Solar radiation effects on evaporative losses of floating roof storage tanks

There are 40 storage tanks in the Khark Island for storing crude oil. Considering the hot summers of the island, light hydrocarbons vaporise and vented to the atmosphere. This process causes environmental pollution and also affects the quality of the crude oil besides the economic detriment. Therefore, crude oil evaporation loss associated with the storage tank is an important issue which should be carefully investigated to identify the potential means of its reduction. The aim of the present work is to determine the evaporative losses from external floating storage tanks and to study the absorptivity effects of their exterior surface paint on the losses due to the solar irradiation. The API standards along with the thermal analysis of the tank have been employed to evaluate the tank temperature variations and the evaporative losses of a typical tank based on the actual ambient conditions of the Khark Island. The results show that the paints with low absorptivity can reduce the evaporative losses significantly. Furthermore, experimental data has been provided to validate the calculated tank temperature variations, and reasonable agreements have been found.