关键词: 有机液体, 储罐, 产气机理, VOCs, 排放量, 深度减排, 废气处理, 控制排放标准

Abstract: Petrochemical industry has the largest storage capacity of organic liquid in domestic. In addition to the gas emission by working and standing loss, the organic liquid storage tank also has the phenomenon of gas emission by thermal cracking during the storage of high temperature heavy oil. There are two main problems in the existing domestic and foreign standards: ①The concentration of VOCs allowed to be discharged from storage tanks is high; ②The differences of emission reduction requirements are dramatic when applying floating roof tank or fixed roof tank+tank top exhaust treatment device. In 2019, VOCs emissions from organic liquid storage sources in domestic were 392~904 kilotons, mainly in the petrochemical industry. To improve our ambient air quality and reduce VOCs emission, deep emission reduction of storage tanks is the key. The criterion of “VOCs deep emission reduction for storage tanks” is proposed. Changing the fixed roof tank for storing diesel into the inner floating roof tank can be considered as deep emission reduction, and adding tank top gas treatment to the current fixed roof tank and floating roof tank can be considered as deep emission reduction. The Tg series storage tank waste gas treatment technology developed by FRIPP with “from low temperature diesel absorption to desulfurization and total hydrocarbon homogenization, then to regenerative oxidation or catalytic oxidation or thermal incinerator” as the core is introduced with examples of application, as well as the VOCs emission reduction technology with built in air bag in inner floating roof tank developed in recent years. Suggestions on VOCs deep emission reduction standards for storage tanks are put forward.

Key words: organic liquid, storage tank, gas production mechanism, VOCs emissions, deep emission reduction, waste gas treatment, emission control standard