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CN-121988136-A - Recovery method and recovery system for tail gas containing butadiene and application of recovery method and recovery system in tail gas treatment of polybutadiene device

CN121988136ACN 121988136 ACN121988136 ACN 121988136ACN-121988136-A

Abstract

The invention discloses a recovery method and a recovery system of tail gas containing butadiene and application of the recovery method and the recovery system in tail gas treatment of a polybutadiene device. The recovery method comprises the steps of (1) sending tail gas into an absorption tower, absorbing butadiene in the tail gas by utilizing an organic absorbent in the absorption tower, obtaining butadiene absorption liquid and residual tail gas after absorption, (2) detecting butadiene content in the residual tail gas, discharging outwards if the butadiene content reaches the standard, (3) stopping the steps (1) and (2) if the butadiene content does not reach the standard, sequentially carrying out pre-regeneration treatment and regeneration treatment on the butadiene absorption liquid in the absorption tower, wherein the sucked butadiene is understood to be used for replacing protective gas in the absorption tower by a pre-regeneration position, and the sucked butadiene is understood to be recycled by a regeneration position, wherein the organic absorbent after the regeneration treatment is reused in the step (1). The invention realizes the cyclic operation of absorption and desorption of butadiene in one absorption tower, does not need higher temperature and pressure, and reduces the running cost of equipment. Therefore, the recovery system of the butadiene-containing tail gas has the advantages of simple structure, low operation cost and simple and convenient maintenance.

Inventors

  • LI RENJIE
  • SUN XIAOXUE
  • WANG DEJU
  • ZHAO SHEN
  • ZUO YU

Assignees

  • 中石化（上海）石油化工研究院有限公司
  • 中国石油化工股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (11)

  1. 1. A recovery method of butadiene-containing tail gas comprises the following steps: (1) The tail gas comprises butadiene and protective gas, the tail gas is sent into an absorption tower, and the organic absorbent in the absorption tower is utilized to absorb the butadiene in the tail gas, so as to obtain butadiene absorption liquid and residual tail gas after absorption; (2) Detecting the butadiene content in the residual tail gas after absorption, and if the butadiene content reaches the standard, optionally further absorbing by a porous material and discharging the residual tail gas outwards; (3) And (3) stopping the step (1) and the step (2) if the content of butadiene does not reach the standard, and sequentially carrying out pre-regeneration treatment and regeneration treatment of desorbing butadiene on the butadiene absorption liquid in the absorption tower, wherein the pre-regeneration site is used for understanding that the sucked butadiene is used for partially or completely replacing protective gas in the absorption tower, the regeneration site is used for understanding that the sucked butadiene is recycled, and the organic absorbent after the regeneration treatment is reused in the step (1).
  2. 2. The method for recovering butadiene-containing tail gas according to claim 1, wherein: Step (1), The mass fraction of butadiene in the tail gas is 1-30%, preferably 1-15%, and/or, The organic absorbent is selected from at least one of C 7 -C 8 alkane, and/or, The volume ratio of the organic absorbent to the tail gas is 1:20-1:40, preferably 1:30-1:35, and/or, The volume airspeed of the tail gas is 15-25 h -1 , preferably 18-22 h -1 .
  3. 3. The method for recovering butadiene-containing tail gas according to claim 2, wherein: The shielding gas is selected from nitrogen, and/or, The organic absorbent is selected from at least one of n-heptane, n-octane or isooctane, and/or, The tail gas is selected from the tail gases in polybutadiene units.
  4. 4. The method for recovering butadiene-containing tail gas according to claim 1, wherein: Step (1), The absorption tower is a filler absorption tower; Preferably, the method comprises the steps of, The absolute pressure of the packed absorber is 100 to 120kpa, preferably 110 to 120kpa, and/or, The temperature of the packed absorber is 10-20 ℃, preferably 10-15 ℃, and/or, The filler in the filler absorption tower is at least one of glass beads, pall rings, saddle rings, isopycnic rings, ladder rings, sea rings, conjugated rings, flat rings or garter fillers, and/or, The diameter of the filler in the filler absorption tower is 1-5 mm, preferably 1-3 mm.
  5. 5. The method for recovering butadiene-containing tail gas according to claim 1, wherein: Step (2), The standard of the butadiene content in the residual tail gas after absorption is that the butadiene content in the residual tail gas after absorption is less than or equal to 1mg/m 3 , preferably the butadiene content in the residual tail gas after absorption is less than or equal to 0.5mg/m 3 , and/or, The porous material comprises an activated carbon adsorbent, preferably, the specific surface area of the activated carbon adsorbent is 500-1000 m 2 /g, preferably 800-1000 m 2 /g.
  6. 6. The method for recovering butadiene-containing tail gas according to claim 1, wherein: step (3), The desorption temperature in the pre-regeneration treatment is less than or equal to the desorption temperature in the regeneration treatment, preferably the desorption temperature in the pre-regeneration treatment is 30-40 ℃, preferably 35-40 ℃, and/or, The absolute desorption pressure of the pre-regeneration treatment is 100-120 kPa, preferably 100-110 kPa, and/or, The pre-regeneration treatment is stopped until the concentration of butadiene in the gas extracted from the absorption tower meets the raw material standard for preparing polybutadiene by polymerizing butadiene, and/or, In the pre-regeneration treatment, the gas extracted from the absorption tower is taken as intermediate gas to be sent into the absorption tower for further absorption treatment.
  7. 7. The method for recovering butadiene-containing tail gas according to claim 1, wherein: step (3), The absolute pressure of desorption of the regeneration treatment is 100-120 KPa, preferably 100-110 kPa, and/or, The desorption temperature of the regeneration treatment is 40-50 ℃, preferably 45-50 ℃, and/or, In the regeneration treatment, the concentration of butadiene in the gas extracted from the absorption tower is more than or equal to 99.6wt%.
  8. 8. A recovery system for butadiene-containing tail gas, comprising: a tail gas inlet line, a butadiene absorption tower, a butadiene content detection unit, an optional intermediate gas collection storage tank, a butadiene collection storage tank, an optional porous material adsorption storage tank; The gas outlet of the butadiene absorption tower is connected with the feed inlet of the butadiene content detection unit, and then is respectively connected with the feed inlet of the intermediate gas collection storage tank, the feed inlet of the butadiene collection storage tank and the feed inlet of the optional porous material adsorption storage tank, and then is connected with the tail gas emptying pipeline; preferably the method for recovering butadiene-containing tail gas as claimed in any one of claims 1 to 7 employs said system.
  9. 9. The butadiene-containing tail gas recovery system of claim 8, wherein: the butadiene absorption tower is also provided with a heat exchange inlet pipeline and a heat exchange outlet pipeline, and/or, The butadiene absorption tower is a filler absorption tower and/or, The butadiene content detection unit is a butadiene gas online analysis pipeline.
  10. 10. The butadiene-containing tail gas recovery system of claim 8, wherein: When an intermediate gas collection tank is included, the discharge port of the intermediate gas collection tank is connected to the tail gas inlet line, and/or, And a discharge port of the butadiene collection storage tank is provided with a butadiene collection pipeline.
  11. 11. Use of the butadiene-containing tail gas recovery method according to any one of claims 1-7 or the butadiene-containing tail gas recovery system according to any one of claims 8-10 in the treatment of polybutadiene plant tail gas.

Description

Recovery method and recovery system for tail gas containing butadiene and application of recovery method and recovery system in tail gas treatment of polybutadiene device Technical Field The invention relates to the technical field of butadiene rubber production, in particular to a recovery method and a recovery system of tail gas containing butadiene and application of the recovery method and the recovery system in tail gas treatment of a polybutadiene device. Background In the production process of polybutadiene rubber, organic waste gas containing butadiene is inevitably generated, and the tail gas of polybutadiene production equipment of a certain enterprise is taken as an example, and consists of butadiene gas accounting for 30% by mass and nitrogen accounting for 70% by mass. Since butadiene tail gas is pollution to environment and inflammable and explosive, the butadiene tail gas must be treated before being discharged. The existing method for treating butadiene tail gas mainly comprises two steps, namely, introducing the tail gas into a torch for burning and then discharging, condensing butadiene into liquid in a pressurizing and cooling mode, and finally, realizing gas-liquid separation. Along with the continuous improvement of domestic environmental protection requirements, the method for treating butadiene tail gas through torch burning is gradually forbidden, and meanwhile, the method is also waste of butadiene resources in the tail gas. The patent CN104307301A, CN110963878A and the patent CN203954988U both adopt a compression condensation mode to recycle the butadiene tail gas, the butadiene recovery rate is higher, but the device construction cost and the operation running cost of a condensation and compression system in the method are high, the method is more suitable for the treatment process of large-batch tail gas, the construction cost of the device is difficult to recycle in the treatment process of small-batch butadiene tail gas, and the construction will of manufacturers is insufficient. The existing butadiene tail gas absorbing device is mainly treated by a kerosene absorbing tower, and has the concrete structure that butadiene tail gas firstly passes through a water-cooling heat exchanger, a liquid phase enters a butadiene recovery storage tank, a gas phase enters the kerosene absorbing tower, the gas phase enters the kerosene absorbing tower and is required to be measured by an online oxygen content analyzer to be lower than oxygen content, once the oxygen content exceeds the regulation, nitrogen is filled to reduce the concentration of oxygen, kerosene sprayed from the top of the kerosene absorbing tower contacts with gas to absorb butadiene in the gas, the gas discharged from the top enters an absorbing tower separator, the separated liquid phase (entrained kerosene) returns to the top of the kerosene absorbing tower, and the gas is discharged from the top of the absorbing tower separator, detected by the online oxygen content analyzer and discharged into the atmosphere. After the butadiene is absorbed by kerosene, the butadiene is discharged from the bottom of the kerosene absorption tower, heated by heater steam, and sent into a butadiene flash separator for flash evaporation to obtain butadiene gas. The kerosene which flashes out butadiene is discharged from the bottom of the butadiene flash separator and is sent into a cooler to be cooled by a solvent circulating pump, and the cooled kerosene is returned to the kerosene absorption tower for recycling. The whole device has a complex structure, is difficult to clean, uses kerosene as a solvent, has large kerosene consumption and large kerosene consumption, has large influence on the environment, uses about 20-30 tons of kerosene each year, calculates about 15 ten thousand yuan of kerosene funds each year according to 6000 yuan of market price, has high treatment cost, and has high energy consumption. In order to purify butadiene tail gas at lower cost, development of a more economic and effective butadiene tail gas recovery treatment method is required, and meanwhile, discharged tail gas is ensured to meet the national environmental protection standard. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a recovery method and a recovery system for tail gas containing butadiene and application of the recovery method and the recovery system in tail gas treatment of a polybutadiene device. The invention provides a butadiene tail gas recovery system with simple structure, low operation cost and convenient maintenance and a recovery method thereof, and solves the problems of complex structure, high treatment cost and high operation energy consumption of the existing butadiene tail gas recovery system. The invention aims at providing a recovery method of butadiene-containing tail gas, which comprises the following steps of: (1) The tail gas comprises butadiene and protective gas, the tail ga