Development of a new method for measurement of the water dew/frost point of gas

The water content of gas is of importance in a wide variety of areas such as oil and gas, carbon capture and storage, medical, nuclear, food and hydrogen cells. In cases where pressurised gas is being used or transported in pipelines (i.e. natural gas, carbon dioxide, compressed air….) changes in temperature or pressure may result in water condensing. The condensed water may cause a number of issues such as corrosion, ice and hydrate formation. In order to avoid water condensing the gas needs to be dried to a level where condensation will not occur at any temperature/pressure conditions encountered. There are a wide variety of methods and equipment available for making water content measurements in laboratory or industrial processes. The available devices vary in terms of different parameters such as accuracy, long-term stability, sensitivity to contaminants, response time, pressure rating, initial and running costs. This paper introduces a new method that can potentially be incorporated into equipment for use in both laboratory and field applications for accurate dew/frost point measurements at a wide range of pressures. Initial measurements have been made for nitrogen, methane and natural gas and the results have been compared with literature data and model predictions.