Recovery method for waste gas of refinery plant sewage tank

Abstract

The invention relates to a recovery method for waste gas of a refinery plant sewage tank, which is used for sewage disposal of refiner plant sewage tanks. The invention discloses (1) a construction procedure of a recovery device for waste gas of a refinery plant sewage tank; and (2) normal operation (all indexes are set according to DCS); segmental automatic control on pressure at the top of the tank (all indexes are set according to DCS); and an instrument control scheme. According to the invention, after top and tail gas of an atmospheric storage tank are pressurized, the top and tail gas is introduced to a low pressure gas flare system of a refinery plant, enters a sewage tank due to self pressure to adjust pressure, and is pressurized together with a condensate separated from a gas-liquid separation tank in a pressurizing water pump, so as to be used as the power source of an injection pressurizer, thus replacing the functions of a steam power source, achieving the purpose of zero emission, solving the difficulties of the atmospheric storage tank that operation pressure is low and operation elasticity is small, and being safe and reliable in operation, less in one-time investment and low operation cost.

Description

technical field [0001] The invention relates to a method for zero discharge of waste gas from sewage tanks in refineries. 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 generally adopted, resulting in the release of high concentrations of hydrocarbons, benzene series, hydrogen su...

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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