If you work in the natural gas industry or are an industrial user of natural gas, water dewpoint is not only a quality measurement but also a big concern. Water condensate presents serious challenges and issues for your process. It is highly corrosive and will form hydrates, which are ice-like solid molecules that can block the flow of gas in pipelines. In cold weather, it will also freeze reducing the pipe pressure.
If you’re a user of moisture analyzers, you’ve probably experienced challenges in performing a quick, accurate measurement using a portable instrument. Portable moisture analyzers are typically used to verify the moisture reading of a fixed-installation instrument or to conduct spot-sampling measurements at remote sites which lack a permanently installed device. In my experience performing portable measurements, I’ve seen several common obstacles a user may encounter:
Measuring Water Vapor in Hydrocarbon Streams
Extracted from a variety of different sources, natural gas is composed of many different hydrocarbons and includes other, less desirable, impurities. These impurities – such as water, carbon dioxide, and hydrogen sulfide – are removed due to adverse effects, including:
- Reducing the heating value of the natural gas
- Damaging piping and other mechanical hardware due to freezing or corrosion
- Meeting tariff limits associated with transaction contracts
Trace moisture measurements in gas applications often appear to be simple and straight forward because the theory is relatively well understood; however, when the analyzer system is in service and we see unexpected measurement results, the head scratching begins.
Electrically everything appears to be correct so we assume the probe/sensor must be out of specification, right???
Topics: Moisture Measurement Solutions