We are proud to announce a new patent for our headspace sampling technology — the ultimate tool for analyzing opaque, complex liquids.
When we first started building analyzers, many customers asked if we could measure H2S in crude oil, frustrated with the unreliable products on the market. The fluid was far too dark and dirty to transmit the UV light pulse that our OMA analyzer used to measure chemical absorbance; we had a serious technical challenge on our hands.
The inspiration for the headspace design came from a very well-known unit operation in chemical engineering that had simply never been applied to measurement. Absorption/Desorption (A/D) is used widely in the chemical industry to separate entrained gases from liquids: most relevantly, oil refineries use A/D as a very stable process for removing H2S from incoming crude (our exact application on an industrial scale).
We built a vertical column that flowed crude oil against a counter current of nitrogen carrier gas, creating an equilibrium between phases and stripping out H2S molecules entrained in the oil. The resulting vapor exiting the column contained — thanks to Henry’s Law — an H2S concentration that could be reliably correlated with the H2S concentration in the oil pipeline.
The system worked beautifully, but we still had a long way to go. To ensure the column was breaking the oil and preventing any wax buildup, we redesigned the mass transfer media with Raschig rings that maximized liquid-gas contact. From working with an early customer who was measuring ammonia in filthy wastewater, we learned that the back-calculation from vapor phase concentration to liquid concentration was unnecessary: our verification readings provided an extremely stable linear correlation to the liquid analyte concentration which accounted for any hidden variables in the complex liquid.
Today, 20 years later, the headspace system is a perfect representation of our ethos at AAI: sound, creative engineering that evolves over decades of experimentation and customer experience. Our team is proud to be the legal owner of this invention, and the world’s sole provider of the headspace sampling technology.
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