Sealed recovery and operation pressure stabilizing control method for tank top tail gas of refinery enterprise atmospheric storage tank

Abstract

The invention relates to a sealed recovery and operation pressure stabilizing control method for tank top tail gas of a refinery enterprise atmospheric storage tank. The sealed recovery and operation pressure stabilizing control method for the tank top tail gas of the refinery enterprise atmospheric storage tank is suitable for production requirements of a refinery enterprise and comprises the steps that the tank top tail gas in a steam jet compressor is subjected to gas-steam on-line supercharging and then conveyed to a cooler to be cooled to 45 DEG C; after the tank top tail gas is subjected to gas-liquid separation, non-condensable gas enters a refinery low-pressure gas flare system, and condensate liquid reflows to a sewage storage tank through self pressure. Normal operation of the sealed recovery and operation pressure stabilizing control method is controlled in a segmented mode, when the tank top pressure is 0-0.3 kPa, a nitrogen adjusting valve is opened, and a steam adjusting valve is closed; when the tank top pressure is 0.3-0.5 kPa, the nitrogen adjusting valve is closed, and the steam adjusting valve is closed; when the tank top pressure is 0.5-1.5 kPa, the nitrogen adjusting valve is closed, and the steam adjusting valve is opened; and when the tank top pressure is greater than or equal to 1.5 kPa, a control brake valve is opened. According to the sealed recovery and operation pressure stabilizing control method for the tank top tail gas of the refinery enterprise atmospheric storage tank, the tank top tail gas of the atmospheric storage tank is led into the refinery low-pressure gas flare system after being supercharged, the zero emission purpose is achieved, and the problem that the atmospheric storage tank is low in operation pressure is solved.

Description

technical field [0001] The invention relates to a method for recovering the tail gas at the top of a normal-pressure storage tank in a refining and chemical enterprise and for controlling the operation and stabilizing the pressure. Background technique [0002] Atmospheric storage tanks in refining and chemical enterprises mainly include acid water tanks, oil product tanks, alkali slag tanks, and coking cold coke water tanks. According to the "Code for Design of Vertical Cylindrical Welded Oil Tanks" (GB50341-2003), the design pressure of fixed-roof oil tanks should be normal pressure or close to normal pressure (negative pressure should not be less than 0.49kPa). A Relevant regulations, the maximum pressure is 6.0kPa, the general operating pressure range is -0.49~2.0kPa, and the operating flexibility is small. In order to avoid damage to the tank due to excessive positive pressure or excessive negative pressure during use, the design of direct access to the atmosphere is g...

AI Technical Summary

Problems solved by technology

In order to avoid damage to the tank due to excessive positive pressure or excessive negative pressure during use, the design of direct access to the atmosphere is generally adopted, resulting in the release of high concentrations of hydrocarbons, benzene series, hydrogen sulfide, and phenols during storage. Harmful gases such as mercaptans and mercaptans are difficult to seal and recover, and become the main source of processing loss in refining and chemical enterprises and the pollution source of excessive discharge of volatile organic compounds (VOC). Environmental pollution caused by emissions

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