Industrial screening experiments

This chapter provides an overview of industrial screening experiments, focusing on process and product design and development. As in any experiment, the pre-experimental planning aspects of a screening experiment are very important. We define pre-experimental planning in terms of the following steps ... 

Some Other Aspects of Industrial Screening Experiments... 

As discussed in section 2.4.4 the coordinating ability of a solvent will often affect the rate of nucleation and crystal growth differently between two polymorphs. This can be used as an effective means of process control and information on solvent effects can often be obtained from polymorph screening experiments. There are no theoretical methods available at the present time which accurately predict the effect of solvents on nucleation rates in the industrial environment. 

Ab initio methods for polymorph, hydrate and solvate prediction are highly prized by the industry and good progress has been made in this field in recent years. This work is still a number of years from routine commercial application however, and polymorph screening experiments together with crystal structure determination, remain critical tasks for today s Pharmaceutical companies. 

We gratefully acknowledge P. L. Dotson for catalyst screening experiments, M. K. Moore for catalyst extraction studies, T. R. Nolen for valuable engineering assistance, A. J. Robertson (Cytec Industries) for phosphonium iodide advice and samples, and the many members of the Eastman Project Team. 

Max Morris is a Professor in the Statistics Department and in the Department of Industrial and Manufacturing Systems Engineering at Iowa State University. His research interests include the development and application of experimental designs and strategies for computer simulations, problems involving spatial and dynamic systems, and factor screening experiments. 

The following characterization by C.W. Raven (33) is probably typical of the present status of PBR screening technigues "Selection from and a mixture of a number of company philosophies, theories, strategies, and experience forms the basis of the modern industrial screening operation and make it a profession of its own "... 

However, it must be underlined that the most important industrial catalytic processes were developed by purely empirical methods and countless screening experiments. The complexity of the solid catalysts still represents a serious obstacle to the understanding of the structure-reactivity relationship. ... 

QRA is generally resource intensive. FEIR, is much less although it uses the framework of QRA for screening and ranking systems by relative risk using order-of-magnitude estimates of the frequencies and consequences of events. It incorporates plant experience and industry data to estimate the potential for future losses. 

The SAIC New York office houses five encoded data sets of the type described above and partial and raw data sets from five other plants. SAIC also maintains a published data source library from various industries. This library has been used to compile generic data sets for PRA screening, supplementing weak areas in plant-specific data sets, and as a basis for comparing plant data with world experience. 

Batchwise operating three-phase reactors are frequently used in the production of fine and specialty chemicals, such as ingredients in drags, perfumes and alimentary products. Large-scale chemical industry, on the other hand, is often used with continuous reactors. As we developed a parallel screening system for catalytic three-phase processes, the first decision concerned the operation mode batchwise or continuous. We decided for a continuous reactor system. Batchwise operated parallel sluny reactors are conunercially available, but it is in many cases difficult to reveal catalyst deactivation from batch experiments. In addition, investigation of the effect of catalyst particle size on the overall activity and product distribution is easier in a continuous device. 

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