CN107042054A - Treatment method of aldehyde waste gas - Google Patents

Abstract

The invention belongs to the field of waste gas treatment, and relates to a method for treating aldehyde waste gas. The method comprises the steps of enabling aldehyde waste gas to sequentially pass through a pretreatment absorption tower, a molecular cracking system and a tail gas absorption tower, wherein a molecular cracking device comprises an energy input system and a reactor system, and generating a high-energy electric field in the reactor through the energy input system to break chemical bonds of pollutants and destroy and degrade the pollutants. The method has the advantages of simple operation, low treatment cost, small device investment and the like.

Description

A kind of processing method of aldehyde waste gas

technical field

The invention belongs to the field of waste gas treatment and relates to a treatment method for aldehyde waste gas.

Background technique

Industrial waste gas includes organic waste gas and inorganic waste gas, among which aldehydes are one of the main pollutants in organic waste gas. The emission of volatile aldehydes will have a certain degree of impact on the surrounding environment and human health. Among them, carcinogenic aldehydes, including formaldehyde, cause more serious damage to the human body; some aldehydes, including crotonaldehyde, have a lower smell threshold and are quite irritating to the surrounding air. Environmental quality has a relatively bad impact.

At present, the treatment of aldehyde waste gas is either treated with simple activated carbon or simply washed with water, but due to the limited treatment effect of activated carbon on the adsorption of aldehyde waste gas, it is easy to be saturated, and the frequency of replacement of activated carbon is relatively high. Low treatment efficiency and large water consumption inevitably increase the operating cost of enterprises in waste gas treatment. At the same time, a large amount of waste activated carbon and aldehyde-containing wastewater will greatly increase the environmental protection pressure and treatment costs of enterprises. In addition, there are some other waste gas treatment technologies applied to aldehyde waste gas treatment, such as RTO, RCO, low temperature plasma, condensation recovery, biological method, etc. However, these methods also have problems such as low processing efficiency, high investment, and high operating costs in the actual application process.

Therefore, there is an urgent need for a more thorough and economical treatment technology and process for aldehyde waste gas.

Contents of the invention

The technical problem to be solved in the present invention is to provide a method for treating aldehyde waste gas with high efficiency and low cost in view of the problems of low efficiency and high cost of the current aldehyde waste gas treatment technology.

The purpose of the present invention can be achieved through the following technical solutions:

A treatment method for aldehyde waste gas, the method comprising the following steps:

(1) described aldehyde waste gas is passed in the spray absorption tower that absorbent A is housed, waste gas is carried out pretreatment; Described absorbent _A is NaHSO any one in aqueous solution, propylene glycol aqueous solution;

(2) The pretreated exhaust gas is passed into the molecular cracking device for destruction and degradation. The molecular cracking device includes an energy input system and a reactor system. The energy input system is used to provide a stable high-pressure energy field, and the reactor system provides a reaction for destroying pollutants. medium;

(3) the exhaust gas after the previous step treatment enters the tail gas absorption tower that absorber B is housed, and absorbs the small molecule pollutants etc. after the cracking treatment; Described absorber B is a kind of in dilute alkali, water.

The spray absorption towers described in step (1) are all packed towers, and the packing material is any one of ceramics, polypropylene PP, and stainless steel; the spray density ranges from 5 to 10m ³ /m ² .h.

_The NaHSO3 aqueous solution concentration described in step (1) is preferably 5wt%～20wt%.

The energy input system described in step (2) is an external energy generator, the frequency and power are continuously adjustable, the frequency range is 400-1000 Hz, and the input power range is 4-10 kw.

The tail gas absorption tower described in step (3) is a packed tower, the packing material is any one of ceramics, polypropylene PP, and stainless steel, and the spray density ranges from 5 to 10 m ³ /m ² .h.

The dilute alkali solution described in step (3) is preferably NaOH, Ca(OH) ₂ or KOH solution, and the concentration is preferably 5 wt% to 20 wt%.

Beneficial effect:

1. The present invention provides an efficient and low-cost method for treating aldehyde waste gas, which has the advantages of simple device structure, simple operation, low processing cost, and small investment.

2. The molecular cracking device adopted in the present invention can directly break and degrade the chemical bonds of various pollutants, destroying the target pollutants.

Description of drawings

Fig. 1 is a flow chart of an aldehyde waste gas treatment method of the present invention.

1 is the spray absorption tower, 2 is the molecular cracking device, and 3 is the tail gas absorption tower.

Fig. 2 Schematic diagram of molecular cracking device.

201 is an air inlet, 202 is an air distribution box, 203 is an energy generator, 204 is a reactor system, and 205 is an air outlet.

Fig. 3 is a schematic diagram of another molecular cracking device used in the present invention.

203 is an energy generator, and 204 is a reactor system.

detailed description

The following examples carry out the treatment of aldehyde waste gas according to the above method:

Example 1

Treat the aldehyde waste gas as described above. The main devices used in this embodiment include: a spray absorption tower, a molecular cracking device, and a tail gas absorption tower.

The concentration of crotonaldehyde waste gas is 45mg/m ³ , the air volume is 100m ³ /h, the waste gas first passes through the spray absorption tower, the absorbent is 10wt% NaHSO ₃ , the spray density is 4m ³ /m ² .h, and the treated waste gas enters the The pyrolysis system has a power of 4kw and a frequency of 500Hz. After the waste gas is degraded by the pyrolysis reaction, it enters the tail gas absorption tower for treatment. The absorbent is 5%wt NaOH aqueous solution, and the spray density is 8m ³ /m ² .h. The above process is continued. The effect of the device is stable after 2 hours of operation, and the removal rate of crotonaldehyde reaches 95.5%.

Example 2

Treat formaldehyde waste gas as above. The main devices used in this embodiment include: a spray absorption tower, a molecular cracking device, and a tail gas absorption tower.

The formaldehyde concentration is about 32mg/m ³ , the air volume is 100m ³ /h, the waste gas first passes through the spray absorption tower, the absorbent is ethylene glycol, and the spray density is 8m ³ /m ² .h, and the treated waste gas enters the molecular cracking system , with a power of 5kw and a frequency of 800Hz. After the waste gas is degraded by the cracking reaction, it enters the tail gas absorption tower for treatment. The absorbent is 5%wt NaOH aqueous solution, and the spray density is 5m ³ /m ² .h. Continue the above process, and the device runs After 2 hours, the effect was stable, and the removal rate of methionine reached 97.3%.

Example 3

Acetaldehyde waste gas is treated as above. The main devices used in this embodiment include: a spray absorption tower, a molecular cracking device, and a tail gas absorption tower.

The concentration of acetaldehyde is about 49mg/m ³ , the air volume is 100m ³ /h, the waste gas first passes through the spray absorption tower, the absorbent is 50wt% propylene glycol aqueous solution, the spray density is 10m ³ /m ² .h, and the waste gas after treatment enters the molecule Cracking system, with a power of 10kw and a frequency of 1000Hz. After the waste gas is degraded by the cracking reaction, it enters the tail gas absorption tower for advanced treatment. The absorbent is 5%wt NaOH aqueous solution, and the spray density is 6m ³ /m ² .h, and the above process is continued , The effect of the device is stable after 2 hours of operation, and the removal rate of methionine reaches 98.5%.

Claims (6)

1. a kind of processing method of aldehydes waste gas, it is characterised in that this method comprises the following steps：

(1) described aldehydes waste gas is passed through in the spray absorber equipped with absorbent A, waste gas is pre-processed；Described Absorbent A is NaHSO₃Any one in the aqueous solution, aqueous solution of propylene glycol；

(2) pretreated waste gas is passed through molecular cleavage device and carries out destruction degraded, and molecular cleavage device includes energy input system System and reactor assembly, energy input system are used to provide stable high-pressure energy, and reactor assembly carries for destruction pollutant For reaction media；

(3) waste gas after previous step processing, which enters, is equipped with absorbent B tail gas absorbers, absorbs the small molecule after being handled by cracking Pollutant etc.；Described absorbent B is one kind in diluted alkaline, water.

2. according to the method described in claim 1, it is characterised in that described spray absorber is packed tower, filler material is Any one in ceramics, polypropylene PP, stainless steel；Sprinkle density scope is 5~10m³/m².h。

3. according to the method described in claim 1, it is characterised in that described NaHSO₃Concentration of aqueous solution is 5wt%~20wt%.

4. according to the method described in claim 1, it is characterised in that the energy input system described in step (2) is external energy Generator, frequency and power continuously adjustabe, 400~1000Hz of frequency range, input power range is 4~10kw.

5. according to the method described in claim 1, it is characterised in that the tail gas absorber described in step (3) is packed tower, filler Material is any one in ceramics, polypropylene PP, stainless steel, and sprinkle density scope is 5~10m³/m².h。

6. according to the method described in claim 1, it is characterised in that NaOH, Ca (OH) that dilute alkaline soln is₂Or KOH solution, concentration For 5wt%~20wt%.