How NIR process analyzers contribute to business value

Process analyzer technology can contribnte valne to the business in two basic ways by redncing risks and by reducing costs. 

Cost reductions usually arise out of improvements to the process control for both continuous and batch processes. Process analyzers enable chemical composition to be monitored essentially in real time. This in turn allows control of the process to be improved by shortening start-up and transition times (for continuous processes) or batch cycle times (for batch processes). This is accomplished by improving the ability to respond to process disturbances, by enabling process oscillations to be detected and corrected, and by reducing product variability. Real-time monitoring of chemical composition in a process allows a manufacturing plant to  

Occasionally attempts to justify a process analyzer are made on the basis that it will reduce the number of grab samples that need to be taken from the process to be analyzed, and therefore reduce the sample load on the QC lab. This is not usually a good justification for an on-line analyzer for two reasons (1) The reduction in lab analyses rarely offsets the cost of analyzer installation and operation (2) An on-line analyzer relies on high quality lab data for calibration, validation, and long-term model maintenance, so the reference method can never be eliminated entirely. 

A fictitious example illustrates the large potential value of even small improvements in the control of a manufacturing process. Suppose one has a continuous process in which the final product (a polymer) is sampled and analyzed to be sure the copolymer composition is within specifications. A sample is taken from the process once every 2 hours, and it takes about 2 hours for the lab to dissolve the polymer and measure its composition. This process produces a number of different copolymer compositions, and it transitions from one product to another about twice a month on average. The 2-hour wait for lab results means that during a transition the new product has been within specification limits for 2 hours before the operators receive lab confirmation and are able to send the product to the in-spec silo. Consequently, on every transition, 2-hours worth of in-spec polymers are sent to the off-spec silo. 

Note The costs of implementing this fictitious analyzer have not been included in the value calculation, though it is a critical aspect. The costs would include hardware, software, facility modifications, personnel time, travel, and ongoing maintenance costs (including the analyzer technician s time) over the expected analyzer lifetime. 

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