Process engineering methods

Design-related and Process Engineering Methods for Optimisation... 

Besides body-orientated and process engineering methods it is possible to minimise laminations, and therefore avoid defects caused by these, by optimising the design and operation of the extruder. In practice it is, however, proven time and again that bodies with a minimum tendency towards laminations are a prerequisite in the avoidance of laminations and the associated defects. Or expressed another way even the best extruder design cannot fully compensate the effects of an unfavourable body composition highly susceptible to laminations. 

For situations where less hazardous materials cannot be substituted in the process, engineering methods are the most important method of control and should be applied in all cases. Engineering methods are defined as any aspects... 

Knowledge of physical properties of fluids is essential to the process engineer because it enables him to specify, size or verify the operation of equipment in a production unit. The objective of this chapter is to present a collection of methods used in the calculation of physical properties of mixtures encountered in the petroleum industry, different kinds of hydrocarbon components, and some pure compounds. 

A panoply of methods whose results can be widely scattered are available to the process engineer not knowing the pitfalls attached to this activity, he would like to have a unique method or an exact guideline for applying these methods. 

A container full of hydrocarbons can be described in a number of ways, from a simple measurement of the dimensions of the container to a detailed compositional analysis. The most appropriate method is usually determined by what you want to do with the hydrocarbons. If for example hydrocarbon products are stored in a warehouse prior to sale the dimensions of the container are very important, and the hydrocarbon quality may be completely irrelevant for the store keeper. However, a process engineer calculating yields of oil and gas from a reservoir oil sample will require a detailed breakdown of hydrocarbon composition, i.e. what components are present and in what quantities. 

Insurance and Ri In the venture-premium method of assessment, risky investments are required to yield a rate of return that adds a premium to the cost of finance. D. F. Rudd and C. C. Watson (The Strategy of Process Engineering, Wiley, New York, 1968, p. 91) consider this relationship ... 

There are many excellent textbooks on the subject of distillation, however with the explosion of information on the World Wide Web, process engineers can now gain almost instant access to calculation methods and model simulations which will walk the engineer through the important design steps. The following Web sites are recommended to be reviewed and accessed by the reader. 

Graphical methods at best are simply illustrative for the student today, but they are occasionally referenced by the process engineer. Extraction, like distillation can be viewed as a stage-wise operation, and hence metliods based on the McCabe Thiele approach briefly described in Chapter 4 have been applied to preliminary design cases. Indeed, both absorption and adsorption are stage-wise operations. 

The methods outlined in this chapter are considered adequate for the stated conditions, yet some specific systems may be exceptions to these generalizations. The process engineer often double checks his results by using a second method to verify the ball-park results, or shortcut recognized as being inadequate for fine detail. 

However, like the scientific method, the engineering method is an interative process and embedded in the engineering method is the systematic use of the scientific method itself to predict behavior of a prototype device or process. This means both methods require the use of trial and error. The interdependency of irtiil and error was explained by someone who said. One cannot have trail and error without error. ... 

Multiphase flow is important in many areas of chemical and process engineering and the behaviour of the material will depend on the properties of the components, the flowrates and the geometry of the system. In general, the complexity of the flow is so great that design methods depend very much on an analysis of the behaviour of such systems in practice and, only to a limited extent, on theoretical predictions. Some of the more important systems to be considered are ... 

The scope of my comments will cover not the development of analytical methods but rather the process of choosing methods which give useful answers to the questions posed by the research chemist, the process engineer or the product marketing manager. The analytical chemist is always faced with the paranoia causing problem of not being able to be confident in a purity measurement until it can be shown that impurities do not interfere. 

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