Liquid phase Chemical engineering

Khadilkar, M. R., Mills, P. L., Dudukovic, M. P., Trickle-bed reactor models for systems with a volatile liquid phase. Chemical Engineering Science, 1999, 54, 2421-2431... 

Kolbel H, Ralek M. The Fischer-Tropsch Synthesis in the Liquid Phase. Chemical Engineering Institute, Technical University, Berhn, FRG. Translation No. UCRL-Trans. 1568, University of California, 1979. 

It seems probable that a fruitful approach to a simplified, general description of gas-liquid-particle operation can be based upon the film (or boundary-resistance) theory of transport processes in combination with theories of backmixing or axial diffusion. Most previously described models of gas-liquid-particle operation are of this type, and practically all experimental data reported in the literature are correlated in terms of such conventional chemical engineering concepts. In view of the so far rather limited success of more advanced concepts (such as those based on turbulence theory) for even the description of single-phase and two-phase chemical engineering systems, it appears unlikely that they should, in the near future, become of great practical importance in the description of the considerably more complex three-phase systems that are the subject of the present review. 

Baroczy, C. J. (1965) Correlation of Liquid Fraction in Two-Phase Flow with Applications to Liquid Metals, Chemical Engineering Progress Symposium Series, Vol. 61(57), pp. 179-191. 

Hikita, H., andKikukawa, H. (1974), Liquid-phase mixing in bubble columns Effect of liquid properties, Chemical Engineering Journal and the Biochemical Engineering Journal, 8(3) 191-197. 

Werner S., Haumann, M. Wasserscheid, P. (2010). Ionic liquids in chemical engineering. Annual Review of Chemical and Biomolecular Engineering, 1,203-230, ISSN 1947-5438 Wolff, M. O., Alexander, K. M. Beider, G. (2000). Uses of quaternary phosphonium compounds in phase transfer catalysis. Chimica Oggi, 18, 1/2, 29-32, ISSN 0392-839X... 

In the petroleum refining and natural gas treatment industries, mixtures of hydrocarbons are more often separated into their components or into narrower mixtures by chemical engineering operations that make use of phase equilibria between liquid and gas phases such as those mentioned below ... 

Ordinary diffusion involves molecular mixing caused by the random motion of molecules. It is much more pronounced in gases and Hquids than in soHds. The effects of diffusion in fluids are also greatly affected by convection or turbulence. These phenomena are involved in mass-transfer processes, and therefore in separation processes (see Mass transfer Separation systems synthesis). In chemical engineering, the term diffusional unit operations normally refers to the separation processes in which mass is transferred from one phase to another, often across a fluid interface, and in which diffusion is considered to be the rate-controlling mechanism. Thus, the standard unit operations such as distillation (qv), drying (qv), and the sorption processes, as well as the less conventional separation processes, are usually classified under this heading (see Absorption Adsorption Adsorption, gas separation Adsorption, liquid separation). 

Conduction with Change of Phase A special type of transient problem (the Stefan problem) involves conduction of heat in a material when freezing or melting occurs. The liquid-solid interface moves with time, and in addition to conduction, latent heat is either generated or absorbed at the interface. Various problems of this type are discussed by Bankoff [in Drew et al. (eds.). Advances in Chemical Engineering, vol. 5, Academic, New York, 1964]. 

R. L. Barton ( Sizing Liquid-Liquid Phase Separators Empirically, Chemical Engineering, July 8, 1974, Copyright (1974) McGraw-Hill, Inc., used with permission) provides the following quick method for sizing liquid-liquid phase sepai ators empirically. 

The separation of mixtures of immiscible liquids constitutes one of the important chemical engineering operations. This empirical design has proven satisfactory for many phase separations. 

Barton, R. L., Sizing Liquid-Liquid Phase Separators Empirically, Chemical Engineering, July 8, 1974. 

The phase rule is a mathematical expression that describes the behavior of chemical systems in equilibrium. A chemical system is any combination of chemical substances. The substances exist as gas, liquid, or solid phases. The phase rule applies only to systems, called heterogeneous systems, in which two or more distinct phases are in equilibrium. A system cannot contain more than one gas phase, but can contain any number of liquid and solid phases. An alloy of copper and nickel, for example, contains two solid phases. The rule makes possible the simple correlation of very large quantities of physical data and limited prediction of the behavior of chemical systems. It is used particularly in alloy preparation, in chemical engineering, and in geology. 

The solid-liquid two-phase flow is widely applied in modern industry, such as chemical-mechanical polish (CMP), chemical engineering, medical engineering, bioengineering, and so on [80,81]. Many research works have been made focusing on the heat transfer or transportation of particles in the micro scale [82-88], In many applications, e.g., in CMP process of computer chips and computer hard disk, the size of solid particles in the two-phase flow becomes down to tens of nanometres from the micrometer scale, and a study on two-phase flow containing nano-particles is a new area apart from the classic hydrodynamics and traditional two-phase flow research. In such an area, the forces between particles and liquid are in micro or even to nano-Newton scale, which is far away from that in the traditional solid-liquid two-phase flow. 

Gavrilescu, M. and R.Z. Tudose, Residence time distribution of the liquid phase in a concentric-tube airlift reactor. Chemical Engineering and Processing, 1999. 38(3) p. 225-238. 

Zahradnik, J. and M. Fialova, The effect of bubbling regime on gas and liquid phase mixing in bubble column reactors. Chemical Engineering Science, 1996. 51(10) p. 2491-2500. 

Intelligent engineering can drastically improve process selectivity (see Sharma, 1988, 1990) as illustrated in Chapter 4 of this book. A combination of reaction with an appropriate separation operation is the first option if the reaction is limited by chemical equilibrium. In such combinations one product is removed from the reaction zone continuously, allowing for a higher conversion of raw materials. Extractive reactions involve the addition of a second liquid phase, in which the product is better soluble than the reactants, to the reaction zone. Thus, the product is withdrawn from the reactive phase shifting the reaction mixture to product(s). The same principle can be realized if an additive is introduced into the reaction zone that causes precipitation of the desired product. A combination of reaction with distillation in a single column allows the removal of volatile products from the reaction zone that is then realized in the (fractional) distillation zone. Finally, reaction can be combined with filtration. A typical example of the latter system is the application of catalytic membranes. In all these cases, withdrawal of the product shifts the equilibrium mixture to the product. 

Figure 14.1 Vapor-liquid equilibrium data and calcidated values for the n-pentane-acetone system, x andy are the mole fractions in the liquid and vapor phase respectively [reproduced with permission from Canadian Journal of Chemical Engineering].

Fig 18. Experimental trickle-bed system A, tube bundle for liquid flow distribution B, flow distribution packing of glass helices C, activated carbon trickle bed 1, mass flow controllers 2, gas or liquid rotameters, 3, reactor (indicating point of gas phase introduction) 4, overflow tank for the liquid phase feed 5, liquid phase hold-up tank 6, absorber pump 7, packed absorption column for saturation of the liquid phase 8, gas-liquid disengager in the liquid phase saturation circuit. (Figure from Haure et ai, 1989, with permission, 1989 American Institute of Chemical Engineers.)... 

---