In the last tip of the month (TOTM) we described the dense phase of a pure compound and how it impacted processes. We illustrated how thermophysical properties change in the dense phase as well as in the neighboring phases. The application of dense phase in the oil and gas industry was discussed briefly. In this TOTM, we will discuss the dense phase behavior of multi-component systems, like natural gases.

When a natural gas, is compressed above the cricondenbar in the region between critical temperature and cricondentherm, it becomes a dense, highly compressible fluid that demonstrates properties of both liquid and gas. For simplicity and convenience, we define the dense phase to be within critical temperature and cricondentherm if the pressure is above the cricondenbar. In practice, there is no clear line (i.e. critical temperature) dividing dense phase from liquid phase or other single line (i.e. cricondentherm) dividing the dense phase from the gas phase.

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