Intensification process, principles

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. 

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 ... 

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]. 

The innovative character of Process Intensification is in nice harmony with the objectives of Process Systems Engineering (Moulijn J.A. et al., 2006). It is so fliat Process Intensification needs the very front-end creativity for the generation of the novel concepts and principles for the processing tasks. Such novel concepts and principles are also the key elements in process synthesis for the generation of the innovative and inventive designs in terms of systems synthesis and equipment design. 

Figure 3.3 PI provides radically innovative principles in process and equipment design that can benefit process and chain efficiency, capital and operating expenses, quality, wastes, process safety and more, and align perfectly with the Triple-P philosophy of sustainable industrial chemistry. Source adapted from EU Roadmap for Process Intensification (www.creative-energy.org).

Process intensification is driven by four generic principles ... 

Fractionation of liquid mixtures with supercritical carbon dioxide in counter-cur-rent columns can be operated continuously, because liquids can be easily pumped into and out of a column. This represents a big advantage over extrachon from solid materials, as it allows real process intensification - large quantities of feed can be processed with only a small volume under high pressure at any given time. Frac-tionahon, mostly of natural products or extracts, has been extensively studied at the laboratory and pilot-plant scale. The design principles of this type of column have been established, and scale-up procedures devised [1,6]. They can be operated with reflux, as in distillation, and frachonahon can therefore become an extremely se-lechve process. Difficult separahons can be effechvely carried out. 

Stankiewicz A., Drinkenburg A.A.H. 2004. Process intensification History, philosophy, principles. In, Chemical Industries, Marcel Dekker, NY pp. 1-32. 

A further meastrre for process intensification is the indirect (or thermal) coupling of columns. In principle, waste heat of the process is internally used to cover the heat demand elsewhere. The prerequisites of this heat matching are appropriate amoimt and temperature level of the heats. In evaporators and condensers, the temperature level can be adjusted by variations of operating pressures. However, as the vapor pressure is, in a first approximation, an exponential function of temperature, rather large pressure changes are necessary for adjusting temperature levels. 

Figure 11.21 illustrates the principle of this new concept. Its major positive features include the realization of notable system simplification and process intensification thermal losses significantly reduced and cooling and heating steps avoided increased activity of catalysts and sorbents abatement of particulates and tar in the gasifier outlet. In all, a combination of the benefits of traditional primary and secondary hot gas treatments without... 

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