Process intensification approach

Figure 2 Process Intensification Approaching the kinetic limit by using the three imperatives (1) Make it small (2) combine (3) intensify the driving force.

Minimize—Use smaller quantities of hazardous substances, including process intensification approaches. Example Use a small, continuous reaction system for the production of nitroglycerine in place of a large batch reactor. 

The use of multiple otherwise incompatible catalysts allows multistep reactions to proceed in one reaction vessel, providing many potential benefits. In this chapter, literature examples of nanoencapsulation for the purpose of process intensification have been discussed comprehensively. Current efforts in the literature are mostly concentrated in the areas of LbL template-based nanoencapsulation and sol-gel immobilization. Other cascade reactions (without the use of nanoencapsulation) that allow the use of incompatible catalysts were also examined and showcased as potential targets for nanoencapsulation approaches. Finally, different methods for nanoencapsulation were investigated, thereby suggesting potential ways forward for cascade reactions that use incompatible catalysts, solvent systems, or simply incompatible reaction conditions. 

Microreactor and microprocess technology has, in some fine-chemical cases, approached commercial applications and become competitive with existing technology. Two main developments are awaited. Firstly, optimizing the process protocol conditions such that the chemistry is set to the limit of the reactor s capabilities in terms of mass and heat transfer. This so-called novel chemistry approach achieves the highest process intensification and can improve the costing of microprocess... 

Microreactors evolved from the process intensification concepts and microfabrication techniques developed for the microelectronics industry. Process intensification was pioneered in the 1970s, arguably by Imperial Chemical Industries (ICI) researcher Colin Ramshaw, who began developing technologies and approaches that considerably reduced the physical size of unit operations while maintaining their... 

There is no doubt that the ultimate development of process intensification leads to the novel field of microreaction technology (Figure 1) (7-9). Because of the small characteristic dimensions of microreaction devices, mass and heat transfer processes can be strongly enhanced, and, consequently, initial and boundary conditions as well as residence times can be precisely adjusted for optimizing yield and selectivity. Microreaction devices are evidently superior, due to their short response time, which simplifies the control of operation. In connection with the extremely small material holdup, nearly inherently safe plant concepts can be realized. Moreover, microreaction technology offers access to advanced approaches in plant design, like the concept of numbering-up instead of scale-up and, in particular, the possibility to utilize novel process routes not accessible with macroscopic devices. 

Wood M, Green A. A methodological approach to process intensification. IchemE Symposium Series No. 144, 1998 405—416. 

Equipment that combines more than one unit operation in a single piece of equipment is another approach to process intensification. Reactive distillation is a good... 

Solvent-resistant nanofiltration and pervaporation are undoubtedly the membrane processes needed for a totally new approach in the chemical process industry, the pharmaceutical industry and similar industrial activities. This is generally referred to as process intensification and should allow energy savings, safer production, improved cost efficiency, and allow new separations to be carried out. 

A very interesting approach to process intensification was recently presented by Jachuck and coworkers. The authors described the development and performance of an isothermal CF reactor to be used in a domestic microwave oven [81]. The small (270 p,L) CF reactor consists of two sections, a microwave transparent PTFE part for the reaction side and an alumina part for heat transfer (Fig. 23). The heat generated due to the activation by microwave irradiation was rapidly absorbed by the heat transfer liquid (H20) pumped through the alumina part. Inlet and outlet temperatures of both the reaction mixture and the heat transfer liquid were monitored using a PICO temperature recorder. 

To this sense, conceptual process synthesis plays a key role and constitutes a major approach for process intensification to achieve the multifunctional and microstructured devices. In this work, a systematic methodology based on conceptual process synthesis for process intensification is presented. 

A large variety of books and review papers is thus available, but often they either do not employ a comprehensive approach or are not consistent with the approach of sustainable industrial chemistry that is the core of this book. In addition, for educational purposes, it is useful to overview the main methods and tools available to develop a novel and innovative sustainable industrial chemistry. This chapter is dedicated to catalysis as key tool for sustainability and process intensification. 

Figure 3.4 Relevant issues in the main four domains that constitute the pillars of the PI approach. Source adapted from EU Roadmap for Process Intensification ...

An approach to overcoming these problems, and which is directly linked to process intensification issues, is to combine microstructured reactor technology to photochemistry and photocatalysis [124,130]. Microstructured reactors have several possible advantages for photochemical processes [131] ... 

Undoubtedly, this new kind of integrated approach is well representative of what should be membrane engineering, with final objectives clearly defined, the right hypothesis and choice of simple equations for modeling, a realistic representation of real complex solutions and the set-up of efficient simulation tools involving successive intra- and extrapolation steps. It appears to be easily extended to other membrane operations, in other fields of applications. It should provide stakeholders with information needed to make their decision costs, safety, product quality, environment impact, and so on of new process. Coupled with the need to check the robustness of the new plant and the quality of final output, it should constitute the right way to develop the use of membranes as essential instruments for process intensification with industrial units at work. 

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