K-Patents has released a new application note on liquid hydrocarbon identification in transportation operation. Chemical plants and refineries receive or deliver many different liquid hydrocarbons, including NGLs which are transported via pipeline, railcar, tanker trucks and/or ship. Many of these products are very similar in properties and appearance, therefore, proper identification or interface detection of these hydrocarbons at transport locations that handle multiple products is important to ensure good quality assurance.
Refractive index can be a reliable method for identifying liquid hydrocarbon products since each hydrocarbon has a different and distinct refractive index. This refractive index is a property inherent to the hydrocarbon, and can be used to "fingerprint" the product for identification.
Two typical products that require proper interface detection are n-butane and isobutane. These are the two structural isomers of butane meaning they have the same molecular formula but different arrangement of the chemical structural. Since they are isomers, the chemical properties of these products are very similar, inparticular, the density. However, the difference in refractive index is wide enough to accurately and reliably distinguish between these two products. K-Patents can provide an accurate and repeatable refractive index measurement to +/-0.0002.
K-Patent Process refractometer is typically installed in main supply line and the inlet of the product storage. This provides adequate timing for interface detection and double assurance of the hydrocarbon product being delivered to the desired storage.
Ref. 8.01.05 Liquid Hydrocarbon Identification (pdf)