Sorption processes equipment

The cost and performance of product/equipment/system or the mode of application are always of concern in controlling process efficiency. Therefore, the sorption capacity and required contact time are two of the most important parameters to understand in a sorption process. Equilibrium analysis is fundamental to evaluate the affinity or capacity of a sorbent. However, thermodynamic data can only predict the final state of a system from an initial... 

This section treats batch and fixed-bed operations and reviews process cycles and equipment. As the processes indicate, fixed-bed operation with the sorbent in granule, bead, or pellet form is the predominant way of conducting sorption separations and purifications. Although the fixed-bed mode is highly useful, its analysis is complex. Therefore, fixed beds including chromatographic separations are given primary attention here with respect to both interpretation and prediction. 

The attachment of particular solute molecules to the surface of the particulate sorption packing material can be achieved by a number of different methods, which are outside the scope of this paper. There are a large number of different sorption materials and complex physical and chemical interactions which must be considered. The most common sorption materials are activated carbon, silica gel, activated alumina, molecular sieves, and ion exchange resins. This chapter deals with the industrial aspects of handling these materials and operating process-scale equipment, but does not look at the choice of sorption material for a particular process. 

Ultrasonic nebulizers have also been employed in continuous flow systems as interfaces between sample preparation steps in the analytical process and detection by virtue of their suitability for operating in a continuous mode. Thus, preconcentration devices have commonly been coupled to atomic spectrometers in order to increase the sensitivity of some analytical methods. An enhancement factor of 100 (10 due to USNn and 10 due to preconcentration) was obtained in the determination of platinum in water using a column packed with polyurethane foam loaded with thiocyanate to form a platinum-thiocyanate complex [51]. An enhancement factor of 216 (12 with USNn and 18 with preconcentration) was obtained in the determination of low cadmium concentrations in wine by sorption of metallic complexes with pyridylazo reagents on the inner walls of a PTFE knotted reactor [52]. One special example is the sequential determination of As(lll) and As(V) in water by coupling a preconcentration system to an ICP-AES instrument equipped with a USN. For this purpose, two columns packed with two different resins selective for each arsenic species were connected via a 16-port valve in order to concentrate them for their subsequent sequential elution to the spectrometer [53]. 

Pressure Swing Adsorption (PSA) unit is a dynamic separation process. In order to create a precise model of the process and thus an accurate design, it is necessary to have a good knowledge of the mixture s adsorption behaviour. Consequently, the dilAision rates in the adsorbent particles and the mixture isotherms are extremely vital data. This article intends to present a new approach to study the adsorption behaviour of isomer mixtures on zeolites. In a combined simulation and experimental project we set out to assess the sorption properties of a series of zeolites. The simulations are based on the configurational-bias Monte Carlo technique. The sorption data are measured in a volumetric set-up coupled with an online Near Infra-Red (NIR) spectroscopy, to monitor the bulk composition. Single component isotherms of butane and iso-butane were measured to validate the equipment, and transient volumetric up-take experiments were also performed to access the adsorption kinetics. 

The process conducted in batch-type counter-flow apparatus (Figure 30.17) equipped with capillary PP Acccurel membranes showed good effectiveness of membrane distillation for purification of radioactive waste. Permeate obtained was pure water. All solutes together with radioactive compounds were rejected by the hydrophobic membrane. At tenfold volume reduction of the initial portion of waste, approximately tenfold concentration of radioactivity in the retentate stream was reached, while radioactivity of permeate retained on the level of namral background (Figure 30.18). As was observed in experiments small sorption in the system took place. However, permeate was free of radioactive substances and other dissolved compounds, the concentration and radioactivity factors sometimes slightly differed from volume reduction factors. 

FIGURE 4-39 The acid deposition process. Acid precursors, notably oxides of nitrogen and sulfur, are emitted to the atmosphere, primarily by fuel-burning equipment. Acid precursors are oxidized in the atmosphere to nitric and sulfuric acids by a variety of homogeneous and heterogeneous reactions. The acids are deposited by precipitation-related processes such as washout and rainout, by sorption of nitric acid vapor, and by dry deposition of acidic particulate material such as ammonium sulfate aerosol. (Stern et ah, 1984.)... 

The different solid-fluid interaction models and the various types and sizes of the sorbent media particles, as well as the purpose of a sorption operation, separation, purihcation, and so on, led to the development of a variety of processes, along with the required equipment types. These processes are associated with the main interaction models discussed earlier adsorption, ion exchange, and chromatography. 

The sorbent can also be used in a chemical reaction, with the adsorbed molecule as one of the reaction products. In sorption-enhanced reaction processes, equilibrium-constrained reactions are driven to the product side, that is, to completion by removing one of the products by using a solid sorbent. The advantage of sorption-enhanced reaction is that the conversion and the separation are combined in just one reactor. Apart from potential equipment savings, reduced energy use for the purification of the main product is the driving... 

Telegin F.Yu., Shormanov A.V., Melnikov B.N. (1997), Description of Kinetic Regularities of the Dyeing Process by the Use of Sorption Curve Moments in Moryganov, A.P., editor. Textile Chemistry - Theory, Technology, Equipment, Nova Sci. Publishers, Inc., Commack, New York, pp. 87-115. 

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