Predicting the true vapor pressure of LPG and natural gasoline

Liquefied petroleum gas (LPG) and natural gasoline are stored between production and shipping operations in storage tanks that usually have a floating roof (external and internal). If the LPG and natural gas products do not meet specifications, the non-specification products may be routed to off-specification storage in a fixed-roof tank (vertical and horizontal) until those are recycled to the stabilization unit by the relevant recycle pump, if the latter is available at the plant. The primary quality criterion for the product is its Reid vapor pressure (Rvp), which is affected by atmospheric pressure (plant elevation) and maximum ambient temperature. To store the products in floating-roof storage tanks, it is very crucial to control the Rvp at the desired level, especially in warm seasons.¹