Heat treatment reaction tail gas purification and recovery technology and system

Abstract

The invention relates to a heat treatment reaction tail gas purification and recovery technology and system. The heat treatment reaction tail gas purification and recovery technology comprises the following steps: tail gas is introduced through the bottom of a spray tower to be in counter-flow contact with a mixture of washing oil and liquid alkanes, so as to remove straight-chain alkanes and arenes; primarily purified tail gas is introduced through the lower part of a packed tower to be in counter-flow contact with an aqueous alkaline solution, so as to remove carbon dioxide, and remove oxygen from the packing material at the same time; purified gas is stored for cyclic utilization; the system comprises a tail gas storage tank which is communicated with the lower part of the inner cavity of the spray tower through a first gas delivery pipe; the upper part of the spray tower is communicated with a first liquid storage tank through a first liquid delivery pipe; first supercharging equipment is arranged on the first liquid delivery pipe; the upper end of the spray tower is communicated with the lower part of the packed tower through a second gas delivery pipe; the upper part of the packed tower is communicated with a second liquid storage tank through a second liquid delivery pipe; second supercharging equipment is arranged on the second liquid delivery pipe; the upper end of the packed tower is communicated with a purified gas storage tank through a third gas delivery pipe. With the adoption of the heat treatment reaction tail gas purification and recovery technology and system, tail gas can be purified, useful chemical raw materials in the tail gas can be recycled, gases after purification can be cyclically utilized, and mass gas transportation and storage can be reduced.

Description

technical field [0001] The invention relates to the technical field of tail gas recovery, in particular to a heat treatment reaction tail gas purification and recovery process and system in the heat treatment process used to prepare mesophase pitch. Background technique [0002] In the process of preparing mesophase pitch by heat treatment process, nitrogen or argon is used as an inert gas to protect the generated mesophase pitch from oxidation. In addition to the main components of nitrogen or argon in the heat treatment tail gas, there is also straight-chain alkanes, aromatics, a small amount of carbon dioxide and oxygen; the existing tail gas purification technology is direct incineration, that is, the tail gas is burned and discharged directly into the atmosphere through a chimney, which not only loses the useful chemical raw materials straight-chain alkanes and aromatics, but also Increased greenhouse gas carbon dioxide emissions, and wasted a lot of nitrogen, argon. ...

AI Technical Summary

Problems solved by technology

[0002] In the process of preparing mesophase pitch by heat treatment process, nitrogen or argon is used as an inert gas to protect the generated mesophase pitch from oxidation. In addition to the main components of nitrogen or argon in the heat treatment tail gas, there is also straight-chain alkanes, aromatics, a small amount of carbon dioxide and oxygen; the existing tail gas purification technology is direct incineration, that is, the tail gas is burned and discharged directly into the atmosphere through a chimney, which not only loses the useful chemical raw materials straight-chain alkanes and aromatics, but also Increased greenhouse gas carbon dioxide emissions, while wasting a lot of nitrogen, argon

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