Examples of Processing Technologies

Coating includes spread, roller, and spray processes for flat substrates, as well as the coating of complex parts using liquid dipping and fluidized-bed equipment. 

Molding processes include compression molding, resin transfer molding (RTM), injection molding and reaction injection molding (RIM), autoclave molding, and several types of specific processes such as shell molding, which is used in foundries. 

Compression molding involves the use of preforms (bulk molding compounds, sheets of glass fibers impregnated with the thermoset precursors, etc.) that are placed in a heated mold. When the mold is closed, the plastified preform flows to fill the mold and cure takes place in about 1-2 min. Then, the mold is opened and the final part ejected. 

RTM involves the pumping of the thermoset precursors into a heated mold cavity containing preplaced fiber mats. Mold filling and fiber impregnation may be assisted by partial evacuation of the mold. 

Autoclave molding has been particularly adapted for the cure of laminates of preimpregnated plies of continuous fibers (prepregs). A lay-up of 

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Today s society asks for technology that has a minimum impact on the environment. Ideally, chemical processes should be clean in that harmful byproducts or waste are avoided. Moreover, the products, e.g. fuels, should not generate environmental problems when they are used. The hydrogen fuel cell (Chapter 8) and the hydrodesulfurization process (Chapter 9) are good examples of such technologies where catalysts play an essential role. However, harmful emissions cannot always be avoided, e.g. in power generation and automotive traffic, and here catalytic clean-up technology helps to abate environmental pollution. This is the subject of this chapter. 

A company sells its products because either they are better than, or they cost less than, a competitive product. If a company does not keep reducing its processing costs and improving quality it can easily lose its markets. An example of how technological improvements in the production of fertilizers have forced many older plants out of business is given in Chapter 3. 

The column methods are much faster and are automated so that a much larger number of samples can be processed per unit time. An example of this technology, described in more detail in Chapter 10 by Lubman and coworkers, is shown in Figure 1.2, where the first dimension is from a chromatofocusing column, which gives separations in pI much like isoelectric focusing, only here the p/ axis is in bands instead of continuous pI increments. The second dimension is by reversed-phase liquid chromatography (RPLC). 

Since 1950, significant technological advances have been made in chemical process safety. Today, safety is equal in importance to production and has developed into a scientific discipline that includes many highly technical and complex theories and practices. Examples of the technology of safety include... 

E. Widjaja, Y.Y. Tan and M. Garland, Application of band-target entropy minimization to on-line Raman monitoring of an organic synthesis. An example of new technology for process analytical technology, Org. Process Res. Dev., 11, 98-103 (2007). 

A recent example of a product that is demanding in terms of process chemistry is a new herbicide from BASF. The seven-step synthesis requires bromination, chlorination, carbonylation, oxydation (with H2O2), hydrogenation, and a reaction with ethylene. As no fine-chemical manufacturer was in a position to offer the whole range of process technologies, the manufacture will be split between two fine-chemical companies. 

Slide 8 A technological expertise name reactions with volume ranges and examples of processes done on industrial scale... 

Figure 4.21 Examples of processes using different raw materials processing technologies and producing products with different end uses.

The schematic shown in Fig. 43(a) is a commercial example of this technology. Stack gas is scrubbed with an alkaline solution of sodium hydroxide, sodium sulfite, and sodium sulfate. The sodium sulfite reacts with SO2 in the stack gas to form sodium bisulfite. This salt solution is processed in a bipolar membrane unit [Type (I) shown in Table IX] to generate an alkaline solution and an acidic solution. The alkaline solution contains regenerated caustic soda and sodium sulfite, and can be recycled to the scrubber, while the sulfurous acid can be further processed to sulfur or sulfuric acid for sale. 

Two examples of this technology are the Amine Guard FS Process and the Amine Guard II Process. A comparison of the two processes is given in Table 5.35200. 

Although the scientific principles behind this simple example of practical technology are easily understood, it illustrates the benefits that can be realized by considering the blending process as a dispersion operalion that may be followed, if necessary, by an operation to retard the rate at which the ingredients of the blend demix. In special cases, of course, the latter operalion may be rendered unnecessary by the selection of blend ingredients that are miscible in the first instance. 

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