Rectification concepts

The catalytic distillation process of Smith [15], by providing for the fixing of the catalyst in a reactive section of a column between nonreactive stripping and rectification sections, and thereby for the continuous removal of MTBE from the reactants, boosts the conversion of isobutene to well in excess of 99%. The concept is still more economically attractive when OCFS are employed to secure the catalyst in the reactive section— DeGarmo et al. [16]—due to their significantly higher mass transfer efficiency. 

The bio-related redox molecular entities shown in Figure 2.8 thus display a pattern which follows consistently the concepts of two-step electrochemical tunnehng and the formalism discussed above. Working principles of redox switching, rectification, and amplification at the single-molecule level of interfacial electrochemical ET have thus been achieved. This can be compared with biological redox macromolecules addressed below. We consider first briefly two cases of biomolecules or bio-related molecules intermediate in size between... 

For absorption the same plate designs as for rectification are used. However, the efficiency of a practical stage is lower in absorption than in rectification. Therefore, besides the conventional columns, equipment with highly intensive contact of the phases, like in a jet washer or spray tower, is used. Hence, in contrast to rectification, the mass-transfer concept (Figure 2.3.3-4), in which gas and liquid transfer units... 

Different approaches to bridge the size gap between conventionally fabricated circuit elements and truly atomic scale components have been discussed. These indude the use of electron transport through single molecules, the concept of molecular rectification, and the design of atomic relays or molecular shuttles. Today, the approach that receives the most attention among the different concepts of futuristic drcuit design is drcuitry based on single-electron transistors. 

Concepts of Simple Distillation, Rectification and Partial Condensation... 

Heat losses Qy from the rectification unit depend on the type and thickness of the insulation material. The reflux is increased by heat losses from the rectification column by a so-called wild reflux . These unavoidable heat losses relaxe the concept of adiabatic operation. 

Table 2-12. Important concepts for planning, correlations and data for a heat pump in combination with a rectification unit [2.24, 2.48, 2.141].

The concept of using heat exchangers for both heat and mass transfer in multi-stage rectification has been around for over 50 years, but more recently companies such... 

Schmidt [9] introduced a concept for the design of columns packed with randomly filled 8—50 mm ceramic Raschig rings. He performed elaborate rectification tests in a column with a diameter of 0.3 m and a packing height of 2 m, using 7 binary mixtures at top pressures ranging between 66 and 1000 mbar, and used the results of... 

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