CN102338391A - Method for treating asphalt flue gas by microwave incineration method - Google Patents

Abstract

The invention provides a method for treating asphalt fume by using microwave incineration method. By placing the silicon carbide rod of the wave-absorbing medium under the microwave to raise the temperature and heat it up; Incinerate together with the pretreated silicon carbide rods, and then directly discharge the incinerated asphalt tail gas. Using microwave incineration to purify and treat asphalt fume, the purification efficiency of asphalt fume can reach more than 95%, and the applicable concentration range is wide and adaptable; the effect is good, the treatment efficiency is high, and the equipment is simple, easy to implement, and easy to operate , easy to control, small system resistance, no secondary pollution and so on.

Description

A method of treating bitumen flue gas by microwave incineration

technical field

The invention relates to a method for treating asphalt fume, in particular to a method for treating asphalt fume by microwave incineration, and belongs to the technical field of environmental protection.

Background technique

At present, research at home and abroad shows that there are three main ways for the migration of harmful components in asphalt: the first is that the volatile components in asphalt migrate into the air in the form of smoke; the second is that asphalt is used in the road surface. , some components in asphalt may migrate into the soil or water source with the rain; the third is that during the road use process, the worn out asphalt components migrate to the soil through deposition and adsorption. For industrial production, the transmission of asphalt harmful substances is mainly the first airborne transmission. For example, in the metallurgical industry, during the roasting process of prebaked anodes of carbon products in the roasting furnace, a large amount of asphalt fume will be discharged. The treatment of aluminum alloys cannot meet the standards, and the impact on environmental protection is extremely serious. This is the reason why huge investments are made at home and abroad to control the environmental protection of the electrolytic aluminum industry.

For the current industrial methods for the treatment of asphalt flue gas at home and abroad, there are mainly electric capture method, adsorption method, incineration method, absorption method and so on. The electric capture method is mainly to treat the asphalt flue gas whose temperature is maintained at 80 to 90 degrees Celsius, let the asphalt flue gas enter the electric tar capture device, and the smoke particles are charged, collected, and purified in the trap, and then in the induced draft fan. Under the action, it is discharged into the atmosphere at the high altitude of the chimney; but the wet electric catcher increases the secondary pollution caused by sewage treatment. The adsorption method is mainly to use porous solids to accumulate or condense one or more components in the fluid mixture on the surface to achieve the purpose of separation. According to the force between the surface of the adsorbent and the adsorbate is caused by the intermolecular attraction Known as "Van der Waals force", no chemical reaction occurs between the adsorbent and the adsorbate, and it is not affected by temperature. The adsorbents for asphalt smoke are mainly activated carbon, coke powder, dolomite powder, etc.; this method has simple process, high purification efficiency, low investment and low operating cost, but the system resistance is relatively large. The incineration method is mainly used in the environment above 700 ℃, using asphalt flue gas containing a large amount of combustible organic matter, which can be completely burned in contact with air, but the incineration method consumes too much energy and costs too much under the low concentration of asphalt. economy. The absorption method, commonly known as the washing method, is a commonly used industrial waste gas treatment method; it uses the different solubility of the mixed components in the waste gas in the selected absorbent, or the reaction of a certain component with the active component in the absorbent. A method to achieve purification of exhaust gas. The absorption and purification method is applied to the treatment of asphalt flue gas, which is to transfer the gaseous pollutants in the flue gas (actually 0.1-1.0m tar fine mist particles) to the liquid phase (absorbent), so as to achieve the purpose of purifying the flue gas; The method has simple equipment, convenient maintenance, small system resistance, and low energy consumption, but it is flammable, and the purification efficiency is not high, and it is not easy to use.

There is no mature process for asphalt flue gas treatment. The above methods all have some disadvantages in industrial production, many of which are due to low gas collection efficiency, complicated process, cumbersome operation and maintenance, and large system resistance. Run stably for a long time and give up at the end.

Contents of the invention

The object of the present invention is to provide a method for incinerating and purifying asphalt flue gas with good treatment effect, high heating efficiency, easy operation, easy control, small system resistance, low operating cost, and simple structure, so as to solve some problems in actual production. disadvantages.

The present invention is realized through the following technical proposals: a method for treating asphalt fume by using microwave incineration, through the following steps:

A． Put the absorbing medium silicon carbide rod under the microwave frequency of 2450MHz, heat it at a heating rate of 5°C/min, and keep it warm for 10min when the temperature rises to 850-1000°C;

B． The mixture of asphalt fume and air with a concentration of asphalt fume of 300-1500mg/m ³ and a temperature of 130-150°C is passed into a microwave oven with a frequency of 2450MHz and a pressure of 47.34-101.28KPa at a flow rate of 1L/min. Next, incinerate together with the silicon carbide rods obtained in step A for 0.5-1 s, and then directly discharge the incinerated asphalt tail gas.

Advantage of the present invention and positive effect are as follows:

Due to the adoption of the above technical scheme, the present invention incinerates the asphalt fume, so that the asphalt fume can be fully burned in the high-temperature incinerator hall, not only has high combustion efficiency, but also greatly reduces the impact of asphalt fume discharged into the air on the environment . It is tested that the concentration of asphalt fume is not more than 50mg/m ³ , and the content of benzopyrene is 346ng/m ³ . After microwave incineration, the treatment time is more than 0.5 seconds, and the content of asphalt fume and benzopyrene basically meets the national emission standards.

The method of using microwave to treat asphalt fume not only has a good effect, but compared with other technologies, the present invention also has the advantages of high microwave heating efficiency, easy operation, easy control, small system resistance, low operating cost, etc., and solves the problem of practical production some of the disadvantages. Especially in the existing incineration method, the problems of high cost of burning flammable gas, easy breakage of resistance wire, slow temperature rise, slow temperature drop, and high energy consumption can all be solved in the microwave incineration treatment of asphalt flue gas:

1. The purification efficiency of asphalt flue gas can reach more than 95%, and the applicable concentration range is wide and adaptable;

2. Using the microwave incineration method to treat asphalt tail gas can improve the efficiency, and the equipment is simple, the system resistance is small, and it is easy to operate;

3. Using air as the carrier gas for incinerating asphalt tail gas Compared with the traditional incineration method: the current incineration method basically uses natural gas incineration method, and the optimal ratio is 2.3:1 (natural gas: asphalt flue gas), resulting in natural gas which is a non-renewable resource A large number of applications, not only the cost is high, but also the energy consumption is large;

4. Silicon carbide rods are selected as the wave-absorbing medium for incineration asphalt flue gas. Not only does the silicon carbide rod have better stability in absorbing waves and heating up, but more importantly, silicon carbide rods are not easy to chemically react with asphalt fume at high temperatures.

Detailed ways

The content of the present invention will be further illustrated below in conjunction with the examples, but these examples do not limit the protection scope of the present invention.

Example 1

A． Put the absorbing medium silicon carbide rod under the microwave frequency of 2450MHz, heat it at a heating rate of 5°C/min, and keep it warm for 10min when the temperature rises to 850°C;

B． Pass the mixture of asphalt fume and air with a concentration of 793.1mg/m ³ and a temperature of 140°C under a microwave with a frequency of 2450MHz and a pressure of 47.34KPa at a flow rate of 1L/min, and step A The obtained silicon carbide rods are incinerated together for 1 second, and then the incinerated asphalt tail gas is directly discharged.

Adopt the method recommended in the ultraviolet spectrophotometric method of asphalt fume, use benzene as the absorbing liquid to detect asphalt fume: the concentration of asphalt fume at the gas outlet is 1.8 mg/m ³ , and the purification efficiency reaches 99.7%.

Example 2

A． Put the absorbing medium silicon carbide rod under the microwave frequency of 2450MHz, heat it at a heating rate of 5°C/min, and keep it warm for 10min when the temperature rises to 900°C;

B． Pass the mixture of asphalt fume and air with a concentration of 300mg/m ³ and a temperature of 130°C under microwaves with a frequency of 2450MHz and a pressure of 81.47KPa at a flow rate of 1L/min, and the mixture obtained in step A The silicon carbide rods are incinerated together for 0.5s, and then the incinerated asphalt tail gas is directly discharged.

Using the method recommended in the ultraviolet spectrophotometric method for the determination of asphalt fume, using benzene as the absorbing liquid to detect asphalt fume: the concentration of asphalt fume at the gas outlet is 16.1 mg/m ³ , and the purification efficiency reaches 94.6%.

Example 3

A． Place the absorbing medium silicon carbide rod under the microwave frequency of 2450MHz, heat it at a heating rate of 5°C/min, and keep it warm for 10min when the temperature rises to 1000°C;

B． Pass the mixture of asphalt fume and air with a concentration of 1500 mg/m ³ of asphalt fume and a temperature of 150 ° C under microwaves with a frequency of 2450 MHz and a pressure of 101.28 KPa at a flow rate of 1 L/min, and the mixture obtained in step A The silicon carbide rods are incinerated together for 1 second, and then the incinerated asphalt tail gas is directly discharged.

Adopt the method recommended in the ultraviolet spectrophotometric method of asphalt fume, and use benzene as the absorbing liquid to detect asphalt fume: the concentration of asphalt fume at the gas outlet is 45 mg/m ³ , and the purification efficiency reaches 97%.

Example 4

A． Place the absorbing medium silicon carbide rod under the microwave frequency of 2450MHz, heat it at a heating rate of 5°C/min, and keep it warm for 10min when the temperature rises to 950°C;

B． Pass the mixture of asphalt fume and air with a concentration of 1064mg/m ³ and a temperature of 135°C under microwaves with a frequency of 2450MHz and a pressure of 68.24KPa at a flow rate of 1L/min, and the mixture obtained in step A The silicon carbide rods are incinerated together for 0.5s, and then the incinerated asphalt tail gas is directly discharged.

Adopt the method recommended in the ultraviolet spectrophotometric method of asphalt fume, use benzene as the absorbing liquid to detect asphalt fume: the concentration of asphalt fume at the gas outlet is 6.2 mg/m ³ , and the purification efficiency reaches 99.4%.

Claims (1)

1. method that adopts the microwave burning method to handle bitumen flue gas is characterized in that through following each step:

A. will inhaling ripple medium silicon carbide rod, to place frequency be under the 2450MHz microwave, heat with the heating rate of 5 ℃/min, and when temperature rises to 850～1000 ℃, insulation 10min;

B. the concentration with bitumen flue gas accounts for 300～1500mg/m ³, temperature is 130～150 ℃ bitumen flue gas and AIR MIXTURES; Being passed into frequency with the flow velocity of 1L/min is that 2450MHz, pressure are under the microwave of 47.34～101.28KPa; Burn 0.5～1s with steps A gained silicon carbide rod, the pitch exhaust emissions after directly will burning then.