Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

Removal of Iron from Metallurgical Grade Silicon with Pressure Leaching

2011 ◽  
Vol 675-677 ◽  
pp. 873-876 ◽  
Author(s):  
Ke Qiang Xie ◽  
Zhan Liang Yu ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Yong Nian Dai
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Removal Efficiency ◽  
Acid Concentration ◽  
Operating Conditions ◽  
Raw Material ◽  
Optimum Operating ◽  
Pressure Leaching ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon

In this paper, removal of iron from metallurgical grade silicon with pressure leaching is carried out. We investigated the factors such as the concentration of hydrochloric, particle size of raw material ground, temperature, pressure and reaction time, which influenced on the removal of iron. The results show that the optimum operating conditions for pressure leaching in hydrochloride are: acid concentration 4 mol/L, diameter for raw material less than 50 μm, leaching temperature 160 0C，leaching pressure 2.0 MPa, leaching time 2.0 h. The content of iron residual in MG-Si powder was reduced to about 200 ppmw. The removal efficiency of iron is up to 90.90 %.

Characterization and Process Optimization of Transition Metal Compound Catalyst in CWAO Applications

2013 ◽  
Vol 849 ◽  
pp. 132-136
Author(s):  
Ping Li ◽  
Yong Li Zhang ◽  
Jin Bing Lin
Keyword(s):  
Reaction Time ◽  
Transition Metal ◽  
Reaction Temperature ◽  
Operating Conditions ◽  
Metal Compound ◽  
Process Conditions ◽  
Catalyst Characterization ◽  
Total System ◽  
Transition Metal Compound ◽  
Influent Concentration

On simulated organic wastewater treatment by catalytic wet oxidation (CWAO) experiments, the transition metal compound Cu-Fe-La/FSC catalysts were characterized by SEM, TEM and FT-IR, and its application in CWAO reaction process conditions were optimized. Catalyst characterization experiments show that the active components on the surface of the Cu-Fe-La/FSC uniformly distribute, and the particle size is 10 to 50 nm; the chemical composition of-OH-and-Al-O-key are remarkable. To optimize the operation process with the orthogonal experiments of catalytic wet air oxidation (CWAO), the results show that in the five factors of influencing CODCrremoval rates of wastewater, they are arranged according to the influences on water treatment from high to low: catalyst dose, system total pressure, influent concentration, reaction temperature, reaction time. The optimized operating conditions: catalyst dose of 8 g/L, total system pressure of 2.0 MPa, influent concentration of 3000 mg/L, reaction temperature of 180 °C¡æ, reaction time of 60 min. Under the optimized operating conditions, the CODCrremoval rate of simulated wastewater reached 77.9%.

scholarly journals Effects of Process Variables on Properties of CoFe2O4 Nanoparticles Prepared by Solvothermal Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3056
Author(s):  
Hong Diu Thi Duong ◽  
Dung The Nguyen ◽  
Kyo-Seon Kim
Keyword(s):  
Particle Size ◽  
Oleic Acid ◽  
Reaction Time ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Synthesis Process ◽  
Process Conditions ◽  
Solvothermal Process ◽  
Cofe2o4 Nanoparticles ◽  
Oleic Acid Concentration

Controlling the morphology and magnetic properties of CoFe2O4 nanoparticles is crucial for the synthesis of compatible materials for different applications. CoFe2O4 nanoparticles were synthesized by a solvothermal method using cobalt nitrate, iron nitrate as precursors, and oleic acid as a surfactant. The formation of CoFe2O4 nanoparticles was systematically observed by adjusting synthesis process conditions including reaction temperature, reaction time, and oleic acid concentration. Nearly spherical, monodispersed CoFe2O4 nanoparticles were formed by changing the reaction time and reaction temperature. The oleic acid-coated CoFe2O4 nanoparticles inhibited the growth of particle size after 1 h and, therefore, the particle size of CoFe2O4 nanoparticles did not change significantly as the reaction time increased. Both without and with low oleic acid concentration, the large-sized cubic CoFe2O4 nanoparticles showing ferromagnetic behavior were synthesized, while the small-sized CoFe2O4 nanoparticles with superparamagnetic properties were obtained for the oleic acid concentration higher than 0.1 M. This study will become a basis for further research in the future to prepare the high-functional CoFe2O4 magnetic nanoparticles by a solvothermal process, which can be applied to bio-separation, biosensors, drug delivery, magnetic hyperthermia, etc.

scholarly journals Enzymatic Transesterification of Waste Frying Oil from Local Restaurants in East Colombia Using a Combined Lipase System

2020 ◽  
Vol 10 (10) ◽  
pp. 3566
Author(s):  
Mary Angélica Ferreira Vela ◽  
Juan C. Acevedo-Páez ◽  
Nestor Urbina-Suárez ◽  
Yeily Adriana Rangel Basto ◽  
Ángel Darío González-Delgado
Keyword(s):  
Reaction Time ◽  
Methyl Esters ◽  
Enzyme Concentration ◽  
Operating Conditions ◽  
Frying Oil ◽  
Biodiesel Production ◽  
Optimum Operating ◽  
Waste Frying Oil ◽  
Production Chain ◽  
Enzymatic Transesterification

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.

scholarly journals Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

2021 ◽  
Author(s):  
Paulo Bisi dos Santos Jr. ◽  
Haroldo Jorge da Silva Ribeiro ◽  
Armando Costa Ferreira ◽  
Caio Campos Ferreira ◽  
Lucas Pinto Bernar ◽  
...  
Keyword(s):  
Refractive Index ◽  
Reaction Time ◽  
Liquid Phase ◽  
Kinematic Viscosity ◽  
Process Analysis ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Dental Resins ◽  
Liquid Products ◽  
The Cross

In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.

scholarly journals Numerical Simulations of Molten Breakup Behaviors of a de Laval-Type Nozzle, and the Effects of Atomization Parameters on Particle Size Distribution

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1027
Author(s):  
Lianghui Xu ◽  
Xianglin Zhou ◽  
Jinghao Li ◽  
Yunfei Hu ◽  
Hang Qi ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Gas Flow ◽  
Nozzle Geometry ◽  
Particle Model ◽  
Process Conditions ◽  
Operating Pressure ◽  
Gas Temperature ◽  
Tracking Model

In this work, an atomizer with a de Laval-type nozzle is designed and studied by commercial computational fluid dynamics (CFD) software, and the secondary breakup process during atomization is simulated by two-way coupling and the discrete particle model (DPM) using the Euler-Lagrange method. The simulation result demonstrates that the gas flow patterns greatly change with the introduction of liquid droplets, which clearly indicates that the mass loading effect is quite significant as a result of the gas-droplet interactions. An hourglass shape of the cloud of disintegrating molten metal particles is observed by using a stochastic tracking model. Finally, this simulation approach is used for the quantitative evaluation of the effects of altering the atomizing process conditions (gas-to-melt ratio, operating pressure P, and operating gas temperature T) and nozzle geometry (protrusion length h, half-taper angle α, and gas slit nozzle diameter D) on the particle size distribution of the powders produced.

scholarly journals The dissolution study of a South African magnesium-based material from different sources using a pH-stat

2011 ◽  
Vol 17 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Rutto Limo ◽  
Christopher Enweremadu
Keyword(s):  
Particle Size ◽  
Dissolution Rate ◽  
South African ◽  
Reaction Temperature ◽  
Liquid Ratio ◽  
Efficient Operation ◽  
Shrinking Core ◽  
Ph Stat ◽  
Hcl Concentration ◽  
Different Sources

One of the main steps in the wet flue gas desulphurization (WFGD) process is the dissolution of either magnesite or limestone. Evaluating the magnesite dissolution rate is vital for the design and efficient operation of wet FGD plants. A study on the dissolution of magnesite from different sources in South Africa is presented in this work. The effect of reaction temperature (303.15-343.15K), solid-to-liquid ratio (0.5-2.5g/200 ml), particle size (25-125?m), pH (4-6) and HCl concentration (0.5-2.5 mol/l) on the dissolution rate was studied. It was found out that the dissolution reaction follows a shrinking-core model with the chemical reaction control as the rate-controlling step. The dissolution rate increased with an increase in concentration and reaction temperature and with a decrease in particle size and solid-to-liquid ratio. The activation energy of this dissolution process was found to be 45.685 kJ/mol.

Optimization of leachate treatment using persulfate/H2O2 based advanced oxidation process: case study: Deir El-Balah Landfill Site, Gaza Strip, Palestine

2015 ◽  
Vol 73 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Ahmed H. Hilles ◽  
Salem S. Abu Amr ◽  
Rim A. Hussein ◽  
Anwar I. Arafa ◽  
Olfat D. El-Sebaie
Keyword(s):  
Reaction Time ◽  
Advanced Oxidation Process ◽  
Gaza Strip ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Leachate Treatment ◽  
Operating Variables ◽  
Treatment Processes ◽  
N Removal

The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O82−, 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O82−/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.

Enhanced Photocatalytic Performance and Mechanism of Ag3PO4 Particles Synthesized via a Sonochemical Process

2018 ◽  
Vol 10 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Chengxiang Zheng ◽  
Hua Yang ◽  
Yang Yang ◽  
Haimin Zhang
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Dye Degradation ◽  
Sonochemical Method ◽  
Simulated Sunlight ◽  
Spherical Nanoparticles ◽  
Direct Oxidation

A facile sonochemical method was used to synthesize Ag3PO4 particles and the effect of pH value, reaction temperature and reaction time on the products was investigated. It is found that the samples prepared at neutral (pH = 7) and alkaline (pH = 11) environments exhibit a similar particle morphology and size. The particles are shaped like spheres with a size distribution majorly focusing on a range of 200–450 nm, and the average particle size is about 300 nm. The sample prepared at acidic environment (pH = 3) is composed of polyhedral microparticles with size of 5–8 μm. At relatively low temperatures of 20–50 °C, the spherical nanoparticles do not undergo obvious morphology/size changes; however, when the temperature is increased up to 80 °C, the nanoparticles are aggregated to form large-sized polyhedral microparticles in the size range of 4–7 μm. Compared to the pH value and reaction temperature, the reaction time has a minor effect on the morphology of Ag3PO4 particles. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the as-prepared Ag3PO4 samples under simulated-sunlight irradiation. It is shown that the samples consisting of spherical nanoparticles exhibit an extremely high photocatalytic activity, and the degradation percentage of RhB after reaction for 50 min reaches over 90%. The samples of polyhedral microparticles have a relatively low photocatalytic activity, which is possibly due to their large particle size. Hydroxyl (.OH) radical was detected by spectrofluorimetry using terephthalic acid as a .OH scavenger and was not found to be produced over the simulated-sunlight-irradiated Ag3PO4 catalyst. The effect of ethanol, benzoquinone and ammonium oxalate on dye degradation was also investigated. Based on experimental results, the direct oxidation by h+ is suggested to the dominant mechanism toward the dye degradation.

Optimization of Synthesis Process for Sodium Ascorbate

2012 ◽  
Vol 550-553 ◽  
pp. 10-15 ◽  
Author(s):  
Jing Chen Wang ◽  
Feng Xia Cui ◽  
Tao Li
Keyword(s):  
Reaction Time ◽  
Sodium Carbonate ◽  
Reaction Temperature ◽  
Conversion Rate ◽  
Sodium Ascorbate ◽  
Synthesis Process ◽  
Esterification Reaction ◽  
Reaction Yield ◽  
Process Conditions ◽  
Reactant Ratio

With 2-keto-L-gulonic acid(2KLG) and methanol as raw materials, 98% concentrated sulfuric acid as catalyst, the methyl esterification reaction is occurred. Then with sodium carbonate as a transforming agent, a conversion reaction sodium carbonate is obtained. In this experiment, the effects of reaction time, reaction temperature and reactant ratio on conversion rate of sodium ascorbate were studied. The results showed that sodium carbonate as the reactant of lactonization reaction can effectively shorten the reaction time and improve reaction yield. By experiment under the optimum process conditions: the reaction temperature is 65 °C, reaction time is 150 minutes and the molar ratio of 2-keto-L-gu methyl to sodium carbonate is 1:0.6, the conversion rate reaches 98 % and the effect is better than with sodium bicarbonate as transforming agent.

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