阅读说明：本技术 一种用于三甘醇脱水的尾气除臭工艺及装置 (Tail gas deodorization process and device for triethylene glycol dehydration ) 是由 胡昌权 吴建祥 冯小波 梁政 张梁 宋文明 罗倩 李博 王新华 甘代福 熊伟 于 2021-05-27 设计创作，主要内容包括：一种用于三甘醇脱水的尾气除臭方法及装置,包括闪蒸罐、重沸器、冷凝分液罐、负压混合器、灼烧炉和废液罐；本发明通过闪蒸罐、重沸器、冷凝分液罐将产生恶臭的成分转化为液体,液体排放至封闭式废液罐中进行收集,避免了恶臭污染空气。同时,利用负压混合器自身所产生的气体压力不同,使气体在混合器内充分混合,进入后端的灼烧炉后,能够充分燃烧,避免了恶臭气体未经充分燃烧,直接从灼烧炉排出进入大气中产生恶臭的问题。本发明不需要外加能量,即可实现本发明的工艺步骤,非常节能环保。(A tail gas deodorization method and a device for triethylene glycol dehydration comprise a flash tank, a reboiler, a condensation liquid separation tank, a negative pressure mixer, a burning furnace and a waste liquid tank; according to the invention, the components generating the odor are converted into liquid through the flash tank, the reboiler and the condensation liquid separation tank, and the liquid is discharged into the closed waste liquid tank for collection, so that the odor is prevented from polluting the air. Meanwhile, the gas pressure generated by the negative pressure mixer is different, so that the gas is fully mixed in the mixer and can be fully combusted after entering the firing furnace at the rear end, and the problem that malodorous gas is directly discharged from the firing furnace to enter the atmosphere to generate malodorous gas after being fully combusted is avoided. The invention can realize the process steps without external energy, and is energy-saving and environment-friendly.)

1. A tail gas deodorization method for triethylene glycol dehydration is characterized in that: the method comprises the following steps:

step 1: discharging the triethylene glycol rich solution into a flash tank, and performing flash evaporation to separate flash evaporation steam and waste liquid; discharging the waste liquid into a reboiler; discharging flash steam into a vortex tube of the condensation liquid separation tank;

step 2: reboiling the waste liquid in the reboiler to separate out regenerated gas and sewage; discharging the sewage into a waste liquid tank, and discharging the regenerated gas into a tank body of a condensation liquid separation tank;

and step 3: separating hot air flow and cold air flow from the flash steam in the step 1 under the action of a vortex tube; hot air flow is discharged from a hot air outlet of the condensation liquid separation tank and enters an air inlet of the negative pressure mixer; cold air flow enters the tank body of the condensate separating tank from the cold air pipe of the vortex pipe through the sieve pipe; mixing the cold airflow with the regenerated gas entering the tank body in the step 2 to form primary mixed gas;

the regeneration gas in the primary mixed gas is cooled in the tank body, the separated water vapor and other dirt are converted into a liquid phase, and the liquid phase is discharged into a waste liquid tank from a waste liquid outlet of the tank body;

discharging the rest primary mixed gas from the gas outlet of the tank body;

and 4, step 4: the hot air flow in the step 3 enters the throat pipe from the air inlet of the negative pressure mixer; step 3, sucking the primary mixed gas discharged from the gas outlet of the tank body into a throat pipe from a gas suction port of the negative pressure mixer to be mixed with hot gas flow to form secondary mixed gas; after the secondary mixed gas is mixed in a mixing chamber of the negative pressure mixer, the formed tail gas is discharged from a tail gas outlet;

and 5: and 4, enabling the tail gas discharged in the step 4 to enter a burning furnace, and discharging the burnt tail gas into the atmosphere.

2. The method according to claim 1, wherein the step of deodorizing the tail gas comprises the steps of: in step 1, the flash steam comprises hydrogen sulfide, methane and water vapor.

3. The method according to claim 1, wherein the step of deodorizing the tail gas comprises the steps of: in the step 1, the pressure of flash steam is controlled to be 0.6-0.8 MPa.

4. The method according to claim 1, wherein the step of deodorizing the tail gas comprises the steps of: in the step 2, the regeneration gas comprises hydrogen sulfide, methane and water vapor.

5. The method according to claim 1, wherein the step of deodorizing the tail gas comprises the steps of: and 3, discharging hot air from the hot air outlet after the hot air passes through a cone valve fixedly connected with the outlet of the hot air pipe, wherein the pressure of the hot air is 0.4-0.6 MPa.

6. A tail gas deodorization device for triethylene glycol dehydration is characterized by comprising a flash tank, a reboiler, a condensation liquid separation tank, a negative pressure mixer, a burning furnace and a waste liquid tank;

the condensation liquid-separating tank comprises a tank body and a vortex tube; the two ends of the vortex tube comprise a hot air tube and a cold air tube which are oppositely arranged; the cold air pipe is communicated with the inner cavity of the tank body through a pipeline; the hot gas pipe is connected with the hot gas outlet through a pipeline;

the negative pressure mixer comprises an air inlet, an air suction port, a throat pipe, a mixing chamber and a tail gas outlet; a contraction section with gradually reduced inner diameter is arranged between the air inlet and the front part of the throat pipe, the rear part of the throat pipe is connected with a mixing chamber, the inner diameter of the connection part of the mixing chamber and the throat pipe is gradually enlarged, and the rear part of the mixing chamber is connected with a tail gas outlet; the air suction port is connected with the middle part of the throat pipe; the sectional area of the inner cavity of the throat pipe is minimum;

the inlet of the flash tank is connected with a tail gas discharge part through a pipeline, and the exhaust port of the flash tank is connected with a nozzle of a vortex tube of a condensation liquid-separating tank through a pipeline; a liquid outlet of the flash tank is connected with a liquid inlet of the reboiler through a pipeline;

an exhaust port of the reboiler is connected with a tank body inlet of the condensation liquid separation tank through a pipeline; the liquid outlet of the reboiler is connected with the liquid inlet of the waste liquid tank through a pipeline;

a hot gas outlet of the condensation liquid separation tank is connected with an air inlet of the negative pressure mixer through a pipeline; the exhaust port of the tank body is connected with the air suction port of the negative pressure mixer through a pipeline; the liquid outlet of the tank body is connected with the liquid inlet of the waste liquid tank through a pipeline;

and a tail gas outlet of the negative pressure mixer is connected with a burning furnace.

7. The triethylene glycol dehydrated tail gas deodorization device according to claim 6, wherein: the central axis of the nozzle of the vortex tube is tangent to the inner cavity of the vortex tube.

8. The triethylene glycol dehydrated tail gas deodorization device according to claim 6, wherein: the pipeline for connecting the cold air pipe of the vortex tube with the inner cavity of the tank body is a sieve pipe, and a cone valve is arranged between the hot air pipe outlet and the hot air outlet of the vortex tube.

9. The triethylene glycol dehydrated tail gas deodorization device according to claim 6, wherein: the contraction section of the negative pressure mixer is a conical surface, and the volume of the mixing chamber is larger than that of the conical surface.

10. The triethylene glycol dehydrated tail gas deodorization device according to claim 6, wherein: and a tail gas outlet of the negative pressure mixer is connected with the bottom of the tail gas outgoing pipe through a pipeline.

Technical Field

The invention relates to a tail gas deodorization process and a tail gas deodorization device for triethylene glycol dehydration in the petroleum and natural gas industry.

Background

The natural gas must be dehydrated before being transported by a pipeline, and the purpose of the dehydration is to remove H in the natural gas₂0, removing the water until the water dew point requirement of the external transportation is met, so that the dehydrated gas does not generate hydrate in transportation to block a pipeline, and the prior art mainly adopts a triethylene glycol dehydration device to remove the water in the natural gas, and absorbs the water in the natural gas by utilizing the difference of the solubility of the water and the natural gas in a triethylene glycol solution, thereby realizing the removal of the water in the natural gas;

the wet natural gas is in countercurrent contact with the lean triethylene glycol flowing downwards from the top of the tower on the tower plate from bottom to top in the absorption tower to absorb water and other impurities in the natural gas. The triethylene glycol rich in which water and other impurities are absorbed flows out from the bottom of the tower, passes through a coil pipe at the top of the rectifying column to exchange heat with regenerated triethylene glycol poor in quality, part of water and other impurities dissolved in the triethylene glycol rich in quality are flashed by a flash tank, enter the rectifying column through mechanical filtration to be regenerated, then flow into a buffer tank, and finally enter the absorption tower again through a series of heat exchange to form a regeneration cycle. In the process of regenerating triethylene glycol, tail gas is generated at two positions of the flash tank and the rectifying column and enters the burning furnace for combustion.

Due to the complex composition of the upstream natural gas, triethylene glycol absorbs a large amount of other impurities, so that tail gas generated at the tops of a flash tank and a rectifying column in the regeneration operation process has strong odor, and the process problem of a burning furnace is solved, so that the tail gas entering the burning furnace cannot be completely burned, the surrounding atmosphere odor is caused, and the normal production, life and body health of surrounding residents and station staff are influenced.

Disclosure of Invention

The purpose of the invention is: in order to solve the problems that the combustion of triethylene glycol dehydration tail gas is insufficient and the tail gas pollutes the environment, the tail gas deodorization method and the tail gas deodorization device for triethylene glycol dehydration are provided.

In order to solve the technical problems, the method for deodorizing the tail gas generated by dehydrating the triethylene glycol comprises the following implementation steps of:

step 1: discharging the triethylene glycol rich solution into a flash tank, and performing flash evaporation to separate flash evaporation steam and waste liquid; discharging the waste liquid into a reboiler; discharging flash steam into a vortex tube of the condensation liquid separation tank;

step 2: reboiling the waste liquid in the reboiler to separate out regenerated gas and sewage; and sewage is discharged into a waste liquid tank, and regenerated gas is discharged into a tank body of a condensation liquid separation tank.

And step 3: separating hot air flow and cold air flow from the flash steam in the step 1 under the action of a vortex tube; hot air flow is discharged from a hot air outlet of the condensation liquid separation tank and enters an air inlet of the negative pressure mixer; cold air flow enters the tank body of the condensate separating tank from the cold air pipe of the vortex pipe through the sieve pipe; mixing the cold airflow with the regenerated gas entering the tank body in the step 2 to form primary mixed gas;

the regeneration gas in the primary mixed gas is cooled in the tank body, the separated water vapor and other dirt are converted into a liquid phase, and the liquid phase is discharged into a waste liquid tank from a waste liquid outlet of the tank body;

and the rest primary mixed gas is discharged from the gas outlet of the tank body.

And 4, step 4: the hot air flow in the step 3 enters the throat pipe from the air inlet of the negative pressure mixer; step 3, sucking the primary mixed gas discharged from the gas outlet of the tank body into a throat pipe from a gas suction port of the negative pressure mixer to be mixed with hot gas flow to form secondary mixed gas; and after the secondary mixed gas is mixed in a mixing chamber of the negative pressure mixer, the formed tail gas is discharged from a tail gas outlet.

And 5: and 4, enabling the tail gas discharged in the step 4 to enter a burning furnace, and discharging the burnt tail gas into the atmosphere.

By adopting the method, the components generating the odor are converted into liquid to be removed, and the liquid is discharged into the closed waste liquid tank to be collected, so that the odor is prevented from polluting the air. Meanwhile, the gas pressure difference generated by the negative pressure mixer is fully utilized, so that the gas is fully mixed in the mixer and can be fully combusted after entering the rear-end burning furnace. By improving the combustion efficiency and fully burning, the problem that part of the regenerated gas and the flash steam are not fully burnt and are directly discharged from the burning furnace to enter the atmosphere to generate stink in the original process is solved. The invention can realize the process steps without external energy, and is energy-saving and environment-friendly.

In a further improvement, in step 1 above, the flash steam comprises hydrogen sulfide, methane and water vapor; preferably, the flash steam pressure is controlled to be 0.6-0.8 MPa.

In the step 2, the regeneration gas comprises hydrogen sulfide, methane and water vapor;

in the step 3, the hot air flow is discharged to the hot air pipe of the vortex tube, and is discharged from the hot air outlet after passing through the cone valve fixedly connected with the outlet of the hot air pipe. The opening degree of the outlet of the hot gas pipe is adjusted by the cone valve, and the pressure of hot gas flow is preferably controlled to be 0.4-0.6 MPa.

The invention also aims to provide a tail gas deodorization device for triethylene glycol dehydration. The device comprises a flash tank, a reboiler, a condensation liquid separation tank, a negative pressure mixer, a burning furnace and a waste liquid tank;

the condensation liquid-separating tank comprises a tank body and a vortex tube; the two ends of the vortex tube comprise a hot air tube and a cold air tube which are oppositely arranged; the cold air pipe is communicated with the inner cavity of the tank body through a pipeline; the hot gas pipe is connected with the hot gas outlet through a pipeline;

the negative pressure mixer comprises an air inlet, an air suction port, a throat pipe, a mixing chamber and a tail gas outlet; a contraction section with gradually reduced inner diameter is arranged between the air inlet and the front part of the throat pipe, the rear part of the throat pipe is connected with a mixing chamber, the inner diameter of the connection part of the mixing chamber and the throat pipe is gradually enlarged, and the rear part of the mixing chamber is connected with a tail gas outlet; the air suction port is connected with the middle part of the throat pipe; the sectional area of the inner cavity of the throat pipe is minimum.

The inlet of the flash tank is connected with a tail gas discharge part through a pipeline, and the exhaust port of the flash tank is connected with a nozzle of a vortex tube of a condensation liquid-separating tank through a pipeline; a liquid outlet of the flash tank is connected with a liquid inlet of the reboiler through a pipeline;

an exhaust port of the reboiler is connected with a tank body inlet of the condensation liquid separation tank through a pipeline; the liquid outlet of the reboiler is connected with the liquid inlet of the waste liquid tank through a pipeline;

a hot gas outlet of the condensation liquid separation tank is connected with an air inlet of the negative pressure mixer through a pipeline; the exhaust port of the tank body is connected with the air suction port of the negative pressure mixer through a pipeline; the liquid outlet of the tank body is connected with the liquid inlet of the waste liquid tank through a pipeline;

and a tail gas outlet of the negative pressure mixer is connected with a burning furnace.

By adopting the device, the tail gas generated by the triethylene glycol dehydration part is subjected to flash evaporation through the flash evaporation tank to separate flash evaporation steam and waste liquid, wherein the flash evaporation steam contains hydrogen sulfide, methane and water vapor; discharging the waste liquid into a reboiler, and introducing flash steam into a condensation liquid separation tank;

separating out regeneration gas and sewage after the waste liquid in the reboiler is reboiled, wherein the regeneration gas comprises hydrogen sulfide, methane and water vapor; and discharging the sewage into a waste liquid tank, and discharging the regenerated gas into a tank body of a condensation liquid separation tank.

The flash steam enters a nozzle of a vortex tube in the condensate separating tank and is separated into hot air flow and cold air flow under the action of the vortex tube; the hot air flow is discharged to a hot air pipe of the vortex tube, and then is discharged from a hot air outlet and enters an air inlet of the negative pressure mixer; the cold air flow is discharged to a cold air pipe of the vortex tube and enters the tank body through a pipeline; the cold airflow is fully mixed with the regenerated gas in the tank body to form primary mixed gas, wherein the regenerated gas is cooled by the cold airflow in the tank body, water vapor and other dirt are fully separated out and converted into a liquid phase, and the liquid phase is discharged into a waste liquid tank from a waste liquid outlet of the tank body; and the residual primary mixed gas is discharged from the gas outlet of the tank body and enters the gas suction port of the negative pressure mixer.

The hot air flow entering the negative pressure mixer then enters the throat pipe, and the flow rate is sharply increased to generate vacuum; the primary mixed gas is absorbed by negative pressure under the action of vacuum, sucked into the throat pipe from the air suction port and meets and is mixed with hot air flow; the formed secondary mixed gas is fully mixed in the mixing chamber to form uniform and stable tail gas which is discharged from a tail gas outlet of the negative pressure mixer; during secondary mixing, hot air flow with high temperature meets primary mixed gas with low temperature in the throat pipe, the temperature of the hot air flow is reduced, the volume of the hot air flow is contracted, the vacuum degree formed in the throat pipe is further improved, and the negative pressure adsorption effect on the primary mixed gas is further enhanced.

And the discharged tail gas enters the burning furnace to be burnt, mainly generates carbon dioxide, and is discharged into the atmosphere.

In the device, the further improvement is that the central axis of the nozzle of the vortex tube is tangent to the inner cavity of the vortex tube.

The further improvement is that the pipeline connecting the cold air pipe of the vortex tube and the inner cavity of the tank body is a sieve pipe, and a cone valve is arranged between the hot air pipe outlet and the hot air outlet of the vortex tube. The cone valve can adjust the opening degree of the outlet of the hot air pipe and control the pressure of the air flow.

The further improvement is that the contraction section of the negative pressure mixer is a conical surface, and the sectional area of the connection part of the mixing chamber and the throat pipe is larger than that of the conical surface.

The further improvement is that a tail gas emergent pipe and a combustor are arranged in the burning furnace, and a tail gas outlet of the negative pressure mixer is connected with the bottom of the tail gas emergent pipe through a pipeline. And tail gas enters the tail gas outgoing pipe from the bottom of the burning furnace, and is discharged after the burner ignites the tail gas discharged from the upper part of the tail gas outgoing pipe. The combustion efficiency can be further improved, and sufficient combustion is ensured.

The condensation divides the fluid reservoir, a jar body is provided with gas outlet, regeneration gas air inlet and waste liquid outlet, and jar body upper end is provided with the vortex tube, and the cold air duct setting of vortex tube lower extreme is at jar body inner chamber, and nozzle center pin and vortex tube inner chamber are tangent, and the hot gas pipe export of vortex tube upper end is fixed with the cone valve, and the cold air duct export of vortex tube lower extreme is fixed with the screen pipe, is provided with the sieve mesh on the pipe wall of screen pipe.

The invention has the beneficial effects that:

(1) the odor components are converted into liquid to be removed, and the generated waste liquid is discharged to the waste liquid tank in a closed manner, so that the odor pollution to air is reduced; meanwhile, the discharged gas is fully mixed before being discharged, so that the gas is fully combusted. The invention realizes the removal of the foul smell of the emissions and achieves the aim of environmental protection.

(2) The invention utilizes the cold air flow generated by the self process to condense and discharge the regenerated gas, does not need external energy to condense or exchange heat, has high energy utilization rate, saves energy and protects environment;

(3) the invention utilizes the pressure difference of high-pressure gas (hot air flow) generated by the self process to low-pressure gas (primary mixed gas), the hot air flow rapidly passes through the throat pipe of the negative pressure mixer and generates vacuum, and the primary mixed gas is sucked, thereby realizing the transmission and discharge in the negative pressure mixer, not needing additional energy to carry the low-pressure gas in a pressurizing way, having high energy utilization rate, saving energy and protecting environment.

(4) The tail gas supplied from the bottom of the burning furnace is used for burning, so that the burning efficiency is further improved, the burning is sufficient, and the pollution is reduced;

(5) the device provided by the invention has the advantages of simple structure, no movement mechanism, reliable action effect, long service life and avoidance of economic loss caused by frequent maintenance.

Drawings

FIG. 1 is a schematic diagram of a tail gas deodorization process and apparatus for triethylene glycol dehydration according to the present invention;

FIG. 2 is a schematic diagram of the structure of a condensate knockout drum of the embodiment;

FIG. 3 is a schematic diagram of a negative pressure mixer according to an embodiment.

In the figure: 1. the system comprises a flash tank, 2, a reboiler, 3, a condensation liquid separation tank, 4, a negative pressure mixer, 5, a burning furnace, 6, a waste liquid tank, 31, a tank body, 32, a sieve tube, 33, a vortex tube, 34, a cone valve, 311, an air outlet, 312, a regeneration gas inlet, 313, a waste liquid outlet, 331, a nozzle, 332, a cold gas tube, 333, a hot gas tube, 341, a hot gas outlet, 41, an air inlet, 42, an air inlet, 43, a throat, 44, a mixing chamber, 45, a tail gas outlet, 51, a tail gas outlet and 52, a combustor.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings.

Examples

As shown in fig. 1, 2 and 3, the tail gas deodorization device for triethylene glycol dehydration of the present invention is composed of a flash tank 1, a reboiler 2, a condensate separation tank 3, a negative pressure mixer 4, a burning furnace 5 and a waste liquid tank 6; the burning furnace 5 includes a tail gas exit pipe 51 and a burner 52.

As shown in FIG. 2, in the condensate knockout drum 3, the tank 31 is provided with an air outlet 311, a regeneration air inlet 312 and a waste liquid outlet 313, the upper end of the tank 31 is provided with a vortex tube 33, the outlet of a cold air tube 332 at the lower end of the vortex tube 33 is fixed with a sieve tube 32, the wall of the sieve tube 32 is provided with a sieve hole, and one end of the sieve tube is arranged in the inner cavity of the tank 31. The central axis of the nozzle 331 is tangent to the inner cavity of the vortex tube 33, the outlet of the hot air tube 333 at the upper end of the vortex tube 33 is fixed with the cone valve 34, and the opening degree of the outlet of the hot air tube 333 is adjusted by the cone valve 34;

the negative pressure mixer 4 shown in fig. 3 is provided with an air inlet 41, an air suction port 42, a throat 43, a mixing chamber 44 and an exhaust gas outlet 45; a contraction section with gradually reduced inner diameter is arranged between the air inlet 41 and the front part of the throat pipe, the contraction section is a conical surface, a mixing chamber 44 is arranged at the rear end of the throat pipe 43, the inner diameter of the connection part of the mixing chamber and the throat pipe is gradually enlarged, the sectional area of the inner cavity of the throat pipe 43 is minimum, and the volume of the mixing chamber is maximum.

The device is used for deodorizing tail gas generated by dehydrating triethylene glycol, and the implementation steps are as follows:

step 1: discharging tail gas generated by a triethylene glycol dehydration device into a flash tank 1, and separating flash steam and waste liquid by flash evaporation, wherein the flash steam contains hydrogen sulfide, methane and water vapor; the waste liquid is discharged into the reboiler 2, the pressure of flash steam is controlled to be 0.6-0.8MPa, and the flash steam is discharged into a nozzle 331 of a vortex tube 33 in the condensate knockout drum 3.

Step 2: reboiling the waste liquid in the reboiler 2, separating out regeneration gas and sewage, the regeneration gas contains hydrogen sulfide, methane and water vapor; the sewage is discharged into the waste liquid tank 6, and the regeneration gas is discharged into a regeneration gas inlet 312 of the tank body 31 in the condensation liquid separation tank 3.

And step 3: the flash steam in the step 1 enters a nozzle 331 of a vortex tube 33 in the condensate separating tank 3, and hot air flow and cold air flow are separated from the flash steam under the action of the vortex tube 33; the hot air flow is discharged to the hot air pipe 333 of the vortex pipe 33 and then discharged from the hot air outlet 341 of the cone valve 34, and the pressure of the hot air flow is 0.4-0.6 MPa; the cold air flow is discharged to a cold air pipe 332 of the vortex pipe 33, enters the sieve tube 32, and enters the tank body 31 through the sieve holes on the sieve tube 32; the cold air flow is fully mixed with the regeneration gas in the tank body 31, the regeneration gas is cooled in the tank body 31, water vapor and other pollutants are fully separated out and converted into a liquid phase, and the liquid phase is discharged into a waste liquid tank 6 from a waste liquid outlet 313 of the tank body 31; the fully mixed regeneration gas and cold gas flow mixed gas is discharged from the gas outlet 311 of the canister 31.

And 4, step 4: the hot air flow discharged from the hot air outlet 341 of the cone valve 34 enters the air inlet 41 of the negative pressure mixer 4, and the mixed gas of the regeneration air and the cold air flow discharged from the air outlet 311 of the tank 31 enters the air inlet 42 of the negative pressure mixer 4; the flow rate of hot air flow entering the throat pipe 43 is sharply increased to generate vacuum; the mixed gas of the regenerated gas and the cold airflow is absorbed by negative pressure under the vacuum action to enter the air suction port 42 in a large quantity, and meets and is mixed with hot airflow in the throat 43; the mixed gas of the regenerated gas and the cold airflow and the hot airflow are fully mixed in the mixing chamber 44 to form uniform and stable tail gas which is discharged from a tail gas outlet 45; the hot air flow with high temperature meets the mixed gas of the regenerated gas and the cold air flow with low temperature in the throat pipe 43, the temperature of the hot air flow is reduced, the volume of the hot air flow is contracted, the vacuum degree formed in the throat pipe 43 is further improved, and the negative pressure adsorption effect on the mixed gas of the regenerated gas and the cold air flow is further enhanced.

And 5: the tail gas discharged from the tail gas outlet 45 of the negative pressure mixer 4 enters the tail gas outgoing pipe 51 of the burning furnace 5, and the burner 52 ignites the tail gas discharged from the tail gas outgoing pipe 51, so that carbon dioxide is mainly generated by burning and is discharged into the atmosphere.