Direct synthesis of hydrogen peroxide from H2 and O2 and in situ oxidation using zeolite-supported catalysts

2007 ◽  
Vol 8 (3) ◽  
pp. 247-250 ◽  
Author(s):  
Gang Li ◽  
Jennifer Edwards ◽  
Albert F. Carley ◽  
Graham J. Hutchings
Keyword(s):  
Hydrogen Peroxide ◽  
Supported Catalysts ◽  
Direct Synthesis ◽  
In Situ Oxidation

Direct synthesis of hydrogen peroxide using in-situ selective layer

2017 ◽  
Author(s):  
I. G. B. N. Makertihartha ◽  
P. T. Dharmawijaya ◽  
M. Zunita ◽  
I. G. Wenten
Keyword(s):  
Hydrogen Peroxide ◽  
Direct Synthesis ◽  
Selective Layer

Direct synthesis of hydrogen peroxide on zirconia-supported catalysts under mild conditions

2006 ◽  
Vol 239 (2) ◽  
pp. 422-430 ◽  
Author(s):  
S MELADA ◽  
R RIODA ◽  
F MENEGAZZO ◽  
F PINNA ◽  
G STRUKUL
Keyword(s):  
Hydrogen Peroxide ◽  
Supported Catalysts ◽  
Direct Synthesis ◽  
Mild Conditions

scholarly journals Microsensor Electrodes for 3D Inline Process Monitoring in Multiphase Microreactors

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4876
Author(s):  
Sebastian Urban ◽  
Vinayaganataraj Tamilselvi Sundaram ◽  
Jochen Kieninger ◽  
Gerald Urban ◽  
Andreas Weltin
Keyword(s):  
Hydrogen Peroxide ◽  
Channel Wall ◽  
Diffusion Processes ◽  
Direct Synthesis ◽  
Vertical Axis ◽  
Three Dimensions ◽  
Channel Bottom ◽  
First Time ◽  
And Diffusion

We present an electrochemical microsensor for the monitoring of hydrogen peroxide direct synthesis in a membrane microreactor environment by measuring the hydrogen peroxide and oxygen concentrations. In prior work, for the first time, we performed in situ measurements with electrochemical microsensors in a microreactor setup. However, the sensors used were only able to measure at the bottom of the microchannel. Therefore, only a limited assessment of the gas distribution and concentration change over the reaction channel dimensions was possible because the dissolved gases entered the reactor through a membrane at the top of the channel. In this work, we developed a new fabrication process to allow the sensor wires, with electrodes at the tip, to protrude from the sensor housing into the reactor channel. This enables measurements not only at the channel bottom, but also along the vertical axis within the channel, between the channel wall and membrane. The new sensor design was integrated into a multiphase microreactor and calibrated for oxygen and hydrogen peroxide measurements. The importance of measurements in three dimensions was demonstrated by the detection of strongly increased gas concentrations towards the membrane, in contrast to measurements at the channel bottom. These findings allow a better understanding of the analyte distribution and diffusion processes in the microreactor channel as the basis for process control of the synthesis reaction.

Chemoenzymatic Epoxidation of α-Pinene Catalyzed by Novozym 435

2013 ◽  
Vol 634-638 ◽  
pp. 896-900 ◽  
Author(s):  
Cheng Zou ◽  
You Yan Liu ◽  
Yi Ming Qin ◽  
Ai Xing Tang ◽  
Li Na Lan
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Phase ◽  
Octanoic Acid ◽  
Novozym 435 ◽  
Phase System ◽  
In Situ Oxidation ◽  
Novozyme 435 ◽  
Three Phase ◽  
Novozym 435 Lipase

The synthesis of α-pinene oxide mediated by Novozym 435 (lipase from Candida antarctica) in a three-phase system was studied in this work. Novozyme 435 catalysed the formation of peroxyoctanoic acid directly from octanoic acid and hydrogen peroxide, which was then applied for in situ oxidation of α-pinene. The highest conversion of a-pinene (approximately 80%) was obtained when the reaction was performed at 30°C and initial hydrogen peroxide concentration in the water phase was set to be 30%. The parameters affecting the lipase activity were also investigated，where the peracid generated in organic phase was obvserved to greatly inactivate the enzyme compared to other components in the organic phase.

In situ diesel desulfurization in divided-cell trickle bed electrochemical reactor

2017 ◽  
Author(s):  
◽  
Ghassan Hamad Abdulla
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfur Content ◽  
Diesel Fuel ◽  
Electrochemical Reactor ◽  
Organosulfur Compounds ◽  
Hydrogen Peroxide Production ◽  
In Situ Oxidation ◽  
Divided Cell ◽  
Trickle Bed

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Crude oil contains natural organic components such as organosulfur compounds, and these compounds largely remain in refined petroleum products such as gasoline, diesel and jet fuel products. During fuel combustion, sulfur was emitted as sulfur dioxide or sulfate, which is one of the main causes of air pollution and acid rain. The oil price is inversely proportional to the sulfur content because upgrade of heavy, high-sulfur-containing oil is much more difficult than the light feeds. Many regulations have been established by different countries to control sulfur level in fuels; in the U.S. the maximum required concentration is 15 ppm (parts per million) sulfur in diesel. The most commonly used technology to remove sulfur from diesel fuel is hydrodesulfurization (HDS). The major drawback of HDS is the harsh operating conditions that require high temperatures and pressures with consumption of a large amount of hydrogen. The HDS process is only able to reduce sulfur content to about 500 ppm in diesel. Further reduction requires more intense processing with a significant increase in hydrogen usage, particularly in removing the refractory sulfur compounds, such as benzothiophene (BT), dibenzothiophene (DBT), and their alkyl derivatives. In this dissertation, an efficient and cost-effective process for oxidation of organosulfur compounds (OSCs) in diesel has been developed and investigated. A divided-cell trickle bed electrochemical reactor (TBER) was first developed to produce hydrogen peroxide. The divided-cell trickle bed electrochemical reactor (TBER) has a porous cathode composed of carbon black and polytetrafluoroethylene. It was designed and fabricated to have hydrophobic and hydrophilic components for liquid and gas flows. Hydrogen peroxide generation was successfully demonstrated from reducing oxygen in concentrated alkaline electrolyte solutions. An important feature of the reactor was a cathode made with stainless steel meshes that divide it into four packed-bed cells. This division into sectional cathode resulted in a concentration of hydrogen peroxide that more than doubles that produced in an undivided cathode. The much-improved performance was attributed to the even distribution of the electrolyte and oxygen in the cathode bed, as well as an effective mass transport of oxygen from the gas phase to the electrolyte-cathode interface. After the successful production of hydrogen peroxide, the TBER was employed for in situ oxidation desulfurization of diesel fuel. The possibility of diesel desulfurization with in situ generated hydrogen peroxide in the presence of DBT was systematically investigated. The maximum concentration of hydrogen peroxide after two-hour electrolysis was 31.79 mM without diesel, whereas in the presence of 10% diesel (by volume) in the electrolyte was 18.0 mM. DBT was successfully oxidized in situ in the TBER, with conversion efficiency of 97.75% in six hours. To further improve the efficiency of the hydrogen peroxide production, cathode was modified with MnO2, a potentially more active catalyst for hydrogen peroxide production in alkaline electrolytes. It was found that incorporation of MnO2 indeed promoted in situ oxidation of DBT which was attributed to more hydrogen peroxide produced. The results showed the in situ oxidation process in the divided-cell TBER is a promising and environmentally friendly approach for desulfurization of diesel.

scholarly journals EXAFS in situ: The effect of bromide on Pd during the catalytic direct synthesis of hydrogen peroxide

2015 ◽  
Vol 248 ◽  
pp. 138-141 ◽  
Author(s):  
P. Centomo ◽  
C. Meneghini ◽  
S. Sterchele ◽  
A. Trapananti ◽  
G. Aquilanti ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Direct Synthesis
Sign in / Sign up

Export Citation Format

Share Document