Absorption of gaseous species into stationary droplets is a fundamental interest of mass transfer between liquid droplets and ambient gas, which plays a key role in atmospheric environment control and many indus trial applications. In this paper, two different considerations including equilibrium and non-eq uilibrium relations at the interface are used to analyze and predict the absorption time for a physical absorption at a relatively low so lubility of gas. For the equilibrium pattern, in the beginning period of absorption, the mass transfer rate is considerably rapid and afterward becomes slower and slower and finally comes to almost zero as the droplet concentration closes to the saturated value. Diferently, when the non-eq uilibrium model is adopted, the interfac ial concentration increases grad ually with the bulk concentration of liquid droplet, and the absorption rate mildly decelerates with the increase of bulk one throughout the process, which lead s to a longer absorption time. Bas ed on the difus ion eq uation of species, the concentration distribution within the droplet at ditierent times is computed. A solution for CO2 abso rption into a small water droplet is given.

Abstract The amino acids are necessarily nutritious components. their diflusions in body fluid and blood that be-long to typical non. Newtonian fluid are of virtual importance to control the diflusive process an d help clinical treatment. In this article. a holoaphic interferometer has been adopted to measure the diffusivity of amino acids in non. Newtonian fluid with the use of rea1. time holographic interference technique. In oIder to prove the reliability of the experimenml instrument. the diflusivities of sucrose aqueous solution at 298. 15K were determined. The meas-ured resultdisplays a satisfactory accuracyofthe apparatusused. Furthermore, thedifusion coeficients ofglynine, L. serine. L. threonine and L. valine in polyacrylamide(1 AM)aqueous solution at 298. 15K were measned, respec- tively. The experimental data were fitted by a newly propo sed correlation equation based on Li’s predictive mode1. The calculating results by me present model ale at considerably good agreement with experimental values, and the maximum average deviation is only 0.5%.

A concept that the driving force of gas-liquid interphase mass transfer comes from the interfacial non-equilibrium is proposed in this paper. For the absorption process, based on the general chemical potential driving force equation, the concentration relation between two phases at interface is derived and solved under dierent conditions as mass transfer occurs, it shows that the interfacial concentration of absorbed component at liquid side is strongly aected by a Biotnumber YO and is bulk concentration dependent. The CO2 interfacial concentration of liquid side in stationary absorption by pure methanol, ethanol and n-propanol absorbent respectively are measured by the use of micro laser holographic interference technique, the experimental results are in good agreement with the computation.

Ths paper focuses on me mechanism of interfacial mass transfer of a single bubble. based on chemi cal potential driving force, an approach for calculating interracial concentration in practical process is proposed. The absorption proc esses of bubble under bom quiescent an d mobile conditions ale analyzed and discussed respectively. For a staftonary absorption. only in me case of liquid bulk concentration near saturated value. Me tefacial concentration could close to me equilibrium value：For a moving bubble, under ordinary operating condi. Tion (y0>1), me interfacial concentration is far from its equilibrium. Only under bulk concentration near saturated value or a smaller Yo (Yo<0.1) which may involve me complication of additional resistance at interface induced surface contamination or sufactant added. me interfacial concentration could be approximate to equilibrium value. The interfacial concentration close to me interface on liquid side for a single CO, bubble absorbed by methanol measured using a modern optical instrumentation in which me laser holographic interference memOd is adopted wim a real-time and amplification technique. Experimental results show mat me interfacial concentration decreases significan tly with increasing Re an d is far from the eq uilibrium one in a larger Re ran ge. Experiments validate proposed mode1.

Mass transfer in gas-liquid bubbling processas is commonly encountered in chemical engineering practice. Forthe research on interphase ma transfer. It is very importantto begin with the description of the interface it self, in which the concentration near the interface has to be pri-marily measured. Formerly, most models developed for describing interphase interphase mass transfer were pragmatically simplified in both of the interface an hydrodynamics. An apparent difficulty is to measure the concentration distribution in the intefacial region. This subject lay dormant until the development of holographic interference technique in early seventies and the experim ental study initiated by VII and his students in nineties [1, 2]. In this paper, two holographic intefer-ometers are successfully used to study the concentration field near the gas-liquid interface of a riaing bubble. The present study may be helpful to broaden the knowledge about the mechanism of mass transfer in bubbling process.