Multifunctional processes

Determination of the acidic sites through IR spectroscopy of adsorbed CO is a valuable tool for the choice of the support when selective or multifunctional processes are to be set up. This technique allowed to identify a particular kind of silica as the support of choice for the selective hydrogenation of citral to citronellal and sepiolite as a Lewis acid support able to promote the one-step transformation of citral into menthol. 

Multifunctional fibers, 13 391 Multifunctional initiators, 24 706 Multifunctional processes, in life cycle assessment, 14 813-814 Multifunctional teams, in the development process, 24 348... 

Work processes take many forms, from the simplest of structure techniques to the most complex multifunctional processes. They are important, and the more complex the innovation task is, the more important they are. Work processes capture the best practices over time, standardize those practices for everyone on the team, and provide a common language for everyone to use. Additionally, they are key to defining success on multiple levels. 

In these multifunctional processes, heat transfer and mass transfer are two combined and simultaneous functions, and the objective is to substantially improve these functions in order to save energy, to increase the process efficiency, and to reduce the size and cost of industrial plants. Corrugated pads are often used in the dehumidification process or in chemical heat pumps, but a higher efficiency could be reached by using diabatic units, where the wall could exchange heat with the liquid film. 

In particular, by varying the support and the reaction conditions it is possible to set up multifunctional processes as already shown in the case of pennyroyal oil [67] or geraniol [30], Moreover, by exploiting the ability of the catalysts to modify the adsorbed molecule from the electronic point of view, it is possible to use them in other kinds of reactions with unsuitable substrates. This has indeed been observed in Sonogashira reactions [83],... 

The integration of unit operations to form multifunctional processes very often gives rise to synergetic effects which can be technically exploited. By suitable process design, an efficient and environmentally benign process operation can be achieved. Possible advantages of process integration include ... 

In a multifunctional process, a Rh/TPPTS system was applied besides a Pd/TPPTS system for a tandem Heck reaction/hydroformylation sequence in one pot (cf. Scheme 2). The results are described in more detail in Sect. 2.1.1.1. 

RD columns share some common features with chemical reactors on the one hand and with distillation columns on the other hand. The behavior of these multifunctional processes may be either close to that of non-RD columns or to chemical reactors. Further, new patterns of behavior can be introduced by the superposition of reaction and separation in a single processing unit. Hence, another interesting question that will be addressed in this chapter, is under what conditions and in what sense is the dynamic behavior of an RD column similar to that of a chemical reactor or to that of a non-RD column. 

In the chemical process industries, chemical reaction and the purification of the desired products by distillation are usually carried out sequentially. In many cases, the performance of this classic chemical process structure can be significantly improved by integration of reaction and distillation in a single multifunctional process unit. This integration concept is called reactive distillation (RD) when heterogeneous catalysts are applied the term catalytic distillation is often used. 

Processing aids 11 and 12 Limits on equipment productivity and processing speed, excessive downtime and startup times Multifunctional processing aids for specific situations... 

Talc-Med PP Fine Organics has reported on the effect of its Plastaid-T multifunctional processing aid on 40% talc-filled... 

Plastaid multifunctional processing aids, supplier product guide. Fine Organics. 

Low-temperature plasma methods were used to modify cotton fibers prior to dyeing. Plasma refers to a partially ionized gas that consists of ions, electrons, and neutral particles (Radetic et al., 2000). Plasma processing is a clean, simple, and multifunctional process that meets today s strict economic and ecological demands. As noted in many previous studies, the main advantages of plasma treattnents are a shortened processing time and the nonexistence of water in the medium (Grzegorz et al., 1983 Oktem et al., 1999, 2000). 

Hilz H (1981) ADP-ribosylation of proteins - a multifunctional process. Hoppe-Seyler s Z Physiol Chem 362 1415-1425... 

A somewhat different issue, related also to the impact of the process scale on LCIs, refers to the case of multifunctional processes. In this case, there are various approaches for allocating LCIs and therefore environmental impacts on the multioutput products, depending also on whether an attributional or consequential LCA is the goal of the study [48,49]. Generally, the following allocation methods appear in practical applications [66] ... 

The LCIs are aUocated to the various products of the multifunctional process based on a characteristic property (e.g., heat content, exergy, economic value). This aUo-cation can be done either for the whole process or on a given process subdivision point. For instance, in process Pj of Fig. 13.1, either the overaU LCIs (Qrl, QrL, QrFi, Qcl, QcL, QcH) are aUocated to A, B, C, and D based on their economic value or Cl is identified as a subdivision point and Qrl, Qcl are aUocated to products A, B and C, D based on their economic value, whUe QrL and QcL are aUocated only to A, B and QrH, QcFl are aUocated only to C, D. 

As can be seen, in multifunctional processes the key question is the utilization of the secondary flows, either as valuable coproducts or waste streams for further treatment. The role of the process scale in this case becomes more relevant when some of the coproducts are produced in s pificandy smaller amounts than the main product as the process scale decreases, the main product (i.e., assuming it exists) can obviously still be utilized or sold, while the coproducts may become valuable chemicals to useful waste streams as energy carriers (e.g., for industrial incineration plants) or waste streams for further treatment. In the example of process P in Fig. 13.1, if products A, B are available in much higher amounts compared to C, D in the MIX stream, in smaller process scales it may not be any more sensible to recover the pure C and D through the distillation in CH instead the stream C, D at the bottom of the column Cl may be considered as fuel, depending on the energy content of C, D, or waste vater stream if one of C, D is actually water. 

Reactive adsorption is a multifunctional process that results by integrating any chemical reaction with adsorption operation in a single unit. Reactive adsorption is favorable for those reactions in which the product of interest is in fluid phase and needs to be separated instantaneously. It is also advantageous to those fluid-solid separations, where the incorporation of reaction... 

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