Chemical manufacturing processes sensors

Small but environrrientallyjnendly. The Chemical Engineer, March 1993 Huge increases in technology in the past distributed manufacturing in small-scale plants miniaturization of processes domestic methanol plant point-of-sale chlorine simpler and cheaper plants economy of plant manufacture process control and automation start-up and shut-down sensor demand [145],... 

Continuous analysis offers another very useful possibility of completely automated chemical control, especially in manufacturing processes, but also in analytical processes such as separational flow techniques where the analytical measurement proper acts as a sensor, usually called the detector. As long as a physical or physico-chemical constant yields a sufficiently accurate and specific... 

A third area in which PLS has become used extensively is in the modeling of the huge data sets measured on chemical and other manufacturing processes. By means of sensor arrays, data characterizing the state of the process are measured and collected at regular time intervals, typically once per minute for fairly fast processes such as distillations, down to once every 6 hours for slow fermentation processes. In addition, samples are occasionally withdrawn and analyzed for product yield, purity, side products, etc. It is of course of great interest to find correlations between many and correlated process variables X, and result variables Y, and PLS has been found to work very well for these purposes. With appropriate software and communication equipment, one can use the PLS models on-line to monitor the process in order to obtain instant warnings of process problems, undesired trends, etc. 

To allow commercial applications of sensors at various potential emission sites, the construction of these sensors from solid materials is desirable, so as to minimize the size of the sensors and simplify the manufacturing process. To date, a number of small CO2 gas sensors have been developed, and these may be categorized by their sensing mechanism, whether based on optical cells, resistance/capacitance of semiconductors, or electromotive force (EMF)/current measurements based on solid electrolytes. However, such sensors continue to exhibit deficits, including low selectivity, poor chemical and physical stability, or high cost, and these problems must be mitigated to improve their usefulness. 

In the area of consumer products, amperometric glucose sensors hold high potential. Industrially, process monitors for the manufacture of consumer chemicals are under development. However, replacement of defective reference electrodes, which in a laboratory environment may be trivial, may be prohibitively difficult m vivo or in an industrial process environment. 

Die Fabrik auf dem Chip, Spektrum der Wissenschafi, October 2002 Miniaturization and modularization of parts of future chemical apparatus general advantages of micro flow expert opinions specialty and fine chemical applications leading position of German technology flexible manufacture large-capacity micro reactors reformers for small-capacity applications compatible and automated micro-reaction systems process-control systems temperature and pressure sensors [209]. 

In Chapter 3 we briefly outline the methods of manufacturing of sensitive elements of semiconductor sensors in order to proceed with the studies of several physical and chemical processes in gases, liquids as well as on the surface of solids. Here we show the peculiarity of preparation of these elements depending on objective pursued and operation conditions. We outline the detection methods (kinetic and stationary), their peculiarities and advantages of their application in various physical and chemical systems. 

The growing nse of more complex PAT (versus the historically used simple univariate sensors such as pressure, temperature, pH, etc.) within manufacturing industries is driven by the increased capabilities of these systems to provide scientihc and engineering controls. Increasingly complex chemical and physical analyses can be performed in, on, or immediately at, the process stream. Drivers to implement process analytics include the opportunity for live feedback and process control, cycle time reduction, laboratory test replacement as well as safety mitigation. All of these drivers can potentially have a very inunediate impact on the economic bottom line, since product quality and yield may be increased and labor cost reduced. 

---