Case studies in chemical product design

Case Studies in Chemical Product Design - Use of CAMD Techniques... 

This chapter contains a discussion of two intermediate level problems in chemical reactor design that indicate how the principles developed in previous chapters are applied in making preliminary design calculations for industrial scale units. The problems considered are the thermal cracking of propane in a tubular reactor and the production of phthalic anhydride in a fixed bed catalytic reactor. Space limitations preclude detailed case studies of these problems. In such studies one would systematically vary all relevant process parameters to arrive at an optimum reactor design. However, sufficient detail is provided within the illustrative problems to indicate the basic principles involved and to make it easy to extend the analysis to studies of other process variables. The conditions employed in these problems are not necessarily those used in current industrial practice, since the data are based on literature values that date back some years. 

In principle, problems related to chemical product design can be formulated and solved in many different ways. The objective here is to highlight some of those that have also been applied in the various product design case studies reported in chapters 2-15 of this book. These solution approaches may be classified under the following types ... 

It is important to collect information on various chemical product design applications in the form of case studies, as they can help to understand the issues and needs related to the development of more efficient and versatile methods and tools. Also, they serve as examples in teaching of chemical product design. 

F. M. Meeuse, Process Synthesis for Stmctured Food Products in K. M. Ng, R. Gani, and K. Dam-Johansen (eds.) Chemical Product Design Towards a Persepective Through Case Studies, Elsevier, Amsterdam, 2006, pp. 167-179... 

Given their complexity and practical importance, it should be no surprise that different approaches for dealing with turbulent reacting flows have developed over the last 50 years. On the one hand, the chemical-reaction-engineering (CRE) approach came from the application of chemical kinetics to the study of chemical reactor design. In this approach, the details of the fluid flow are of interest only in as much as they affect the product yield and selectivity of the reactor. In many cases, this effect is of secondary importance, and thus in the CRE approach greater attention has been paid to other factors that directly affect the chemistry. On the other hand, the fluid-mechanical (FM) approach developed as a natural extension of the statistical description of turbulent flows. In this approach, the emphasis has been primarily on how the fluid flow affects the rate of chemical reactions. In particular, this approach has been widely employed in the study of combustion (Rosner 1986 Peters 2000 Poinsot and Veynante 2001 Veynante and Vervisch 2002). 

Baculovirus-based protein expression in insect ceU culture represents today a ripened method for the rapid production of proteins up to pilot scale. Recent advances on all levels of the production process such as optimized expression vectors, chemically defined media, optimized nutritional and kinetic parameters as well as the design of novel cultivation systems contribute to drastically increased protein yields with concomitant reduction of process time and costs. This chapter provides a comprehensive overview on recent research and achievements on the successive steps in a protein expression process, with a focus on how to integrate these findings for achieving overall optimized performance. A case study on the production of a secreted protein illustrates the impact of the different optimization steps on the overall process yields. 

The case study from chapter 7 is concerned with the design and improvement of chemically-active ship bottom paints known as antifouling paints. A hybrid experiment-model based approach is employed here. Experiments and use of expert knowledge are employed to identify product alternatives, whose evaluation in terms of performance as a marine biofouling protector is verified through a model-based approach. 

The non-random two-liquid segment activity coefficient model is a recent development of Chen and Song at Aspen Technology, Inc., [1], It is derived from the polymer NRTL model of Chen [26], which in turn is developed from the original NRTL model of Renon and Prausznitz [27]. The NRTL-SAC model is proposed in support of pharmaceutical and fine chemicals process and product design, for the qualitative tasks of solvent selection and the first approximation of phase equilibrium behavior in vapour liquid and liquid systems, where dissolved or solid phase pharmaceutical solutes are present. The application of NRTL-SAC is demonstrated here with a case study on the active pharmaceutical intermediate Cimetidine, and the design of a suitable crystallization process. 

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