Technology and system for recovering coked tailing gas using coal gas purifying system

Abstract

The invention relates to a technology and system for recovering coked tailing gas using a coal gas purifying system. The system comprises a coal gas purifying system, a first flow rate control device,a pressure control device, a defusing gas buffering tank, a second flow rate control device and an air inducing machine; a coal gas purifying pipeline at the downstream of the coal gas purifying system is connected with sealing gas inlets formed in the tops of all oil product storage tanks, defusing gas outlets formed in the tops of the oil product storage tanks are connected with a defusing gasinlet of the defusing gas buffering tank, the defusing gas outlet of the defusing gas buffering tank is connected with a coal gas absorbing pipeline located on the upstream of the coal gas purifying system, and a side coal gas pipeline is arranged between a defusing gas main pipe and a sealed coal gas pipeline. According to the system, nitrogen is replaced with coke oven coal gas of a coke-oven plant, the coke oven coal gas is adopted as a sealing gas source of the defusing system, the defusing gas is introduced into a negative pressure coal gas system in a controllable state, and an existingcoal gas purifying system is used for recovering the defusing gas in coking industry raw materials or product storage tanks.

Description

technical field [0001] The invention relates to the technical field of coking, in particular to a process and system for recovering coking tail gas by using a gas purification system, which is applicable to the method of introducing vented gas into a negative pressure gas system. Background technique [0002] At present, there are three methods for the treatment of asphalt flue gas in the coking industry: [0003] The first is the absorption method, which is to directly transport the diffused gas collected by the diffused gas main pipe to the jet mixer, and use the negative pressure generated by the circulating washing oil to pass through the nozzle of the jet mixer at high speed, suck the diffused gas into the jet mixer, and mix with it The washing oil is strongly mixed, so that most of the harmful substances are absorbed to achieve the purpose of washing. The gas-liquid mixture from the jet mixer is separated from the gas and liquid in the oil washing tank, and the gas is ...

AI Technical Summary

Problems solved by technology

[0004] The second is the absorption method plus incineration method, that is, on the basis of the absorption method, the exhaust gas from the exhaust cleaning tower is sent to the incinerator through the exhaust fan, and the remaining harmful substances are completely removed by combustion. However, this method cannot solve the problem of ultra-clean emissions of sulfur and nitrate, and cannot meet the ultra-clean emission standards

However, in the currently attempted process, in order to reduce the oxygen content of the vented gas, nitrogen seals are used; a large amount of nitrogen enters the negative pressure gas system, which not only consumes a lot of nitrogen, but also causes a great burden on the stable operation of the system, and has a negative impact on the gas quality. certain influence

At the same time, in order to save money and reduce the amount of nitrogen used, nitrogen is added only when the pressure is lower than the set value. Therefore, the pressure fluctuation of the venting gas system is extremely large, and the gap between the maximum and minimum nitrogen volume is huge, which brings a negative impact on the operation of the nitrogen production system. Difficulties come. Taking the scale of tar distillation with an annual output of 300,000 tons as an example, it is only used for product oil depot sealing, and the peak value of nitrogen flow is up to 3000Nm 3 / h, while the flow rate during normal operation may be less than 500Nm 3 / h, because the nitrogen cannot be replenished in time during the peak period, it often happens that a large amount of air enters the negative pressure gas system through the safety facilities, resulting in an increase in the oxygen content in the gas purification system, causing the entire gas purification system to shut down, affecting the recovery effect of the released gas and gas purification system safety

Therefore, the huge fluctuation of the total amount of released gas and the uncontrollable oxygen content are the biggest reasons why the process cannot be put into use at this stage

Of course, the huge consumption of nitrogen is also a huge burden that the factory cannot bear

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