Mass-Transfer Rate-Limitation Effects in Liquid-Phase Oxidation

1972 ◽  
Vol 11 (2) ◽  
pp. 220-225 ◽  
Author(s):  
C. C. Hobbs ◽  
E. H. Drew ◽  
H. A. Van't Hof ◽  
F. G. Mesich ◽  
M. J. Onore
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Liquid Phase Oxidation ◽  
Phase Oxidation

Granulated Carbon Nanotubes as the Catalyst Support for Pt for the Hydrogenation of Nitrobenzene

2010 ◽  
Vol 63 (1) ◽  
pp. 131 ◽  
Author(s):  
Shao Jin ◽  
Weizhong Qian ◽  
Yi Liu ◽  
Fei Wei ◽  
Dezeng Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mass Transfer ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Liquid Phase ◽  
Transfer Rate ◽  
High Selectivity ◽  
Mass Transfer Rate ◽  
Catalyst Support ◽  
Liquid Phase Hydrogenation

Granulated Pt/carbon nanotubes (CNTs) were found to have a much better catalytic activity in the liquid phase hydrogenation of nitrobenzene than Pt/activated carbon (AC). The granulated CNTs had much larger pores than the AC particles, which gave a faster mass transfer rate of H2 that helped produce aniline with high selectivity.

Numerical Study on the Characteristics of Natural Supercavitation by Planar Symmetric Cavitators With Streamlined Headforms

2017 ◽  
Author(s):  
Zhi-Ying Zheng ◽  
Lu Wang ◽  
Qian Li ◽  
Yue Wang ◽  
Wei-Hua Cai ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Vapor Phase ◽  
Transfer Rate ◽  
Numerical Study ◽  
Mass Transfer Rate ◽  
Three Dimensional ◽  
Pressure Drag ◽  
Hyperbolic Cosine ◽  
Blade Shape

A novel supercavitation-based device named Rotational Supercavitating Evaporator (RSCE) was recently designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization and then design three-dimensional blades, two-dimensional numerical simulations are conducted on the supercavitating flows (with cavitation number ranging from 0.055 to 0.315) around six planar symmetric cavitators with different streamlined headforms utilizing k – ε – v′2 – f turbulence model and Schnerr-Sauer cavitation model. We obtain the characteristics of natural supercavitation for each cavitator, including the shape and resistance characteristics and the mass transfer rate from liquid phase to vapor phase. The effects of the shape of the headform on these characteristics are analyzed. The results show that the supercavity sizes for most cavitators with streamlined headforms are smaller than that for wedge-shaped cavitator, except for the one with the profile of the forebody concaving to the inside of the cavitator. Cavitation initially occurs on the surface of the forebody for the cavitators with small curvature of the front end. Even though the pressure drag of the cavitator with streamlined headform is dramatically reduced compared with that of wedge-shaped cavitator, the pressure drag still accounts for most of the total drag. Both the drag and the mass transfer rate from liquid phase to vapor phase are in positive correlation with the supercavity size, indicating that the cavitators with the elliptic and hyperbolic cosine-type forebodies could be utilized for the optimal design of three-dimensional blade shape of RSCE.

Influence of a Second Liquid Phase upon Carbon Dioxide Chemical Absorption

2013 ◽  
Vol 11 (1) ◽  
pp. 511-516 ◽  
Author(s):  
A. Couvert ◽  
A. García‐Abuín ◽  
D. Gómez‐Díaz ◽  
J. M. Navaza ◽  
P. Rodríguez-Dafonte
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Transfer Rate ◽  
Gas Flow ◽  
Silicone Oil ◽  
Mass Transfer Rate ◽  
Liquid System ◽  
Carbon Dioxide Absorption ◽  
Chemical Absorption

Abstract This work analyzes carbon dioxide mass transfer rate during chemical absorption from a gas phase to a liquid–liquid system based on an aqueous phase (glucosamine or pyrrolidine solutions) and an organic one. Two different kinds of silicone oil with different viscosity were used to perform the liquid phases, and it allows the analysis of the influence of this variable upon mass transfer rate. In these systems, a surfactant (Tween80) was added to stabilize the liquid–liquid system, and therefore, the influence of the presence of this surfactant in the liquid phase was studied. This substance produces a positive effect upon carbon dioxide absorption rate in glucosamine aqueous solutions, but the opposite effect was observed for the other amine employed in this work. Also, the influence caused by different operation variables, such as the gas flow-rate fed to the bubble contactor or the silicone oil concentration in the liquid phase, was studied.

Free Convective Mass Transfer at Isosceles Triangular Surfaces of Varying Inclination

2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Mass Transfer Process ◽  
Sulfate Solution ◽  
Convective Mass Transfer ◽  
Varying Length ◽  
Inclined Surface ◽  
Vertical Case ◽  
Limiting Diffusion Current

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.

Sign in / Sign up

Export Citation Format

Share Document