A high-temperature clean gasification device and method for achieving a high carbon conversion rate of carbon-containing materials

Abstract

A vertical melting gasifier (100) and method for harmlessly disposing carbon-containing materials. The furnace sequentially includes a low-carbon slag section (A), a high-carbon slag section (B), a flash pyrolysis redox section (C), and a temperature reduction and reduction section (D) from bottom to top. The low-carbon slag section includes a first gasifying agent inlet (11), a slag auxiliary gas inlet (1), and a liquid slag discharge outlet (10); the high-carbon slag section includes a second gasifying agent inlet (2); the flash pyrolysis redox section includes a carbon-containing material inlet (3), a third gasifying agent inlet (4), and a carbon fine powder inlet (9); the temperature reduction and reduction section includes a cooling device configured to lower the temperature inside the section, and a high-temperature raw syngas outlet (7). Under normal operating conditions, the pyrolytic carbon particles falling into the high-carbon slag section do not have adhesiveness or fluidity due to the carbon content being higher than the threshold; the pyrolytic carbon particles falling into the low-carbon slag section have adhesiveness or fluidity due to the carbon content being lower than the threshold; the carbon-containing materials fed into the flash pyrolysis redox section undergo flash pyrolysis, and some of the pyrolysis products undergo redox reactions; the CO2, H2O in the gas entering the temperature reduction and reduction section, and the carbon in the carbon-containing fly ash undergo reduction reactions to generate CO and H2.

Description

Technical Field

[0001] This application relates to the technical field of harmless treatment of carbon-containing materials, and particularly relates to a high-temperature clean gasification device and method for achieving a high carbon conversion rate of carbon-containing materials. Background Art

[0002] Carbon-containing materials widely exist in nature, including both naturally formed coal, petroleum, and trees, as well as various synthetic plastics, rubbers, domestic waste, organic hazardous waste, etc. Waste materials that have lost their use value after being used by humans often need to be disposed of appropriately to avoid harming the environment. In particular, hazardous waste often has dangerous characteristics such as corrosiveness, toxicity, flammability, reactivity, and infectivity. Random dumping or improper utilization and disposal will seriously endanger human health and even cause irreparable damage to the ecological environment. Currently, the operation and technical level of facilities for the utilization and disposal of hazardous waste need to be improved, and there are phenomena of exceeding the standard emissions. The pollution problem of hazardous waste containing heavy metals is particularly prominent.

[0003] Current disposal methods for hazardous waste include landfill, incineration, co-disposal in cement kilns, and plasma melting, etc. Among them, landfill requires a large amount of land and is prone to land pollution; incineration has problems such as incomplete disposal and secondary pollution of flue gas; co-disposal in cement kilns has certain technical advantages due to high temperature and long residence time, etc., but it requires that the disposal materials do not affect the quality of cement, and the disposal volume is limited; plasma melting is a newly emerging hazardous waste disposal technology in recent years, with advantages such as thorough harmlessness and obvious reduction in volume, and basically solves the problem of secondary pollution of solid substances, but there are also problems such as a complex flue gas treatment system, easy occurrence of secondary pollution, and high disposal costs.

[0004] The most important thing for achieving harmlessness after the disposal of solid waste is to solve the harmlessness problems of the solid-phase slag and gas phase after disposal. Due to the presence of harmful substances such as heavy metals in the solid-phase slag, vitrification is an important way to achieve harmlessness. The harmful substances in the gas phase mainly include NO x, SO2, HCl, H2S, organic substances such as dioxins, fly ash containing heavy metals, etc. The best way to eliminate gas-phase pollution is to avoid generation during the disposal process. The second is to capture through purification means to avoid discharging into the environment. The technical solutions disclosed in Chinese patents CN104053949B and CN105605581B have basically achieved the vitrification of solid-phase slag. However, due to the existence of medium and low-temperature pyrolysis, there are still problems such as incomplete gas-phase disposal and easy generation of tar-like substances. The technical solution disclosed in Chinese patent application CN109210541A has solved the vitrification problem of solid-phase slag and basically solved the problem of tar-like substances. However, the effective gas content in the synthesis gas is low. At the same time, due to the relatively low gasification temperature (900 - 1000°C), especially under fluctuating furnace conditions, there are still problems of incomplete decomposition of some toxic organic substances. Summary of the Invention

[0005] An object of the present application is to make the products generated after the disposal of carbon-containing materials all have the characteristics of being clean and harmless.

[0006] According to one aspect of the present application, a vertical melting gasification furnace for harmlessly disposing carbon-containing materials is provided. The melting gasification furnace sequentially includes a low-carbon slag section, a high-carbon slag section, a flash pyrolysis redox section, and a cooling reduction section from bottom to top. The low-carbon slag section includes a first gasifying agent inlet, a slag auxiliary combustion gas inlet, and a liquid slag discharge outlet. Under normal operating conditions, the pyrolytic carbon particles falling into the low-carbon slag section have adhesiveness or fluidity due to the carbon content being lower than a threshold value. The high-carbon slag section includes a second gasifying agent inlet. Under normal operating conditions, the pyrolytic carbon particles falling into the high-carbon slag section do not have adhesiveness or fluidity due to the carbon content being higher than the threshold value. The flash pyrolysis redox section includes a carbon-containing material inlet, a third gasifying agent inlet, and a carbon fine powder inlet. Under normal operating conditions, the carbon-containing materials fed into the flash pyrolysis redox section undergo flash pyrolysis, and some of the pyrolysis products undergo redox reactions. The cooling reduction section includes a cooling device configured to lower the temperature inside this section and a high-temperature raw synthesis gas outlet. Under normal operating conditions, CO2, H2O in the gas entering the cooling reduction section and carbon in the carbon-containing fly ash undergo reduction reactions to generate CO and H2.

[0007] According to some embodiments, under normal operating conditions, the temperature in the flash pyrolysis redox section is 1250°C to 2500°C; the inlet temperature of the cooling reduction section is 1150°C to 2500°C, and the outlet temperature is lower than the ash deformation temperature; the temperature in the high-carbon slag section is 1350°C to 2500°C; and the temperature in the low-carbon slag section is at least 50°C to 200°C higher than the ash melting point.

[0008] According to some embodiments, the first gasifier inlet, the second gasifier inlet, and the third gasifier inlet are configured to inject pure oxygen or oxygen-enriched air and are each provided with a flow rate regulating device, which can adjust the injection amounts of the first, second, and third gasifying agents according to the CO2 content, slag discharge temperature, and furnace temperature of the gas discharged from the high-temperature raw syngas outlet.

[0009] According to some embodiments, the slag auxiliary gas inlet is configured to inject auxiliary gas or inert gas, and is provided with a flow rate regulating device, which can adjust the injection amount of the auxiliary gas or inert gas according to the slag discharge condition and furnace temperature.

[0010] According to some embodiments, the carbonaceous material inlet is connected to a continuous feeding device and is located vertically between the second gasifier inlet and the third gasifier inlet.

[0011] According to some embodiments, the carbonaceous fine powder inlet is configured to inject carbonaceous fine powder and is provided with a flow rate regulating device, which can adjust the injection amount of the carbonaceous fine powder according to the CO2 content of the gas discharged from the high-temperature raw syngas outlet and the inlet temperature of the cooling and reduction section.

[0012] According to some embodiments, the cooling device includes a cooling medium inlet configured to inject a cooling medium into the internal space of the cooling and reduction section and / or a circulating cooling system provided in the furnace wall of the cooling and reduction section.

[0013] According to another aspect of the present application, there is also provided a method for melting and gasifying a carbonaceous material using the vertical melting gasifier as described above, including the following steps:

[0014] - Continuously feed the carbonaceous material through the carbonaceous material inlet into the flash pyrolysis redox section and inject the third gasifying agent and carbonaceous fine powder through the third gasifier inlet and the carbonaceous fine powder inlet respectively, so that the carbonaceous material undergoes flash pyrolysis to generate pyrolysis gas, pyrolysis carbon, and carbonaceous fly ash. The pyrolysis gas and carbonaceous fly ash react rapidly with the third gasifying agent and carbonaceous fine powder to generate small molecule gases mainly composed of CO, CO2, H2, and H2O and entrain carbonaceous fly ash and possibly remaining macromolecular organic matter into the cooling and reduction section, and the pyrolysis carbon falls into the high-carbon slag section under the action of gravity;

[0015] - In the gas entering the cooling and reduction section from the flash pyrolysis redox section, CO2, H2O, and carbon in the carbonaceous fly ash undergo a reduction reaction to generate CO and H2, and the possibly remaining macromolecular organic matter continues to decompose;

[0016] -Inject a second gasifying agent into the high-carbon slag section through the second gasifying agent inlet. The second gasifying agent agitates the falling pyrolytic carbon, causing it to decompose and break, and undergoing an exothermic redox reaction. The generated high-temperature gas entrains the carbon-containing fly ash produced by the fragmentation and enters the flash pyrolysis redox section. At the same time, as the carbon content in the pyrolytic carbon continuously decreases, it becomes low-carbon molten slag and falls to the low-carbon slag section; and

[0017] -Inject a first gasifying agent into the low-carbon slag section through the first gasifying agent inlet. The first gasifying agent agitates the slag and reacts exothermically with the combustible substances in the slag, further reducing the residual carbon in the slag and making it homogeneously vitrified. The vitrified liquid slag is discharged from the liquid slag discharge port.

[0018] According to some embodiments, before the step of feeding the carbon-containing material, there is also a step of pre-treating the carbon-containing material, and the carbon-containing material after pre-treatment meets the homogenization requirements.

[0019] According to some embodiments, before the step of feeding the carbon-containing material, there are also the following steps: Feed a slag-producing material into the molten gasifier, and inject a combustion-supporting gas and a first gasifying agent through the combustion-supporting gas inlet for slag and the first gasifying agent inlet respectively, so that the combustion-supporting gas and the first gasifying agent undergo a combustion reaction, heating the molten slag-producing material until a stable molten pool is established, the temperature of each section in the furnace reaches a predetermined temperature, and the slag discharge condition is satisfied.

[0020] According to some embodiments, the method further includes the following steps: By adjusting the amount of the combustion-supporting gas or inert gas injected through the combustion-supporting gas inlet for slag and the amount of the first gasifying agent injected through the first gasifying agent inlet, the temperature of the low-carbon slag section is at least 50°C to 200°C higher than the ash melting point under normal operating conditions.

[0021] According to some embodiments, under normal operating conditions, the temperature in the high-carbon slag section is 1350°C to 2500°C.

[0022] According to some embodiments, under normal operating conditions, the temperature in the flash pyrolysis redox section is 1250°C to 2500°C, and the inlet temperature of the cooling and reduction section (D) is 1150°C to 2500°C.

[0023] According to some embodiments, the cooling device includes a cooling medium inlet configured to inject a cooling medium into the internal space of the cooling and reduction section and / or a circulating cooling system provided in the furnace wall of the cooling and reduction section. By adjusting the cooling device, the outlet temperature of the cooling and reduction section is lower than the ash deformation temperature under normal operating conditions.

[0024] According to some embodiments, the cooling medium is selected from: water mist, water vapor, cooled syngas, carbon dioxide gas, and combinations thereof.

[0025] According to some embodiments, the particle size of the carbonaceous fine powder is less than 200 microns, preferably less than 100 microns.

[0026] According to some embodiments, the first gasifying agent, the second gasifying agent, and the third gasifying agent are all pure oxygen or oxygen-enriched air.

[0027] According to some embodiments, by adjusting the amounts of various materials fed into the furnace, the total molar ratio of carbon to oxygen in the materials fed into the furnace is 0.9 to 1.3, preferably 0.95 to 1.2, and more preferably 1.

[0028] According to some embodiments, the combustion-supporting gas is fuel gas or atomized fuel oil.

[0029] In the present application, the term "vertical melting gasifier" refers to a furnace with a longitudinal axis in the vertical direction, which is used to burn and gasify combustibles in the materials fed into it and heat and melt ash and incombustibles.

[0030] In the present application, the term "carbonaceous material" refers to a material that at least partially includes carbonaceous combustibles, such as coal, petroleum, coke, biomass, plastics, rubber, domestic waste, pharmaceutical residues, oil sludge, etc.

[0031] In the present application, the term "cohesiveness" means that particles have a tendency to agglomerate and grow and will adhere to the liquid slag.

[0032] In the present application, the term "flowability" means that the particles have become liquid, merged with the liquid slag, and can flow like a liquid, but the carbon content therein is still higher than 1% and does not yet constitute a qualified liquid slag.

[0033] In the present application, the term "flash pyrolysis" refers to pyrolysis with a heating rate greater than 5000 degrees per second and a final pyrolysis temperature exceeding 1000 degrees.

[0034] In the present application, the term "pure oxygen" refers to a gas with an oxygen volume content greater than or equal to 90%, and the term "oxygen-enriched air" refers to air with an oxygen volume content greater than or equal to 22%.

[0035] In the present application, the term "homogenization requirement" means that during the material transportation process, the change in the characteristic indexes (such as calorific value, ash composition, water content) of the materials passing through a certain cross-section in the previous minute and the materials passing through in the next minute does not exceed 6%, and more preferably does not exceed 3%.

[0036] In the present application, the term "slag-producing material" refers to the materials fed into the furnace to help establish a stable molten pool before the melting gasifier enters the normal operating condition, including but not limited to coke, firewood, coal, and ash slag.

[0037] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the present invention. Other features, objects, and advantages of the present invention will become apparent from the specification, the drawings, and the claims. Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only show some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a schematic structural diagram of a vertical melting gasifier according to some embodiments of the present application.

[0040] Figure 2 It is a flowchart of a method for melting and gasifying carbonaceous materials according to some embodiments of the present application. Detailed Embodiments

[0041] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0042] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "the", and "said" used in this application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. Words such as "including" or "comprising" mean that the elements or items appearing before "including" or "comprising" cover the elements or items listed after "including" or "comprising" and their equivalents, and do not exclude other elements or items. Words such as "connected" or "coupled" are not limited to physical or mechanical connections and may include electrical connections, whether direct or indirect. "Plurality" includes two, which is equivalent to at least two. It should be understood that although the terms first, second, third, etc. may be used in this invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information.

[0043] The following refers to Figure 1 The vertical melting gasifier 100 according to an embodiment of the present application will be described. This figure schematically shows the structure of the furnace. The melting gasifier is used for harmless treatment of various carbonaceous materials, especially carbonaceous waste. The melting gasifier sequentially includes a low-carbon slag section A, a high-carbon slag section B, a flash pyrolysis redox section C, and a temperature reduction reduction section D from bottom to top. The low-carbon slag section A includes a first gasifier inlet 11, a slag auxiliary gas inlet 1, and a liquid slag discharge outlet 10. Under normal operating conditions, the pyrolytic carbon particles falling into the low-carbon slag section A have adhesiveness or fluidity due to the carbon content being lower than a threshold value. The high-carbon slag section B includes a second gasifier inlet 2. Under normal operating conditions, the pyrolytic carbon particles falling into the high-carbon slag section B do not have adhesiveness or fluidity due to the carbon content being higher than the threshold value. The threshold value depends on the specific composition of the material to be treated and is usually between 10 wt% and 35 wt%. The flash pyrolysis redox section C includes a carbonaceous material inlet 3, a third gasifier inlet 4, and a carbonaceous fine powder inlet 9. Under normal operating conditions, the carbonaceous materials fed into the flash pyrolysis redox section C undergo flash pyrolysis, and some of the pyrolysis products undergo redox reactions. The temperature reduction reduction section D includes a cooling device for reducing the temperature inside this section and a high-temperature raw syngas outlet 7. Under normal operating conditions, the CO2, H2O, and carbon in the carbonaceous fly ash in the gas entering the temperature reduction reduction section D undergo reduction reactions to generate CO and H2.

[0044] In the above-mentioned molten gasifier, by setting up the low-carbon slag section A, high-carbon slag section B, flash pyrolysis redox section C and cooling reduction section D that cooperate with each other and work together, the carbon-containing materials fed into the furnace can ultimately be converted into vitrified liquid slag and a gas-phase product mainly composed of CO and H2 without macromolecular organic substances, thus meeting the requirements of cleanliness and harmlessness. In addition, since the vitrified slag has a high density and can be used as building materials, the purposes of reduction and resource utilization are achieved. Moreover, the residual carbon content in the slag discharged from the above-mentioned molten gasifier can reach an extremely low level, such as less than 1%, so a high carbon conversion rate can be achieved, that is, a high proportion of carbon in the carbon-containing materials is converted into small-molecule carbon-containing gases such as CO and CO2. In addition, for common carbon-containing materials, after being treated by the molten gasifier of the present application, the volume content of effective gases (CO and H2) in the gas-phase product can reach more than 80% (a significant increase compared with the prior art), and it does not contain macromolecular organic substances. It can be conveniently and pollution-free further processed into a raw material gas (CO + H2) with industrial utilization value or the CO therein can be further reacted to generate H2, which can be filled and sold as a product, thus greatly reducing the gas emissions into the environment and achieving the reduction of emissions and the resource utilization of products.

[0045] In Figure 1 the illustrated embodiment, the first gasifier inlet 11, the second gasifier inlet 2 and the third gasifier inlet 4 are used for injecting gasifying agents, and the position of the first gasifier inlet 11 is set such that it can inject the gasifying agent into the middle and lower parts of the molten pool. In some embodiments, the gasifying agent used is a gas with an oxygen volume content greater than or equal to 90% (hereinafter referred to as pure oxygen), such as a gas with an oxygen content of 92%, 95%, 98%, 99%. In other embodiments, the gasifying agent used is air with an oxygen volume content greater than or equal to 22% (hereinafter referred to as oxygen-enriched air). Using pure oxygen or oxygen-enriched air as the gasifying agent is beneficial to promoting the combustion reaction of combustibles, generating high-temperature gases, quickly establishing a high-temperature environment, and at the same time is beneficial to increasing the content of effective gases. However, it should be understood that other gasifying agents can also be used. In Figure 1 the illustrated embodiment, the first gasifier inlet 11, the second gasifier inlet 2 and the third gasifier inlet 4 are respectively provided with flow regulating devices 1101, 201, 401, and these flow regulating devices can adjust the injection amounts of the first, second and third gasifying agents according to the CO2 content in the gas discharged from the high-temperature raw syngas outlet 7, the slag discharge temperature and the furnace temperature. According to a possible implementation manner, these flow regulating devices are communicatively connected to a controller, and the controller receives the signals of the gas composition analysis sensor and the temperature sensor and issues a flow regulation command to these flow regulating devices according to the signals.

[0046] In Figure 1In the illustrated embodiment, the slag auxiliary gas inlet 1 is used to inject auxiliary gas or inert gas. The auxiliary gas can be any combustible gas (i.e., fuel gas), such as natural gas, liquefied gas, propane, or atomized fuel oil; the inert gas can be any gas that does not react with the liquid slag, such as CO2, N2. As Figure 1 shown, the slag auxiliary gas inlet 1 is provided with a flow regulating device 101, which can adjust the injection amount of the auxiliary gas or inert gas according to the slag discharge situation and the furnace temperature.

[0047] In Figure 1 the illustrated embodiment, the carbonaceous material inlet 3 is connected to a continuous feeding device 302 (e.g., a screw feeding device). In this way, the carbonaceous material (e.g., a mixture obtained by proportioning several of coal, petroleum, coke, biomass, plastics, rubber, domestic waste, pharmaceutical residues, and oil sludge according to indicators) that meets the homogenization requirements after pretreatment can be continuously fed into the molten gasifier, ensuring the stability of the furnace temperature and the composition of the high-temperature raw syngas produced. In addition, the carbonaceous material inlet 3 is located between the second gasifying agent inlet 2 and the third gasifying agent inlet 4 in the vertical direction. As described above, the carbonaceous material immediately undergoes flash pyrolysis after entering the furnace, decomposing into falling pyrolytic carbon and rising pyrolytic gas. The pyrolysis process requires heat absorption, so heat needs to be continuously supplied to the flash pyrolysis redox section C. Otherwise, the temperature of this section will decrease and cannot meet the requirements of flash pyrolysis. The second gasifying agent injected from the second gasifying agent inlet 2 undergoes an exothermic reaction with the pyrolytic carbon falling from the flash pyrolysis redox section C, and the generated high-temperature gas enters the flash pyrolysis redox section C to provide heat supply for the flash pyrolysis of the carbonaceous material, so that the temperature near the carbonaceous material inlet 3 always meets the requirements of flash pyrolysis. The third gasifying agent injected from the third gasifying agent inlet 4 located above the carbonaceous material inlet 3 is mainly used to control the temperature of the rising gas phase, ensuring that the temperature of the gas phase entering the cooling reaction section D meets the requirement of above 1150 °C. At the same time, the oxygen in the third gasifying agent reacts quickly with the rising macromolecular organic matter, which is beneficial to the rapid elimination of macromolecular organic matter.

[0048] In Figure 1 the illustrated embodiment, the carbonaceous fine powder inlet 9 is used to inject carbonaceous fine powder and is provided with a flow regulating device 901, which can adjust the injection amount of the carbonaceous fine powder according to the CO2 content in the gas discharged from the high-temperature raw syngas outlet 7 and the inlet temperature of the cooling reduction section D. Advantageously, the particle size of the carbonaceous fine powder is less than 200 microns, preferably less than 100 microns. The carbonaceous fine powder with a small particle size has a larger residual carbon surface area, so it is easier to react with CO2 and H2O, resulting in a faster heating rate and ensuring the complete pyrolysis of the carbonaceous material.

[0049] In Figure 1In the illustrated embodiment, the cooling device of the cooling and reduction section D includes a cooling medium injection port 8 for injecting a cooling medium into the internal space of this section and a circulating cooling system provided within the furnace wall of this section. The cooling medium injection port 8 and the cooling medium passage of the circulating cooling system are arranged near the high-temperature raw syngas outlet 7 so as to cool the gas near this outlet. The cooling medium injection port 8 is provided with a flow regulating device 801 which can regulate the injection amount of the cooling medium. The cooling medium injected from the cooling medium injection port 8 can be water mist, water vapor, cooled syngas, carbon dioxide gas or one or several of them that reach a predetermined temperature. Figure 1 Only the circulating cooling medium inlet 5 and the circulating cooling medium outlet 6 of the circulating cooling system are shown, but those skilled in the art can understand that a cooling medium passage fluidly communicating with the inlet 5 and the outlet 6 is also provided within the furnace wall. The circulating cooling medium can be a low-temperature fluid such as water, oil, etc. By injecting a cooling medium from the cooling medium injection port 8 into the internal space of the cooling and reduction section D and allowing the circulating cooling medium to circulate within the passage in the furnace wall, it is possible to make the outlet temperature of the cooling and reduction section D lower than the deformation temperature of the ash (different ashes have different deformation temperatures, which can be measured by standard test methods, and the deformation temperature of common ashes is generally 900°C to 1200°C), so that the ash loses its viscosity and avoids sticking and clogging in the high-temperature raw syngas outlet 7 and subsequent pipelines. In this way, the molten gasifier can operate for a long time without frequent shutdown for cleaning. Since the circulating cooling system can also play a role in cooling the gas within the cooling and reduction section D, the amount of the cooling medium injected from the cooling medium injection port 8 can be reduced. In addition, setting up the circulating cooling system has another advantage, that is, high-quality waste heat can be recovered through the heat exchange between the circulating cooling medium and the high-temperature gas, improving the thermal efficiency of the system. It should be understood that the cooling medium injection port 8 and the circulating cooling system can replace each other and are not necessarily provided simultaneously. In some embodiments, only the cooling medium injection port 8 is provided and no circulating cooling system is provided within the furnace wall of this section. In other embodiments, it is just the opposite.

[0050] It should be understood that Figure 1Only a possible shape of the smelting gasifier according to some embodiments is schematically shown. In the embodiment shown in this figure, the smelting gasifier has the shape of a cylinder with a longitudinal axis in the vertical direction, but it should be understood that it can also have other shapes. In some embodiments, the smelting gasifier has a tubular shape with a cross-section being a polygon (such as a quadrilateral, pentagon, hexagon). In other embodiments, the smelting gasifier has a frustum shape with the cross-sectional area gradually changing in the vertical direction. In some embodiments, some or all of the segments of the smelting gasifier have different shapes. Moreover, it should be understood that the above-mentioned low-carbon slag segment A, high-carbon slag segment B, flash pyrolysis redox segment C, and temperature reduction reduction segment D are only a general functional partition, without strict physical boundaries, and there is even a situation where at least part of adjacent segments overlap. In addition, the height of each of the above segments and the proportion of the height occupied can be determined by those skilled in the art, for example, according to the properties and quantity of the material to be processed, and are not limited in this application.

[0051] It should also be understood that Figure 1 Only the approximate positions of the respective inlets and outlets are schematically shown, and only one inlet and outlet is schematically shown for each, but those skilled in the art can adjust the positions and quantities of each inlet and outlet according to actual needs. For example, a plurality of inlets and outlets can be arranged at intervals in the circumferential direction of the furnace, and multiple layers of inlets and outlets can also be arranged in the height direction of the furnace. Additionally, some inlets can even coincide. For example, the carbonaceous material inlet 3 and the third gasifying agent inlet 4 can be the same opening, and the carbonaceous material and the third gasifying agent are simultaneously injected through a tube with a double channel from this opening.

[0052] It should also be understood that although not shown in the figure, the smelting gasifier according to the embodiments of the present application can also include various sensors at appropriate positions, such as temperature sensors, gas composition analysis sensors, flow sensors, etc., for transmitting signals to the controller, and the controller controls the flow regulating devices at each inlet according to these signals, so that the injection amounts and injection timing of various substances injected into the furnace are as optimal as possible, thereby enabling the smelting gasifier to operate in the best state.

[0053] Next, with reference to Figure 1 and Figure 2 a method for smelting and gasifying carbonaceous materials using the above-mentioned smelting gasifier will be described. Figure 2 is a schematic flow chart of the method according to some embodiments of the present application. It should be understood that although Figure 2The steps in the flowchart are shown in sequence according to the arrows, but these steps do not necessarily need to be executed in the order indicated by the arrows. Unless otherwise clearly stated in this document, there is no strict order restriction for the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figure may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily need to be completed at the same time, but can be executed at different times, and their execution order does not necessarily need to be sequential, but can be executed alternately or in rotation with at least a part of other steps or sub-steps or stages of other steps.

[0054] In Figure 2 the illustrated embodiment, the method includes the following steps:

[0055] Step S1: Continuously feed the carbonaceous material into the flash pyrolysis redox section C through the carbonaceous material inlet 3, and spray the third gasifying agent and carbonaceous fine powder through the third gasifying agent inlet 4 and the carbonaceous fine powder inlet 9 respectively, so that the carbonaceous material undergoes flash pyrolysis to generate pyrolysis gas (the composition varies with the fed carbonaceous material and may include one or more of CO, H2, CO2, CH4, H2S, etc.), pyrolysis carbon, and carbonaceous fly ash. The pyrolysis gas and carbonaceous fly ash react rapidly with the third gasifying agent and carbonaceous fine powder to generate small molecule gases mainly composed of CO, CO2, H2, and H2O, and entrain the carbonaceous fly ash and possibly remaining macromolecular organic matter into the cooling and reduction section D. The pyrolysis carbon falls into the high-carbon molten slag section B under the action of gravity;

[0056] Step S2: The CO2, H2O in the gas entering the cooling and reduction section D from the flash pyrolysis redox section C and the carbon in the carbonaceous fly ash undergo a reduction reaction to generate CO and H2, and the possibly remaining macromolecular organic matter continues to decompose;

[0057] Step S3: Spray the second gasifying agent into the high-carbon molten slag section B through the second gasifying agent inlet 2. The second gasifying agent agitates the falling pyrolysis carbon to decompose and break it, and undergoes an exothermic redox reaction. The generated high-temperature gas entrains the carbonaceous fly ash generated by the fragmentation into the flash pyrolysis redox section C. At the same time, the pyrolysis carbon becomes low-carbon molten slag and falls to the low-carbon molten slag section A as the carbon content continuously decreases; and

[0058] Step S4: Spray the first gasifying agent into the low-carbon molten slag section A through the first gasifying agent inlet 11. The first gasifying agent agitates the molten slag and reacts exothermically with the combustible substances in the molten slag to further reduce the residual carbon in the molten slag and make it homogenously vitrified. The vitrified liquid slag is discharged from the liquid slag discharge port 10.

[0059] In the above method, under normal operating conditions, the flash pyrolysis redox section C has a high-temperature environment (in some embodiments, up to 1250 °C to 2500 °C), causing the fed carbon-containing material to instantaneously undergo pyrolysis (i.e., flash pyrolysis), generating pyrolysis gas, pyrolysis carbon, and carbon-containing fly ash. On the one hand, the pyrolysis gas and carbon-containing fly ash, together with the third gasifying agent sprayed from the third gasifying agent inlet 4, a small amount of carbon-containing fine powder sprayed from the carbon-containing fine powder inlet 9, and the high-temperature gas generated in the high-carbon slag section B, quickly mix and react in the high-temperature environment of the flash pyrolysis redox section C to generate small-molecule gases mainly composed of CO, CO2, H2, and H2O. This gas entrains carbon-containing fly ash and possibly remaining macromolecular organic matter into the temperature-reducing reduction section D, which also has a high-temperature environment (in some embodiments, the inlet temperature of this section is 1150 °C to 2500 °C, and the outlet temperature is lower than the ash deformation temperature). In this section, CO2 and H2O in it react with the carbon in the carbon-containing fly ash to generate CO and H2, and the possibly remaining macromolecular organic matter continues to decompose into small-molecule gases at high temperatures, greatly reducing the remaining carbon content in the fly ash and making the gas finally discharged from the high-temperature raw syngas outlet 7 contain more than 80% (volume ratio) of CO and H2, a small amount of CO2 (volume content less than 10%, less than 5% under stable operating conditions), H2O, trace amounts of small-molecule gases such as CH4, H2S, N2, and a small amount of fly ash, without any macromolecular organic matter, thus effectively avoiding the generation of tar-like substances in the conventional combustion and medium- and low-temperature pyrolysis processes, and avoiding the generation of benzene, phenol, dioxin-like substances from the source, achieving the harmlessness of the gas phase. Moreover, compared with the prior art, the content of effective gases (i.e., CO and H2) in the gas discharged from the high-temperature raw syngas outlet 7 is significantly increased, enabling it to be processed through subsequent treatment (subsequent treatment equipment is not shown in the drawings of this application) to become a raw material gas (CO + H2) with industrial utilization value or to further react the CO in it to generate H2, which can be filled and sold as a product, realizing the resource utilization of the product. Only extremely small amounts of CO2 and H2O are finally discharged into the atmosphere, thereby greatly reducing the impact on the environment. On the other hand, the pyrolysis carbon (solid phase) generated by flash pyrolysis falls by gravity into the high-carbon slag section B, which also has a high-temperature environment (in some embodiments, up to 1350 °C to 2500 °C). In this section, the pyrolysis carbon is further decomposed, broken, and undergoes oxidation-reduction reactions under the agitation of the second gasifying agent sprayed from the second gasifying agent inlet 2 and in the high-temperature environment, releasing a large amount of heat. The generated high-temperature gas (mainly composed of CO and CO2, with a temperature up to 1500 °C to 3000 °C) entrains the carbon-containing fly ash generated by the breaking into the flash pyrolysis redox section C. At the same time, the pyrolysis carbon becomes low-carbon molten slag and falls to the low-carbon slag section A as the carbon content continuously decreases (the temperature changes greatly here, but the lowest temperature is 50 °C to 200 °C higher than the ash melting point, and the highest temperature may exceed 2500 °C).In the low-carbon slag section A, the pyrolytic carbon melts into a liquid state and fuses with the slag. The first gasifying agent injected from the first gasifying agent inlet 11 agitates the slag and reacts with combustible substances such as carbon in the slag to release heat, further reducing the residual carbon in the slag and making it homogeneously vitrified, effectively solidifying heavy metals, thereby realizing the harmless treatment of the solid-phase slag. Moreover, since the vitrified slag has a high density and can be used as a building material, reduction and resource utilization are achieved. In addition, due to the long residence time of the solid phase in the high-temperature environment in the furnace (successively passing through the flash pyrolysis redox section C, high-carbon slag section B, and low-carbon slag section A) and being fully mixed and thoroughly reacted under the agitation of the gasifying agent, most of the carbon therein is finally converted into small-molecule carbon-containing gases such as CO and CO2, and the residual carbon content in the slag is less than 1 wt%, thereby achieving a high carbon conversion rate. Even for materials with poor reactivity, this goal can be achieved. Additionally, due to the long residence time of the ash slag in the high-temperature environment in the furnace, the temperature field distribution in the furnace is uniform, the reaction rate is fast under the action of gas stirring, and the carbon reacts fully with oxygen, so the slag is thoroughly homogenized, better vitrified, and more conducive to the solidification of heavy metals.

[0060] When the carbon-containing material to be treated does not meet the requirements, it needs to be pretreated before being put into the furnace. Therefore, in some embodiments, the above method further includes a step of pretreating the carbon-containing material, for example, drying several different materials and then mixing them according to the indexes so that the carbon-containing material after pretreatment meets the homogenization requirements, that is, during the material transportation process, the change in the characteristic indexes (such as calorific value, ash composition, water content) of the material passing through a certain cross-section in the previous minute and the material passing through in the next minute does not exceed 6%, and more preferably does not exceed 3%. Through the pretreatment of the material, the properties of the material entering the molten gasification furnace are relatively stable, and it is not necessary to frequently adjust the various preset operating parameters of the furnace, and the furnace can operate stably for a long time. In addition, through the pretreatment, the molten gasification furnace can also dispose of more types of carbon-containing materials and has a wide adaptability range.

[0061] In accordance with Figure 2In the method of the illustrated embodiment, before step S1, there is also step S0. In step S0, slag-producing materials (such as coke, firewood, coal, ash, etc.) are put into the molten gasifier, and auxiliary combustion gas (such as any combustible gas like natural gas, liquefied gas, propane, or atomized fuel oil) and the first gasifying agent (such as pure oxygen, oxygen-enriched air) are respectively sprayed into the molten slag auxiliary combustion gas inlet 1 and the first gasifying agent inlet 11, so that the auxiliary combustion gas and the first gasifying agent undergo a combustion reaction to heat the molten slag-producing materials until a stable molten pool is established, each section in the furnace reaches a predetermined temperature, and slag discharge conditions are met. Subsequently, the carbon-containing material to be treated is fed into the furnace and a predetermined amount of the corresponding substances is sprayed through the above-mentioned various inlets, causing various reactions as described above. Since most of these reactions are exothermic reactions and generate a large amount of heat, under normal operating conditions, the temperature in the flash pyrolysis redox section C can be maintained at 1250°C to 2500°C, the temperature in the high-carbon slag section B can be maintained at 1350°C to 2500°C, the temperature in the low-carbon slag section A is at least 50°C to 200°C higher than the ash melting point (the slag discharge temperature is adjusted by the molten slag auxiliary combustion gas sprayed through the molten slag auxiliary combustion gas inlet 1), and the inlet temperature of the cooling and reduction section D is 1150°C to 2500°C, and the outlet temperature is lower than the ash deformation temperature (achieved through a cooling device). Generally, only a small amount of auxiliary combustion gas or only an inert gas needs to be introduced to keep the pipe orifice unobstructed during normal operation. When it is necessary to increase the slag discharge amount or block the slag, the amount of the auxiliary combustion gas sprayed through the molten slag auxiliary combustion gas inlet 1 can be appropriately increased to make it reach a suitable chemical equivalent ratio with the first gasifying agent (such as the complete combustion chemical equivalent ratio), thereby increasing the slag discharge temperature. When it is necessary to reduce the slag discharge or not discharge slag, the injection amount of the auxiliary combustion gas can be reduced or the auxiliary combustion gas can be switched to an inert gas to keep this inlet unobstructed. In addition, when the calorific value of the carbon-containing material fed into the molten gasifier is low or the temperature in the furnace cannot reach the required value due to fluctuations in the furnace conditions, the amount of the auxiliary combustion gas sprayed through the molten slag auxiliary combustion gas inlet 1 can be increased to ensure a high-temperature environment in the furnace.

[0062] In some embodiments, the method further includes the following steps: By adjusting the amounts of various materials entering the furnace (i.e., all substances entering the furnace, including the auxiliary combustion gas, the gasifying agent, the carbon-containing material, and the carbon-containing fine powder), the total molar ratio of carbon to oxygen in the materials entering the furnace is made to be 0.9 to 1.3, preferably 0.95 to 1.2, and more preferably 1. In this way, a higher cold gas efficiency (i.e., the ratio of the calorific value of the effective gas produced by the same amount of materials entering the furnace to the calorific value of the materials entering the furnace) can be obtained, improving the economy.

[0063] Taking the molten gasifier according to some embodiments as an example below, the effects achieved by the present application will be described.

[0064] Example 1: A melting gasifier capable of processing 240 tons of solid materials per day, in which the inner diameters of the low-carbon slag section A and the high-carbon slag section B are 2200 mm, and the total height is 2400 mm. The inner diameters of the flash pyrolysis redox section C and the cooling reduction section D are 2800 mm, and the total height is 11500 mm. The materials fed into the furnace are a mixture of pretreated domestic waste and tar slag, with a calorific value of 25634 Kj / kg, and the specific components are shown in Table 1:

[0065] Table 1

[0066] Furnace inlet composition (including combustion-supporting gas) Mass percentage Moisture content 8 Ash content 18 C 61.46 H 3.56 O 7.21 S 0.9 N 0.87

[0067] The main operating parameters of the melting gasifier when disposing of the above materials and the parameters of the final products are shown in Table 2:

[0068] Table 2

[0069]

[0070]

[0071] It can be seen from the above data that in this example, the high-temperature raw syngas generated after the carbon-containing materials are disposed of by the melting gasifier does not contain any macromolecular organic substances, and the content of effective gases (CO and H2) after removing H2O is as high as 94.79%. The by-product steam has high thermal efficiency, the solid slag has low carbon content and is vitreous, meeting the requirement of harmless disposal of solid waste, that is, solving the problem of harmlessness of the solid-phase slag and gas phase after disposal.

[0072] Example 2: A melting gasifier capable of processing 360 tons of solid materials per day, in which the inner diameters of the low-carbon slag section A and the high-carbon slag section B are 2400 mm, and the total height is 2800 mm. The inner diameters of the flash pyrolysis redox section C and the cooling reduction section D are 3000, and the total height is 13500 mm. The materials fed into the furnace are pretreated domestic waste, with a calorific value of 20285 Kj / kg, and the specific components are shown in Table 3:

[0073] Table 3

[0074] Furnace inlet composition (including combustion-supporting gas) Mass percentage Moisture content 5 Ash content 25 C 54 H 2.55 O 12.16 S 0.32 N 0.97

[0075] The main operating parameters of the melting gasifier when disposing of the above materials and the parameters of the final products are shown in Table 4:

[0076] Table 4

[0077] Item Unit Value Gasification temperature ℃ 1350 Furnace inlet material quantity t / h 15 Furnace inlet oxygen quantity <![CDATA[Nm 3 / h]]> 6570 Synthesis gas flow rate <![CDATA[Nm 3 / h]]> 23565 <![CDATA[Effective gas (CO + H2) flow rate]]> <![CDATA[Nm 3 / h]]> 18975 Steam output t / h 20 Carbon conversion rate ％ 99.9 Carbon content in solid slag <0.5％ CO %(volume ratio) 62.38 <![CDATA[H2]]> %(volume ratio) 18.13 <![CDATA[CO2]]> %(volume ratio) 8.15 <![CDATA[H2O]]> %(volume ratio) 7.47 <![CDATA[CH4]]> ppm(volume ratio) 661.49 <![CDATA[H2S]]> %(volume ratio) 0.12 <![CDATA[N2]]> %(volume ratio) 3.68

[0078] As can be seen from the above data, in this embodiment, the high-temperature raw syngas generated after the carbonaceous material is treated in the molten gasifier does not contain any macromolecular organic substances. After removing H2O, the content of effective gases (CO and H2) is as high as 87.01%. The by-product steam has a high thermal efficiency, and the solid slag has a low carbon content and is vitreous, meeting the requirement of harmless treatment of solid waste, that is, solving the problem of harmlessness of the solid phase slag and gas phase after treatment.

[0079] In summary, the molten gasifier provided by the embodiment of the present application and the method for harmless treatment of carbonaceous materials using this furnace have many advantages and broad application prospects, especially being able to achieve harmlessness, material reduction, and resource utilization during the treatment process.

[0080] The accompanying drawings and the above description depict non-limiting specific embodiments of the present application. To teach the principles of the invention, some conventional aspects have been simplified or omitted. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc., made within the spirit and principles of the present application should be included within the protection scope of the present application. Those skilled in the art should understand that the above features can be combined in various ways without conflict to form multiple variations of the present application. Thus, the present invention is not limited to the above specific embodiments, but is only defined by the claims and their equivalents.

Claims

1. A vertical melting gasifier (100) for harmlessly disposing of carbon-containing materials, characterized in that, The molten gasifier sequentially includes a low-carbon slag section (A), a high-carbon slag section (B), a flash pyrolysis redox section (C), and a temperature reduction and reduction section (D) from bottom to top. Among them, the low-carbon slag section (A) includes a first gasifier inlet (11), a slag auxiliary gas inlet (1), and a liquid slag discharge outlet (10). Under normal operating conditions, the pyrolytic carbon particles falling into the low-carbon slag section have adhesiveness or fluidity due to the carbon content being lower than a threshold value. Among them, the high-carbon slag section (B) includes a second gasifier inlet (2). Under normal operating conditions, the pyrolytic carbon particles falling into the high-carbon slag section do not have adhesiveness or fluidity due to the carbon content being higher than the threshold value. Among them, the flash pyrolysis redox section (C) includes a carbonaceous material inlet (3), a third gasifier inlet (4), and a carbonaceous fine powder inlet (9). Under normal operating conditions, the carbonaceous material fed into the flash pyrolysis redox section undergoes flash pyrolysis, and some of the pyrolysis products undergo redox reactions. And Among them, the temperature reduction and reduction section (D) includes a cooling device configured to lower the temperature inside this section, and a high-temperature raw syngas outlet (7). Under normal operating conditions, the carbon in CO2, H2O, and carbonaceous fly ash in the gas entering the temperature reduction and reduction section undergoes a reduction reaction to generate CO and H2.

2. The vertical melting gasifier according to claim 1, wherein, Under normal operating conditions, the temperature in the flash pyrolysis redox section (C) is 1250 °C to 2500 °C; the inlet temperature of the temperature reduction and reduction section (D) is 1150 °C to 2500 °C, and the outlet temperature is lower than the ash deformation temperature; the temperature in the high-carbon slag section (B) is 1350 °C to 2500 °C; and the temperature in the low-carbon slag section (A) is at least 50 °C to 200 °C higher than the ash melting point.

3. The vertical melting gasifier according to claim 1, wherein, The first gasifier inlet (11), the second gasifier inlet (2), and the third gasifier inlet (4) are configured to inject pure oxygen or oxygen-enriched air and are each provided with a flow rate regulating device (1101, 201, 401). The flow rate regulating device (1101, 201, 401) can adjust the injection amounts of the first, second, and third gasifiers according to the CO2 content, slag discharge temperature, and furnace internal temperature of the gas discharged from the high-temperature raw syngas outlet (7).

4. The vertical melting gasifier according to any one of claims 1 to 3, wherein, The slag auxiliary gas inlet (1) is configured to inject auxiliary gas or inert gas, and is provided with a flow rate regulating device (101). The flow rate regulating device (101) can adjust the injection amount of the auxiliary gas or inert gas according to the slag discharge situation and furnace internal temperature.

5. The vertical melting gasifier according to any one of claims 1-3, wherein, The carbonaceous material inlet (3) is connected to a continuous feeding device (302) and is located vertically between the second gasifier inlet (2) and the third gasifier inlet (4).

6. The vertical melting gasifier according to any one of claims 1-3, wherein, The carbonaceous fine powder inlet (9) is configured to inject carbonaceous fine powder and is provided with a flow rate regulating device (901). The flow rate regulating device (901) can adjust the injection amount of the carbonaceous fine powder according to the CO2 content of the gas discharged from the high-temperature raw syngas outlet (7) and the inlet temperature of the temperature reduction and reduction section.

7. The vertical melting gasifier according to any one of claims 1-3, wherein, The cooling device includes a cooling medium injection port (8) configured to inject a cooling medium into the internal space of the temperature reduction and reduction section and / or a circulating cooling system provided in the furnace wall of the temperature reduction and reduction section.

8. A method for melting and gasifying carbonaceous materials using the vertical melting gasifier (100) according to any one of the preceding claims, comprising the following steps: - Continuously feed the carbonaceous material into the flash pyrolysis oxidation reduction section (C) through the carbonaceous material inlet (3), and inject a third gasifying agent and carbonaceous fines through the third gasifying agent inlet (4) and the carbonaceous fines inlet (9) respectively, so that the carbonaceous material undergoes flash pyrolysis to generate pyrolysis gas, pyrolysis carbon, and carbonaceous fly ash. The pyrolysis gas and carbonaceous fly ash react rapidly with the third gasifying agent and carbonaceous fines to generate small molecule gases mainly composed of CO, CO2, H2, and H2O, and entrain carbonaceous fly ash and possibly remaining macromolecular organic matter into the temperature reduction and reduction section (D). The pyrolysis carbon falls into the high-carbon molten slag section (B) under the action of gravity; - The carbon in CO2, H2O, and carbonaceous fly ash in the gas entering the temperature reduction and reduction section (D) from the flash pyrolysis oxidation reduction section (C) undergoes a reduction reaction to generate CO and H2, and the possibly remaining macromolecular organic matter continues to decompose; - Inject a second gasifying agent into the high-carbon molten slag section (B) through the second gasifying agent inlet (2). The second gasifying agent agitates the falling pyrolysis carbon to decompose and break it, and undergoes an exothermic oxidation reduction reaction. The generated high-temperature gas entrains the carbonaceous fly ash generated by the fragmentation into the flash pyrolysis oxidation reduction section (C). At the same time, the pyrolysis carbon becomes low-carbon molten slag and falls to the low-carbon molten slag section (A) as the carbon content continuously decreases; and - Inject a first gasifying agent into the low-carbon molten slag section (A) through the first gasifying agent inlet (11). The first gasifying agent agitates the molten slag and reacts exothermically with the combustible substances in the molten slag to further reduce the residual carbon in the molten slag and make it homogeneously vitrified. The vitrified liquid slag is discharged from the liquid slag discharge port (10).

9. The method according to claim 8, wherein, Before the step of feeding the carbonaceous material, there is also a step of pre-treating the carbonaceous material, and the carbonaceous material after pre-treatment meets the homogenization requirements.

10. The method according to claim 8, wherein, Before the step of feeding the carbonaceous material, there are also the following steps: Put slag-producing materials into the melting gasifier, inject combustion-supporting gas and a first gasifying agent through the slag combustion-supporting gas inlet (1) and the first gasifying agent inlet (11) respectively, so that the combustion-supporting gas and the first gasifying agent undergo a combustion reaction to heat the molten slag-producing materials until a stable molten pool is established, the temperatures of each section in the furnace reach a predetermined temperature, and the slag discharge condition is met.

11. The method according to any one of claims 8-10 further comprises the following steps: By adjusting the amount of the combustion-supporting gas or inert gas injected through the slag combustion-supporting gas inlet (1) and the amount of the first gasifying agent injected through the first gasifying agent inlet (11), the temperature of the low-carbon molten slag section (A) is at least 50 °C to 200 °C higher than the ash melting point under normal operating conditions.

12. The method according to any one of claims 8-10, wherein, Under normal operating conditions, the temperature in the high-carbon molten slag section (B) is 1350 °C to 2500 °C.

13. The method according to any one of claims 8 to 10, wherein, Under normal operating conditions, the temperature in the flash pyrolysis redox section (C) is 1250 °C to 2500 °C, and the inlet temperature of the cooling and reduction section (D) is 1150 °C to 2500 °C.

14. The method according to any one of claims 8-10, wherein, The cooling device includes a cooling medium injection port (8) configured to inject a cooling medium into the internal space of the cooling and reduction section and / or a circulating cooling system provided in the furnace wall of the cooling and reduction section. By adjusting the cooling device, the outlet temperature of the cooling and reduction section under normal operating conditions is lower than the ash deformation temperature.

15. The method according to claim 14, wherein, The cooling medium is selected from: water mist, water vapor, cooled syngas, carbon dioxide gas, and combinations thereof.

16. The method according to any one of claims 8-10, wherein, The particle size of the carbonaceous fine powder is less than 200 microns.

17. The method according to any one of claims 8-10, wherein, The particle size of the carbonaceous fine powder is less than 100 microns.

18. The method according to any one of claims 8-10, wherein, The first gasifying agent, the second gasifying agent, and the third gasifying agent are all pure oxygen or oxygen-enriched air.

19. The method according to any one of claims 8-10, wherein, By adjusting the amounts of various materials charged into the furnace, the total molar ratio of carbon to oxygen in the materials charged into the furnace is 0.9 to 1.

3.

20. The method according to any one of claims 8-10, wherein, By adjusting the amounts of various materials charged into the furnace, the total molar ratio of carbon to oxygen in the materials charged into the furnace is 0.95 to 1.

2.

21. The method according to any one of claims 8 to 10, wherein, By adjusting the amounts of various materials charged into the furnace, the total molar ratio of carbon to oxygen in the materials charged into the furnace is 1.

22. The method according to claim 10, wherein, The combustion-supporting gas is fuel gas or atomized fuel oil.

Images