Breathing losses from fixed-roof tanks by heat and mass transfer diffusion

Abstract

A simultaneous heat and mass transfer diffusion model was developed that predicts volatile breathing losses at terminal state for isobaric fixed-roof tanks experiencing a sinusoid temperature perturbation on the top dome. Typically thermal penetration into the stagnant gas phase appears to be limited to 2-3 m for a 24thermal cycle. The predicted breathing emissions compared closely with the emission data from the 1977 WOGA tests of industrial tanks. The diffusion model may be extremely beneficial in the prediction of hydrocarbon losses fro fixed-roof storage tanks.