CN114165789A

CN114165789A - Solar cell panel pyrolysis and waste gas treatment and resource utilization method thereof

Info

Publication number: CN114165789A
Application number: CN202111405553.1A
Authority: CN
Inventors: 刘景洋; 董莉; 毕莹莹
Original assignee: Chinese Research Academy of Environmental Sciences
Current assignee: Chinese Research Academy of Environmental Sciences
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-03-11

Abstract

The invention discloses a solar cell panel pyrolysis and waste gas treatment and resource utilization method thereof. The adopted processing equipment comprises: pyrolysis oven, waste gas burn burning furnace and condensation purification subassembly. Preheating a solar cell panel with a frame, a junction box and a back film removed, pyrolyzing the solar cell panel in a pyrolysis furnace, starting a thermal circulation fan and an exhaust fan, discharging pyrolysis tail gas from the pyrolysis furnace, passing through a pipeline, and burning the pyrolysis tail gas in a waste gas incinerator, wherein the burning temperature is not lower than 730 ℃; and one part of burned gas in the waste gas incinerator returns to the pyrolysis furnace through a pipeline for recycling, and the other part of gas is discharged after passing through the condensation purification assembly. According to the invention, the organic waste gas incinerator is adopted to treat and strip the pyrolysis waste gas of the solar cell panel, and the combustion flue gas part returns to the pyrolysis furnace to be used as the supplement of a heat source, so that the self-circulation of waste heat is realized, and the energy is effectively saved; and at high temperature, the pyrolysis waste gas is not condensed, the treatment products mainly comprise carbon dioxide and water, the products are simple, and the pollution is reduced.

Description

Solar cell panel pyrolysis and waste gas treatment and resource utilization method thereof

Technical Field

The invention relates to the technical field of resource recovery, in particular to a method for pyrolysis of a solar cell panel and treatment and resource utilization of pyrolysis waste gas.

Background

At present, the recycling process of solar panels is researched more at home and abroad, and the pyrolysis method is one of the commonly used methods. The pyrolysis method is that under the condition of oxygen deficiency, the solar panel is stripped from the frame, the junction box and the fluorine-containing back plate, the whole body is preheated and then heated in a pyrolysis furnace, organic matter components are broken in chemical chains in the heating process, most of the organic matter components are converted into low-grade organic matter and become gaseous pyrolysis products. The solar cell panel contains an EVA adhesive film, pyrolysis is carried out at medium temperature, decomposition and combustion are carried out, due to the fact that a furnace body is closed, oxygen is limited, various substances generated in the thermal decomposition process cannot be fully oxidized, combustion is incomplete, combustible organic substances, CO, fixed carbon and other substances are generated, black smoke is presented, certain pungent taste is provided, and condensate liquid is generated at the part after the temperature is reduced and is condensed on the tube wall. In order to maintain the integrity of the solar panel, the equipment for pyrolysis of the module needs to be adapted to the module, so that the treatment and recycling of the pyrolysis waste gas need to be matched with the module. VOCs are of various types and complex sources, so that treatment methods are also diversified. At present, few reports are reported on the treatment of pyrolysis gas generated by a pyrolysis recovery solar panel. There are also many disadvantages to the waste gas recovery method using pyrolysis of other substances. The chinese patent publication No. CN207298981U discloses a recycling process of organic solid waste pyrolysis waste gas, but does not disclose the pyrolysis temperature of organic solid waste, the waste gas property, and key parameters of each link of waste gas recycling. Chinese patent publication No. CN210398942U discloses an apparatus for organic waste gas incineration and waste heat utilization, in which a method for waste heat recovery is implemented by heat exchange of combustion flue gas, and in this patent, no unsuitable flue gas types and no process parameters such as incineration temperature are mentioned. In the Chinese patent with publication No. CN109945211A, firstly, the semi-coke pyrolysis waste gas needs to be introduced into an organic absorbent, and the concentrated waste liquid needs to be separated and treated, so that the complexity of the operation is increased; secondly, the combustion products are directly separated and discharged, which causes waste heat.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a method for treating and recycling pyrolysis waste gas of a solar cell panel, which realizes self-heating circulation and has high treatment efficiency.

The purpose of the invention is realized as follows:

a solar cell panel pyrolysis and waste gas treatment and resource utilization method thereof adopts treatment equipment comprising: the system comprises a pyrolysis furnace, a waste gas incinerator and a condensation purification assembly, wherein the pyrolysis furnace is provided with a hot air circulating fan, a pyrolysis tail gas outlet and an incineration gas inlet which are communicated with the inside of the pyrolysis furnace, and the pyrolysis tail gas outlet is provided with a frequency-adjustable exhaust fan; the waste gas incinerator is provided with a combustion chamber, a pyrolysis tail gas inlet, an incineration gas outlet, an air inlet and a fuel inlet; the condensation purification component comprises 3 parts of a water cooling device, a spray tower and an active carbon adsorption device; the pyrolysis tail gas outlet and the pyrolysis tail gas inlet are connected through a second pipeline, the incineration gas outlet is respectively connected with the gas inlet ends of a first pipeline and a third pipeline through a three-way valve, the gas outlet end of the first pipeline is connected to the incineration gas inlet, and the gas outlet end of the third pipeline is connected to the gas inlet end of the condensation passing assembly; the first pipeline is provided with a first regulating valve communicated with outside air and a second regulating valve inside the pipeline, and the second pipeline is provided with a third regulating valve communicated with the outside air;

the method comprises the following steps:

A. preheating a solar cell panel at 200 ℃, pyrolyzing the solar cell panel in a pyrolysis furnace, starting a thermal circulation fan and an exhaust fan, discharging pyrolysis tail gas through a pyrolysis tail gas outlet, flowing into a pyrolysis tail gas inlet through a second pipeline, and entering a waste gas incinerator;

B. burning the pyrolysis tail gas in a waste gas incinerator, wherein the burning temperature is not lower than 730 ℃;

C. and opening a second regulating valve to enable part of gas burnt in the waste gas incinerator to enter the burning gas inlet through the first pipeline and return to the pyrolysis furnace for recycling, and the other part of gas is discharged after passing through the condensation purification assembly.

The solar cell panel is a component for removing the frame, the junction box and the fluorine back plate and comprises glass, a cell piece and an EVA (ethylene vinyl acetate) adhesive film.

Further optimizing, a control panel is installed on one side of the pyrolysis furnace, and valve switches for controlling the adjusting valves are arranged on the control panel; heated air circulation fan, pyrolysis tail gas export, burn gaseous import and air exhauster all set up at the top of pyrolysis oven, and the pyrolysis oven waste gas outlet outside, burn burning furnace gas outlet outside and second regulating valve's import department position all is equipped with temperature detector for monitor the flue gas temperature in each place.

Further, the inside of waste gas incinerator is equipped with the combustion chamber, the combustion chamber lateral wall is equipped with pyrolysis tail gas import, the combustion chamber top is equipped with burns the gas outlet, the combustion chamber bottom is equipped with air intlet, combustion chamber below lateral wall is equipped with fuel inlet, the sub-unit connection of combustion chamber has the combustor, the outside of combustion chamber is provided with insulation material, be equipped with double-deck porous ceramic's heat accumulation baffle in the combustion chamber, the combustion chamber space on heat accumulation baffle upper portion with burn the gas outlet connection.

Furthermore, a water cooling device, a spray tower and an active carbon adsorption device in the condensation purification assembly are sequentially connected, and the air outlet end of the third pipeline is connected to the air inlet of the water cooling device.

Further, the incineration temperature in the step B is as follows: 730 ℃.

Further, be provided with VOC concentration sensor in the pyrolysis oven, VOC concentration sensor is connected with smoke alarm device, and VOCs concentration surpasss and sets for threshold value (20% volume concentration) in the flue gas in the pyrolysis oven and triggers alarm device promptly and send out the police dispatch newspaper, and VOCs concentration is in normal threshold value in the flue gas in the frequency control pyrolysis oven through adjusting the air exhauster earlier, and after 60 seconds, VOCs volume concentration fails to reduce to below 20%, and the pipeline is opened with the interior VOCs concentration of instantaneous reduction pyrolysis oven with the valve of external gas intercommunication automatically, reduces the risk.

The invention has the advantages and beneficial effects that:

1) according to the invention, the organic waste gas incinerator is adopted to treat and strip the pyrolysis waste gas of the solar cell panel (glass/cell piece/EVA), and the combustion flue gas part returns to the pyrolysis furnace to be used as the supplement of a heat source, so that the self-circulation of waste heat is realized, and the energy is effectively saved; and at high temperature, the pyrolysis waste gas is not condensed, the treatment products mainly comprise carbon dioxide and water, the products are simple, and the pollution is reduced.

2) The invention ensures that the VOC concentration in the pyrolysis furnace is lower than an alarm line through two-stage control: at first through pyrolysis tail gas export air regulation, make in the pyrolysis oven VOC concentration be less than the alarm line, after 60 seconds, VOCs volume concentration fails to reduce to below 20% in the pyrolysis oven, further comes instantaneous reduction VOCs concentration through the control of pipeline and external gas intercommunication valve, reduces the risk.

3) In the invention, the pyrolysis waste gas is treated by the organic waste gas incinerator, the structure is simple, the operation is convenient, and the optimal incineration temperature parameter is obtained: not lower than 730 ℃.

Drawings

The invention is further illustrated by the following figures and examples.

FIG. 1 is a schematic view of the overall structure of the treating apparatus of the present invention.

Reference numerals: 1. a pyrolysis furnace; 1-1, a hot air circulating fan; 1-2, a pyrolysis tail gas outlet; 1-3, an incineration gas inlet; 1-4. an exhaust fan; 1-5. control panel; 1-6, opening and closing a valve; 2. an exhaust gas incinerator; 2-1, a combustion chamber; 2-2, pyrolysis tail gas inlet; 2-3, an incineration gas outlet; 2-4, air inlet; 2-5, fuel inlet; 2-6. a burner; 2-7, heat storage partition board; 2-8, heat insulation material; 3. a water cooling device; 4. a spray tower; 5. an activated carbon adsorption unit; 6. a first duct (i.e., a circulating flue gas duct); 7. a second conduit; 8. a third pipeline; 9. a first regulating valve; 10. a second regulating valve; 11. a third regulating valve;

temperature detectors

12, 13, 14.

Detailed Description

Example 1:

as shown in fig. 1, a method for pyrolysis of a solar cell panel and treatment and resource utilization of waste gas thereof adopts treatment equipment comprising: the device comprises a pyrolysis furnace 1, a waste gas incinerator 2 and a condensation purification assembly, wherein the pyrolysis furnace 1 is provided with a hot air circulating fan 1-1, a pyrolysis tail gas outlet 1-2 and an incineration gas inlet 1-3 which are communicated with the inside of the pyrolysis furnace, and the pyrolysis tail gas outlet 1-2 is provided with an exhaust fan 1-4 with adjustable frequency; the waste gas incinerator 2 is provided with a combustion chamber 2-1, a pyrolysis tail gas inlet 2-2, an incineration gas outlet 2-3, an air inlet 2-4 and a fuel inlet 2-5; the condensation purification component comprises 3 parts including a water cooling device 3, a spray tower 4 and an active carbon adsorption device 5; the pyrolysis tail gas outlet 1-2 is connected with the pyrolysis tail gas inlet 2-2 through a second pipeline 7, the incineration gas outlet 2-3 is respectively connected with the gas inlet ends of a first pipeline (circulating flue gas pipeline) 6 and a third pipeline 8 through a three-way valve, the gas outlet end of the first pipeline 6 is connected with the incineration gas inlet 1-3, and the gas outlet end of the third pipeline 8 is connected with the gas inlet end of a condensation passing assembly; a first regulating valve 9 communicated with outside air and a second regulating valve 10 in the pipeline are arranged on the first pipeline (circulating flue gas pipeline) 6, and a third regulating valve 11 communicated with the outside air is arranged on the second pipeline 7;

the processing method comprises the following steps:

A. the solar cell panel (including glass, battery piece and EVA) preheats the back and pyrolyzes in pyrolysis oven 1, and the pyrolysis temperature is: starting a thermal circulation fan 1-1 and an exhaust fan 1-4 at 500 ℃, discharging pyrolysis tail gas through a pyrolysis tail gas outlet 1-2, flowing into a pyrolysis tail gas inlet 2-2 through a second pipeline 7, and entering a waste gas incinerator 2;

B. burning the pyrolysis tail gas in a waste gas incinerator 2, wherein the burning temperature is not lower than 730 ℃; preferably 730 deg.C

C. And opening a second regulating valve 10 to enable a part of gas in the waste gas incinerator 2 to enter the incineration gas inlets 1-3 through the first pipeline 6 and return to the pyrolysis furnace 1 for recycling, and the other part of gas is discharged after passing through the condensation purification assembly.

In the embodiment, one side of the pyrolysis furnace 1 is provided with control panels 1-5, and the control panels 1-5 are provided with valve switches 1-6 for controlling various regulating valves; the hot air circulating fan 1-1, the pyrolysis tail gas outlet 1-2, the incineration gas inlet 1-3 and the exhaust fan are all arranged at the top of the pyrolysis furnace 1, and gas circulation is facilitated.

Temperature detectors

12, 13 and 14 are arranged at positions of the pyrolysis tail gas outlet 1-2, the incineration gas outlet 2-3 and the first pipeline (circulating flue gas pipeline) 6 close to the second regulating valve 10 and used for monitoring the temperature of each flue gas flow.

In the embodiment, a combustion chamber 2-1 is arranged in the waste gas incinerator 2, a pyrolysis tail gas inlet 2-2 is arranged on the side wall of the combustion chamber 2-1, the top of the combustion chamber 2-1 is provided with an incineration gas outlet 2-3, the bottom of the combustion chamber 2-1 is provided with an air inlet 2-4, the side wall below the combustion chamber 2-1 is provided with a fuel inlet 2-5, the lower part of the combustion chamber 2-1 is connected with a combustor 2-6, the outside of the combustion chamber 2-1 is provided with a heat insulation material 2-8, the combustion chamber 2-1 is internally provided with a heat storage partition plate 2-7 in the horizontal direction, the combustion chamber space above the heat storage partition plate 2-7 is connected with the incineration gas outlet 2-3, and the incineration gas outlet 2-3 is connected with a first pipeline (a circulating flue gas pipeline) 6, so that gas circulation is facilitated.

The water cooling device 3, the spray tower 4 and the activated carbon adsorption device 5 in the condensation purification assembly are sequentially connected, and the air outlet end of the third pipeline 8 is connected to the air inlet of the water cooling device 3.

Be provided with VOC concentration sensor in the pyrolysis oven 1, VOC concentration sensor is connected with smoke alarm device, VOCs concentration surpasss the settlement threshold value (20% volume concentration) and triggers alarm device promptly and sends the police dispatch newspaper in the flue gas in the pyrolysis oven, VOCs concentration is in normal threshold value in the flue gas in the frequency control pyrolysis oven through adjusting air exhauster 1-4 earlier, after 60 seconds, VOCs volume concentration fails to reduce to below 20%, the pipeline is opened with the interior VOCs concentration of instantaneous reduction pyrolysis oven with the valve of external gas intercommunication automatically, the risk is reduced.

The EVA pyrolysis waste gas adopts a thermal combustion process, auxiliary fuel liquefied petroleum gas or natural gas is used as fuel, the temperature in an incinerator is heated to a certain temperature, and then the tail gas VOCs is thermally destroyed to generate CO₂And H₂And O. Through experimental attempt, 730 ℃ high temperature can make the pyrolysis product reaction complete, consequently, in the processing procedure, the furnace that burns burning furnace is for being not less than 730 ℃, the fan of pyrolysis tail gas outlet of EVA in the pyrolysis furnace can frequency regulation size, VOCs's concentration prevents to exceed the alarm line and triggers the warning in the flue gas in the control furnace, after 60 seconds when the fan is adjusted, VOCs volume concentration fails to reduce to below 20%, the pipeline is opened with the instantaneous VOCs concentration in the reduction pyrolysis furnace with the valve of external gas intercommunication is automatic.

The temperature of the flue gas of the waste gas incinerator is not lower than 680 ℃, and a large amount of flue gas waste heat can be used. When the flue gas combusted in the waste gas incinerator is circulated, a part of the flue gas is circulated back to the pyrolysis furnace to be used as supplement of a heat source through the control of a three-way valve, experiments show that the reflux temperature of the part of the flue gas is not lower than 400 ℃, and the other part of the flue gas is discharged after being condensed by water through an exhaust fan.

Finally, it should be noted that the above only illustrates the technical solution of the present invention, but not limited thereto, and although the present invention has been described in detail with reference to the preferred arrangement, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made thereto without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A solar cell panel pyrolysis and waste gas treatment and resource utilization method thereof is characterized in that the adopted treatment equipment comprises: the device comprises a pyrolysis furnace (1), a waste gas incinerator (2) and a condensation purification assembly, wherein a hot air circulating fan (1-1), a pyrolysis tail gas outlet (1-2) and an incineration gas inlet (1-3) which are communicated with the inside of the pyrolysis furnace (1) are arranged on the pyrolysis furnace (1), and an exhaust fan (1-4) with adjustable frequency is arranged at the pyrolysis tail gas outlet (1-2); the waste gas incinerator (2) is provided with a combustion chamber (2-1), a pyrolysis tail gas inlet (2-2), an incineration gas outlet (2-3), an air inlet (2-4) and a fuel inlet (2-5); the condensation purification component comprises 3 parts of a water cooling device (3), a spray tower (4) and an active carbon adsorption device (5); the pyrolysis tail gas outlet (1-2) is connected with the pyrolysis tail gas inlet (2-2) through a second pipeline (7), the incineration gas outlet (2-3) is respectively connected with the gas inlet ends of a first pipeline (a circulating flue gas pipeline) (6) and a third pipeline (8) through a three-way valve, the gas outlet end of the first pipeline (6) is connected to the incineration gas inlet (1-3), and the gas outlet end of the third pipeline (8) is connected to the gas inlet end of a condensation passing assembly; a first regulating valve (9) communicated with outside air and a second regulating valve (10) in the pipeline are arranged on the first pipeline (circulating flue gas pipeline) (6), and a third regulating valve (11) communicated with the outside air is arranged on the second pipeline (7);

the method comprises the following steps:

A. preheating a solar panel at 200 ℃, pyrolyzing the solar panel in a pyrolysis furnace (1), starting a thermal circulation fan (1-1) and an exhaust fan (1-4), discharging pyrolysis tail gas through a pyrolysis tail gas outlet (1-2), flowing into a pyrolysis tail gas inlet (2-2) through a second pipeline (7), and entering a waste gas incinerator (2);

B. burning the pyrolysis tail gas in a waste gas incinerator (2), wherein the burning temperature is not lower than 730 ℃;

C. and opening a second adjusting valve (10), so that a part of gas after incineration in the waste gas incinerator (2) enters an incineration gas inlet (1-3) through a first pipeline (6) and returns to the pyrolysis furnace (1) for recycling, and the other part of gas is discharged after passing through a condensation purification assembly.

2. The solar panel pyrolysis and waste gas treatment and resource utilization method according to claim 1, characterized in that: the solar cell panel is a component for removing the frame, the junction box and the fluorine back plate and comprises glass, a cell piece and an EVA adhesive film.

3. The solar panel pyrolysis and waste gas treatment and resource utilization method according to claim 1, characterized in that: a control panel (1-5) is installed on one side of the pyrolysis furnace (1), and valve switches (1-6) for controlling each regulating valve are arranged on the control panel (1-5); the hot air circulating fan (1-1), the pyrolysis tail gas outlet (1-2), the incineration gas inlet (1-3) and the exhaust fan are all arranged at the top of the pyrolysis furnace (1), and temperature detectors are arranged at the outer side of the pyrolysis furnace waste gas outlet (1-2), the outer side of the incinerator gas outlet (2-3) and the inlet of the second adjusting valve (10) and used for monitoring the temperature of the flue gas in each place.

4. The solar panel pyrolysis and waste gas treatment and resource utilization method according to claim 1, characterized in that: a combustion chamber (2-1) is arranged in the waste gas incinerator (2), the side wall of the combustion chamber (2-1) is provided with a pyrolysis tail gas inlet (2-2), the top of the combustion chamber (2-1) is provided with an incineration gas outlet (2-3), the bottom of the combustion chamber (2-1) is provided with an air inlet (2-4), the side wall below the combustion chamber (2-1) is provided with a fuel inlet (2-5), the lower part of the combustion chamber (2-1) is connected with a combustor (2-6), the outside of the combustion chamber (2-1) is provided with a heat insulation material (2-8), a double-layer porous ceramic heat storage partition plate (2-7) is arranged in the combustion chamber (2-1), and the combustion chamber space at the upper part of the heat storage partition plate (2-7) is connected with an incineration gas outlet (2-3).

5. The solar panel pyrolysis and waste gas treatment and resource utilization method according to claim 1, characterized in that: the water cooling device (3), the spray tower (4) and the activated carbon adsorption device (5) in the condensation purification assembly are sequentially connected, and the air outlet end of the third pipeline (8) is connected to the air inlet of the water cooling device (3).

6. The solar cell pyrolysis and waste gas treatment and resource utilization method of claim 1, wherein the method comprises the following steps: the incineration temperature in the step B is as follows: 730 ℃.

7. The solar panel pyrolysis and waste gas treatment and resource utilization method according to claim 1, characterized in that: be provided with VOC concentration sensor in pyrolysis oven (1), VOC concentration sensor is connected with smoke alarm device, VOCs concentration surpasss and sets for threshold value (20% volume concentration) in the pyrolysis oven in the flue gas triggers alarm device promptly and sends the police dispatch newspaper, VOCs concentration is in normal threshold value in the frequency control pyrolysis oven flue gas through adjusting air exhauster (1-4) earlier, after 60 seconds, VOCs volume concentration fails to reduce to below 20%, the pipeline is opened with instantaneous VOCs concentration in the reduction pyrolysis oven with the valve of external gas intercommunication automatically, the risk is reduced.