Research on Affecting Factor of Preparation of Calcium Sulfate Whisker with FGD Gypsum

2014 ◽  
Vol 624 ◽  
pp. 82-85
Author(s):  
Ying Wang ◽  
Dan Jun Tan ◽  
Xiao Li ◽  
Fan Li ◽  
Peng Qi Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Calcium Sulfate ◽  
Ph Value ◽  
Synthesis Method ◽  
Raw Material ◽  
Optimum Conditions ◽  
Fgd Gypsum ◽  
Slurry Concentration ◽  
Calcium Sulfate Whisker

Using FGD gypsum as raw material, calcium sulfate whisker was prepared by hydrothermal synthesis method. Through testing the aspect ratio of calcium sulfate whisker, the effect of reaction temperature, reaction time, desulfurization gypsum slurry concentration and pH value on the growth of calcium sulfate whisker were deeply researched. The optimum conditions for the preparation were that the reaction temperature was 150 °C, reaction time was 270min, the slurry concentration was 10% and the slurry pH value was 6.

scholarly journals Facile Synthesis of Silver Nanoparticles and Preparation of Conductive Ink

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 171
Author(s):  
Gui Bing Hong ◽  
Yi Hua Luo ◽  
Kai Jen Chuang ◽  
Hsiu Yueh Cheng ◽  
Kai Chau Chang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electrical Resistivity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Chemical Reduction ◽  
Flexible Substrate ◽  
Synthesis Method ◽  
Future Research ◽  
Conductive Ink

In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research.

The Effect of Process Conditions on the Preparation of α-Calcium Sulfate Hemihydrate from FGD Gypsum Using the Hydrothermal Method under Atmospheric Pressure

2011 ◽  
Vol 250-253 ◽  
pp. 881-889 ◽  
Author(s):  
Xian Feng Liu ◽  
Jia Hui Peng ◽  
Chen Yang Zou ◽  
Leng Bai ◽  
Mei Li
Keyword(s):  
Hydrothermal Method ◽  
Reaction Temperature ◽  
Salt Concentration ◽  
Atmospheric Pressure ◽  
Calcium Sulfate ◽  
Ph Value ◽  
Fgd Gypsum ◽  
Rate Of Reaction ◽  
Percent Conversion ◽  
Calcium Sulfate Hemihydrate

This paper studies the laws of crystal growth, percent conversion and the rate of reaction of α-calcium sulfate hemihydrate from FGD gypsum under different conditions using the hydrothermal method under atmospheric pressure. The crystal morphology was observed by using SEM, polarizing microscope profile, and percent conversion and the rate of reaction were obtained by assaying crystal water content and calculating. The results showed, (1) with the increase of reaction temperature, the dehydration rate increased and the formed α-calcium sulfate hemihydrate crystal had a larger particle size; (2) with the increase of salt concentration or slurry concentration, the formed α-calcium sulfate hemihydrate crystal was smaller, percent conversion and the rate of reaction was nearly unchanged; (3) with the increase of pH value of solution, the rate of reaction increased and percent conversion was nearly unchanged, and with pH value ranging from 5 to 7 the formed α-calcium sulfate hemihydrate crystal was crassitude. In conclusion, the perfect technological parameters were as follows: reaction temperature ranging from 95°C to 100°C, salt concentration ranging from 15% to 20%, slurry concentration ranging from 15% to 20%, pH value ranging from 5 to 7, and reaction time not exceeding 90min.

Study on Saccharification and Hydrolysis in Cellulose of Bagasse

2011 ◽  
Vol 236-238 ◽  
pp. 428-431
Author(s):  
Ying Xiao Mu ◽  
Hong Xiang Zhu ◽  
Hui He ◽  
Hai Nong Song ◽  
Shuang Fei Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Cellulose Hydrolysis ◽  
Reducing Sugar ◽  
Optimum Conditions ◽  
Value System ◽  
Percent Conversion ◽  
Substrate Size ◽  
Bagasse Pulp

The effect of the reaction time, the amount of enzyme, the reaction temperature and the pH value system, also the substrate size on bagasse pulp cellulose hydrolysis in the rate of reducing sugar was studied. And the optimum conditions response was researched. Under these conditions, we also studied the percent conversion of reducing sugar, and analyzed the changes of crystallinity after the bagasse pulp cellulose hydrolysis.

Preparation of Calcium Sulfate Whisker by Hydrothermal Method from Flue Gas Desulfurization (FGD) Gypsum

2012 ◽  
Vol 268-270 ◽  
pp. 823-826 ◽  
Author(s):  
Liu Shuan Yang ◽  
Xiao Wang ◽  
Xin Feng Zhu ◽  
Ling Zhi Du
Keyword(s):  
Hydrothermal Method ◽  
Reaction Temperature ◽  
Flue Gas ◽  
Calcium Sulfate ◽  
Raw Materials ◽  
Flue Gas Desulfurization ◽  
Minor Effect ◽  
Fgd Gypsum ◽  
Excellent Quality ◽  
Calcium Sulfate Whisker

In this paper, utilizing the purified flue gas desulfurization (FGD) gypsum as raw materials to prepare calcium sulfate whisker (CSW) by hydrothermal method, the effects of the dosage of crystal modifier, reaction temperature, pH, etc. on the crystal morphology of CSW were discussed. The results show that the purified FGD gypsum can replace high-quality natural gypsum for the preparation of the CSW with excellent quality. The dosage of crystal modifier (K2SO4) and reaction temperature have a significant effect on the morphology and aspect ratio of CSW, while pH and reaction time have a minor effect. When the dosage of K2SO4 is 3 wt%, pH is adjusted to 2 and the solution is reacted at 130 °C for 60 min, CSW with excellent quality can be obtained.

Catalysis of metalloporphyrins for selective hydroxylation of phenol by H2O2

2006 ◽  
Vol 10 (02) ◽  
pp. 96-103 ◽  
Author(s):  
Hai-Qiang Zeng ◽  
Quan Jiang ◽  
Yun-Fei Zhu ◽  
Xu-Hui Yan ◽  
Xue-Bo Liang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Solvent Ratio ◽  
Optimum Conditions ◽  
Hydroxylation Of Phenol ◽  
Water As Solvent ◽  
Selective Hydroxylation

Liquid phase catalytic selective hydroxylation of phenol to catechol and hydroquinone was carried out in the presence of metalloporphyrins using hydrogen peroxide as oxidant and water as solvent. Five kinds of metal tetra(p-chlorophenyl)porphrin ( T (p- Cl ) PPMCl , M = Fe , Co , Mn , Cu , Zn ) were studied. It was found that T (p- Cl ) PPFeCl had high catalytic activity and diphenol selectivity for the hydroxylation of phenol to catechol and hydroquinone. The influence of various reaction parameters, namely, reaction temperature, solvent, ratio of substrate and oxidant, substrate concentration, the amount of catalyst, reaction time and pH value were investigated systematically. When water was used as solvent (10 mL), the optimum conditions were following: pH = 7, the concentration of phenol was 0.3 g/mL, the molar ratio of phenol and H 2 O 2 was 1/2, the molar ratio of catalyst and phenol was 7/100000, the reaction temperature was 65°C and the reaction time was 1.5 h. Under above optimum conditions, the phenol conversion was up to 55.1%, and the selectivity of diphenol was almost up to 99.9%, the molar turnover numbers of the catalyst was about 7500. A possible mechanism was also proposed.

Batch Supercritical Hydrothermal Synthesis of CeO2 Nanoparticles

2011 ◽  
Vol 284-286 ◽  
pp. 773-780
Author(s):  
Dan Zhao ◽  
Da Liang Li ◽  
Xin Qiang Wu ◽  
En Hou Han
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
Ph Value ◽  
Synthesis Method ◽  
Additional Treatment ◽  
Reactant Concentration ◽  
Size And Morphology ◽  
Supercritical Hydrothermal Synthesis

CeO2 nanoparticles with diameter of about 5 nm were prepared by batch supercritical hydrothermal synthesis method at 390 °C without additional treatment. It was found that the characteristics of products depended on the pH value, reactant concentration (C0), and reaction temperature. The reaction time and coexisting cations (Li+, Na+ and K+) had little effect on the size and morphology of CeO2 particles. Uniform CeO2 nanoparticles were synthesized at 390 °C, pH = 9 and C0 = 0.06 M. The mechanism for batch supercritical hydrothermal synthesis of CeO2 nanoparticles is discussed.

scholarly journals Process optimization for biodiesel production from neutralized waste cooking oil and the effect of this biodiesel on engine performance

2018 ◽  
Vol 8 (1) ◽  
pp. 121-127 ◽  
Author(s):  
Tanzer Eryilmaz
Keyword(s):  
Reaction Time ◽  
Methyl Ester ◽  
Reaction Temperature ◽  
Direct Injection ◽  
Engine Performance ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Phase Reaction ◽  
Optimum Conditions ◽  
Cooking Oils

In this study, the methyl ester production process from neutralized waste cooking oils is optimized by using alkali-catalyzed (KOH) single-phase reaction. The optimization process is performed depending on the parameters, such as catalyst concentration, methanol/oil ratio, reaction temperature and reaction time. The optimum methyl ester conversion efficiency was 90.1% at the optimum conditions of 0.7 wt% of potassium hydroxide, 25 wt% methanol/oil ratio, 90 min reaction time and 60°C reaction temperature. After the fuel characteristics of the methyl ester obtained under optimum conditions were determined, the effect on engine performance, CO and NOx emissions of methyl ester was investigated in a diesel engine with a single cylinder and direct injection. When compared to diesel fuel, engine power and torque decreased when using methyl ester, and specific fuel consumption increased. NOx emission increases at a rate of 18.4% on average through use of methyl ester.

Research of Preparation Factors on Magnetic Cassava Starch Microspheres

2013 ◽  
Vol 634-638 ◽  
pp. 1513-1517
Author(s):  
Ping Lan ◽  
Yu Xian Feng ◽  
A Ming Chen ◽  
Lei Lei Qiao ◽  
Li Hong Lan ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Influence Factors ◽  
Cassava Starch ◽  
Raw Material ◽  
Speed Ratio ◽  
Optimal Conditions

Magnetic cassava starch microspheres have been prepared by means of the method of precipitation magnetization, cassava starch as raw material adsorbing or embedding Fe3O4, many influence factors on magnetic cassava starch iron rate such as pH, reaction time, stirring speed, ratio of Fe+3 to Fe+2, reaction temperature also investigated in this paper. On the base above research, we preliminary got the optimal conditions on the synthesis of magnetic cassava starch microspheres.

Experimental Researches on the Preparation of High-Efficient Active Floridin by Mixed Acids

2012 ◽  
Vol 510 ◽  
pp. 713-718
Author(s):  
Ming Yong Shu ◽  
Hai Ying Yin ◽  
Guang Hui Liu
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Volume Ratio ◽  
Raw Material ◽  
Activation Effect ◽  
Solid Ratio ◽  
High Efficient ◽  
Main Factors ◽  
Experimental Researches ◽  
Mixed Acids

Taking ca-bentonite as the raw material, the activation effect of active floridin prepared by mixed acids of H2SO4, HCl and C2H2O4 is studied. The research results indicate that the main factors influencing the activity and decolorization ratio of floridin include volume ratio of mixed acids, liquid-to-solid ratio, reaction temperature and reaction time. When the volume ratio of mixed acids H2SO4: HCl: C2H2O4=5:5:1, liquid-to-solid ratio =4:1, reaction temperature 80 and reaction time 4h, it is possible to prepare high-efficient active floridin.

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.

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