Topic
Mass transfer coefficient
About: Mass transfer coefficient is a research topic. Over the lifetime, 7827 publications have been published within this topic receiving 168354 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: Fujasova et al. as mentioned in this paper measured impeller power and volumetric mass transfer coefficient in a pilot-plant single-, double-and triple-impeller vessels of inner diameter 0.6m.
57 citations
TL;DR: The experimental results obtained for simulated broths indicated a considerable increase of kLa in the presence of n-dodecane, and the existence of a certain value ofn-d Dodecane concentration that corresponds to a maximum mass transfer rate of oxygen.
Abstract: Oxygen mass transfer represents the most important parameter involved in the design and operation of mixing-sparging equipment for bioreactors. It can be described and analyzed by means of the mass transfer coefficient, k(L) a. The k(L) a values are affected by many factors such as geometrical and operational characteristics of the vessels, media composition, type, concentration and microorganism morphology, and biocatalysts properties. The efficiency of oxygen transfer could be enhanced by adding oxygen-vectors in broths, such as hydrocarbons or fluorocarbons, without increasing the energy consumption for mixing or aeration. The experimental results obtained for simulated broths indicated a considerable increase of k(L) a in the presence of n-dodecane, and the existence of a certain value of n-dodecane concentration that corresponds to a maximum mass transfer rate of oxygen. The magnitude of the positive effect of n-dodecane depends both on the broths' characteristics and operational conditions of the bioreactor.
57 citations
TL;DR: In this article, a photographic technique was used to determine mass transfer rates from single drops and the reduction due to the surface active material was evaluated, based on the interpretation of measurements in terms of an active and inactive surface region.
56 citations
TL;DR: In this article, a series of experiments performed on the two main types of hollow fiber membrane contactors (microporous PTFE and dense PMP skin composite membrane) under different sets of operating conditions were compared with the membrane mass transfer coefficient as the only adjustable parameter.
56 citations
TL;DR: In this article, the effect of increasing the liquid viscosity on the mass transfer coefficient in co-current upflow is quantified and correlated to the frictional pressure drop, a measure of the energy dissipation.
Abstract: The gas–liquid mass transfer coefficient and other hydrodynamic parameters such as liquid holdup and frictional pressure drop are presented for gas and liquid moving in co-current upflow and downflow through solid foam packings of 10 and of 40 pores per linear inch (ppi). The effect of increasing the liquid viscosity on the mass transfer coefficient in co-current upflow is quantified and correlated to the frictional pressure drop, a measure of the frictional energy dissipation: k L a GL ɛ L ( S c L / S c water ) 0.69 = 2.05 × 1 0 − 4 P f 0.8 (mL3 mP−3 s−1). The gas–liquid mass transfer coefficient in co-current downflow is correlated to the liquid velocity and the Schmidt number using the correlation proposed by Sherwood and Holloway [Sherwood, T. and Holloway, F., 1940, Performance of packed towers—liquid film data for several packings, Transactions of the American Institute of Chemical Engineers 36: 39–70]: k L a GL ɛ L D L − 1 = 3.7 ( u L ρ L μ L − 1 ) 1.16 ( S c L ) 0.5 (mL mP−3). The results for the gas–liquid mass transfer coefficient in co-current upflow were correlated with a similar equation, where the influence of the gas velocity is included, similar to the correlations for packed beds of spherical particles proposed in Fukushima and Kusaka [Fukushima, S. and Kusaka, K., 1979, Gas–liquid mass transfer and hydrodynamic flow region in packed columns with cocurrent upward flow, Journal of Chemical Engineering of Japan 12 (4): 296–301]: k L a GL ɛ L D L − 1 = 311 u G 0.44 ( u L ρ L μ L − 1 ) 0.92 ( S c L ) 0.5 (mL mP−3). In this study the liquid Schmidt number dependency of the gas–liquid mass transfer coefficient points to the penetration theory describing the rate of mass transfer for gas–liquid flow through solid foam packings.
56 citations