scholarly journals Contributions of Experimental Data Obtained in Concentrated Mixtures to Kinetic Studies: Application to Monomethylhydrazine Pyrolysis

2020 ◽  
Vol 124 (30) ◽  
pp. 6214-6236
Author(s):  
Pascal Diévart ◽  
Laurent Catoire
Keyword(s):  
Experimental Data ◽  
Kinetic Studies

scholarly journals Equilibrium, Kinetic, and Thermodynamic Studies of Anionic Dyes Adsorption on Corn Stalks Modified by Cetylpyridinium Bromide

2018 ◽  
Vol 3 (1) ◽  
pp. 4 ◽  
Author(s):  
Liudmyla Soldatkina ◽  
Marianna Zavrichko
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Cationic Surfactant ◽  
Kinetic Studies ◽  
Batch Adsorption ◽  
Cetylpyridinium Bromide ◽  
Anionic Dyes ◽  
Pseudo Second Order ◽  
Dyes Adsorption

Corn stalks (CS) were modified by a cationic surfactant, cetylpyridinium bromide (CPB), and used as an adsorbent (CS-CP) to remove anionic dyes [Acid Red (AR) and Acid Orange (AO)] from aqueous solutions. The FTIR analysis and the obtained calculations based on the determination of the adsorption capacity of CS towards CPB confirmed that the cationic surfactant had been adsorbed on the surface of corn stalks. Adsorption of the anionic dyes on modified corn stalks was investigated in a series of batch adsorption experiments at 303–328 K. The adsorption data were analyzed using Langmuir, Freundlich, and Temkin models. The Langmuir model was found to be more suitable for the experimental data of the anionic dyes on CS-CP than other adsorption models. Kinetic studies revealed that the pseudo-second order model showed the best fit to the experimental data. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic. Mechanisms involving ion exchange and chemisorption might be responsible for the uptake of the anionic dyes on CS-CP. Obtained results imply that CS-CP could be applied as an effective adsorbent to remove anionic dyes from aqueous solutions.

scholarly journals Data acquisition system for chemical kinetic studies

1989 ◽  
Vol 11 (3) ◽  
pp. 113-118
Author(s):  
Yu-zhen Zhu ◽  
Xin Zhou ◽  
Xiang-sheng Zang
Keyword(s):  
Experimental Data ◽  
Ethyl Acetate ◽  
Specific Problem ◽  
Reference Value ◽  
Kinetic Studies ◽  
Data Acquisition System ◽  
Chemical Kinetic ◽  
Interval Method ◽  
Starting Time

The computer-interfaced system for second-order chemical kinetic studies was applied to the determination of the rate constant of the saponification of ethyl acetate at 35°C. For this specific problem, an averaging treatment was used which can be called an interval method. The use of this method avoids the diffcully of measuring the starting time of the reaction. Two groups of experimental data and results were used to evaluate the systems performance. All of the results obtained are in agreement with the reference value.

scholarly journals Conversion of mineral components manganese ore at temperature conditions of formation of agglomerates

2019 ◽  
pp. 42-51
Author(s):  
Mianovska Yana ◽  
Proidak Yuriy ◽  
Kamkina L
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Weight Loss ◽  
Manganese Oxides ◽  
Kinetic Studies ◽  
Manganese Ore ◽  
Manganese Ores ◽  
Temperature Range ◽  
Natural Minerals ◽  
Mineral Components

Purpose: to determine the effect of temperature and duration of firing on the dissociation-reduction reaction of mineral components of manganese ores. Recovery of manganese ore is carried out in four stages, which are determined by temperatures: <150°C, 150°C - 300°C, 300°C - 480°C, above 480°C. Topicality. Ores and concentrates undergo a number of complex transformations during heat treatment (agglomeration, firing of pellets and briquettes, preheating). The nature of such transformations is largely determined by chemical, mineralogical and particle size distribution, as well as other properties of the source ore. In addition to external conditions (temperature, pressure, nature of recovery, gas flow rate), the reaction rate is influenced by the physicochemical properties of the renewable substance, its mineralogical composition, structure, surface condition. The kinetic features of the reduction of pure manganese oxides are difficult to apply to manganese ores and concentrates with a rather complex structure and chemical composition. Understanding the basic chemical processes occurring in the smelting of manganese alloys is important for finding and justifying technological solutions to increase the efficiency of smelting of alloys. Method. Kinetic studies at different temperatures and fractional composition of the components under study. Results. The available literature data clearly indicate the dependence of the kinetic parameters of the processes occurring when heating manganese oxides in reducing conditions, from their physicochemical nature. To a lesser extent, process performance differs for natural minerals, although the composition of minerals may vary depending on the place of extraction. In this paper, it seems more appropriate to study the transformations that occur with manganese ores when heated, to use as an object of study the natural minerals that are part of these ores. Experimental data obtained in the study of physicochemical characteristics of the reducing processes of natural minerals can be used in the analysis of ore reduction and improvement of ferroalloy production processes. Scientific novelty. Kinetic studies of the process of interaction of minerals with reducing gas were performed at a constant heating rate of 14 degrees in the temperature range of 25-1000°C. Oxide concentrate and natural minerals lose moisture in the first 5-6 minutes. Their recovery proceeded at high speeds at temperatures of 300-4000C. A significant increase in speed was observed during the transition from a temperature of 4000C to a temperature of 6000C. Subsequent heating at 2000C led to a small increase in the total process speed. The total weight loss of the samples during heat treatment consisted of weight loss due to dissociation of manganese dioxide, weight loss due to dehydration and dissociation of carbonates that are part of the concentrate, as well as oxygen loss due to reduction. Calculations showed that the temperature of the beginning of the dissociation of MnO2 in a helium atmosphere is 460K. Dissociation of pure MnO2 is thermodynamically possible in the studied temperature range. The final decomposition product can only be manganese oxide. Practical significance. The obtained experimental data allowed to draw a conclusion about the inefficiency of grinding of oxidative manganese materials smaller than to the fraction -2.0 +1.5 mm before their heat or reduction-heat treatment in the processes of preparation of the charge for melting manganese ferroalloys. Key words: manganese ore, minerals, dissociation, kinetics, ore fractions

scholarly journals Removal of Carcinogenic Dyes Congo red (CR) and Bismarck brown Y (BBY) by Adsorption onto Reusable Hydrogels Derived from Acrylamide

2021 ◽  
Vol 2063 (1) ◽  
pp. 012011
Author(s):  
Huda S Al-Niaeem ◽  
Ali A Abdulwahid ◽  
Whidad S Hanoosh
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Congo Red ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Sulphonic Acid ◽  
Isotherm Models ◽  
Anionic Dyes ◽  
Best Fitting ◽  
Pseudo Second Order

Abstract Hydrogels of acrylamide (AM), acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid (AMS), and acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid\graphene oxide (AMSGO) were prepared as adsorbents to remove carcinogenic dyes Congo red (CR) and Bismarck brown Y (BBY) from aqueous solutions. Hydrogels were characterized using FSEM and XRD analyses. For both dyes, the synthesized hydrogels demonstrated high adsorption capability at near-neutral pH. Experimental adsorption data were analyzed using the Langmuir and Freundlich isotherm models. It was found that the Langmuir model was more suitable for the experimental data. Kinetic studies found that the pseudo-second-order model demonstrated the best fitting to the experimental data. In addition, thermodynamic studies suggest that the adsorption process was spontaneous and endothermic. The prepared hydrogels were regenerated and reused in four consecutive cycles and it could be applied to remove anionic dyes from aqueous solutions as an effective adsorbent.

Degradation Kinetic of Oxytetracycline Antibiotic inside UV Reactor in the Presence of H2O2

2014 ◽  
Vol 625 ◽  
pp. 901-906
Author(s):  
Anisa Ur Rahmah ◽  
Sabtanti Harimurti ◽  
Abdul Aziz Omar ◽  
Thanabalan Murugesan
Keyword(s):  
Experimental Data ◽  
Kinetic Study ◽  
Regression Coefficient ◽  
Kinetic Studies ◽  
Second Order ◽  
Degradation Kinetic ◽  
First Order ◽  
Uv Reactor ◽  
Pseudo First Order ◽  
Veterinary Antibiotic

–Oxytetracycline (OTC), a widely used of veterinary antibiotic, was degraded inside a UV/H2O2system. Kinetic study was conducted at 30°C of temperature and pH 6.37, as suggested by the previous optimization experiment. About 250, 375 and 500 ppm initial OTC concentration were used for the kinetic studies, at H2O2concentration of 0.116 M. The experimental data were plotted against the pseudo zero-th, first and second order of kinetic. Based on regression coefficient value, the data was well fitted with the pseudo first order of kinetic. The calculated value ofkobswas 0.181 min-1.

scholarly journals Kinetic Study on the Pyrolysis of Medium Density Fiberboard: Effects of Secondary Charring Reactions

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2481 ◽  
Author(s):  
Longwei Pan ◽  
Yong Jiang ◽  
Lei Wang ◽  
Wu Xu
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Kinetic Study ◽  
Mass Loss Rate ◽  
Medium Density Fiberboard ◽  
Kinetic Studies ◽  
Product Yield ◽  
Reaction Scheme ◽  
Medium Density ◽  
Pyrolysis Mechanism

The reaction models employed in the kinetic studies of biomass pyrolysis generally do not include the secondary charring reactions. The aim of this work is to propose an applicable kinetic model to characterize the pyrolysis mechanism of medium density fiberboard (MDF) and to evaluate the effects of secondary charring reactions on estimated products yields. The kinetic study for pyrolysis of MDF was performed by a thermogravimetric analyzer over a heating rate range from 10 to 40 °C/min in a nitrogen atmosphere. Four stages related to the degradation of resin, hemicellulose, cellulose, and lignin could be distinguished from the thermogravimetric analyses (TGA). Based on the four components and multi-component parallel reaction scheme, a kinetic model considering secondary charring reactions was proposed. A comparison model was also provided. An efficient optimization algorithm, differential evolution (DE), was coupled with the two models to determine the kinetic parameters. Comparisons of the results of the two models to experiment showed that the mass fraction (TG) and mass loss rate (DTG) calculated by the model considering secondary charring reactions were in better agreement with the experimental data. Furthermore, higher product yields than the experimental values will be obtained if secondary charring reactions were not considered in the kinetic study of MDF pyrolysis. On the contrary, with the consideration of secondary charring reactions, the estimated product yield had little error with the experimental data.

Isotherms and kinetic studies on adsorption of Hg(II) ions onto Ziziphus spina-christi L. from aqueous solutions

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Ali Hashem ◽  
Alaauddin Al-Anwar ◽  
Negma M. Nagy ◽  
Doaa M. Hussein ◽  
Sara Eisa
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Low Cost ◽  
Kinetic Studies ◽  
Plant Residue ◽  
Batch Adsorption ◽  
Pseudo First Order Reaction ◽  
Solution Ph ◽  
Equilibrium Data ◽  
Pseudo Second Order

AbstractL. (ZscL) is a plant residue that has been used as adsorbent for the removal of Hg(II) ions from an aqueous solution. The ability of ZscL to adsorb Hg(II) ions was investigated by using the batch adsorption procedure. It was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to support the adsorption of Hg(II) ions. The effects of various parameters on the adsorption process, such as contact time, adsorbent concentration, solution pH and initial concentrations of metal ions were studied to optimize the conditions for maximum adsorption. Experimental equilibrium data were fitted to the Freundlich, Langmuir, Dubinin-Radushkevich, Halsey and Temkin (two parameter models), Redlich-Peterson, Sips, Khan, Hill, Radke-Prausnitz, Langmuir-Freundlich and Toth (three parameter models), Fritz-Schlunder and Baudu (four parameter models) and Fritz-Schlunder (five parameter model) at 30°C by using nonlinear regression analysis. The examination of error analysis methods showed that the Halsey model provides the best fit for experimental data compared with the other isotherms. Various kinetic models have been applied to the experimental data to predict the adsorption kinetics. It was found that pseudo-second-order rate was better obeyed than pseudo-first-order reaction, supporting that the chemisorption process was involved. The obtained results show that ZscL can be used as an effective and natural low-cost adsorbent for the removal of Hg(II) ions from aqueous solutions.

Hydrogenation of Acetylene: Kinetic Studies and Reactor Modeling

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Navid Mostoufi ◽  
Ali Ghoorchian ◽  
Rahmat Sotudeh-Gharebagh
Keyword(s):  
Experimental Data ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Kinetic Studies ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Reactor Modeling ◽  
Deactivation Rate Constant ◽  
Hydrogenation Reactor ◽  
Kinetics Of

The kinetics of acetylene hydrogenation has been studied in a fixed bed reactor of a commercial Pd/Al2O3 catalyst. The experiments were carried out at 30, 50 and 70 ºC with various feed compositions at atmospheric pressure. The experiments were repeated at 70 ºC in the presence of the used catalyst to determine the effect of the catalyst deactivation where the corresponding deactivation rate constant was determined in order to predict the activity of the catalyst during each run. Two well known kinetic models were used for a nearly similar catalyst to predict the experimental data of this work and none of them were found satisfactory. A new model was then proposed to fit the experimental data. The hydrogenation reactor was also simulated at industrial operating conditions with the proposed kinetics for both plug and dispersion flows. The results of these simulations were almost close to each other in most cases.

scholarly journals SYNTHESIS OF STARCH MODIFIED MONTMORILLONITE AS AN EFFECTIVE ADSORBENT FOR Pb (II) REMOVAL FROM WATER

2019 ◽  
Vol 57 (3A) ◽  
pp. 94
Author(s):  
Tam Hoang Luu ◽  
Hung Van Nguyen ◽  
Nhan Thuc Chi Ha ◽  
Khoa Nguyen Dang Vo
Keyword(s):  
Experimental Data ◽  
Kinetic Studies ◽  
Batch Process ◽  
Second Order ◽  
X Ray Diffraction ◽  
Equilibrium Studies ◽  
Factors Affecting ◽  
Order Rate ◽  
Monolayer Adsorption ◽  
Pseudo Second Order

The adsorbent is prepared by the montmorillonite co-modification with starch for the removal of Pb (II) ions from aqueous solution. The Fourier-transformed infrared (FTIR), X-ray diffraction (XRD) spectroscopies were used to determine the structure and characteristics of the adsorbent. The main factors affecting the removal of Pb (II) ions were investigated, including the effect of pH, contact time, adsorbent dosage and the initial concentration of Pb (II). Batch process can be used for adsorption and equilibrium studies. The experimental data were fitted using Freundlich and Langmuir adsorption models. The Langmuir isotherm best fitted the experimental data with R2> 0.99 and maximum Pb (II) adsorption capacity of 21.5 mg/g indicated monolayer adsorption. Kinetic studies using pseudo-first-order and pseudo-second-order rate models showed that the process complied well with the pseudo second-order rate model.

scholarly journals Characterization of charcoal produced by different Pyrolyzing techniques

2020 ◽  
Author(s):  
Ma. Grace Curay ◽  
Abigail Joy Ching ◽  
Kazel Duran ◽  
Regine Mary Talingting ◽  
Sheila Balladares
Keyword(s):  
Experimental Data ◽  
Adsorption Capacity ◽  
Kinetic Studies ◽  
Production Method ◽  
Volatile Matter ◽  
Proximate Analysis ◽  
Adsorption Kinetic ◽  
Coefficient Of Determination ◽  
Fixed Carbon

Different pyrolyzing techniques are assumed to yield products with different content and adsorption rate. This study aimed to characterize five coconut charcoal samples from different pyrolyzing techniques such as Drum Kiln, Pit Method, Top Lift Updraft Method for TLUD – Top Sample & TLUD – Bottom Sample, and Hookway Retort to determine the best production method that will yield a quality of charcoal suitable for adsorption applications. Proximate analysis and adsorption kinetic studies were done to characterize and determine the rate of adsorption. Charcoal samples were ranked based on the following criteria and weights: 70% for adsorption capacity, 20% for fixed carbon, and 10% for the volatile matter. High adsorption capacity, high fixed carbon, and low volatile matter are good charcoal qualities for adsorption. For proximate analysis, ASTM Methods (ASTM D3302, ASTM D3175-17, ASTM D3174-12, ASTM D3172-13) were used. Experimental data showed that fixed carbon content of charcoal samples from Drum Kiln, Pit Method, TLUD-Top, TLUD-Bottom, and Hookway was 54.63%, 56.84%, 64.77%, 45.85%, and 56.59% respectively; while 30.69%, 31.65%, 20.65%, 43.39%, and 24.13% respectively for the volatile matter. For adsorption kinetic studies, optimization was done using Box-Behnken design with initial concentration, adsorbent dose, and pH as factors. The Hookway sample was subjected to optimization, where its optimum conditions were used for the rest of the charcoal samples. The experimental data for the adsorption kinetic studies showed that the pseudo-second-order exhibited the best fit for all the charcoal samples. The coefficient of determination for charcoal samples from Drum Kiln, Pit Method, TLUD-Top, TLUD-Bottom, and Hookway Method are 0.9253, 0.944, 0.7267, 0.9885, and 0.9216. Applying the weights, the best charcoal sample is from Kiln, followed by Pit, TLUD-Bottom, TLUD-Top, and Hookway. Production temperature, pressure, and humidity could be employed in future studies to determine what affects the quality of charcoal during pyrolysis.

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