Impurities in Polymer Grade Propylene
Purity in the production of polyethylene and polypropylene affects the highly sensitive and costly polymerization catalysts that are fundamental to the production process.
Precise measurement of low level impurities in the production stream can increase the yield and extend the life expectancy of these expensive catalysts. Additionally, producers will be amazed by how fast and cost-effective the analysis is.
The state-of-the-art inductively coupled plasma-mass spectrometer (ICP-MS) (when used as a gas chromatographic detector) enables detection limits at single digit part-per-billion levels for sulfur and phosphorus compounds, and detection of many other species at part-per-trillion levels. This sensitivity enables determination of product quality with a confidence level heretofore not obtainable. Furthermore, unlike other detectors, there is virtually no interference from the hydrocarbon matrix.
CONSCI's detection limits (DLs) of propylene impurities are significantly lower than the typical maximum amount allowed by the polymerization catalyst.
Impurity | Typical Max Allowed | Our Detection Limit | Technique |
---|---|---|---|
Arsine | 20 ppb | 0.05 ppb | GC-ICP-MS |
Carbon dioxide | 3 ppm | 0.1 ppm | GC-PDD |
Carbon monoxide | 1 ppm | 0.1 ppm | GC-PDD |
Carbonyl sulfide | 1 ppm | 5.0 ppb | GC-ICP-MS |
Hydrocarbon contaminants | 30 ppm | 0.1 ppb | GC-FID |
Hydrogen | 30 ppm | 0.1 ppb | GC-FID |
Hydrogen sulfide | 1 ppm | 5.0 ppb | GC-ICP-MS |
Oxygen | 5 ppm | 0.1 ppm | GC-PDD |
Phosphine | 20 ppb | 0.2 ppb | GC-ICP-MS |
Water vapor | 5 ppm | 0.1 ppm | Quartz Microbalance |
Every producer should require detection limits of single digit ppb levels for sulfur and phosphorus compounds and detection of many other species at part per trillion concentrations to determine product quality with a confidence level heretofore unobtainable.