Exposing chemical engineering

FIG. 26-32 Methods of diking for flammable hqiiids (a) traditional diking method allows leaks to accumulate around the tank. In case of fire, the tank will he exposed to flames that can he supplied hy fuel from the tank and will he hard to control, (h) In the more desirable method, leaks are directed away from the tank. In case of fire, the tank wiU he shielded from most flames and fire wiU he easier to fight. (From Englund, in Advances in Chemical Engineering, vol. 15, Academic Press, San Diego, 1.9.90, pp. 73—135, hy permission. )... 

Process Safety Management (PSM), under OSHA, attempts to protect employees exposed to toxicity, tire, or explosion. Many plants employing chemical engineers must do a PSM consisting of fourteen parts. Some of the parts are greatly facilitated if the team includes chemical engineers. 

The new research frontiers in chemical engineering, some of which represent new applications for the discipline, have important implications for education. A continued emphasis is needed on basic principles that cut across many apphcations, but a new way of teaching those principles is also needed. Students must be exposed to both traditional and novel applications of chemical engineering. The American Institute of Chemical Engineers (AIChE) has set in motion a project to incorporate into undergraduate chemical engineering courses examples and problems from emerging applications of the discipline. The committee applauds this work, as well as recent AIChE moves to allow more flexibility for students in accredited departments to take science electives. 

Most of you have probably been exposed to Laplace transforms in a mathematics course, but we will lead off this chapter with a brief review of some of the most important relationships. Then we will derive the Laplace transformations of commonly encountered functions. Next we will develop the idea of transfer functions by observing what happens to the differential equations describing a process when they are Laplace-transformed. Finally, we will apply these techniques to some chemical engineering systems. 

The greatest safety hazard in chemical engineering operations is without question caused by uncontrolled chemical reactions, either within the chemical reactor or when flammable chemicals escape from storage vessels or pipes. Many undergraduate students are never exposed to the extremely nonlinear and potentially hazardous characteristics of exothermic free radical processes. 

This text is focused primarily on chemical reactors, not on chemical kinetics. It is common that undergraduate students have been exposed to kinetics first in a course in physical chemistry, and then they take a chemical engineering kinetics course, followed by a reaction engineering course, with the latter two sometimes combined. At Minnesota we now have three separate courses. However, we find that the physical chemistry course... 

Fig. 6. Ethylene and methyl jasmonate (MJ) interaction when MJ is supplied as ethanolic solution to the suspension cell cultures of T. cuspidata. All cultures were exposed to 10% (v/v) oxygen, 0.5% (v/v) carbon dioxide and designated headspace concentrations of ethylene. A 0 ppm B 5 ppm C 10 ppm. 0 pM MJ ( ) 10 pM MJ ( ) 100 pM MJ (a). Reprinted with the permission of the American Chemical Society and the American Institute of Chemical Engineers [27]...

The second topic within the scope of chemical engineering applications concerns the relation of particle-size to chemical reaction—such as rates of solution and oxidation. This is a subject complicated by many indeterminate factors. In general, however, the main item concerned is particle-surface. As is well known, where solids are involved, reactions of a chemical nature are greatly influenced by the amount of surface exposed. 

In addition to training, engineering controls are the most effective way of minimizing exposure to harmful chemicals. Engineering controls include process or equipment modifications that reduce the amount of potentially hazardous materials to which an employee may be exposed. Isolation and ventilation are the primary methods of control. Engineering controls also include the maintenance, policing, and changing of work practices when necessary. 

Preliminary data from a second workplace survey, the National Occupational Exposure Survey (NOES), conducted by NIOSH from 1980 to 1983, indicated that 1,957 workers, including 272 women, were potentially exposed to 1,1-dichloroethane in the workplace in 1980 (NIOSH 1984). The exposed workers were employed in the chemical and allied products and business service industries, as chemical technicians plumbers, pipefitters, and steamfitters supervisors in production occupations electricians machinists chemical engineers and welders and cutters. The estimates were based on direct observation by the surveyor of the actual use of the compound (100%). 

Di Blasi, C., (1996) Heat, momentum and mass transport through a shrinking biomass particle exposed to thermal radiation, Chemical Engineering Science, Vol.5,No7.1121-1132... 

The time is ripe for the broader chemical engineering community to be exposed to Car-Parrincllo methods and their potential for chemical engineering. Computational methods, even very advanced ones, will continue to become more and more routine for nonspecialists. Having these computational methods in the chemical engineer s toolbox will necessarily lead to enhanced ability to make significant advances, both experimental and theoretical. 

The objective of this article is to expose the chemical engineering community to Car-Parrinello methods, what they have accomplished, and what their potential is for chemical engineering. Consistent with this objective, in Section IV, I give an overview of the most widely used quantum mechanical method for solving the many-body electronic problem, density-functional theory, but describe other methods only cursorily. I also describe the practical solution of the equations of density-functional theory for molecular and extended systems via the plane-wave pseudopotential method, mentioning other methods only cursorily. Finally, I end this section with a description of the Car-Parrinello method itself. 

The publication in 1960 of Transport Phenomena by Bird, Stewart and Lightfoot was an important milestone in the establishment of the chemical engineering science approach. Bird and Lightfoot had joined the staff of the Chemical Engineering Department at Wisconsin in 1953. Bird had just spent a summer at the Du Pont Experimental Station in Wilmington, where he had been exposed to a large number... 

Reizner, J.R. Exposing Coriolis Mass Flowmeters Dirty Little Secret. Chemical Engineering Progress March (2004) 24-30. 

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