Flare gas recovering technique during producing polypropylene using interval liquid-phase substantial method

Abstract

The invention discloses a flare gas recovery process in the production process of polypropylene by an intermittent liquid-phase entity method. The flare gas is collected in a vent line (200); polypropylene particles are removed by a dust collector (15); and then the flare gas is input to a tail gas cabinet (14) for storage; after being compressed by a compressor (16) and condensed by a condenser (17), the tail gas enters a liquid storage tank (18); and non-condensable gas passes through a membrane separation system (13), the high-concentration propylene gas obtained by separation enters the tail gas cabinet (14); and extremely small amount of the lean propylene gas is discharged to a flare (20) by a flare gas vent buffer tank (19), thus actually reducing flare gas emission or even emitting no flare gas; when the content of the propylene at a primary membrane outlet is more than 30%, the flare gas enters a secondary membrane separation system, and a linkage program (100) is designed between a trip valve of a recovery buffer tank and the tail gas cabinet (14). The flare gas recovery process has the advantages of effectively recovering the propylene, environmental protection, saving resources and having positive popularization significance.

Description

technical field [0001] The invention relates to a flare gas recovery process, in particular to a flare gas recovery process in the intermittent liquid-phase bulk polypropylene production process. Background technique [0002] Flare gas is a combustible gas emitted by petrochemical enterprises during production and failure. Flare is a safety device for incinerating these gases. Flare gas contains a large amount of energy and useful components. Recycling flare gas is a major energy-saving and emission-reduction measure. Especially in the process of preparing polypropylene by the batch liquid phase bulk method, due to the characteristics of its own production process, the discharged flare gas contains a large amount of propylene. At this time, it is particularly important to adopt a comprehensive and safe flare recovery system. figure 1 It is a flow chart of the flare gas discharge process in the existing intermittent liquid-phase bulk process polypropylene production process....

AI Technical Summary

Problems solved by technology

In the actual operation process, the vented propylene gas from the safety valve, compressor and propylene pump cannot enter the tail gas recovery system, and most of it is discharged into the atmosphere or discharged into the torch 2 for incineration after the buffer tank 1 is emptied through the flare gas, which wastes raw materials. and pollute the air

Images