Liquid-phase effect

Our data can be used to estimate the effective temperatures reached in each site through comparative rate thermometry, a technique developed for similar use in shock tube chemistry (32). Using the sonochemical kinetic data in combination with the activation parameters recently determined by high temperature gas phase laser pyrolysis (33), the effective temperature of each site can then be calculated (8),(34) the gas phase reaction zone effective temperature is 5200 650°K, and the liquid phase effective temperature is 1900°K. Using a simple thermal conduction model, the liquid reaction zone is estimated to be 200 nm thick and to have a lifetime of less than 2 usee, as shown in Figure 3. 

Sonoluminescence mainly occurs inside the bubbles (or in their immediate surroundings) and thus cannot be representative of what happens in the liquid phase where most of the events used in ultrasound application occur. In particular the temperature and frequency dependence of sonoluminescence is quite different from that of other effects, thus luminescence decreases with temperature, while liquid-phase effects usually increase to a maximum, and then decrease [19]. 

Immiscible liquid-liqnid mixing involves dispersion, snspension, and coalescence of liquid drops in a second liquid phase. Effects of mixing are complex, often poorly understood, and lack industrially usable measuring tools. Scale-np is particnlarly difficult, since coalescence dispersion and suspension are affected to different degrees by scale. For a more in-depth treatment of this subject, see Chapter 12 by Leng and Calabrese in the Handbook of Industrial Mixing [1]. 

As shown in Problem 3.23, scrubbing of hydrogen sulfide from natural gas using water is not practical since it requires large amounts of water, due to the low solubility of H2S in water. If a 2 N solution of monoethanolamine (MEA) in water is used as the absorbent, however, the required liquid flow rate is reduced dramatically because the MEA reacts with the absorbed H2S in the liquid phase, effectively increasing its solubility. 

Figure 7.31 Liquid-phase effectiveness as a function of observable quantities for a pseudo-first-order reaction foifowing the theory of Kramers and Westerterp. [After J.J. Carberry, Chemical and Catalytic Reaction Engineering, with permission of McGraw-Hill Book Co., New York, NY, (1976).]...

D.l liquid phase effective diffusivity in axial direction in a multiphase packed bed mt.. m, hr m , /m, s... 

However, in contrast to regime A, the homogeneous reaction is significantly rapid as compared to the diffusion process in the film (Cg Bg k a). This ensures almost complete consumption of the amount of A supplied to the bulk liquid phase. Effectively, this implies Ag 0. In terms of Hatta number ... 

Transport phenomena induced by temperature difference across a porous partition separating two liquid phases (effect of thermodialysis) has been only recently studied in its general aspects (1-7). Clear-cut differences appear between thermodialysis and the closely related effect of thermoosmosis (8-14), in various quantitative as well as qualitative aspects. On the other hand various significant analogies with non-isothermal matter transport in the bulk liquid (effect of thermal diffusion) have already emerged (3, 6, 7). 

A dynamic mathematical model of the three-phase reactor system with catalyst particles in static elements was derived, which consists of the following ingredients simultaneous reaction and diffusion in porous catalyst particles plug flow and axial dispersion in the bulk gas and liquid phases effective mass transport and turbulence at the boundary domain of the metal network and a mass transfer model for the gas-liquid interface. 

The water resistance in terms of liquid-phase effects can be expressed as pressure differential sum. Such differences will develop as the resistance originates at motion of gas in the dry apparatus and pressure, which is... 

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