Industrial monitoring and process control

Indeed, in the context of fundamental chemical processes in dilute environments, which are at the heart of this book (i.e. reaction processes in or supported by the gas phase), are combustion processes. As was pointed out in the introductory summary to these application chapters, combustion is all-present in our lives, and is encountered in internal combustion engines, in domestic and large-scale power generation by boilers and furnaces, in incineration of waste, in smelting and glass production, and so on. Not surprisingly, the analysis, monitoring and control of these combustion processes have featured prominently in the transfer of laser chemical methods from the laboratory to the real world. 

In the next two sections we will discuss examples of applications to internal combustion engines (Section 

in Section 29.3, an emerging technology in the field of nano-patteming is discussed, a technique involving laser-assisted reactions of adsorbates on surfaces. Although this is still very much in its infancy, the potential in our miniaturized world is enormous. 

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Research and development of chalcogenide glass chemical sensors are gaining more attention. Analytical applications of this type of sensors for environmental monitoring and process control have been reported for the detection of microgram levels of copper (II), iron (III), chromium (VI), lead, cadmium and mercury in natural and waste waters (27,28). In addition, the applications of chalcogenide glass sensors for laboratory analysis, industrial control and... 

Emissions monitoring is essential in controlling industrial environments and processes to ensure good air quality standards are maintained. It is also required in order that the various regulations and guidelines related to air quality are met. In addition to gaseous emissions, such as sulfur dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, and many others, the emissions of particulate material and heavy metals must also be controlled. 

Electrophoresis can also be conducted on-line, as an element of industrial process monitoring and/or control. In this case a slip-stream sample is usually withdrawn from a process vessel, diluted in a mixing tank to reduce the sample turbidity, and then pumped through an electrophoresis cell that is fitted with stop-flow solenoid valves. The flow is stopped for long enough to make an electrophoresis measurement and then resumed. The sampling can be either intermittent or continuous. An example is described in reference [265]). 

Some typical important industrial applications of coulometry include the continuous monitoring of mercaptan concentration in the materials used in rubber manufacture. The sample continuously reacts with bromine, which is reduced to bromide. A third electrode measures the potential of B12 vs. Br and, based on the measurement, automatically regulates the coulometric generation of the bromine. Coulometry is used in commercial instruments for the continuous analysis and process control of the production of chlorinated hydrocarbons. The chlorinated hydrocarbons are passed through a hot furnace, which converts the organic chloride to HCl. The latter is dissolved in water and the Cl titrated with Ag" ". The Ag" " is generated by coulometry from a sUver electrode, Ag°. It is necessary for the sample flow rate to be constant at all times. Integration of the coulometric current needed to oxidize the silver to silver ion results in a measurement of the Cl concentration. 

Sensors provide information about the automated system environment. They are the link between the technical process and its control system and can be seen as the sense organ of the technical system. They are used for a number of tasks, such as material flow control, process monitoring and regulation, control of industrial robot movements, quality inspections and industrial metrology, and for security protection and as safeguards against collisions. 

Electrophoresis can also be conducted online, as an element of industrial process monitoring and/or control. In this case, a slip-stream sample is usually withdrawn from a process vessel, diluted in a mixing tank to reduce the sample... 

Industrial monitors used for control purposes can be implemented in different ways depending on 1) the corrosion interaction between the process stream analysed and the sensor, 2) on the degree of contamination of the medium by the sensor and 3) by the additives necessary to the operation of the sensor. 

The data given by Reeves help answering the question as to why the industry requires an ever increasing number of monitors for process control. He shows that the analytical information produced by monitors and used to control the process reduces process costs. I think this is an important stimulus for both fundamental research and monitor development. 

Industrial process monitoring and their control is one of the fields of applications where laser chemistry seems to be without bounds. With the rapid progress of laser technology and the relatively low costs of mod-... 

GACP, GMP and GLP standards. During the industrial manufacturing of herbal medicinal products not only the raw material is subject to rigid quality control, but also the quality of the semi-manufactured and finished product is monitored (in-process controls) and evaluated (end controls on content, identity, purity). Finally a pharmaceutical dosage form should comply with the applicable pharmacopoeial standards (e.g., crush strength of tablets, disintegration time of tablets and capsules, uniformity of mass and content [11-13]). 

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