Synthesis and development of specialty chemical processes.

摘要

The chemical processing industries (CPI) in the developed countries have shifted away from commodity chemicals towards the high-value-added specialty chemicals, which are the major ingredients in consumer products such as cosmetics, pharmaceuticals, and personal care products. The quality of these products depends not only on purity, but also on structural attributes such as droplet size, particle size, shape, and morphology. For this reason, the product requirements for specialty chemicals are much more complex than that for commodity chemicals. The widening product requirements lead to increasing process complexity, as indicated by three characteristic features. First, the product is normally a solid, and crystallization is commonly used in its recovery and purification. Second, handling of solids is required in most parts of the manufacturing process. Third, various ingredients with potentially very different forms and properties need to be combined to form the final, structured product. Besides the increasing product and process complexity, there is an intensifying pressure to shorten time-to-market. Therefore, it is very important that process synthesis and development of specialty chemicals is done quickly and effectively.; In response to these challenges, a framework for systematic development of specialty chemical processes is presented. Systematic procedures are developed for selected key issues centered on three main themes: crystallization, solids processing, and consumer product manufacturing. These include the design and synthesis of crystallization-based separation processes, integrated crystallization-downstream processing systems, bulk solids processing systems, and dispersed systems. A general framework for product-oriented process synthesis and development is also presented.; The procedures are presented in a step-by-step manner, guiding the user to first focus on the general problem, then progressively refine their thinking to address more detailed issues. There are three important components to each procedure. First, the engineering science principles behind the problem serve as the basis for the procedure. Second, related knowledge is systematized and summarized in the form of look-up tables, diagrams, and heuristics. Third, for quantitative comparison between process alternatives, shortcut models are used to obtain quick but reasonable estimates. Together, these components form a coherent framework for systematically solving the problem at hand.