Device and method for recycling low-concentration multicomponent low-pressure refined tail gas

Abstract

The invention discloses a device for recycling low-concentration multicomponent low-pressure refined tail gas. The device comprises a fan, a first vacuum pump, a second vacuum pump and an adsorption device, wherein the adsorption device comprises a first-stage adsorption device and a second-stage adsorption device, the fan is connected with the first-stage adsorption device, a first program-controlled valve is also arranged at the outlet end of the first-stage adsorption device, and the first-stage adsorption device is connected with the second-stage adsorption device; the outlet end of the second-stage adsorption device is connected with the inlet end of the first-stage adsorption device, a second program-controlled valve is arranged between the outlet end of the second-stage adsorption device and the inlet end of the first-stage adsorption device, the second-stage adsorption device is connected to a main body device, and a third program-controlled valve is arranged between the second-stage adsorption device and the second vacuum pump. The invention further discloses a method for recycling the low-concentration multicomponent low-pressure refined tail gas. The device is simple in structure, treated purified gas can return a system or reach a discharging standard, and recovered hydrocarbon components can be reused as chemical raw materials, so that pollution on atmosphere is reduced, the cost is reduced, and resources are saved.

Description

technical field [0001] The invention relates to a tail gas recovery device, in particular to a device and method for recovering low-concentration, multi-component, low-pressure refinery tail gas, and belongs to the technical field of gas recovery and treatment. Background technique [0002] A large amount of low-concentration hydrocarbon (CxHy) tail gas will be produced in the production process of the refining and chemical industry. The hydrocarbon components mainly include ethylene, propylene, etc., and the balance gas is nitrogen. The current conventional treatment method for this type of tail gas is to burn it into the torch, or discharge it to the atmosphere after simple adsorption treatment, and its hydrocarbon concentration is far below the requirements of the emission standard. Strong odor, irritating and toxic, and easy to form organic fine particles in the atmosphere, is the precursor of PM2.5, one of the causes of smog. [0003] For a long time, the focus of wast...

AI Technical Summary

Problems solved by technology

At present, domestic enterprises engaged in organic waste gas treatment mostly adopt a high-pressure adsorption treatment process using activated carbon as an adsorbent for tail gas recovery. The actual operation results show that the regeneration efficiency of the adsorbent is low, and the recovery efficiency of hydrocarbon components is low and the concentration is low. It is difficult to reuse , the concentration of non-methane total hydrocarbons in the exhaust gas is difficult to meet the requirements of environmental protection standards

In foreign countries, the recovery process of compression condensation + pressure swing adsorption is mainly used to first compress the exhaust gas, then pass through multi-stage condensation, and finally recover through pressure swing adsorption, which can almost reach 100% recovery efficiency.

However, this process has its limitations, mainly the following disadvantages: firstly, the compression system and low-temperature condensation system have high investment and high power consumption, and the operation cost of the whole set of equipment is relatively high; secondly, the dust in the treatment gas will seriously affect the compressor and the entire system. System security and stability

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