Effect of Rim Seal on Evaporation Loss from Khark Island Storage Tanks

Abstract

Evaporation loss is a natural process in which part of liquid is turning to vapor and vanishing into the atmosphere. Crude oil compound from the several hydrocarbons in which some of them evaporate and could be released into the atmosphere at ambient temperature and pressure. This process causes to pollute the environment and has effects on crude oil quality. Any reduction in the loss will also have financial benefit. This makes the phenomena, crude oil evaporation loss an important issue, which should be carefully investigated and effects of various parameters be studied. The aim of the present work is to determine the evaporation rates from external floating storage tanks and to study the effects of rim seal type on the losses. In this study, a numerical scheme has been developed for estimating the time variations of the storage tank temperature and evaporative losses. The scheme validated against the measured values of the storage tank temperature at different times during a day, where reasonable agreements observed. Furthermore, the numerical value of monthly averaged evaporation losses also have been compared with the estimations based on the API AP-42 standard. In this paper, seal type on the evaporation loss has bee n investigated and determined. Further evaporate loss from rim seals for the Khark Island storage tanks are compared. Nine types of the primary/secondary seal configurations have been studied. The results unveiled that one type of the primary/secondary seal configuration has advantages over the other configurations in preventing evaporative loss.