Study on the effect of temperature on the gas–liquid mass transfer rate of volatile liquid

Author(s):  
Wenjie Liu ◽  
Chunhua Bai ◽  
Qingming Liu ◽  
Jian Yao
RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109978-109982 ◽  
Author(s):  
Young-Kee Kim ◽  
Sung-Yeob Lee ◽  
Byung-Keun Oh

In an enzyme process using a gas substrate, the enhanced gas liquid mass transfer rate of the gas substrate by methyl-functionalized mesoporous nanoparticles could improve the productivity.


2017 ◽  
Vol 57 (11) ◽  
pp. 1902-1910 ◽  
Author(s):  
Takahiro Okuno ◽  
Md. Azhar Uddin ◽  
Yoshiei Kato ◽  
Sang Beom Lee ◽  
Yong Hwan Kim

2007 ◽  
Vol 13 (3) ◽  
pp. 167-168 ◽  
Author(s):  
Aleksandar Dudukovic ◽  
Rada Pjanovic

The scope of this paper is to explain effect of eddy viscosity and turbulent Schmidt number on mass transfer rate. New, theoretically based correlation for gas-liquid mass transfer coefficients are proposed.


2012 ◽  
Vol 66 (9) ◽  
pp. 1914-1922 ◽  
Author(s):  
Takuro Kobayashi ◽  
Kai-Qin Xu ◽  
Yu-You Li ◽  
Yuhei Inamori

Biological desulfurization using a bubble column reactor was investigated in a continuous biogas treatment. Rapid biogas circulation between the digester and the bubble column for biological desulfurization was used to stimulate the gas–liquid mass transfer of H2S. A positive correlation between the biogas circulation rate and H2S removal rate was observed. Moreover, the increase in the circulation rate stimulated the O2 mass transfer, eventually translating into an increase in sulfate production from the oxidation of H2S. Throughout the continuous experiment, the reactor retained sufficient levels of sulfide-oxidizing bacteria. A comparison of the results of the continuous biogas treatment and batch tests suggests that the gas–liquid mass transfer rate of H2S was the rate-limiting step in the biological desulfurization in the reactor, indicating that the mass transfer efficiency of H2S needs to be improved to enhance the desulfurization performance.


2016 ◽  
Vol 73 (8) ◽  
pp. 1969-1977 ◽  
Author(s):  
Kangning Yao ◽  
Yong Chi ◽  
Fei Wang ◽  
Jianhua Yan ◽  
Mingjiang Ni ◽  
...  

A commonly used aeration device at present has the disadvantages of low mass transfer rate because the generated bubbles are several millimeters in diameter which are much bigger than microbubbles. Therefore, the effect of a microbubble on gas-liquid mass transfer and wastewater treatment process was investigated. To evaluate the effect of each bubble type, the volumetric mass transfer coefficients for microbubbles and conventional bubbles were determined. The volumetric mass transfer coefficient was 0.02905 s−1 and 0.02191 s−1 at a gas flow rate of 0.67 L min−1 in tap water for microbubbles and conventional bubbles, respectively. The degradation rate of simulated municipal wastewater was also investigated, using aerobic activated sludge and ozone. Compared with the conventional bubble generator, the chemical oxygen demand (COD) removal rate was 2.04, 5.9, 3.26 times higher than those of the conventional bubble contactor at the same initial COD concentration of COD 200 mg L−1, 400 mg L−1, and 600 mg L−1, while aerobic activated sludge was used. For the ozonation process, the rate of COD removal using microbubble generator was 2.38, 2.51, 2.89 times of those of the conventional bubble generator. Based on the results, the effect of initial COD concentration on the specific COD degradation rate were discussed in different systems. Thus, the results revealed that microbubbles could enhance mass transfer in wastewater treatment and be an effective method to improve the degradation of wastewater.


2016 ◽  
Vol 37 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Magdalena Olak-Kucharczyk ◽  
Stanisław Ledakowicz

Abstract Ozonation is a heterogeneous process of chemical absorption often controlled by a gas-liquid mass transfer rate. This paper presents the results of kinetics in a reaction between phenylphenol isomers and ozone. The degradation of phenylphenol isomers during ozonation proceeds quite fast. In order to avoid the influence of mass transfer limitation the kinetics experiments were conducted in a homogenous liquid-liquid system. The second-order rate constants were determined using classical and competition methods, which are especially recommended for fast reactions. The determined rate constants at pH 2 using the two different methods are almost the same. The increase of pH causes an increase of rate constants for the reaction of phenylphenol isomers with ozone.


Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1266
Author(s):  
Kelly Chung Shi Liew ◽  
Athina Rasdi ◽  
Wiratni Budhijanto ◽  
Mohd Hizami Mohd Yusoff ◽  
Muhmmad Roil Bilad ◽  
...  

Microbubbles with slow rising speed, higher specific area and greater oxygen dissolution are desired to enhance gas/liquid mass transfer rate. Such attributes are very important to tackle challenges on the low efficiency of gas/liquid mass transfer that occurs in aerobic wastewater treatment systems or in the aquaculture industries. Many reports focus on the formation mechanisms of the microbubbles, but with less emphasis on the system optimization and assessment of the aeration efficiency. This work assesses the performance and evaluates the aeration efficiency of a porous venturi-orifice microbubble generator (MBG). The increment of stream velocity along the venturi pathway and orifice ring leads to a pressure drop (Patm > Pabs) and subsequently to increased cavitation. The experiments were run under three conditions: various liquid velocity (QL) of 2.35–2.60 m/s at fixed gas velocity (Qg) of 3 L/min; various Qg of 1–5 L/min at fixed QL of 2.46 m/s; and free flowing air at variable QLs. Results show that increasing liquid velocities from 2.35 to 2.60 m/s imposes higher vacuum pressure of 0.84 to 2.27 kPa. They correspond to free-flowing air at rates of 3.2–5.6 L/min. When the system was tested at constant air velocity of 3 L/min and under variable liquid velocities, the oxygen dissolution rate peaks at liquid velocity of 2.46 m/s, which also provides the highest volumetric mass transfer coefficient (KLa) of 0.041 min−1 and the highest aeration efficiency of 0.287 kgO2/kWh. Under free-flowing air, the impact of QL is significant at a range of 2.35 to 2.46 m/s until reaching a plateau KLa value of 0.0416 min−1. The pattern of the KLa trend is mirrored by the aeration efficiency that reached the maximum value of 0.424 kgO2/kWh. The findings on the aeration efficiency reveals that the venturi-orifice MBG can be further optimized by focusing on the trade-off between air bubble size and the air volumetric velocity to balance between the amount of available oxygen to be transferred and the rate of the oxygen transfer.


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