Three-layer liquid molten liquid phase catalyst molten iron bath gasification device and its processing method

Abstract

The present invention relates to a three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device and a processing method thereof, the scheme comprising: a gasifier, wherein molten lead-bismuth alloy liquid, molten iron liquid and molten slag liquid are sequentially arranged inside from bottom to top, and the temperatures of the molten lead-bismuth alloy liquid, molten iron liquid and molten slag liquid are sequentially increased from bottom to top; a gasifier cover, which is arranged at the top of the gasifier and is sealed with the gasifier; a solid waste feeding pipe, which is obliquely arranged at the side of the gasifier and inserted into the molten lead-bismuth alloy liquid in the gasifier, and is used to feed solid waste into the molten lead-bismuth alloy liquid for pyrolysis; a top-blowing oxygen gun, which is detachably arranged at the top of the gasifier cover and is sealed with the gasifier cover; a bottom-blowing device, which is arranged at the bottom of the gasifier; and a synthesis gas outlet, which is arranged on one side of the top of the gasifier cover. The present invention utilizes the low melting point characteristics of the molten lead-bismuth alloy liquid and the cooperation of the bottom-blowing device, so that the damage speed of the solid waste feeding pipe immersed in the lead-bismuth alloy liquid is greatly reduced, and the service life is significantly improved.

Description

Technical Field

[0001] The invention relates to the field of energy technology, and in particular to a three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device and a processing method thereof. Background Art

[0002] In terms of garbage solid waste and biomass waste treatment, compared with traditional processes, the iron bath is a more advanced process for converting hazardous waste into low-carbon energy. The iron bath is to spray organic solid waste particles into the molten bath at high speed, and blow in gasifying agents such as pure oxygen for thorough treatment and conversion, converting hydrocarbon elements into clean synthesis gas (carbon monoxide and hydrogen), which can be used as fuel gas and can also be used for chemical synthesis, such as methanation to produce natural gas, Fischer-Tropsch synthesis to produce gasoline and diesel, etc., while most of the inorganic matter remains in the slag floating on the surface, achieving reduction and harmless treatment.

[0003] However, current technology usually involves inserting a feeding tube into the molten slag and molten iron for immersion feeding. Since the temperature of the molten iron and molten slag is as high as 1500°C, the feeding tube or spray gun will be damaged quickly and need to be replaced frequently, which is costly.

[0004] Therefore, a three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device and a processing method thereof are urgently needed to solve the problems existing in the prior art and significantly improve the service life of the feeding pipe. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems existing in the prior art and provide a three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device and a processing method thereof.

[0006] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme: a three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device comprises:

[0007] A gasifier, wherein molten lead-bismuth alloy liquid, molten iron liquid and molten slag liquid are sequentially arranged from bottom to top, and the temperatures of the molten lead-bismuth alloy liquid, the molten iron liquid and the molten slag liquid increase sequentially from bottom to top;

[0008] A gasifier cover, which is arranged on the top of the gasifier and is sealed with the gasifier;

[0009] A solid waste feeding pipe is obliquely arranged on the side of the gasifier and inserted into the molten lead-bismuth alloy liquid in the gasifier, and is used to feed the solid waste into the molten lead-bismuth alloy liquid for pyrolysis;

[0010] A top-blowing oxygen lance is detachably mounted on the top of the gasifier cover and is sealed with the gasifier cover to blow oxygen into the gasifier;

[0011] A bottom blowing device, arranged at the bottom of the gasifier, is used to blow oxygen or carbon dioxide into the gasifier to achieve temperature control of the molten lead-bismuth alloy liquid;

[0012] The synthesis gas outlet is arranged on one side of the top of the gasification furnace cover and is used to discharge the synthesis gas.

[0013] Working principle and beneficial effects: 1. Compared with the prior art, the present invention adds a layer of molten lead-bismuth alloy liquid with a low melting point at the bottom on the basis of the original molten iron liquid layer and the molten slag liquid layer. The molten lead-bismuth alloy liquid is temperature-controlled by blowing oxygen or carbon dioxide into it through a bottom blowing device, thereby controlling the molten lead-bismuth alloy liquid within a suitable temperature, which can significantly improve the service life of the feeding pipe;

[0014] 2. At the same time, the solid waste feeding pipe is tilted and directly inserted into the molten lead-bismuth alloy liquid of the gasifier, completely abandoning the traditional structure of vertical insertion through the molten slag liquid and molten iron liquid, so that the feeding pipe will not contact the high-temperature molten slag liquid and molten iron liquid. After the material enters the lead-bismuth liquid, it is pyrolyzed and divided into two parts. The volatile gas phase is pyrolysis gas, and the solid is pyrolysis semi-coke and inert ash. The gas phase and solid phase formed by the pyrolysis of the material in the lead-bismuth liquid continue to rise under the buoyancy of the lead-bismuth liquid and enter the higher temperature molten iron liquid and molten slag liquid to be completely cracked. The top-blown oxygen gun is used to blow in part of the oxygen, and the slag is heated through the incomplete reaction of carbon and oxygen, the combustion of part of the hydrogen, and the secondary combustion of part of the CO gas, and at the same time, it is completely gasified. In this way, the organic solid waste can still be immersed in all the molten liquid phase catalysts for thermal cracking-gasification, and the environmental protection characteristics of submerged gasification are maintained. The working temperature of the spray gun and the feeding pipe can be reduced from 1500°C to about 600°C, and the service life is increased by dozens of times.

[0015] Furthermore, the temperature of the molten lead-bismuth alloy liquid is 600-1200°C, and the temperature gradually decreases from top to bottom. This ensures that the ambient temperature of the solid waste feeding pipe inserted into the molten lead-bismuth alloy liquid is far below 1200°C, and is just suitable for the inclined setting of the solid waste feeding pipe, effectively increasing the service life of the solid waste feeding pipe.

[0016] Furthermore, the temperature of the molten iron is higher than 1200° C. Because the temperature of the molten slag is the highest, exceeding 1500° C. or close to 1500° C., and the temperature of the highest layer of the molten iron is close to the temperature of the molten slag, which is 1500° C., and the temperature of the lowest layer is about 1200° C., thus ensuring that the temperature of the highest part of the molten lead-bismuth alloy liquid does not exceed 1200° C., and the temperature of its lowest layer is much lower than 1200° C.

[0017] Furthermore, the solid waste feeding pipe blows the solid waste into the molten lead-bismuth alloy liquid through the feeding spray gun, and the outlet position of the feeding spray gun is located within 1 / 3 of the lead-bismuth alloy liquid close to the furnace bottom. This setting can use inert gas as a carrier gas to blow organic solid waste into the molten lead-bismuth alloy liquid, while ensuring that the outlet position of the feeding spray gun and most of the positions (located in the gasifier) ​​are in a relatively low temperature state, ensuring the service life of the feeding spray gun and the feeding pipe.

[0018] Furthermore, the number of solid waste feeding pipes is an even number, and they are evenly spaced in the circumferential direction of the gasifier. This arrangement aims to use an even number of pipes in a symmetrical layout to offset the vibration effect of the airflow impact jet on the furnace body.

[0019] Furthermore, the extended lines of the central axes of the two symmetrical solid waste feeding pipes intersect above the bottom of the gasifier and are no higher than 1 / 3 of the height of the lead-bismuth alloy liquid. This arrangement can avoid direct airflow impact on the refractory at the bottom of the furnace.

[0020] Furthermore, the solid waste feeding pipe conveys the solid waste into the molten lead-bismuth alloy liquid through the spiral material conveying pipe, and the spiral material conveying pipe extends out of the solid waste feeding pipe and enters the molten lead-bismuth alloy liquid. This arrangement does not require the use of an even number of spiral material conveying pipes, has fewer restrictions, can also convey larger particles of organic solid waste, and has lower costs.

[0021] Furthermore, the bottom temperature of the molten lead-bismuth alloy liquid is controlled at 600-800°C by adding oxygen or carbon dioxide through a bottom blowing device. In this configuration, oxygen can increase the temperature of the bottom lead-bismuth liquid, and carbon dioxide can reduce the temperature, which can flexibly adjust the bottom temperature of the lead-bismuth liquid and always maintain a low temperature of about 600°C.

[0022] Furthermore, a furnace gas settling chamber is provided on the syngas outlet, which is used to settle the lead-bismuth alloy liquid in the syngas and re-input the lead-bismuth alloy liquid into the feeding pipe through the lead-bismuth liquid off-blower and the lead-bismuth liquid return flow pipe, so as to reuse the lead-bismuth alloy liquid. This setting can effectively perform preliminary treatment on the syngas and then recycle the lead-bismuth liquid, which is more environmentally friendly and saves costs.

[0023] The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification processing method uses the above-mentioned three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device, comprising the following steps:

[0024] The solid waste is added into the molten lead-bismuth alloy liquid through the solid waste feeding pipe, and oxygen is blown into the molten lead-bismuth alloy liquid through the top-blowing oxygen lance to pyrolyze and gasify the solid waste, and the generated synthesis gas is discharged from the synthesis gas outlet;

[0025] The bottom blowing device blows in oxygen or carbon dioxide for temperature control, and controls the temperature at the location of the solid waste feeding pipe at 600°C or close to 600°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 It is the binary alloy phase diagram of lead-bismuth alloy;

[0028] Figure 3 It is the phase diagram of bismuth-iron binary alloy;

[0029] Figure 4 It is the phase diagram of iron-lead binary alloy.

[0030] In the figure, 1. high-pressure oxygen; 2. top-blowing oxygen lance; 3. gas seal; 4. synthesis gas pipeline; 5. gasification furnace; 6. molten slag liquid; 7. slag layer temperature sensor; 8. molten iron liquid; 9. iron liquid layer temperature sensor; 10. lead-bismuth liquid bottom temperature sensor; 11. lead-bismuth liquid middle layer temperature probe; 12. furnace gas settling chamber; 13. synthesis gas outlet; 14. lead-bismuth liquid fan off; 15. lead-bismuth liquid return flow pipe; 16. first solid waste feeding pipe; 17. first Solid waste material; 18. first inclined pipe flange; 19. first feeding inclined pipe; 20. first lead-bismuth liquid; 21. pyrolysis semi-coke particles; 22. bottom blowing device; 23. bottom blowing gas switching valve; 24. bottom blowing oxygen inlet pipe; 25. bottom blowing carbon dioxide inlet pipe; 26. bottom lead-bismuth liquid; 27. second lead-bismuth liquid; 28. second feeding inclined pipe; 29. ​​second solid waste feeding pipe; 30. second solid waste material; 31. second inclined pipe flange; 32. gasification furnace cover. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0032] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0033] Example 1

[0034] like Figure 1 As shown, the three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device comprises:

[0035] The gasification furnace 5 has molten lead-bismuth alloy liquid, molten iron liquid 8 and molten slag liquid 6 arranged therein from bottom to top, and the temperatures of the molten lead-bismuth alloy liquid, the molten iron liquid 8 and the molten slag liquid 6 increase from bottom to top;

[0036] Among them, the temperature of the molten slag liquid 6 is the highest, exceeding 1500°C or close to 1500°C, while the temperature of the highest layer of the molten iron liquid 8 (1200-1500°C) is close to the temperature of the molten slag liquid 6, which is 1500°C, and the temperature of the lowest layer is about 1200°C, thus ensuring that the temperature of the highest point of the molten lead-bismuth alloy liquid will not exceed 1200°C, and the temperature of its lowest layer is much lower than 1200°C, while the temperature of the molten lead-bismuth alloy liquid is 600-1200°C, and the temperature gradually decreases from top to bottom. In this way, it is ensured that the ambient temperature of the solid waste feeding pipe inserted into the molten lead-bismuth alloy liquid is much lower than 1200°C, and it is just suitable for the inclined setting of the solid waste feeding pipe, which effectively improves the service life of the solid waste feeding pipe.

[0037] The gasifier cover 32 is disposed on the top of the gasifier 5 and is sealed with the gasifier 5;

[0038] The matching method between the gasifier cover 32 and the gasifier 5 is the existing technology, which will not be described in detail here.

[0039] A solid waste feeding pipe is obliquely arranged on the side of the gasifier 5 and inserted into the molten lead-bismuth alloy liquid in the gasifier 5, and is used to feed the solid waste into the molten lead-bismuth alloy liquid for pyrolysis;

[0040] In one embodiment, the solid waste feeding pipe blows the solid waste into the molten lead-bismuth alloy liquid through a feeding spray gun, and the outlet position of the feeding spray gun is located within 1 / 3 of the lead-bismuth alloy liquid near the furnace bottom. The number of solid waste feeding pipes is an even number, and they are evenly spaced in the circumferential direction of the gasifier 5. The extension lines of the central axes of the two symmetrical solid waste feeding pipes intersect above the furnace bottom position of the gasifier 5 and are not higher than 1 / 3 of the height of the lead-bismuth alloy liquid. In this way, the organic solid waste can be blown into the molten lead-bismuth alloy liquid by using an inert gas as a carrier gas, and at the same time, the outlet position of the feeding spray gun and most of the positions (located in the gasifier 5) are ensured to be in a relatively low temperature state, thereby ensuring the service life of the feeding spray gun and the feeding pipe.

[0041] like Figure 1The first feeding inclined tube 19 and the second feeding inclined tube 28 are connected to the first solid waste feeding tube 16 through the first inclined tube flange 18. There are at least two first feeding inclined tubes 19. During recycling, one of them can be used to recycle lead-bismuth liquid, such as the first lead-bismuth liquid 20 in the figure. The first solid waste material 17 can be added to the first solid waste feeding tube 16. Similarly, the second feeding inclined tube 28 is connected to the second solid waste feeding tube 29 through the second inclined tube flange 31. There are at least two second feeding inclined tubes 28. During recycling, one of them can be used to recycle lead-bismuth liquid, such as the second lead-bismuth liquid 27 in the figure. The second solid waste material 30 can be added to the second solid waste feeding tube 29.

[0042] In another embodiment, the solid waste feeding pipe transports the solid waste into the molten lead-bismuth alloy liquid through a spiral material conveying pipe, and the spiral material conveying pipe extends out of the solid waste feeding pipe and enters the molten lead-bismuth alloy liquid. In this way, any number of spiral material conveying pipes can be used, and the outlet position of the spiral material conveying pipe is ensured to extend out of the root of the solid waste feeding pipe, so that the solid material at the outlet can easily float up due to the gravity of the lead-bismuth liquid.

[0043] The top-blowing oxygen lance 2 is detachably disposed on the top of the gasification furnace cover 32 and is sealed with the gasification furnace cover 32, such as the airtight seal 3, and is used to blow oxygen into the gasification furnace 5;

[0044] Part of the high-pressure oxygen 1 is blown into the top-blown oxygen lance 2, and the slag is heated and completely gasified through incomplete carbon-oxygen reaction, partial hydrogen combustion, and partial CO gas secondary combustion.

[0045] A bottom blowing device 22 is provided at the bottom of the gasification furnace 5 and is used to blow oxygen or carbon dioxide into the gasification furnace 5 to achieve temperature control of the molten lead-bismuth alloy liquid;

[0046] The bottom blowing gas is oxygen / carbon dioxide gas. Oxygen can heat up the bottom lead-bismuth liquid, while carbon dioxide can cool it down. The bottom temperature of the lead-bismuth liquid can be flexibly adjusted to always maintain a low temperature of about 600°C.

[0047] In this embodiment, the bottom blowing device 22 includes a bottom blowing gas switching valve 23 for switching between oxygen and carbon dioxide, a bottom blowing oxygen inlet pipe 24 for introducing oxygen, and a bottom blowing carbon dioxide inlet pipe 25 for introducing carbon dioxide.

[0048] The synthesis gas outlet 13 is provided on one side of the top of the gasification furnace cover 32 and is used to discharge the synthesis gas.

[0049] The syngas pipeline 4 of the syngas outlet 13 is provided with a furnace gas settling chamber 12, which is used to settle the lead-bismuth alloy liquid in the syngas and re-input the lead-bismuth alloy liquid into the feeding pipe through the lead-bismuth alloy liquid shut-off fan 14 and the lead-bismuth alloy liquid return flow pipe 15, so as to reuse the lead-bismuth alloy liquid. The syngas can be preliminarily treated effectively, and then the lead-bismuth alloy liquid can be recovered, which is more environmentally friendly and saves costs.

[0050] In this embodiment, the gasifier 5 is provided with a slag layer temperature sensor 7 corresponding to the molten slag liquid 6, an iron liquid layer temperature sensor 9 corresponding to the molten iron liquid 8, a lead-bismuth liquid bottom temperature sensor 10 corresponding to the lead-bismuth liquid, and a lead-bismuth liquid middle layer temperature probe 11, which can accurately measure the temperature of each layer.

[0051] In this way, a layer of molten lead-bismuth alloy liquid with a low melting point located at the bottom is added on the basis of the original molten iron liquid 8 layer and the molten slag liquid 6 layer. The molten lead-bismuth alloy liquid is simultaneously blown with oxygen or carbon dioxide through the bottom blowing device 22 to control the temperature, thereby controlling the molten lead-bismuth alloy liquid within a suitable temperature, which can significantly improve the service life of the feeding pipe. At the same time, the structural setting of the solid waste feeding pipe being obliquely inserted directly into the molten lead-bismuth alloy liquid of the gasification furnace 5 completely abandons the traditional structure of vertically inserting through the molten slag liquid 6 and the molten iron liquid 8, so that the feeding pipe will not contact the high-temperature molten slag liquid 6 and the molten iron liquid 8. After the material enters the bottom lead-bismuth liquid 26, it undergoes pyrolysis and is divided into two parts. The volatile gas phase is pyrolysis gas, and the solid is pyrolysis semi-coke particles 21 and inert ash, which are coordinated at the same time. In this way, the organic solid waste can still be immersed in all molten liquid phase catalysts for thermal cracking and gasification. While maintaining the environmental protection characteristics of submerged gasification, the operating temperature of the spray gun and feeding pipe can be reduced from 1500°C to about 600°C, and the service life is increased by dozens of times.

[0052] Example 2

[0053] A three-layer liquid-melting liquid-phase catalyst molten iron bath gasification processing method, using the three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device of Example 1, comprises the following steps:

[0054] Solid waste is added into the molten lead-bismuth alloy liquid through the solid waste feeding pipe, and oxygen is blown into the top-blown oxygen lance 2 to pyrolyze and gasify the solid waste, and the generated synthesis gas is discharged from the synthesis gas outlet 13;

[0055] The bottom blowing device 22 blows in oxygen or carbon dioxide for temperature control, and controls the temperature at the location of the solid waste feeding pipe to 600°C or close to 600°C.

[0056] Among them, the basic properties of lead-bismuth liquid are introduced.

[0057] 1. Melting point of lead-bismuth alloy: Lead-bismuth alloy is a common low-melting-point alloy with a density greater than that of molten metal iron or alloy (about 7000kg / M3). The density can be calculated according to the following formula, which is about 9543kg / M3 at 900 degrees Celsius.

[0058] ρ Pb-Bi (kg / M 3 )=11096-1.3236·T(K)

[0059] The melting points of lead and bismuth metals are low, and as alloys, the melting points are further reduced. The lowest melting point of lead-bismuth alloy is only about 130°C, as shown below Figure 2 As shown in the binary alloy phase diagram in . The temperature range from melting point to boiling point is wide, which is more suitable for use as a molten pool.

[0060] 2. Volatility of lead-bismuth alloy: The vapor pressure of lead and bismuth metals can be calculated using the following formula.

[0061] log(P Bi (Pa))=-10400 / T(K)-1.26log(T(K))+14.475

[0062] log(P Pb (Pa))=-10130 / T(K)-0.985log(T(K))+13.2855

[0063] The calculated vapor pressure is shown in Table 1 below:

[0064] Temperature T(℃) Bismuth Bi vapor pressure (Pa) Vapor pressure of metal lead (Pa) 600 0.07 0.06 650 0.30 0.25 700 1.05 0.85 750 3.28 2.62 800 9.20 7.23 850 23.48 18.19 900 55.15 42.24 950 120.55 91.41 1000 247.31 185.85 1050 479.64 357.62 1100 884.87 655.22 1150 1561.20 1149.03 1200 2646.33 1937.31

[0065] Table 1

[0066] In particular, after the lead-bismuth alloy is mutually melted, the activity interaction is negatively biased, resulting in a further decrease in its vapor pressure. The activity coefficients are shown in Table 2 below:

[0067]

[0068] Table 2

[0069] It can be seen that near the atomic ratio of 0.5, the activity coefficient is less than 1, which means that the lead-bismuth alloy has a negative deviation and its volatilization is suppressed. It is conducive to the stability of the process. At 1150°C, when the lead-bismuth alloy atoms each account for half, the vapor pressure of lead is only 465Pa, and the vapor pressure of bismuth is only 634Pa, totaling only 1099Pa, accounting for 1.1% of the gas phase volume of atmospheric synthesis gas. Generally, according to the output of 1700 standard cubic meters of crude synthesis gas per ton of organic solid waste, only 18 standard cubic meters of lead-bismuth alloy volatilize, which is about 167 kilograms. According to the density of 9543kg / M3, the volume of liquid alloy is equivalent to 17 liters, which is only 1.7% of the volume of 1 cubic meter of lead-bismuth alloy liquid layer. The latent heat of vaporization of lead-bismuth alloy is about 179KJ / mol, and the volatilization endothermic heat of about 167 kilograms is 143MJ, which is only equivalent to 4% of the sensible heat of synthesis gas per ton of organic solid waste. The heat can be collected again in the sensible heat recovery link of synthesis gas. The volatilized lead-bismuth alloy also settles into a condensed state during the synthesis gas cooling step and is returned to the molten pool of the gasifier 5.

[0070] 3. Natural stratification of lead-bismuth alloy and molten iron: Figure 3 Bismuth-Iron binary alloy phase diagram and Figure 4 The iron-lead binary alloy phase diagram shows that in the high-temperature molten state, in the liquid molten state, lead and bismuth are not miscible with the molten metal iron. Since the lead-bismuth alloy is not miscible with iron, the denser lead-bismuth alloy liquid completely settles in the lower layer of the iron liquid, forming an independent metal liquid phase, which is naturally stratified with the metal molten iron.

[0071] Example 3

[0072] In this embodiment, a method for controlling the temperature gradient of lead-bismuth liquid is also disclosed:

[0073] Therefore, in order to ensure that the bottom layer of low-melting-point lead-bismuth alloy liquid has a certain temperature gradient, appropriate temperature control measures are adopted to make the top of the lead-bismuth liquid 1200°C, which is higher than the melting point of carbon-saturated iron liquid 1150°C, and the bottom layer of lead-bismuth liquid 600-800°C, so that the feeding pipe deeply immersed in the lead-bismuth liquid can withstand it and has a longer life.

[0074] 1. Endothermic pyrolysis of organic solid waste materials: the first thermal effect

[0075] Organic matter is added to the bottom of the lead-bismuth liquid and undergoes thermal cracking at 600-800°C to obtain volatile gases and solid carbonaceous semi-coke. The thermal decomposition is an endothermic effect, which has a cooling effect on the bottom of the lead-bismuth liquid.

[0076] Generally, the heat absorbed by thermal decomposition of each kilogram of organic solid waste is about 1600-2500 kJ of heat. Based on the gasification of 1000 kg of organic solid waste per hour, the heat absorbed by the bottom lead-bismuth liquid 26 is 1600-2500 MJ, which is the first thermal effect and has a cooling effect.

[0077] 2. Heat conduction from the iron liquid layer to the lead-bismuth liquid: the second thermal effect

[0078] The temperature of the top iron liquid layer and the lead-bismuth liquid is 1200℃, and the temperature of the bottom lead-bismuth liquid is 600℃, with a temperature difference of 600℃. According to the lead-bismuth liquid layer with a cross-sectional area of ​​1 square meter and a depth of 2 meters, the heat flow from the top to the bottom per hour is 20.5MJ, which is the second thermal effect, and it increases the temperature of the bottom layer. The thermal conductivity coefficient is shown in Table 3 below:

[0079] Temperature Celsius Absolute temperature K Thermal conductivity of lead bismuth W / mK 200 473 10.39589781 300 573 11.73078921 400 673 13.03086061 500 773 14.29611201 600 873 15.52654341 700 973 16.72215481 800 1073 17.88294621 900 1173 19.00891761 1000 1273 20.10006901 1100 1373 21.15640041 1200 1473 22.17791181 1300 1573 23.16460321 1400 1673 24.11647461

[0080] Table 3

[0081] 3. Convective heat transfer of iron liquid layer to lead-bismuth liquid: the third thermal effect

[0082] As the lead-bismuth alloy liquid is a liquid, there is no natural flow heat exchange between the top high-temperature layer and the bottom low-temperature layer. However, under the action of the volatile gas of the material in the gasifier 5, a certain forced convection heat exchange effect will be generated, which will serve as a third thermal effect, causing the bottom low-temperature lead-bismuth liquid to heat up.

[0083] In general, in fluid mechanics and fluid heat transfer, multiple dimensionless similarity criteria, Reynolds number Re, Prandtl number Pr, and Nusselt number Nu, are used to quantitatively estimate the effect of convective heat transfer. The Reynolds number characterizes the flow state of the fluid, the Prandtl number is a dimensionless combination number that represents the mutual influence of the energy and momentum migration process in the fluid, indicating the relationship between the temperature boundary layer and the flow boundary layer, and the Nusselt number is the ratio of the convective heat across the boundary to the conductive heat.

[0084] Nu=0.664Re 1 / 2 Pr 1 / 3

[0085] h=Nu·k / L

[0086] According to the test results of hydraulic physical models and industrial practical experience, the Reynolds number Re and Prandtl number Pr were estimated using the fluid flow velocity and physical properties, and Nu was calculated to be 10.8. The convective heat transfer coefficient h of the lead-bismuth alloy liquid was calculated to be 167W / M2 K based on the thermal conductivity k and the characteristic length L. The heating power of the bottom convective heat transfer is about 100KW, and the heat flux input to the bottom layer per hour is 361MJ, which is the third thermal effect.

[0087] 4. Exothermic reaction of carbon and oxygen caused by blowing oxygen at the bottom: the fourth thermal effect

[0088] After the organic matter is pyrolyzed, part of the carbon element becomes pyrolysis semi-coke solid particles, which float up in the lead-bismuth liquid due to buoyancy. The bottom blowing gas can be switched or combined between oxygen O2 and CO2 gas, because the incomplete oxidation and complete oxidation of carbon and oxygen are both exothermic reactions, as shown in the following formula.

[0089]

[0090] C+O2=CO2(ΔH=-394kJ / mol)

[0091] The chemical equilibrium and corresponding heat release of each standard cubic meter of O2 reacting with excess C element are shown in Table 4 below.

[0092]

[0093]

[0094] Table 4

[0095] The amount of oxygen required per ton of organic solid waste is generally in the range of 500-700 standard cubic meters. By blowing oxygen from the bottom, the temperature of the bottom lead-bismuth liquid 26 can be effectively increased. For example, 136 standard cubic meters of oxygen is blown in from the bottom blowing device 22, which can generate heat income to offset the first, second, and third thermal effects. The remaining oxygen is blown in from the top blowing oxygen gun 2 to heat the molten iron layer and the slag layer to maintain the temperature of the upper part at 1500°C.

[0096] 5. Bottom-blown carbon dioxide absorbs heat: the fifth thermal effect

[0097] Under certain uncertain conditions, assuming that the bottom lead-bismuth liquid 26 is overheated, the temperature is lowered by blowing carbon dioxide gas from the bottom. CO2, as a weak oxidant, can react with C to regenerate CO. This process is an endothermic reaction, also known as the Boudouard reaction.

[0098] CO2+C=2CO(ΔH=172kJ / mol)

[0099] As a reversible reaction, the thermodynamic free energy of this reaction is as follows

[0100] Δ r G°=137890-126.52·T(K)

[0101] As the temperature increases, the reaction proceeds to the right and the degree of reaction increases. The chemical equilibrium and heat absorption of the reaction of each standard cubic meter of CO2 with excess C element are shown in Table 5 below.

[0102]

[0103]

[0104] Table 5

[0105] 6. Temperature control negative feedback mechanism

[0106] There are three negative feedback mechanisms for the temperature gradient stability control, which can realize a flexible and stable temperature gradient. That is, the temperature control logic of the bottom blowing device 22 in Example 2.

[0107] Negative feedback 1:

[0108] The higher the temperature T of the bottom lead-bismuth alloy liquid, the smaller the temperature difference with the top 1200°C, and the smaller the heat transfer drive. Then the second thermal effect and the third thermal effect are reduced accordingly, achieving negative feedback.

[0109] Negative feedback mechanism 2:

[0110] The higher the bottom temperature, the greater the temperature rise of the organic waste such as waste plastic particles blown in, the more heat is absorbed, the more thorough the cracking, the more heat is absorbed, and this brings the driving force for the bottom lead-bismuth liquid temperature to drop again.

[0111] Negative feedback 3:

[0112] The higher the bottom temperature, the greater the degree of reaction between the bottom-blown CO2 and C. Considering that the chemical equilibrium of the Boudouard reaction intensifies to the right, for example, the reaction rate at 500-600-700-800-900 degrees Celsius gradually increases, the chemical endothermic heat is also greater, which can rapidly reduce the temperature of the bottom lead-bismuth liquid 26.

[0113] The parts not described in detail in the present invention are prior art, so the present invention does not describe them in detail.

[0114] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0115] Although this article uses more high-pressure oxygen 1, top-blown oxygen lance 2, gas seal 3, synthesis gas pipeline 4, gasifier 5, molten slag 6, slag layer temperature sensor 7, molten iron 8, iron layer temperature sensor 9, lead-bismuth liquid bottom temperature sensor 10, lead-bismuth liquid middle layer temperature probe 11, furnace gas settling chamber 12, synthesis gas outlet 13, lead-bismuth liquid fan 14, lead-bismuth liquid return flow pipe 15, first solid waste feeding pipe 16, first solid waste material 17, first inclined Professional terms such as pipe flange 18, first feeding inclined pipe 19, first lead-bismuth liquor 20, pyrolysis semi-coke particles 21, bottom blowing device 22, bottom blowing gas switching valve 23, bottom blowing oxygen inlet pipe 24, bottom blowing carbon dioxide inlet pipe 25, bottom lead-bismuth liquor 26, second lead-bismuth liquor 27, second feeding inclined pipe 28, second solid waste feeding pipe 29, second solid waste material 30, second inclined pipe flange 31, gasification furnace cover 32, etc. are used, but the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

[0116] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device, characterized in that: include: A gasifier, wherein molten lead-bismuth alloy liquid, molten iron liquid and molten slag liquid are sequentially arranged from bottom to top, and the temperatures of the molten lead-bismuth alloy liquid, the molten iron liquid and the molten slag liquid increase sequentially from bottom to top; A gasifier cover, which is arranged on the top of the gasifier and is sealed with the gasifier; a solid waste feeding pipe, which is obliquely arranged at the side of the gasifier and inserted into the molten lead-bismuth alloy liquid in the gasifier, and is used to feed the solid waste into the molten lead-bismuth alloy liquid for pyrolysis; A top-blowing oxygen lance is detachably mounted on the top of the gasifier cover and is sealed with the gasifier cover to blow oxygen into the gasifier; A bottom blowing device, disposed at the bottom of the gasifier, for blowing oxygen or carbon dioxide into the gasifier to achieve temperature control of the molten lead-bismuth alloy liquid; The synthesis gas outlet is arranged on one side of the top of the gasification furnace cover and is used to discharge the synthesis gas.

2. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 1 is characterized in that: The temperature of the molten lead-bismuth alloy liquid is 600-1200° C., and the temperature gradually decreases from top to bottom.

3. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 2 is characterized in that: The temperature of the molten iron is higher than 1200°C.

4. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 1 is characterized in that: The solid waste feeding pipe blows the solid waste into the molten lead-bismuth alloy liquid through a feeding spray gun, and the outlet position of the feeding spray gun is located within 1 / 3 of the lead-bismuth alloy liquid close to the furnace bottom.

5. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 4 is characterized in that: The solid waste feeding pipes are in an even number and are evenly spaced in the circumferential direction of the gasifier.

6. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 5 is characterized in that: The extended lines of the central axes of the two symmetrical solid waste feeding pipes intersect above the bottom of the gasifier and are no higher than 1 / 3 of the height of the lead-bismuth alloy liquid.

7. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to claim 1 is characterized in that: The solid waste feeding pipe conveys the solid waste into the molten lead-bismuth alloy liquid through the spiral material conveying pipe, and the spiral material conveying pipe extends out of the solid waste feeding pipe and enters the molten lead-bismuth alloy liquid.

8. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to any one of claims 1 to 7, characterized in that: The bottom temperature of the molten lead-bismuth alloy liquid is controlled at 600-800° C. by adding oxygen or carbon dioxide through the bottom blowing device.

9. The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to any one of claims 1 to 7, characterized in that: A furnace gas settling chamber is provided on the synthesis gas outlet for settling the lead-bismuth alloy liquid in the synthesis gas and re-introducing the lead-bismuth alloy liquid into the feeding pipe through the lead-bismuth alloy liquid shut-off fan and the lead-bismuth alloy liquid return flow pipe, so as to reuse the lead-bismuth alloy liquid.

10. A three-layer liquid-melting liquid-phase catalyst molten iron bath gasification processing method, characterized in that: The three-layer liquid-melting liquid-phase catalyst molten iron bath gasification device according to any one of claims 1 to 9 comprises the following steps: The solid waste is added into the molten lead-bismuth alloy liquid through the solid waste feeding pipe, and oxygen is blown into the molten lead-bismuth alloy liquid through the top-blowing oxygen lance to pyrolyze and gasify the solid waste, and the generated synthesis gas is discharged from the synthesis gas outlet; The bottom blowing device blows in oxygen or carbon dioxide for temperature control, and controls the temperature of the lead-bismuth liquid at the location of the solid waste feeding pipe at 600°C.

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