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.

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.

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.

Esterification of Menthol and Lactic Acid by Silicotungstic Acid Catalyst Supported on Bentonite

2013 ◽  
Vol 634-638 ◽  
pp. 647-650
Author(s):  
Jian Zhong Jin ◽  
Na Bo Sun
Keyword(s):  
Lactic Acid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Catalyst ◽  
Molar Ratio ◽  
Main Reaction ◽  
Silicotungstic Acid ◽  
Optimum Conditions ◽  
Reaction Parameters ◽  
Acid Loading

The silicotungstic acid catalyst supported on bentonite was employed in the esterification of menthol and lactic acid. The main reaction parameters were silicotungstic acid loading on bentonite, the amounts of catalyst, molar ratio of reactants, reaction temperature and reaction time. The optimum conditions were determined as follows : silicotungstic acid loading on bentonite 50 wt %, catalyst 1.25 g , mole ratio of menthol to lactic acid 1:1.1, reaction temperature 130 °C and reaction time 3 h . The esterification yield of menthyl lactiate was about 83.97 %. The catalyst could be used repeatedly for many times without distinct loss in activity.

Application of Modified Chitosan for Treatment of Silk Degumming Wastewater

2012 ◽  
Vol 441 ◽  
pp. 573-577
Author(s):  
Lei Wang ◽  
Lan Wang ◽  
Jun Xiong Lin ◽  
Duan Ni
Keyword(s):  
Reaction Time ◽  
Ammonium Chloride ◽  
Reaction Temperature ◽  
High Performance ◽  
Water Solubility ◽  
Ph Value ◽  
Molar Ratio ◽  
Optimum Process ◽  
Trimethyl Ammonium Chloride ◽  
Modified Chitosan

Chitosan was modified by 2,3-epoxypropyl trimethyl ammonium chloride (ETA) to prepare 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with good water-solubility. The optimum process of modification was studied. Then the HACC was used as coagulant to treat silk degumming wastewater and recycle sericin. The result showed that the HACC with over 90% degree of substitution had high performance for treating the wastewater, which could be prepared by controlling the reaction temperature at 70°C, molar ratio of ETA to chitosan at 3:1, reaction time for 8 hours and pH at 8. When it was used to treat the degumming wastewater, the optimum treating process was 8 for pH value and 1 g/L of coagulant.

Study on Preparation of Biodiesel with Monomer Acid

2014 ◽  
Vol 521 ◽  
pp. 72-75
Author(s):  
Xiao Feng Liu
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Catalyst Concentration ◽  
Diesel Oil ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Optimum Conditions ◽  
Toluenesulfonic Acid ◽  
Acid Reaction ◽  
Single Factor Experiment

An esterification reaction of monomer acid with methanol using p-toluenesulfonic acid as catalyst for the preparation of biodiesel was studied. The process variables that influence the esterification of monomer acid, such as catalyst concentration, molar ratio of methanol to acid, reaction time and reaction temperature, were investigated and optimized. Through the single factor experiment, the optimum conditions obtained for the esterification were molar ratio of methanol to acid 3:1, usage amount of p-toluenesulfonic acid 6% and reaction time 3h, reaction temperature 70°C.The produced biodiesel was found to exhibit fuel properties within the limits prescribed by the latest American Standards for Testing Material (ASTM) and 0#diesel oil.

Synthesis and Properties of Rosin-Modified Lignosulfonates

2013 ◽  
Vol 634-638 ◽  
pp. 456-460 ◽  
Author(s):  
Le Le Zhao ◽  
Zu Guang Liu ◽  
Xue Er Huang ◽  
Ya Hong Liu
Keyword(s):  
Molecular Structure ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Kraft Lignin ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Propyl Ester ◽  
Rosin Ester

Rosin-modified lignosulfonates were prepared according to the following procedure: firstly, sulfomethylation of kraft lignin; secondly, preparation of 2,3-epoxypropyl ester of rosin; thirdly, preparation of modified-rosin lignosulfonates via etherification of sulfomethylated lignin with 2,3-epoxy propyl ester of rosin. Experimental results show that the optimum conditions for synthesis of 2,3-epoxy propyl ester of rosin are as follows: molar ratio for n(rosin): n (epichlorohydrin): n (NaOH) is1:6:1, reaction temperature is 100 °C(for rosin ester) and 75 °C(for 2,3-epoxypropyl ester of rosin, the same below), reaction time is 5.5 h and 3 h respectively. When molar ratio of lignosulfonate to 2,3-epoxypropylester of rosin is 1/5, rosin-modified lignosulfonates were prepared at 55 °Cfor 4.5 h with pH 11.5. Hydrophilic sulfonic group and the lipophilic adbietic group were incorporated into the molecular structure of kraft lignin via corresponding reactions. The surface tension of 10 g/L aqueous solution of rosin-modified lignosulfonate is 49.3 mN/m.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

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.

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.

scholarly journals Optimization of Enzymatic Synthesis of Betulinic Acid Amide in Organic Solvent by Response Surface Methodology (RSM)

2019 ◽  
Vol 19 (4) ◽  
pp. 849
Author(s):  
Nurul Atikah Amin Yusof ◽  
Nursyamsyila Mat Hadzir ◽  
Siti Efliza Ashari ◽  
Nor Suhaila Mohamad Hanapi ◽  
Rossuriati Dol Hamid
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Betulinic Acid ◽  
Enzymatic Synthesis ◽  
Acid Amide ◽  
Molar Ratio ◽  
Percentage Yield ◽  
Substrate Molar Ratio

Optimization of the lipase catalyzed enzymatic synthesis of betulinic acid amide in the presence of immobilized lipase, Novozym 435 from Candida antartica as a biocatalyst was studied. Response surface methodology (RSM) and 5-level-4-factor central-composite rotatable design (CCRD) were employed to evaluate the effects of the synthesis parameters, such as reaction time (20–36 h), reaction temperature (37–45 °C), substrate molar ratio of betulinic acid to butylamine (1:1–1:3), and enzyme amounts (80–120 mg) on the percentage yield of betulinic acid amide by direct amidation reaction. The optimum conditions for synthesis were: reaction time of 28 h 33 min, reaction temperature of 42.92 °C, substrate molar ratio of 1:2.21, and enzyme amount of 97.77 mg. The percentage yield of actual experimental values obtained 65.09% which compared well with the maximum predicted value of 67.23%. The obtained amide was characterized by GC, GCMS and 13C NMR. Betulinic acid amide (BAA) showed a better cytotoxicity compared to betulinic acid as the concentration inhibited 50% of the cell growth (IC50) against MDA-MB-231 cell line (IC50 < 30 µg/mL).

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