular association opposed by a first-order dissociation [Formula: see text] For the forward reaction ΔH≠ is 18.0 kcal mole−1 and ΔS≠ is 19.4 cal mole−1 deg−1.

scholarly journals Temperature and pH effects on the kinetics of 2-aminophenol auto-oxidation in aqueous solution

2003 ◽  
Vol 1 (3) ◽  
pp. 233-241 ◽  
Author(s):  
Dumitru Oancea ◽  
Mihaela Puiu
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Aqueous Solution ◽  
Ph Effects ◽  
Influence Of Temperature ◽  
First Order ◽  
Incremental Methods ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetics Of

AbstractThe kinetics of the auto-oxidation of 2-aminophenol (OAP) to 2-amino-phenoxazin-3-one (APX) was followed in air-saturated aqueous solutions and the influence of temperature and pH on the auto-oxidation rate was studied. The kinetic analysis was based on a spectrophotometric method following the increase of the absorbance of APX. The process follows first order kinetics according to the rate law—d[OAP]/dt=k′[OAP]. The experimental data, within the pH range 4–9.85, were analyzed using both differential and incremental methods. The temperature variation of the overall rate constant was studied at pH=9.85 within the range 25–50°C and the corresponding activation energy was evaluated.

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