Researchers at the National Institute of Standards and Technology (NIST) and Colorado School of Mines (CSM) have developed a prototype system that quickly detects very small amounts of hydrogen accumulated in coated pipeline steel.
The system could provide early warning of pipes that have accumulated excessive amounts of hydrogen – a notorious source of embrittlement – and avert potentially disastrous failures of pipelines carrying hydrogen fuel.
Hydrogen is attractive as a fuel because it burns cleanly without carbon emissions and can be derived from domestic sources. However, one challenge is that hydrogen can cause gradual embrittlement in conventional pipelines by slowly diffusing into the metal.
Building on the fact that a pipe’s impedance increases with increasing hydrogen content, the system sends a current through the pipe and measures any changes in its impedance. The data is then used to provide an indication of the hydrogen content within the steel and the overall steel pipe integrity.
The measurement sensitivity of the sensor in the system is exceptional: the sensor can measure hydrogen content levels in pipeline steel well below 1 part per million (ppm). This is very useful as high-strength pipeline steels can tolerate only a few parts per million of hydrogen before significant problems arise.
By contrast, conventional analytical techniques do not have sensitivity or accuracy below 1ppm.