A garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation and its working method

Abstract

The present invention relates to a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation and a working method thereof, wherein the garbage pyrolysis gasification furnace comprises a pyrolysis gasification furnace body, a material conveying screw and a combustion chamber sleeve; the pyrolysis gasification furnace body is composed of a furnace body, a pyrolysis material feed port, a catalyst feed port, a porous carbon collection port, a catalyst collection port, a circulating flue gas inlet, a synthesis gas outlet and a synthesis gas branch; the internal space of the furnace body is functionally divided into a pyrolysis area and a gasification area; the outer end of the furnace body corresponding to one end of the synthesis gas outlet pipe and the combustion chamber sleeve are separated into a combustion area by an air baffle, and the rest of the part between the combustion chamber sleeve and the furnace body forms a jacket heat exchange structure. The present invention can realize continuous feeding, and the pyrolysis process is heated more evenly, the synthesis gas quality is higher, and the harmful pollutants and tar content are lower.

Description

Technical Field

[0001] The invention relates to the technical field of garbage disposal, and in particular to a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation and a working method thereof. Background Art

[0002] Pyrolysis technology is an emerging technology that solves the shortcomings of urban waste incineration technology and realizes efficient and harmless treatment of solid waste. Since the heating process of garbage pyrolysis technology is carried out in an oxygen-deficient atmosphere, less oxygen-containing toxic pollutants are produced, the generated synthesis gas has a higher calorific value and a smaller volume, and can also produce porous carbon materials with higher added value as by-products, which is conducive to meeting different energy needs. However, since the pyrolysis process is carried out in an oxygen-deficient atmosphere and under high temperature conditions, a large amount of pyrolysis tar will exist in the pyrolysis synthesis gas, which has become one of the difficulties hindering the large-scale application of solid waste pyrolysis technology. Pyrolysis tar will not only affect the gas quality of the synthesis gas and reduce the calorific value of the synthesis gas, but will also condense in the downstream equipment and affect its normal operation. At present, the application of pyrolysis technology in garbage treatment still has problems such as high tar treatment cost, low calorific value of synthesis gas, and uneven heating during the pyrolysis process. Summary of the invention

[0003] The present invention provides a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation and a working method thereof, which can realize continuous feeding, and the pyrolysis process is heated more evenly, the quality of the synthesis gas is higher, and the harmful pollutants and tar content are lower.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation, comprising a pyrolysis gasification furnace body, a material conveying screw and a combustion chamber sleeve; the pyrolysis gasification furnace body consists of a furnace body, a pyrolysis material feed port, a catalyst feed port, a porous carbon collection port, a catalyst collection port, a circulating flue gas inlet, a synthesis gas outlet and a synthesis gas branch; the furnace body is arranged horizontally, a pyrolysis material feed port is arranged at the top of one end of the furnace body, and a catalyst feed port is arranged at the top of the other end of the furnace body; a porous carbon collection port and a catalyst collection port are arranged at the bottom of the furnace body near the center of the furnace body; the internal space of the furnace body is functionally divided into a pyrolysis area and a gasification area; the furnace body between the discharge end of the pyrolysis material feed port and the feed end of the porous carbon collection port is the pyrolysis area, and the furnace body between the discharge end of the catalyst feed port and the feed end of the catalyst collection port is the gasification area; a material conveying screw is arranged in the furnace chamber of the furnace body along the longitudinal direction, and one end of the material conveying screw is provided by a screw arranged in the combustion chamber The motor outside the casing is driven, and one section of spiral blades with opposite rotation directions are respectively arranged on the material conveying screw corresponding to the pyrolysis area and the gasification area; the conveying direction of the spiral blades corresponding to the pyrolysis area is from one end of the pyrolysis material feed port to one end of the porous carbon collection port; the conveying direction of the spiral blades corresponding to the gasification area is from one end of the catalyst feed port to one end of the catalyst collection port; a synthesis gas outlet pipe is arranged on the upper part of the furnace body corresponding to the outer end of the gasification area; the combustion chamber casing is sleeved on the outside of the furnace body with a gap between the two, and the outer end of the furnace body corresponding to one end of the synthesis gas outlet pipe and the combustion chamber casing are separated into a combustion area by an air separation baffle, and the remaining part between the combustion chamber casing and the furnace body forms a jacket heat exchange structure; a plurality of burners are arranged on the air separation baffle, and the burners are connected to the external oxygen conveying pipeline through an oxygen inlet pipe, and connected to the synthesis gas outlet pipe through a synthesis gas branch pipe; a circulating flue gas inlet is arranged on the upper part of the furnace body corresponding to the outer end of the pyrolysis area and is connected to the jacket heat exchange structure.

[0006] The plurality of burners are evenly arranged along the circumference of the furnace body, and the burners are further connected to an external fuel delivery pipeline through an external fuel inlet pipe.

[0007] The outer wall of the combustion chamber sleeve is provided with a heat-insulating layer.

[0008] The material conveying screw is supported in the furnace of the furnace body by a screw support.

[0009] Control valves are respectively arranged at the pyrolysis material feed port, the catalyst feed port, the porous carbon collection port and the catalyst collection port.

[0010] Thermocouples are respectively arranged in the furnace body corresponding to the pyrolysis area, in the furnace body corresponding to the gasification area, on the synthesis gas outlet pipe, in the jacket heat exchange structure and at the circulating flue gas inlet.

[0011] The synthesis gas outlet pipe, the synthesis gas branch pipe, the oxygen inlet pipe and the circulating flue gas inlet are respectively provided with regulating valves.

[0012] The material conveying screw and the spiral blades thereon are both made of ceramic or quartz materials.

[0013] The air baffle is composed of an air baffle 1 arranged on the inner side of the combustion chamber sleeve and an air baffle 2 arranged on the outer side of the furnace body. The air baffle 1 and the air baffle 2 are riveted or fixed by bolts.

[0014] A method for operating a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation, comprising:

[0015] 1) The biomass pyrolysis materials including domestic garbage are stored in the material feed bin. When the garbage pyrolysis gasification furnace is in operation, the pyrolysis materials are continuously fed into the furnace of the pyrolysis gasification furnace body through the pyrolysis material feed port. Under the conveying action of the material conveying screw, the biomass pyrolysis materials move in the pyrolysis area and undergo pyrolysis reaction at the same time. The porous carbon produced by pyrolysis is sent to the porous carbon collection bin through the porous carbon collection port.

[0016] 2) The catalyst for gasification is stored in the catalyst feed bin. When the garbage pyrolysis gasification furnace is in operation, it is continuously fed into the furnace of the pyrolysis gasification furnace through the catalyst feed port. Under the conveying action of the material conveying screw, the catalyst moves in the gasification area and performs catalytic gasification reaction. The reacted catalyst is sent to the catalyst collection bin through the catalyst collection port;

[0017] 3) At the initial stage of operation of the garbage pyrolysis gasification furnace, a portion of biomass pyrolysis materials and catalysts are supplied into the furnace of the pyrolysis gasification furnace body, and then CO2 gas is supplied into the furnace for gas washing operation; when the CO2 atmosphere in the furnace body reaches the set concentration, fuel and oxygen are respectively supplied into the burner through the synthesis gas branch pipe and the oxygen inlet pipe, and high-temperature flue gas is generated through the burner combustion;

[0018] 4) When the temperature of each section in the furnace body reaches the operating requirements, that is, the furnace temperature corresponding to the pyrolysis area reaches 500-550°C, and the furnace temperature corresponding to the gasification area reaches 900-950°C, the synthesis gas generated by the pyrolysis and gasification process in the furnace body is gradually used to replace the external fuel and supplied to the burner; the pyrolysis material feed amount, catalyst feed amount, synthesis gas recovery rate, and oxygen supply rate are adjusted by the temperature reflected by the thermocouples arranged in the furnace body of the pyrolysis area, the furnace body of the gasification area, the synthesis gas outlet pipe, the jacket heat exchange structure, and the circulating flue gas inlet, so that the temperature of each area meets the operating requirements of the pyrolysis gasifier;

[0019] 5) The temperature of the synthesis gas generated in the furnace body is above 900℃. Part of the synthesis gas is sent out through the synthesis gas outlet pipe, and the other part of the synthesis gas is sent into the burner through the synthesis gas branch pipe for combustion. The temperature of the high-temperature flue gas generated is above 900℃; the high-temperature flue gas flows in the jacket heat exchange structure, and flows through the outer side of the furnace body corresponding to the gasification area and the pyrolysis area in turn, and performs indirect heat exchange through the outer wall of the furnace body, so that the furnace temperature of the corresponding area is maintained at the operating requirements; the jacket heat exchange structure and the combustion area are blocked by an air baffle to prevent the high-temperature flue gas from flowing back and affecting the heat transfer effect; the temperature of the flue gas cooled after heat exchange is within 500℃, and it enters the furnace body from the circulating flue gas inlet as the pyrolysis protection gas and heat carrier in the pyrolysis area, and the gasification agent in the gasification area. The flue gas after combustion contains NH3, NO X The pollutants inside are gradually decomposed under the action of catalyst and high temperature.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) The pyrolysis gasifier includes a pyrolysis area and a gasification area. The products such as oil, gas, water vapor, tar, etc. produced during the pyrolysis process can be further upgraded and catalytically cracked through the high-temperature gasification area. At the same time, the toxic pollutants produced can also be further decomposed under the action of the catalyst through the high-temperature gasification area.

[0022] 2) A material conveying screw is provided in the furnace of the pyrolysis gasification furnace, and a section of spiral blades is provided on the material conveying screw corresponding to the pyrolysis area and the gasification area respectively. The rotation directions of the two sections of spiral blades are opposite, and the conveying direction is relative conveying. The material conveying screw is driven by a motor, which can realize uninterrupted supply and discharge of pyrolysis materials and catalysts during the operation of the equipment.

[0023] 3) The synthesis gas outlet pipe is connected to multiple burners arranged on the gas baffle through the synthesis gas branch pipe. The burners are respectively connected to the synthesis gas branch pipe and the oxygen inlet pipe, so that the high-quality synthesis gas generated by the pyrolysis and gasification process can be directly utilized. After the pyrolysis gasifier is operating normally, it only needs to supply oxygen into the pyrolysis gasifier to carry out the combustion reaction.

[0024] 4) Since the temperature of the synthesis gas produced during the gasification process is relatively high (reaching over 900°C) and the oxygen supplied is relatively small, the CO2-rich and oxygen-poor flue gas produced can be quickly heated to over 900°C. Compared with the traditional pyrolysis technology that uses low-temperature oxygen-poor air and nitrogen as protective gases for the pyrolysis process, the present invention uses less synthesis gas to achieve the heating temperature required to maintain its own stable operation.

[0025] 5) The garbage pyrolysis gasification body of the present invention is provided with a jacket heat exchange structure, and the high-temperature flue gas generated by the combustion of the synthesis gas can flow through the outer wall of the furnace body in the gasification area and the pyrolysis area in turn to supply heat to the corresponding areas, so that the catalyst in the gasification area and the pyrolysis material in the pyrolysis area are maintained in a relatively stable and ideal temperature range, thereby realizing the step-by-step utilization of the high-temperature exhaust gas temperature.

[0026] 6) The jacket heat exchange structure is connected to the furnace of the pyrolysis area through the circulating flue gas inlet. The flue gas (about 500°C) cooled after heating the gasification area and the pyrolysis area can flow back into the furnace body as an inert carrier gas for the pyrolysis process; the temperature of the gas heat carrier is relatively uniform, and it can directly flow around the material to heat it. Compared with the traditional single external heating or solid medium heating method, the present invention has the characteristics of high heat transfer efficiency and uniform heating.

[0027] 7) The flue gas after combustion in the present invention can be used as a gasifying agent in the gasification process. Compared with the pyrolysis atmosphere dominated by N2 in the traditional pyrolysis process, the high concentration of CO2 / H2O in the flue gas can not only continuously react with the coke for gasification, thereby re-exposing the active sites of the catalyst covered by carbon deposits due to the tar cracking reaction, but also facilitates the gasification reaction to proceed in the direction of generating reducing gas, thereby significantly improving the yields of H2 and CO.

[0028] 8) The pyrolysis materials and catalysts enter and exit the furnace separately without interfering with each other, which is conducive to the recovery and utilization of the porous carbon generated after pyrolysis and the used catalyst.

[0029] 9) The material conveying screw rotates continuously during the conveying process, driving the pyrolysis material and catalyst to flip and move forward. Compared with the traditional fixed bed pyrolysis furnace, it is beneficial for the uniform heating of the material and catalyst and can prevent coking. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a top view of a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to the present invention.

[0031] Figure 2 It is a front view of a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to the present invention.

[0032] Figure 3 It is a right view of a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to the present invention.

[0033] Figure 4 yes Figure 3 AA view in.

[0034] Figure 5 yes Figure 3 BB view in.

[0035] Figure 6 yes Figure 2 The CC view in .

[0036] Figure 7 yes Figure 2 DD view in .

[0037] In the figure: 1. Material conveying screw 2. Pyrolysis gasification furnace body 3. Combustion chamber casing 4. Pyrolysis material feed port 5. Porous carbon collection port 6. Catalyst feed port 7. Catalyst collection port 8. Synthesis gas outlet pipe 9. Synthesis gas branch pipe 10. Oxygen inlet pipe 11. Gas baffle 1 12. Gas baffle 2 13. Burner 14. Jacket heat exchange structure 15. Circulating flue gas inlet 16. Pyrolysis area 17. Gasification area DETAILED DESCRIPTION

[0038] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0039] like Figure 1-Figure 7As shown, the garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation of the present invention comprises a pyrolysis gasification furnace body 1, a material conveying screw 1 and a combustion chamber sleeve 3; the pyrolysis gasification furnace body 1 is composed of a furnace body, a pyrolysis material feed port 4, a catalyst feed port 6, a porous carbon collection port 5, a catalyst collection port 7, a circulating flue gas inlet 15, a synthesis gas outlet pipe 8 and a synthesis gas branch pipe 9; the furnace body is arranged horizontally, a pyrolysis material feed port 4 is arranged at the top of one end of the furnace body, and a catalyst feed port 6 is arranged at the top of the other end of the furnace body; A porous carbon collecting port 5 and a catalyst collecting port 7 are arranged at the bottom of the furnace body near the center of the furnace body; the internal space of the furnace body is divided into a pyrolysis area 16 and a gasification area 17 according to the function; the furnace body between the discharge end of the pyrolysis material feed port 4 and the feed end of the porous carbon collecting port 5 is the pyrolysis area 16, and the furnace body between the discharge end of the catalyst feed port 6 and the feed end of the catalyst collecting port 7 is the gasification area 17; a material conveying screw 1 is arranged along the longitudinal length of the furnace chamber of the furnace body, and one end of the material conveying screw 1 is provided by a screw arranged at the combustion chamber. The motor outside the chamber sleeve 3 is driven, and a spiral blade with opposite rotation direction is respectively arranged on the material conveying screw 1 corresponding to the pyrolysis area 16 and the gasification area 17; the conveying direction of the spiral blade corresponding to the pyrolysis area 16 is from the pyrolysis material feed port 4 to the porous carbon collection port 5; the conveying direction of the spiral blade corresponding to the gasification area 17 is from the catalyst feed port 6 to the catalyst collection port 7; the upper part of the furnace body corresponding to the outer end of the gasification area 17 is provided with a synthesis gas outlet pipe 8; the combustion chamber sleeve 3 is sleeved on the outside of the furnace body and A gap is left between the two. The outer end of the furnace body corresponding to one end of the synthesis gas outlet pipe 8 and the combustion chamber sleeve 3 are separated into a combustion area by an air-isolating baffle, and the remaining part between the combustion chamber sleeve 3 and the furnace body forms a jacket heat exchange structure 14; a plurality of burners 13 are arranged on the air-isolating baffle, and the burners 13 are connected to the external oxygen delivery pipeline through the oxygen inlet pipe 10, and connected to the synthesis gas outlet pipe 8 through the synthesis gas branch pipe 9; a circulating flue gas inlet 15 is arranged on the upper part of the furnace body corresponding to the outer end of the pyrolysis area 16, which is connected to the jacket heat exchange structure 14.

[0040] The plurality of burners 13 are evenly arranged along the circumference of the furnace body, and the burners 13 are also connected to an external fuel delivery pipeline through an external fuel inlet pipe.

[0041] The outer wall of the combustion chamber sleeve 3 is provided with a heat-insulating layer.

[0042] The material conveying screw 1 is supported in the furnace of the furnace body by a screw support.

[0043] Control valves are respectively arranged at the pyrolysis material feed port 4 , the catalyst feed port 6 , the porous carbon collection port 5 , and the catalyst collection port 7 .

[0044] Thermocouples are respectively provided in the furnace body corresponding to the pyrolysis area 16 , in the furnace body corresponding to the gasification area 17 , on the synthesis gas outlet pipe 8 , in the jacket heat exchange structure 14 and at the circulating flue gas inlet 15 .

[0045] The synthesis gas outlet pipe 8, the synthesis gas branch pipe 9, the oxygen inlet pipe 10, and the circulating flue gas inlet 15 are respectively provided with regulating valves.

[0046] The material conveying screw 1 and the spiral blades thereon are both made of ceramic or quartz material.

[0047] The air baffle is composed of an air baffle 11 arranged on the inner side of the combustion chamber sleeve 3 and an air baffle 2 12 arranged on the outer side of the furnace body. The air baffle 11 and the air baffle 2 12 are riveted or fixed by bolts.

[0048] A working method of a garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation, comprising:

[0049] 1) The biomass pyrolysis material including domestic garbage is stored in the material feed bin. When the garbage pyrolysis gasification furnace is in operation, the biomass pyrolysis material is continuously fed into the furnace of the pyrolysis gasification furnace body 2 through the pyrolysis material feed port 4. Under the conveying action of the material conveying screw 1, the biomass pyrolysis material moves in the pyrolysis area 16 while undergoing pyrolysis reaction. The porous carbon produced by pyrolysis is delivered to the porous carbon collection bin through the porous carbon collection port 5.

[0050] 2) The catalyst for gasification is stored in the catalyst feed bin. When the garbage pyrolysis gasification furnace is in operation, the catalyst is continuously fed into the furnace of the pyrolysis gasification furnace body 2 through the catalyst feed port 6. Under the conveying action of the material conveying screw 1, the catalyst moves in the gasification area 17 and performs a catalytic gasification reaction. The reacted catalyst is sent to the catalyst collection bin through the catalyst collection port 7;

[0051] 3) At the initial stage of operation of the garbage pyrolysis gasification furnace, a portion of biomass pyrolysis materials and catalysts are supplied into the furnace of the pyrolysis gasification furnace body 2, and then CO2 gas is supplied into the furnace for gas washing operation; when the CO2 atmosphere in the furnace body reaches the set concentration, fuel and oxygen are respectively supplied into the burner 13 through the synthesis gas branch pipe 9 and the oxygen inlet pipe 10, and the burner 13 burns to generate high-temperature flue gas;

[0052] 4) When the temperature of each section in the furnace body reaches the operation requirements, that is, the furnace temperature corresponding to the pyrolysis area 16 reaches 500-550°C, and the furnace temperature corresponding to the gasification area 17 reaches 900-950°C, the synthesis gas generated by the pyrolysis and gasification process in the furnace body is gradually used to replace the external fuel and supplied to the burner 13; the pyrolysis material feed amount, catalyst feed amount, synthesis gas recovery rate, and oxygen supply rate are adjusted by the temperature reflected by the thermocouples arranged in the furnace body of the pyrolysis area 16, the furnace body of the gasification area 17, the synthesis gas outlet pipe 8, the jacket heat exchange structure 14, and the circulating flue gas inlet 15, so that the temperature of each area meets the operation requirements of the pyrolysis gasification furnace;

[0053] 5) The temperature of the synthesis gas generated in the furnace body is above 900°C. A part of the synthesis gas is sent out through the synthesis gas outlet pipe 8, and the other part of the synthesis gas is sent to the burner 13 through the synthesis gas branch pipe 9 for combustion, and the temperature of the high-temperature flue gas generated is above 900°C; the high-temperature flue gas flows in the jacket heat exchange structure 14, and flows through the outer side of the furnace body corresponding to the gasification area 16 and the pyrolysis area 17 in turn, and indirectly exchanges heat through the outer wall of the furnace body, so that the furnace temperature of the corresponding area is maintained at the operating requirements; the jacket heat exchange structure 14 and the combustion area are blocked by an air baffle to prevent the high-temperature flue gas from flowing back and affecting the heat transfer effect; the temperature of the flue gas cooled after heat exchange is within 500°C, and enters the furnace body from the circulating flue gas inlet 15 as the pyrolysis protection gas and heat carrier of the pyrolysis area 16, and the gasification agent of the gasification area 17. The flue gas after combustion contains NH3, NO X The pollutants inside are gradually decomposed under the action of catalyst and high temperature.

[0054] In the garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation described in the present invention, the pyrolysis material feed bin is connected to the pyrolysis area 16 of the furnace body through the pyrolysis material feed port 4, and the bottom of the pyrolysis area 16 corresponding to the end of the pyrolysis material conveying direction is provided with a porous carbon collection port 5 connected to the porous carbon collection bin; the catalyst feed bin is connected to the gasification area 17 of the furnace body through the catalyst feed port 6, and the bottom of the gasification area 17 corresponding to the end of the catalyst conveying direction is provided with a catalyst collection port 7 connected to the catalyst collection bin. The furnace of the pyrolysis area 16 is directly connected to the furnace of the gasification area 17, and a material conveying screw 1 is provided in the furnace of the entire furnace body along the longitudinal direction. The two sections of spiral blades on the material conveying screw corresponding to the pyrolysis area 16 and the gasification area 17 have opposite rotation directions. The material conveying screw 1 is driven by an external motor, and the conveying direction of the biomass pyrolysis material is from the pyrolysis material feed port 4 to the porous carbon collection port 5; the conveying direction of the catalyst is from the catalyst feed port 6 to the catalyst collection port 7.

[0055] As required, a plurality of burners 13 may be provided to ensure that the circumferential temperature of the jacket heat exchange structure 14 is uniform.

[0056] As needed, thermocouples may be provided in the pyrolysis area 16 in the furnace body, the gasification area 17 in the furnace body, the synthesis gas outlet 8, the jacket heat exchange structure 14 and the circulating flue gas inlet 15, respectively, to monitor the temperature and operating conditions of various parts of the furnace body in real time.

[0057] As needed, control valves can be correspondingly provided at the pyrolysis material feed port 4, the catalyst feed port 6, the porous carbon collection port 5, and the catalyst collection port 7 to adjust the gas supply / feed amount and gas / discharge amount of each part according to the operating status of the garbage pyrolysis gasification furnace.

[0058] As needed, waste heat recovery devices can be installed at the porous carbon collection bin, catalyst collection bin, and synthesis gas outlet pipe 8, and the recovered heat can be used to preheat the material feed bin, catalyst feed bin, oxygen inlet pipe 10, etc.

[0059] As required, the material conveying screw 1 and the spiral blades thereon can be made of ceramic or quartz material to facilitate equipment cleaning, and they are more corrosion-resistant and have a longer service life.

[0060] In the present invention, biomass pyrolysis materials and catalysts are respectively supplied into the furnace body from both ends of the furnace body and transported toward each other; the porous carbon produced after the pyrolysis of the biomass pyrolysis materials and the catalyst after the reaction are discharged separately from the corresponding collecting ports without interfering with each other; a part of the synthesis gas generated by the reaction is directly used for combustion and then supplied to the furnace body for heating, and the heated high-temperature flue gas supplies heat to the gasification area 17 and the pyrolysis area 16 in turn, and the flue gas cooled from about 1000°C to about 500°C after heating is directly sent into the furnace of the pyrolysis area 16 through the circulating flue gas inlet 15 as a pyrolysis protective gas atmosphere.

[0061] In conventional pyrolysis gasifiers, tar often undergoes cracking reactions in the gasification area and produces carbon deposits, which cover the active sites of the catalyst and reduce the activity of the catalyst. In the present invention, since the main components of the flue gas entering the furnace are CO2 and H2O, the catalyst in the gasification area 17 will be continuously gasified, exposing the active sites of the catalyst, thereby effectively improving the utilization rate of the catalyst and increasing the production of CO / H2 in the synthesis gas.

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation, characterized in that: It comprises a pyrolysis gasification furnace body, a material conveying screw and a combustion chamber sleeve; the pyrolysis gasification furnace body consists of a furnace body, a pyrolysis material feed port, a catalyst feed port, a porous carbon collection port, a catalyst collection port, a circulating flue gas inlet, a synthesis gas outlet and a synthesis gas branch; the furnace body is arranged horizontally, a pyrolysis material feed port is arranged at the top of one end of the furnace body, and a catalyst feed port is arranged at the top of the other end of the furnace body; a porous carbon collection port and a catalyst collection port are arranged at the bottom of the furnace body near the center of the furnace body; the internal space of the furnace body is functionally divided into a pyrolysis area and a gasification area; the furnace body between the discharge end of the pyrolysis material feed port and the feed end of the porous carbon collection port is the pyrolysis area, and the furnace body between the discharge end of the catalyst feed port and the feed end of the catalyst collection port is the gasification area; a material conveying screw is arranged in the furnace chamber of the furnace body along the longitudinal length, and one end of the material conveying screw is driven by a motor arranged outside the combustion chamber sleeve, A section of spiral blades with opposite rotation directions are respectively arranged on the material conveying screw corresponding to the pyrolysis area and the gasification area; the conveying direction of the spiral blades corresponding to the pyrolysis area is from one end of the pyrolysis material feed port to one end of the porous carbon collection port; the conveying direction of the spiral blades corresponding to the gasification area is from one end of the catalyst feed port to one end of the catalyst collection port; a synthesis gas outlet pipe is arranged on the upper part of the furnace body corresponding to the outer end of the gasification area; the combustion chamber sleeve is arranged on the outside of the furnace body with a gap left between the two, and the outer end of the furnace body corresponding to one end of the synthesis gas outlet pipe and the combustion chamber sleeve are separated into a combustion area by an air separation baffle, and the remaining part between the combustion chamber sleeve and the furnace body forms a jacket heat exchange structure; a plurality of burners are arranged on the air separation baffle, and the burners are connected to the external oxygen conveying pipeline through an oxygen inlet pipe, and connected to the synthesis gas outlet pipe through a synthesis gas branch pipe; a circulating flue gas inlet is arranged on the upper part of the furnace body corresponding to the outer end of the pyrolysis area and is connected to the jacket heat exchange structure.

2. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The plurality of burners are evenly arranged along the circumference of the furnace body, and the burners are further connected to an external fuel delivery pipeline through an external fuel inlet pipe.

3. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The outer wall of the combustion chamber sleeve is provided with a heat-insulating layer.

4. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The material conveying screw is supported in the furnace of the furnace body by a screw support.

5. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: Control valves are respectively arranged at the pyrolysis material feed port, the catalyst feed port, the porous carbon collection port and the catalyst collection port.

6. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: Thermocouples are respectively arranged in the furnace body corresponding to the pyrolysis area, in the furnace body corresponding to the gasification area, on the synthesis gas outlet pipe, in the jacket heat exchange structure and at the circulating flue gas inlet.

7. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The synthesis gas outlet pipe, the synthesis gas branch pipe, the oxygen inlet pipe and the circulating flue gas inlet are respectively provided with regulating valves.

8. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The material conveying screw and the spiral blades thereon are both made of ceramic or quartz materials.

9. The garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to claim 1, characterized in that: The air baffle is composed of an air baffle 1 arranged on the inner side of the combustion chamber sleeve and an air baffle 2 arranged on the outer side of the furnace body. The air baffle 1 and the air baffle 2 are riveted or fixed by bolts.

10. The method for operating the garbage pyrolysis gasification furnace with catalytic pyrolysis flue gas circulation according to any one of claims 1 to 9, characterized in that: include: 1) The biomass pyrolysis materials including domestic garbage are stored in the material feed bin. When the garbage pyrolysis gasification furnace is in operation, the pyrolysis materials are continuously fed into the furnace of the pyrolysis gasification furnace body through the pyrolysis material feed port. Under the conveying action of the material conveying screw, the biomass pyrolysis materials move in the pyrolysis area and undergo pyrolysis reaction at the same time. The porous carbon produced by pyrolysis is sent to the porous carbon collection bin through the porous carbon collection port. 2) The catalyst for gasification is stored in the catalyst feed bin. When the garbage pyrolysis gasification furnace is in operation, it is continuously fed into the furnace of the pyrolysis gasification furnace through the catalyst feed port. Under the conveying action of the material conveying screw, the catalyst moves in the gasification area and performs catalytic gasification reaction. The reacted catalyst is sent to the catalyst collection bin through the catalyst collection port; 3) At the initial stage of operation of the garbage pyrolysis gasification furnace, a portion of biomass pyrolysis materials and catalysts are supplied into the furnace of the pyrolysis gasification furnace body, and then CO2 gas is supplied into the furnace for gas washing operation; when the CO2 atmosphere in the furnace body reaches the set concentration, fuel and oxygen are respectively supplied into the burner through the synthesis gas branch pipe and the oxygen inlet pipe, and high-temperature flue gas is generated through the burner combustion; 4) When the temperature of each section in the furnace body reaches the operating requirements, that is, the furnace temperature corresponding to the pyrolysis area reaches 500-550°C, and the furnace temperature corresponding to the gasification area reaches 900-950°C, the synthesis gas generated by the pyrolysis and gasification process in the furnace body is gradually used to replace the external fuel and supplied to the burner; the pyrolysis material feed amount, catalyst feed amount, synthesis gas recovery rate, and oxygen supply rate are adjusted by the temperature reflected by the thermocouples arranged in the furnace body of the pyrolysis area, the furnace body of the gasification area, the synthesis gas outlet pipe, the jacket heat exchange structure, and the circulating flue gas inlet, so that the temperature of each area meets the operating requirements of the pyrolysis gasifier; 5) The temperature of the synthesis gas generated in the furnace body is above 900℃. Part of the synthesis gas is sent out through the synthesis gas outlet pipe, and the other part of the synthesis gas is sent into the burner through the synthesis gas branch pipe for combustion. The temperature of the high-temperature flue gas generated is above 900℃; the high-temperature flue gas flows in the jacket heat exchange structure, and flows through the outer side of the furnace body corresponding to the gasification area and the pyrolysis area in turn, and performs indirect heat exchange through the outer wall of the furnace body, so that the furnace temperature of the corresponding area is maintained at the operating requirements; the jacket heat exchange structure and the combustion area are blocked by an air baffle to prevent the high-temperature flue gas from flowing back and affecting the heat transfer effect; the temperature of the flue gas cooled after heat exchange is within 500℃, and it enters the furnace body from the circulating flue gas inlet as the pyrolysis protection gas and heat carrier in the pyrolysis area, and the gasification agent in the gasification area. The flue gas after combustion contains NH3, NO X The pollutants inside are gradually decomposed under the action of catalyst and high temperature.

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