Carbon fiber waste gas treatment device and process combining multi-stage condensation and ultra-micro nano bubble ozonation

Abstract

The invention discloses a carbon fiber waste gas treatment device and process combining multi-stage condensation with ultramicro nano bubble ozonation. The carbon fiber waste gas treatment device comprises a first-stage condenser, a second-stage condenser, a third-stage condenser, a primary oxidation tower, a micro-nano bubble oxidation tower and a water washing tower which are sequentially connected through pipelines, waste gas sequentially passes through the first-stage condenser, the second-stage condenser and the third-stage condenser, dimethyl sulfoxide and part of acrylonitrile are condensed and recycled, and then the waste gas passes through the second-stage condenser and the third-stage condenser. Then, the wastewater enters a primary oxidation tower to be subjected to primary oxidation, then is subjected to deep oxidation treatment in a micro-nano bubble oxidation tower, finally enters a water washing tower, and is discharged after residual ozone is digested. The process is safe and environment-friendly, and the treatment efficiency of non-methane hydrocarbon in the carbon fiber waste gas can reach 98% or above.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon fiber waste gas treatment, and relates to a multi-stage condensation combined ultra-micro-nano bubble ozone oxidation carbon fiber waste gas treatment device and process. BACKGROUND

[0002] With the increasing demand for high-performance materials worldwide, carbon fiber, as a lightweight, high-strength advanced composite material, has been widely used in aerospace, automobiles, sports equipment and other fields. Carbon fiber wastewater mainly comes from the production process of carbon fiber, such as polyacrylonitrile (PAN) based carbon fiber, which needs to use a large amount of organic solvents and acid and alkali chemicals in the preparation process. Among them, acrylonitrile monomer, dimethyl sulfoxide and its decomposition products, etc. Organic matter will volatilize into waste gas, making waste gas treatment more difficult. The traditional carbon fiber waste gas treatment technology is spray oxidation, which has low treatment efficiency and unstable effect. SUMMARY

[0003] The purpose of the present application is to provide a multi-stage condensation combined ultra-micro-nano bubble ozone oxidation carbon fiber waste gas treatment device and process. The process combines multi-stage condensation with ultra-micro-nano bubble ozone oxidation, which can efficiently treat high non-methane total hydrocarbon carbon fiber waste gas and make it meet the emission standard.

[0004] The technical solution to achieve the purpose of the present application is as follows:

[0005] The multi-stage condensation combined ultra-micro-nano bubble ozone oxidation carbon fiber waste gas treatment device comprises a first condenser, a second condenser, a third condenser, a primary oxidation tower, a micro-nano bubble oxidation tower and a water washing tower connected in sequence through pipelines. The cavity of the micro-nano bubble oxidation tower is in communication with an ozone ultra-micro-nano bubble generator. The primary oxidation tower contains sodium hypochlorite solution. The micro-nano bubble oxidation tower contains absorption liquid.

[0006] Further, the sodium hypochlorite solution is industrial grade, and the effective chlorine content is ≥10%.

[0007] Further, the absorption liquid in the micro-nano bubble oxidation tower is an aqueous solution rich in ozone ultra-micro-nano bubbles.

[0008] Further, the condenser is a shell-and-tube condenser.

[0009] The multi-stage condensation combined with ultra-micro-nano bubble ozone oxidation carbon fiber waste gas treatment process uses the device, and comprises the following steps: the carbon fiber waste gas to be treated is sequentially passed through a first condenser, a second condenser, and a third condenser, and dimethyl sulfoxide and part of acrylonitrile in the waste gas are recovered by condensation; the waste gas with a certain non-methane total hydrocarbon concentration from the waste gas outlet of the third condenser is sent to a primary oxidation tower, and sodium hypochlorite solution is used for primary oxidation treatment; the waste gas from the outlet of the primary oxidation tower is sent to a micro-nano bubble oxidation tower, the cavity of the micro-nano bubble oxidation tower is communicated with an ozone ultra-micro-nano bubble generator, the ozone ultra-micro-nano bubble generator inhales ozone after being turned on, simultaneously inhales the absorption liquid from the micro-nano bubble oxidation tower, generates a micro-nano bubble gas-liquid dispersion system in the micro-nano bubble oxidation tower, and sprays the micro-nano bubble gas-liquid dispersion system into the micro-nano bubble oxidation tower to form a circulating operation state, the micro-nano bubble gas-liquid dispersion system can improve the solubility of ozone in the absorption liquid, and release hydroxyl radicals with high oxidation capacity in the absorption liquid, so as to perform deep oxidation treatment on the waste gas; and the waste gas from the outlet of the micro-nano bubble oxidation tower is sent into a water washing tower, and residual ozone is decomposed before being discharged.

[0010] Further, the inlet gas temperature of the carbon fiber waste gas to be treated into the first condenser is 70-95 DEG C, and the outlet gas temperature of the third condenser is lower than 30 DEG C.

[0011] Further, in the primary oxidation tower, the effective chlorine dosage is 300-500 mg / L.

[0012] Further, the pressure in the ozone ultra-micro-nano bubble generator is 0.3-0.5 MPa, the generated bubble diameter is less than 300 nm, the gas-water ratio is 1:3-1:5, and the ozone concentration is 100-200 mg / L.

[0013] Further, an online monitoring gas sensor is arranged at the outlet of the water washing tower, and is used for measuring the non-methane total hydrocarbon concentration of the gas at the outlet.

[0014] Compared with the traditional spraying oxidation technology, the present application has the following advantages:

[0015] (1) In the present application, the dimethyl sulfoxide and part of acrylonitrile in the high-concentration waste gas are recovered by passing the waste gas into the third condenser, so that the pollutant concentration is greatly reduced, and the subsequent process operation pressure is reduced. The recovered dimethyl sulfoxide and acrylonitrile are reused as raw materials for carbon fiber polymerization liquid production.

[0016] (2) The ozone ultra-micro-nano bubble generator releases hydroxyl radicals with high oxidation capacity in the absorption liquid, and cooperates with the ozone micro-nano bubbles to oxidize and degrade the organic pollutants in the waste gas, so that the oxidation performance is stronger.

[0017] (3) The process system can reach a non-methane total hydrocarbon treatment efficiency of more than 98% compared with a traditional process. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A schematic diagram of a multi-stage condensation combined ultra-micro-nano bubble ozone oxidation carbon fiber waste gas treatment device. DETAILED DESCRIPTION

[0019] The application will be further described in detail below in combination with specific embodiments and drawings.

[0020] Comparative Example 1

[0021] A waste gas from a certain section of a carbon fiber production process was collected, and the initial non-methane total hydrocarbon concentration was about 500 mg·m -3 . The inlet flow rate of the waste gas was 1000 m 3 ·h -1 . The waste gas was treated by two-stage sodium hypochlorite spraying and one-stage water washing. The effective chlorine dosage of the spraying tower was 500 mg / L. After outlet detection, the non-methane total hydrocarbon concentration was reduced to 150 mg·m -3 , and the treatment efficiency reached 70%.

[0022] Comparative Example 2

[0023] A waste gas from a certain section of a carbon fiber production process was collected, and the initial non-methane total hydrocarbon concentration was about 500 mg·m -3 . The dry filter had a filtering precision of 1 μm, and the inlet flow rate of the waste gas was 1000 m 3 ·h -1 . The waste gas was sent into a primary oxidation tower for primary oxidation treatment. The waste gas from the outlet of the primary oxidation tower was sent into a micro-nano bubble oxidation tower. After the ozone ultra-micro-nano bubble generator was turned on, ozone was inhaled, and 15 wt.% sodium hypochlorite solution was inhaled from the micro-nano bubble oxidation tower to generate a micro-nano bubble gas-liquid dispersion system in the micro-nano bubble oxidation tower, and the micro-nano bubble gas-liquid dispersion system was sprayed back into the micro-nano bubble oxidation tower to form a circulating operation state. The bubbles generated by the ozone ultra-micro-nano bubble generator had a diameter of less than 300 nm, the gas-water ratio was 1:3~1:5, and the ozone concentration was 100~200 mg / L. The waste gas from the outlet of the micro-nano bubble oxidation tower was sent into a water washing tower for residual ozone digestion and then discharged. After outlet detection, the non-methane total hydrocarbon concentration was reduced to 55 mg·m -3 , and the treatment efficiency reached 89%.

[0024] Example 1

[0025] A waste gas from a certain section of a carbon fiber production process was collected, and the initial non-methane total hydrocarbon concentration was about 500 mg·m -3, dry filter filtration precision 1 μm, exhaust gas into the flow rate of 1000 m 3 ·h -1 . The carbon fiber exhaust gas was sequentially passed through a primary condenser, a secondary condenser, and a tertiary condenser to recover dimethyl sulfoxide and part of acrylonitrile therein, and the temperature at the outlet of the tertiary condenser was 30℃. The exhaust gas from the outlet of the condenser was sent to a primary oxidation tower, and the effective chlorine dosage of the primary oxidation tower was 500 mg / L for preliminary oxidation treatment. The exhaust gas from the outlet of the primary oxidation tower was sent to a micro-nano bubble oxidation tower, ozone was inhaled after the ozone ultra-micro-nano bubble generator was turned on, and 15wt.% sodium hypochlorite solution was inhaled from the micro-nano bubble oxidation tower at the same time. A micro-nano bubble gas-liquid dispersion system was generated in the micro-nano bubble oxidation tower, and the micro-nano bubble gas-liquid dispersion system was sprayed back into the micro-nano bubble oxidation tower to form a circulating operation state. The bubble diameter generated by the ozone ultra-micro-nano bubble generator was less than 300 nm, the gas-water ratio was 1:3~1:5, and the ozone concentration was 100~200 mg / L. The exhaust gas from the outlet of the micro-nano bubble oxidation tower was passed into a water washing tower for residual ozone digestion and then discharged. The non-methane total hydrocarbon concentration was reduced to 7 mg·m -3 -3 after outlet detection, and the treatment efficiency reached 98.6%.

Claims

1. A carbon fiber waste gas treatment device combining multi-stage condensation and ultra-micro nanobubble ozone oxidation, characterized in that, It includes a primary condenser, a secondary condenser, a tertiary condenser, a primary oxidation tower, a micro-nano bubble oxidation tower, and a water washing tower, which are connected in sequence by pipes. The cavity of the micro-nano bubble oxidation tower is connected to an ozone ultra-micro-nano bubble generator. The primary oxidation tower contains a sodium hypochlorite solution, and the micro-nano bubble oxidation tower contains an absorbent.

2. The carbon fiber waste gas treatment device according to claim 1, characterized in that, The sodium hypochlorite solution is industrial grade, with an available chlorine content of ≥10%.

3. The carbon fiber waste gas treatment device according to claim 1, characterized in that, The absorbent in the micro-nano bubble oxidation tower is an aqueous solution rich in ozone-rich ultra-micro and nano bubbles.

4. The carbon fiber waste gas treatment device according to claim 1, characterized in that, The condenser is a shell-and-tube condenser.

5. A carbon fiber waste gas treatment process combining multi-stage condensation and ultra-micro nanobubble ozone oxidation, characterized in that, The apparatus according to any one of claims 1 to 4 comprises the following steps: passing the carbon fiber waste gas to be treated sequentially through a primary condenser, a secondary condenser, and a tertiary condenser to condense and recover dimethyl sulfoxide and a portion of acrylonitrile from the waste gas; sending the waste gas from the outlet of the tertiary condenser into a primary oxidation tower for preliminary oxidation treatment using sodium hypochlorite solution; sending the waste gas from the outlet of the primary oxidation tower into a micro-nano bubble oxidation tower, where an ozone ultra-micro-nano bubble generator is activated to draw in ozone, and simultaneously drawing in absorbent liquid from the micro-nano bubble oxidation tower to generate a micro-nano bubble gas-liquid dispersion system within the tower, and then injecting the micro-nano bubble gas-liquid dispersion system back into the tower to form a circulating operation state for deep oxidation treatment of the waste gas; and passing the waste gas from the outlet of the micro-nano bubble oxidation tower into a water washing tower for residual ozone decomposition before discharge.

6. The carbon fiber waste gas treatment process according to claim 5, characterized in that, The inlet temperature of the carbon fiber exhaust gas to be treated is 70~95℃ when it enters the first-stage condenser, and the outlet temperature of the third-stage condenser is less than 30℃.

7. The carbon fiber waste gas treatment process according to claim 5, characterized in that, In the primary oxidation tower, the effective chlorine dosage is 300~500 mg / L.

8. The carbon fiber waste gas treatment process according to claim 5, characterized in that, The pressure in the ozone ultra-micro nano bubble generator is 0.3~0.5MPa, the generated bubble diameter is less than 300nm, the gas-to-water ratio is 1:3~1:5, and the ozone concentration is 100~200mg / L.

9. The carbon fiber waste gas treatment process according to claim 5, characterized in that, An online gas sensor is installed at the outlet of the water washing tower to measure the concentration of non-methane total hydrocarbons in the gas at the outlet.

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