Remote sensing technology - a novel solution in safe refinery process control - Presented by Modcon at PEFTEC 2015

Cost efficient refinery operation requires continuous control of quality parameters, which is essential to ensure in-spec products with minimum giveaways throughout the entire production process. A broad range of different physical properties classifies refinery products. Therefore, it is a common practice in refineries not to rely on the measurement of one single physical property to determine the product quality, but on analytical data of a number of different physical properties. Each of them must conform its specification.

Flammable and explosion hazardous environments are characteristic for refineries, blending stations, tankfarms and petrochemical plants. Installation of multiple analyzer systems in an unsafe area, the Ex zone, involves additional investment in costly ATEX approved enclosures or analyzer houses. In addition to that, maintenance of multiple analyzer systems is expensive and danger to personal of being exposed to hazardous materials is not always unavoidable.

Refineries and petrochemical plants are spread out over large territories. Inside process units, the complex construction of distillation towers or reactors makes access to different process streams often being complicated. 

The unique Remote Sensor Technology provides a solution to quantify remotely multiple-property chemical and physical properties in refinery processes, without any need to place the analyzer in an Ex Zone.

The technology allows multiple analyses of physical properties measured at a distance of up to 3 km (2miles) away from the analyzer. This achieved by utilizing NIR spectrometry, where the analyzer is connected by economic standard optical communication fibers to its measuring probes (Field Units). These measuring probes are intrinsically safe, as they do not contain any electrical or moving parts. 

Up to eight different measuring probes, field units, can be connected to each analyzer, and are sequentially, almost simultaneous, measured. 

This concept allows the analyzer to be placed in a safe area, such as a control room, while the measuring probes, are installed at different locations in the Ex Zone of a process unit. 

NIR spectrometry is a correlative method which is based on the correlation between NIR spectral measurements, and quantified values of various physical properties. Accurate analyses require analytical measurements to continuously be validated against laboratory measurements, performed according to official ASTM methods. To maintain full credibility and compliance of the NIR measured analytical properties incorporated Freetune software performs automatically corrective actions, in case of continuous discrepancies between analyzer and laboratory results. 

Centralization of the real time on-online analytical data, measured at different locations, in the control room provides an excellent tool to the operators to optimize process conditions that will lead to a most cost effective refinery operation.

The remote NIR sensing analyzer is characterization as a low OPEX technology for on-line analysis of petroleum products. Optimized process conditions, based on real time analytical data, lead to maximum capacity of in-spec products, without giveaways and at lowest cost. The requirement of only one analyzer for different measurements, and the absence of moving parts results in minor cost of maintenance.

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