Potential distribution in a trickle-bed electrode

1989 ◽  
Vol 54 (12) ◽  
pp. 3144-3153
Author(s):  
Otomar Špalek ◽  
Karel Balogh
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Electrode Potential ◽  
Potential Distribution ◽  
Graphite Particle ◽  
Current Yield ◽  
Electrolyte Flow ◽  
Flow Rates ◽  
Voltage Loss ◽  
Trickle Bed

The performance of trickle-bed electrodes of crushed graphites in oxygen reduction to hydrogen peroxide has been investigated. Results are presented for the effects of the current density, gas and electrolyte flow rates, pressure, and graphite particle size on the electrode potential, voltage loss in the electrode material, and current yield of the process.

Calculation of potential and concentration gradients in trickle-bed electrodes producing hydrogen peroxide

1986 ◽  
Vol 51 (9) ◽  
pp. 1883-1898 ◽  
Author(s):  
Otomar Špalek
Keyword(s):  
Mathematical Model ◽  
Hydrogen Peroxide ◽  
Current Density ◽  
Potential Distribution ◽  
Current Flow ◽  
Anode Chamber ◽  
Current Yield ◽  
Concentration Gradients ◽  
Electrolyte Flow ◽  
Trickle Bed

A mathematical model for describing the trickle-bed electrode has been developed and used to calculate the potential distribution along the current flow and the hydrogen peroxide concentration profile along the electrolyte flow (normal to the direction of current). Polarization curves and dependences of the current yield of hydrogen peroxide and the peroxide losses due to the processes occurring (reduction, decomposition, and transport into the anode chamber) on the current density have also been calculated. A comparison is made between calculated and measured dependences of the current yield of hydrogen peroxide on the current density.

Reduction of oxygen to peroxide in a trickle electrode

1989 ◽  
Vol 54 (6) ◽  
pp. 1564-1574 ◽  
Author(s):  
Otomar Špalek ◽  
Karel Balogh
Keyword(s):  
Particle Size ◽  
Current Efficiency ◽  
Electrode Material ◽  
Pressure Loss ◽  
Peroxide Formation ◽  
Liquid Holdup ◽  
Electrolyte Flow ◽  
Electrode Thickness ◽  
Material Particle ◽  
Flow Rates

The effects of the electrode material particle size, electrode thickness, diaphragm properties and gas and electrolyte flow rates on the pressure loss and liquid holdup in the electrode and on the current efficiency of peroxide formation by oxygen reduction were studied in a trickle electrode. The results are discussed using trickle-bed electrode calculations.

149 Evaluation of Hammermill Tip Speed, Air Assist, and Screen Hole Diameter on Ground Corn Characteristics

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 134-135
Author(s):  
Michaela B Braun ◽  
Kara M Dunmire ◽  
Michael Sodak ◽  
Jerry Shepherd ◽  
Randy Fisher ◽  
...  
Keyword(s):  
Particle Size ◽  
Geometric Mean ◽  
Air Flow ◽  
Hole Diameter ◽  
Experimental Unit ◽  
Flow Index ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Composite Flow ◽  
Ground Corn

Abstract This study was performed to evaluate hammermill tip speed, assistive airflow and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills (Model: 4330–6, Andritz Feed & Biofuel, Muncy,PA) measuring 1-m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with 3 tip speeds (3,774, 4,975, and 6,176 m/min), 3 screen hole diameters (2.3, 3.9 and 6.3 mm), and 3 air flow rates (1,062, 1,416, and 1,770 fan RPM). Corn was ground on 3 separate days to create 3 replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with grinding run serving as the experimental unit and day serving as the block. There was a 3-way interaction for standard deviation (Sgw), (linear screen hole diameter × linear hammer tip speed × linear air flow, P = 0.029). There was a screen hole diameter × hammer tip speed interaction (P < 0.001) for geometric mean particle size dgw (P < 0.001) and composite flow index (CFI) (P < 0.001). When tip speed increased from 3,774 to 6,176 m/min the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm resulting in a 67, 111, and 254 µm decrease in dgw for corn ground using the 2.3, 3.9, and 6.3 mm screen hole diameter, respectively. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 µm.

Influence of the natural flake graphite particle size on the textural characteristic of exfoliated graphite used for heavy oil sorption

Carbon ◽  
2006 ◽  
Vol 44 (12) ◽  
pp. 2590-2592 ◽  
Author(s):  
F. Vieira ◽  
I. Cisneros ◽  
N.G. Rosa ◽  
G.M. Trindade ◽  
N.D.S. Mohallem
Keyword(s):  
Particle Size ◽  
Heavy Oil ◽  
Graphite Particle ◽  
Exfoliated Graphite ◽  
Flake Graphite ◽  
Textural Characteristic ◽  
Oil Sorption

Influence of hydrodynamics of electrolyte flow during electrochemical treatment on the quality of the treated surface

2021 ◽  
pp. 55-60
Author(s):  
Keyword(s):  
Electrical Conductivity ◽  
Current Density ◽  
Electrochemical Treatment ◽  
Flow Lines ◽  
Electrolyte Flow ◽  
Flow Rates ◽  
Average Flow ◽  
Electrochemical Processing ◽  
Interelectrode Gap

The features of the hydrodynamics of the electrolyte in the interelectrode gap during electrochemical processing of a profile axisymmetric workpiece are considered. The distribution of average flow rates and flow lines is calculated for a specified electrolyte supply. The nature and rate of the electrolyte flow are established. The unevenness of the current density is determined taking into account the change in the electrical conductivity of the electrolyte from heating and gas filling of the interelectrode gap, as well as the quality of the treated surface. Keywords: electrochemical treatment, roughness, electrolyte, electrical conductivity, gas filling. [email protected]

Preparation of All-Trans-Retinoic Acid-Loaded mPEG-PLGA Nanoparticles Using Microfluidic Flow-Focusing Device for Controlled Drug Delivery

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050101
Author(s):  
Mojdeh Safari ◽  
Amir Amani ◽  
Tajudeen Adebileje ◽  
Jafar Ai ◽  
Seyed Mahdi Rezayat ◽  
...  
Keyword(s):  
Particle Size ◽  
Retinoic Acid ◽  
Plga Nanoparticles ◽  
Process Conditions ◽  
Flow Focusing ◽  
Flow Rates ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Microfluidic Flow ◽  
Minimum Particle Size

In recent years, microfluidic devices present unique advantages for the development of a new generation of nanoparticle synthesis method compared to bulk methods. In this study, we report a microfluidic flow-focusing method for the production of all trans retinoic acid (ATRA)-loaded methoxy poly(ethylene glycol)-poly(lactide-coglycolide) (mPEG-PLGA) nanoparticles (NPs). Box–Behnken experimental design (BBD) was applied to optimize of formulation ingredients and process conditions with minimum particle size, maximum drug loading% (DL%) and encapsulation efficiency% (EE%). Polymer concentration, drug concentration and flow rates of solvent (S) and antisolvent (AS) were selected as independent variables. Based on optimization strategy, minimum particle size achieved shows average (SD) particle size of [Formula: see text][Formula: see text]nm with DL of [Formula: see text][Formula: see text]wt.% and EE of [Formula: see text][Formula: see text]wt.%, respectively. While maximum DL has been reported to be [Formula: see text][Formula: see text]wt.% with particle size of [Formula: see text][Formula: see text]nm and EE of [Formula: see text][Formula: see text]wt.%, respectively. Moreover, the results have shown that the AS/S ratio represents the most significant effect on particle size. Indeed, increasing the AS flow rate directly results in generating smaller particles. The AS/S ratio represents the least significant effect on DL%, such that, at fixed flow rates, higher DL was observed at high concentration of drug and lower concentration of polymer. In conclusion, optimization of the ATRA-loaded mPEG-PLGA NPs by BBD yielded in a favorable drug carrier for ATRA that could provide a new treatment modality for different malignancies.

Effect of Graphite Particle Size on Irreversible Capacity Loss

2000 ◽  
Vol 147 (6) ◽  
pp. 2110 ◽  
Author(s):  
Karim Zaghib ◽  
Gabrielle Nadeau ◽  
Kimio Kinoshita
Keyword(s):  
Particle Size ◽  
Graphite Particle ◽  
Irreversible Capacity ◽  
Capacity Loss

Optical imaging of the potential distribution at transparent electrode/solution interfaces

2020 ◽  
Vol 56 (33) ◽  
pp. 4531-4534 ◽  
Author(s):  
Ling Li ◽  
Changyin Zhong ◽  
Bomin Feng ◽  
Nan Chen ◽  
Jun Dai ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Electrode Potential ◽  
Potential Distribution ◽  
Transparent Electrode ◽  
Optical Monitoring ◽  
Transparent Electrodes

Optical monitoring of the electrode potential and imaging of its distribution on transparent electrodes are achieved by using OIRD technology.

Sign in / Sign up

Export Citation Format

Share Document