Application Brief: Detecting the Interface Between Sequential Compounds in a Pipeline

When you move different chemicals in sequence through a single pipeline, you often need to detect the interface — the transition point between one chemical product and the next.

For example, when crossing over between batches of diesel, you will need to divert the stream for reprocessing to a holding tank. The amount that will be sent for reprocessing should be minimized to meet product specifications. Reliable interface detection is critical to maintain efficiency and product quality.

The OMA instantly detects the interface by watching for change in the aromatic optical fingerprint of the product flowing through the pipeline. Using high-resolution UV spectrophotometry, the OMA measures the absorbance of aromatic hydrocarbons present in the chemical product.

Any change in the aromatic fingerprint is an instant indicator that the interface has arrived. There’s no need for chemical tracers or artificial coloring to identify batches — the OMA monitors change directly in the composition of the pipeline fluid.

Another important application is dye interface in a pipeline: in many countries, fuel products legally must be dyed to distinguish between taxed use and non-taxed use. In the US, for example, heating oil (non-taxed) is dyed red to deter people from using it as jet fuel (taxed), even though they are essentially the same chemical product.

The OMA can be easily implemented to monitor dye interface in a pipeline. When color changes between product batches, the OMA instantly recognizes and confirms a change in the UV-Vis absorbance spectrum directly in the pipeline. This enables operators to automate their adherence to local tax laws while reducing the labor/efficiency costs of these regulations.

Documents:

AN-021: Monitoring Interface Between Compounds in a Pipeline

AN-007: Measuring Aromatic Hydrocarbons (BTX)

DS-001A: OMA-300 Process Analyzer