Continuous-contact operations membrane processes

Chapter 6 deals with phase equilibria, which are mainly composed of topics not generally covered in conventional thermodynamics courses. These equilibria are used in Chapter 7 to analyze compartmental models and staged processes. Included in this chapter is a unique treatment of percolation processes, which should appeal to environmental and chemical engineers. Chapter 8 takes up the topic of modeling continuous-contact operations, among which the application to membrane processes is given particular prominence. Finally, in Chapter 9 we conclude the text with a brief survey of simultaneous mass and heat transfer. 

Membrane contactors provide a continuous process for contacting two different phases in which one of the phases must be a fluid. Whether using a flat-sheet, hollow-fiber, or spiral-wound type, the membrane acts as a separator for two interfaces as it has two sides compared to conventional separation processes, which involve only one interface in a two-phase system. Therefore, it allows the formation of an immobilized phase interface between the two phases participating in the separation process [9]. Generally, there are five different classes of contacting operations gas-liquid, liquid-liquid, supercritical fluid-liquid, liquid-solid, and contactors as reactors [10]. The most commonly used operation in industry are gas-liquid also known as vapor-liquid, liquid-liquid, and supercritical fluid-liquid. Each class of system has its own modes of operation but in this study, emphasis will be focused on the gas-Uquid contacting systans. Table 9.1 describes the membrane contactor in summary. 

Since separations are ubiquitous in chemical plants and petroleum refineries, chemical engineers must be familiar with a variety of separation methods. We will first focus on some of the most common chemical engineering separation methods flash distillation, continuous column distillation, batch distillation, absorption, stripping, and extraction. These separations all contact two phases and can be designed and analyzed as equilibrium stage processes. Several other separation methods that can also be considered equilibrium stage processes will be briefly discussed. Chapters 17 and 18 e5q)lore two inportant separations—membrane separators and adsorption processes— that do not operate as equilibrium stage systems. 

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