A better way to analyse VOCs

Jon Lawson

Analytical Systems Keco has introduced the Model 204 Hydrocarbon VOC in Water analyser with an enhanced method of analytically quantifying total hydrocarbons and volatile organic compounds (VOCs) in cooling towers, heat exchangers, holding ponds, run-off water, and wastewater. Utilising an exclusive sample transfer stripper and solid-state sensor, the water analyser measures oil and VOCs directly in the water as opposed to the air around the water, a method that misses VOCs and results in non-alarm events. It also measures very low levels (parts per billion) to detect a small leak very early before becoming an environmental issue.  

The analyser provides a capability for environmental pollution control for wastewater treatment plants that must measure VOC contaminants to ensure water is properly treated before released, chemical/petrochemical plants that measure VOC directly in the water to ensure no hydrocarbon product leaked from pipes, and power plants for cooling towers and heat exchanger leak detection. 

In operation, liquid flows into the analyser and enters a heated Sample Transfer Stripper (ASI Membrane Technology) unit that effectively strips the volatile hydrocarbons from the oil in the water. The carrier air then sweeps the hydrocarbons to a advanced solid state sensor for quantitative analysis in ppb or ppm levels. The transmitter electronics quantify and display the values on a back-lit LCD and can provide outputs including a 4-20mA output loop and RS232/485 Modbus for remote and web-based monitoring and control.  

An optional ‘True’ Liquid Validation System by PermTube verifies proper operation of the entire analyser system, not just the sensor, with a flip of a switch or remote activation. This onboard functional validation option introduces hydrocarbons into the analyser flow path via a Permeation Tube.

This is more accurate in quantifying aliphatic and aromatic hydrocarbons in water (including carcinogenic compounds like benzene, toluene, and xylene) than UV Fluorescence methods that cannot measure aliphatic compounds and often provide false high readings and alarms by accidentally measuring debris and contamination. The Hydrocarbon VOC in Water analyser is both economically and operationally superior to inaccurate laboratory analysers where unstable grab samples result in oil deterioration that produces analytical errors.


 

 

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