scholarly journals The Studies on α-Pinene Oxidation over the TS-1. The Influence of the Temperature, Reaction Time, Titanium and Catalyst Content

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7799
Author(s):  
Agnieszka Wróblewska ◽  
Jadwiga Grzeszczak ◽  
Piotr Miądlicki ◽  
Karolina Kiełbasa ◽  
Marcin Kujbida ◽  
...  
Keyword(s):  
Reaction Time ◽  
Oxidation Process ◽  
Practical Importance ◽  
Kinetic Studies ◽  
Titanium Content ◽  
Temperature Reaction ◽  
Campholenic Aldehyde ◽  
Catalyst Temperature ◽  
Catalyst Content ◽  
Ti Content

The work presents the results of studies on α-pinene oxidation over the TS-1 catalysts with different Ti content (in wt%): TS-1_1 (9.92), TS-1_2 (5.42), TS-1_3 (3.39) and TS-1_4 (3.08). No solvent was used in the oxidation studies, and molecular oxygen was used as the oxidizing agent. The effect of titanium content in the TS-1 catalyst, temperature, reaction time and amount of the catalyst in the reaction mixture on the conversion of α-pinene and the selectivities of appropriate products was investigated. It was found that it is most advantageous to carry out the process of α-pinene oxidation in the presence of the TS-1 catalyst with the titanium content of 5.42 wt% (TS-1_2), at the temperature of 85 °C, for 6 h and with the catalyst TS-1 content in the reaction mixture of 1 wt%. Under these conditions the conversion of α-pinene amounted to 34 mol%, and the selectivities of main products of α-pinene oxidation process were: α-pinene oxide (29 mol%), verbenol (15 mol%) and verbenone (12 mol%). In smaller quantities also campholenic aldehyde, trans-pinocarveol, myrtenal, myrtenol, L-carveol, carvone and 1,2-pinanediol were also formed. These products are of great practical importance in food, cosmetics, perfumery and medicine industries. Kinetic studies were also performed for the studied process.

scholarly journals Catalytic isomerization of substituted vinylcyclopropanes

2019 ◽  
Vol 487 (3) ◽  
pp. 266-269
Author(s):  
G. Z. Raskil’dina ◽  
Yu. G. Borisova ◽  
A. R. Davletshin ◽  
S. S. Zlotsky
Keyword(s):  
Reaction Time ◽  
Zeolite Catalysts ◽  
Temperature Reaction ◽  
Reaction Products ◽  
Number Of Factors ◽  
Catalytic Isomerization ◽  
Catalyst Temperature

The catalytic isomerization of substituted vinyl-gem-dichlorocyclopropanes was studied in the presence of a series of zeolite catalysts. It is shown that the only reaction products are substituted gem-dichlorocyclopentenes. The influence of a number of factors (type of catalyst, temperature, reaction time) on the yield of isomerization products was investigated.

scholarly journals Clinoptilolite as a natural, active zeolite catalyst for the chemical transformations of geraniol

2021 ◽  
Author(s):  
Anna Fajdek-Bieda ◽  
Agnieszka Wróblewska ◽  
Piotr Miądlicki ◽  
Jadwiga Tołpa ◽  
Beata Michalkiewicz
Keyword(s):  
Reaction Time ◽  
Nitrogen Adsorption ◽  
Carbon Chain ◽  
Raw Material ◽  
Chemical Transformations ◽  
Renewable Biomass ◽  
Ft Ir ◽  
Catalyst Content ◽  
Favorable Conditions ◽  
Instrumental Methods

AbstractThis work presented the studies with the natural zeolite—clinoptilolite as the catalyst for the isomerization of geraniol. During the research, it turned out that the studied process is much more complicated, and not only isomerization takes place in it, but also dehydration, oxidation, dimerization, cyclization and fragmentation of the carbon chain. Geraniol is an organic raw material which can be obtained not only by a chemical synthesis but also from plants (renewable biomass) by distillation or extraction method, for example a source of geraniol can be a plant—geranium. Before catalytic tests clinoptilolite was characterized by the instrumental methods, such as: XRD, porosity studies—nitrogen adsorption at 77 K, SEM, EDXRF, and FT-IR. Gas chromatography analyses showed that the main products of geraniol isomerization process were 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol. The selectivity of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol depended on the temperature, catalyst content and reaction time. These parameters were changed in the following ranges: 80–150 °C (temperature), 5–15 wt% (catalyst content) and 15–1440 min. (reaction time). The most favorable conditions for 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol obtaining were: temperature 140 ºC, catalyst content 12.5 wt% and reaction time 180 min. At these conditions, the conversion of geraniol amounted to 98 mol%, and the selectivities of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol amounted to 14 and 47 mol%, respectively.

scholarly journals UV/Vis-Based Persulphate Activation for p-Nitrophenol Degradation

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 480
Author(s):  
Valentin Dubois ◽  
Carmen S. D. Rodrigues ◽  
Ana S. P. Alves ◽  
Luis M. Madeira
Keyword(s):  
Reaction Time ◽  
Oxidation Process ◽  
Activation Process ◽  
Direct Photolysis ◽  
Simulated Solar Light ◽  
Uv Visible ◽  
Oxidation Efficiency ◽  
Nitrophenol Degradation ◽  
Persulphate Oxidation ◽  
Radiation Type

In the present work, the degradation of p-nitrophenol (PNP) and its mineralization by a UV/Vis-based persulphate activation process was investigated. Firstly, a screening of processes as direct photolysis, persulphate alone and persulphate activated by radiation was performed. The incidence of radiation demonstrated to have an important role in the oxidant activation, allowing to achieve the highest PNP and total organic carbon (TOC) removals. The maximum PNP oxidation (100%) and mineralization (61.6%)—both after 2 h of reaction time—were reached when using T = 70 °C, (S2O82−) = 6.4 g/L and I = 500 W/m2. The influence of radiation type (ultraviolet/visible, visible or simulated solar light) was also evaluated, being found that the source with the highest emission of ultraviolet radiation (UV/visible) allowed to achieve the best oxidation efficiency; however, solar radiation also reached very-good performance. According to quenching experiments, the sulphate radical is key in the activated persulphate oxidation process, but the hydroxyl radical also plays an important role.

Study on Pretreatment of Dye Wastewater by Fenton Oxidation Process

2012 ◽  
Vol 627 ◽  
pp. 378-381
Author(s):  
Bi Rong Wang
Keyword(s):  
Reaction Time ◽  
Oxidation Process ◽  
Removal Rate ◽  
Fenton Oxidation ◽  
Dye Wastewater ◽  
Dyeing Wastewater ◽  
Reaction Conditions ◽  
Fenton Oxidation Process

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.

scholarly journals The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Allyl Alcohol ◽  
Water Solution ◽  
Reaction Medium ◽  
Diglycidyl Ether ◽  
Molar Ratio ◽  
Water Medium ◽  
Catalyst Content ◽  
Allyl Alcohol Epoxidation

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

Study on Extracting Potassium from Potassium Feldspar with Molten Salt Leaching Method

2012 ◽  
Vol 524-527 ◽  
pp. 1078-1081
Author(s):  
Jian Guo Song ◽  
Xin Zhi Wang ◽  
Shao Dan Xiao ◽  
Wei Liu
Keyword(s):  
Reaction Time ◽  
Molten Salt ◽  
Potassium Feldspar ◽  
Process Conditions ◽  
Temperature Reaction ◽  
Optimal Process ◽  
Potash Feldspar ◽  
Salt Leaching ◽  
Effects Of Temperature

This article aims to study the technology of extracting potassium from potassium feldspar with molten salt leaching method and to analyze the effects of temperature, reaction time and other factors on extracting potassium, concluding the optimal process conditions of extracting potassium with molten leaching method from potash feldspar.

scholarly journals Comparative Studied of Degradation of Textile Brilliant Reactive Red Dye Using H2O2, TiO2, UV and Sunlight

2019 ◽  
Vol 22 (1) ◽  
pp. 31-36
Author(s):  
Forqan Mohammed ◽  
Khalid M. Mousa
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
Uv Radiation ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Textile Wastewater ◽  
Cost Effective ◽  
H2o2 Concentration ◽  
Solution Ph ◽  
Red Dye

In this study sunlight and UV radiation were used to compare the efficiency of decolorization of textile wastewater containing brilliant reactive red dye K-2BP (λmax = 534 nm) by the advanced oxidation process (AOP) using (H2O2/sunlight, H2O2/UV, H2O2/TiO2/sunlight, and H2O2/TiO2/UV). The results studied the effect of solution pH, applied H2O2 concentration, TiO2 concentration (nanoparticle), and initial dye concentration were studied. The experimental results showed that decolorization percentage with H2O2/sunlight and TiO2/H2O2/sunlight under the following conditions: - reaction time 150 of minutes, [ 500 ppm] H2O2, [100 ppm] TiO2, pH=3, initial dye concentration =15 ppm and at ambient temperature were 95.7% and 98.42% respectively. For the same conditions using H2O2/UV, H2O2/TiO2 /UV, the percentage of decolorization were 97.85% and 96.33% respectively. The results also indicated that the sunlight is more economic and cost-effective than UV radiation.

scholarly journals Isolation and ldentification of 2,6- Dimethyl- and 2,2,6 -Trimethyl-4-piperidone, Artifacts Produced by the Reaction of Cigarette Smoke Condensate and Acetone

1978 ◽  
Vol 9 (4) ◽  
Author(s):  
W. N. Einolf ◽  
R. N. Ferguson ◽  
J. F. Whidby ◽  
J. F. DeBardeleben
Keyword(s):  
Reaction Time ◽  
Cigarette Smoke ◽  
Temperature Reaction ◽  
Cigarette Smoke Condensate ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

AbstractCigarette smoke condensate (CSC) processed with acetone was found to contain 2,2,6-trimethyl-4-piperidone and the cis and trans isomers of 2,6-dimethyl-4-piperidone. The compounds were found to be artifacts formed by the reaction of the smoke components ammonia and acetaldehyde with the solvent acetone. Conditions which affected the yield of the artifacts from the processed CSC include pH, temperature, reaction time, and levels of ammonia and acetaldehyde present in CSC.

Partition mechanism of adsorption and the absence of displacement phenomena in the zonal analytical chromatography of proteins on bead 2-hydroxy-3-phenoxypropyl-cellulose

1989 ◽  
Vol 54 (9) ◽  
pp. 2375-2385 ◽  
Author(s):  
Peter Gemeiner ◽  
Eva Hrabárová ◽  
Magdaléna Zacharová ◽  
Albert Breier ◽  
Milan J. Beneš
Keyword(s):  
Reaction Time ◽  
Perchloric Acid ◽  
Adsorption Mechanism ◽  
Spherical Shape ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Hydrophobic Region ◽  
Bead Cellulose ◽  
To Come

Hydrophobization of bead cellulose is described, carried out by its alkylation with 1,2-epoxy-3-phenoxypropane under the conditions of acid (perchloric acid, borontrifluoride diethyl etherate) and basic (sodium hydroxide) catalysis. Reaction conditions (temperature, reaction time, molar ratio of reactants) have been determined, allowing the hydrophobization of bead cellulose to be carried out to the largest possible extent while maintaining its spherical shape. The nonstoichiometric mechanism suggested for the adsorption of amphiphilic adsorptives on bead 2-hydroxy-3-phenoxypropyl-cellulose (HPP-C) was checked by means of adsorption of six proteins. It was found that the surface of the hydrophobic segment of the adsorbent must be sufficiently large to be able to come in touch with the hydrophobic region of the protein through its multiple residues. In such cases the partitioning of the protein between the hydrophobic segment present as a liquid-like film and the surrounding solution becomes the predominant step of the adsorption. This adsorption mechanism is also reflected in zonal chromatography on bead HPP-C, as no displacement phenomena could be observed in any of the six proteins used. Retention of these proteins has been affected to a decisive extent by the degree of hydrophobization of HPP-C.

In air synthesis of GA-cl-poly(MAA) hydrogel and study of its salt- resistant swelling behavior in different salts

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
B. S. Kaith ◽  
Shabnam Ranjta ◽  
Kiran Kumar
Keyword(s):  
Free Radical ◽  
Reaction Time ◽  
Methacrylic Acid ◽  
Salt Concentration ◽  
Gum Arabic ◽  
Swelling Behavior ◽  
Temperature Reaction ◽  
Reaction Parameters ◽  
Potassium Persulphate ◽  
Cross Linker

AbstractA novel hydrogel has been synthesized by grafting methacrylic acid (MAA) onto Gum arabic (GA) through free radical graft co-polymerization in the presence of potassium persulphate (KPS) as an initiator and hexamethylene tetramine (HMTA) as a cross-linker. Various reaction parameters like reaction temperature, reaction time, concentration of initiator, amount of solvent, pH, concentration of monomer and concentration of cross-linker were optimized. GAcl-poly(MAA) was characterized by FTIR spectroscopy, SEM and TGA-DTA techniques. Optimized polymer was studied for its salt-resistant swelling behavior in different solutions: NaCl, MgCl2, CaCl2, FeCl3, ZnCl2 and BaCl2 as a function of salt concentration, temperature and pH. It was observed that GA-cl-poly(MAA) exhibits following salt-resistant swelling trend in different salts: NaCl > ZnCl2 > MgCl2 > CaCl2 > BaCl2 > FeCl3

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