Intensification principle

Process intensification is achieved through the application of one or more of the following intensification principles ... 

The reactions are still most often carried out in batch and semi-batch reactors, which implies that time-dependent, dynamic models are required to obtain a realistic description of the process. Diffusion and reaction in porous catalyst layers play a central role. The ultimate goal of the modehng based on the principles of chemical reaction engineering is the intensification of the process by maximizing the yields and selectivities of the desired products and optimizing the conditions for mass transfer. 

In chemical micro process technology there is a clear dominance of pressure-driven flows over alternative mechanisms for fluid transport However, any kind of supplementary mechanism allowing promotion of mixing is a useful addition to the toolbox of chemical engineering. Also in conventional process technology, actuation of the fluids by external sources has proven successful for process intensification. An example is mass transfer enhancement by ultrasonic fields which is utilized in sonochemical reactors [143], There exist a number of microfluidic principles to promote mixing which rely on input of various forms of energy into the fluid. 

They observed the complete deactivation of the rhodium catalyst whether immobilized or not in the presence of free amines. When no amine was present, styrene formation was not observed. After 17 h of a reaction in which both catalysts were immobilized, the yield of the product, ethylbenzene, was 52%, again demonstrating the principle of enabling two otherwise incompatible catalysts to work concomitantly in order to achieve process intensification. 

Similar analysis can be made for other types of materials. Thus, as a generalization, the curvature of a surface causes field intensification, which results in a higher current than that on a flat surface. Although the detailed current flow mechanism can be different for different types of materials under different potentials and illumination conditions, the effect of surface curvature on the field intensification at local areas is the same. The important point is that the order of magnitude for the radius of curvature that can cause a significant effect on field intensification is different for the substrates of different widths of the space charge layer. This is a principle factor that determines the dimensions of the pores. 

This principle corresponds to the maximum of oscillation intensification taking place in the phase. Modifying the rule of adding energy reciprocals of subsystems as applied to complex structures we can obtain the equation for calculating Pc-parameter of complex structure ... 

Process intensification (PI) is currently one of the most significant trends in chemical engineering and process technology. It is attracting more and more of the attention of the research world. Four international conferences, several smaller symposia/workshops every year, and a number of dedicated issues of professional journals are clear proof of it. A number of commercial-scale applications of the PI principles have already taken place. But how did it all begin ... 

The overview in Table 1 holds, in principle, for any type of chemical industry. Additionally, different types of chemical industries may have different focuses, depending on their starting position and on their business requirements. Knowledge of the perspectives helps in determining the main cost drivers from the fist given in Table 1 and helps therefore in finding the starting points for process intensification studies. Table 2 presents an overview of some of the main types of chemical industries and the specific demands they posed on process intensification when applied in these industries. A distinction can thus be made between ... 

Meanwhile, the data obtained [87, 116] unambiguously indicate that the catalase activity increase is associated with non-classical peroxidase activity intensification. It is obvious that the last circumstance casts some suspicion on the interpretation of reactions (6.17) and (6.18) as the competing ones, because in this case, intensification of one reaction should cause suppression of the other. Moreover, as follows from Kremer s data [118], the catalase reaction rate is five orders of magnitude higher than the peroxidase reaction rate. Therefore, comparison of these reactions from competition positions is very suspect. An article by Chance and coworkers [119] can be mentioned as evidence that a H202 concentration increase in the system in the presence of ethanol intensifies peroxidase activity (hence, intensification of the catalase activity is implied). Because catalase activity increase causes the Chance complex formation at higher rate, the peroxidase reaction (6.18) rate is also increased owing to chemical induction principle. 

Finally, it is worth mentioning that a successful integration of catalytic reaction steps with product separation and catalyst recovery operations will also be dependent on innovative chemical reaction engineering. This will require the widespread application of sustainable engineering principles [48].In this context process intensification , which involves the design of novel reactors of increased volumetric productivity and selectivity with the aim of integrating different unit operations to reactor design, and miniaturization will play pivotal roles [49, 50]. 

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