Specialized pilot-plant equipment

The goal of this work was to establish a method that allowed the selection of batch size and agitation speed during scale-up, with the objective of reproducing the selectivity of the system as measured by the amount of ethanol formed. It is important to remember that in the pharmaceutical industry, scale-up often occurs using existing multipurpose equipment. In some cases, when economical factors allow, specialized pilot-plant equipment is designed. 

This chapter deals briefly with some of the specialized techniques required when working with larger scale reactions. For the purposes of this chapter we will define a large scale reaction as one involving reaction volumes of between 2 and 5 litres. Working on reaction volumes in excess of this usually requires the use of pilot-plant equipment and is beyond the scope of this book. 

After development of a new process scheme at laboratory scale, constmction and operation of pilot-plant faciUties to confirm scale-up information often require two or three years. An additional two to three years is commonly required for final design, fabrication of special equipment, and constmction of the plant. Thus, projections of raw material costs and availabiUty five to ten years into the future become important in adopting any new process significantly different from the current technology. 

The first major objective for the inherent safety review is the development of a good understanding of the hazards involved in the process. Early understanding of these hazards provides time for the development team to implement recommendations of the inherent safety effort. Hazards associated with flammability, pressure, and temperature are relatively easy to identify. Reactive chemistry hazards are not. They are frequently difficult to identify and understand in the lab and pilot plant. Special calorimetry equipment and expertise are often necessary to fully characterize the hazards of runaway reactions and decompositions. Similarly, industrial hygiene and toxicology expertise is desirable to help define and understand health hazards associated with the chemicals employed. 

At Rohm and Haas a committee of several experts contributed to the successes described In this paper. Discussions with Prof. John MacGregor (HcHaster University), Jeff Nathanson, Tom Shannon and Tom Throne were especially Important. Special thanks are due to Chris Altomare, who always had the proper equipment and Instrximentatlon ready for the pilot plant trials. We also would like to acknowledge Prof. Don Watts (Queens University) for assisting with the time series modeling and Prof. 

Granting of freebies, such as free offers, free samples, free pilot plant tests, free pilot plant quantities, pilot plant quantities at industrial scale prices, execution of nonqualifying projects, capital investment in special equipment, plant adaptation, capacity expansion, new plant construction... 

Equipment. The special equipment which may need to be hired and its cost listed. Consideration should be given to the need to use pilot plant facilities or large scale testing facilities. 

Taste Evaluation. The four hydrolysates produced in pilot plant were evaluated for bitter taste by the laboratory s taste panel. Tasting took place in the taste panel room which is equipped with separate booths, and the panel has been selected and trained specially for discrimination of bitterness. The panel was instructed to rank two samples and four bitter-tasting standards, containing 20, 40, 80, and 160 ppm quinine hydrochloride dissolved in non-bitter iso-electric soluble soy protein hydrolysate (5, 6). 20 ppm quinine hydrochloride in this solvent had in previous experiments been established as the panel s threshold value. The protein (N x 6.25) concentration in the samples and standards was 4.0% and pH was adjusted to 6.5 with 4 N NaOH or 6 N HC1. 

If new equipment is needed, laboratory or pilot-plant studies are recommended. Often unique product features involve unusual or special fluid properties, whidi makes prediction of mixer performance almost impossible. The objective is to find potentially suitable equipment and test available mixers. Most equipment vendors have equipment to rent or a demonstration laboratory to test their mixers. 

TIP In a pilot plant most reactions can be readily conducted in the temperature range of — 40°C to +120°C. Temperatures outside this range may require specialized equipment. To develop processes that can readily be introduced to scale-up facilities, try to run reactions in the range of —40°C to +120°C. 

Process considerations to prepare for and execute a scale-up run can be broken down into seven areas safety, documentation, personnel, equipment ability, analytical support, chemicals, and operations. The following checklists will help prepare for a scale-up run and provide guidelines for implementing the run in the pilot plant or the kilo laboratory. Section IV.B reviews the salient points of the checklists, and IV.C provides special reminders about kilo lab procedures. 

While the pilot plant approach during project development must be investigated and decided upon on an individual basis, testing of equipment is always necessary. For that reason, essentially all manufacturers and/or vendors maintain sometimes rather elaborate facilities (Section 9.1 and [B.48, B.97]), which normally feature machines of different sizes, including, in some cases, large scale equipment, to avoid scale-up problems. These test facilities must also include some peripheral equipment, such as mixers, heaters or coolers, conveyors, crushers, dryers, screens, etc., although the variations that are available in these special areas from outside sources can not be offered. Therefore, additional tests for the evaluation and selection of the best peripheral equipment are often necessary at different facilities. 

Fig. 9.13 Manufacturer s pilot plant with a roller press for high-pressure agglomeration of dry particulate solids Fig. 9.14 Temporarily assembled system for the testing of iron ore processing, pelletizing, firing (sintering), and cooling in a specialized vendor s fadlity Fig. 9.15 Test fadlily of a tablettmg machine manufacturer Fig. 9.16 Testing fadlily of a coating equipment manufacturer...

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