Gasification method and device for coking fly ash solid waste

Abstract

The invention provides a gasification method and device for coking fly ash solid waste. According to the device, a multi-reaction-zone coupling principle is adopted, a local high-temperature zone (gt, 2500 DEG C) is created in a gasification furnace through material blending and reactor structure design, the gasification reaction rate is increased, and the adaptability of gasification raw materials is improved; through partitioned combination of high-temperature gasification, slag solidification and chilling deslagging, the requirement of a traditional gasification furnace for the viscosity-temperature characteristic of slag is met, the raw material fluctuation resistance of the gasification furnace is improved, the slag blocking risk of a deslagging opening is reduced, and efficient gasification of unconventional carbon-containing raw materials of coking fly ash is achieved; and the CO-rich gasified gas and the H2-rich coke oven gas are further co-supplied and co-produced, the carbon-hydrogen ratio of the synthesis gas is flexibly adjusted, and cross-system hydrogen-carbon complementation between coal coking and coal gasification is realized, so that the energy efficiency of the coupling system is improved, and the emission of carbon dioxide is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solid waste treatment and chemical technology, and particularly relates to a gasification method and device for coking dedusting ash solid waste. BACKGROUND

[0002] In recent years, with the upgrading of energy saving and carbon reduction in the coking industry, especially the large-scale popularization and application of dry quenching technology, the output of coking dedusting ash solid waste has increased year by year. According to statistics, the amount of dedusting ash generated in the process of coal loading, coke pushing, dry quenching, and coke screening accounts for about 4% of the coke output, that is, about 15-20 million tons of dedusting ash solid waste is generated in the country every year. The long-term stacking of a large amount of coking dedusting ash not only causes serious environmental pollution, but also causes resource waste, so it is of great significance to develop resource utilization technology for dedusting ash solid waste.

[0003] Dry quenching primary dedusting ash with high carbon content and high calorific value can be directly used for coal blending for coking or as blast furnace injection fuel, but for dry quenching secondary dedusting ash and environmental dedusting ash with high ash content and small particle size, especially a large amount of high-sulfur, low-value environmental dedusting ash generated by the desulfurization and denitrification system, it is difficult to meet the requirements of coal blending for coking and sintering burdening, and there is a lack of efficient and environmentally friendly resource utilization method. Coking dedusting ash has the characteristics of high fixed carbon content, low volatile matter, high strength, and high calorific value, and is a high-quality gasification raw material. Dedusting ash gasification to produce synthesis gas (CO+H2) can produce high-value chemicals or liquid fuels through Fischer-Tropsch synthesis, which not only can make full use of the advantages of dedusting ash, such as small particle size, high carbon content, and high calorific value, to realize resource utilization and high-value utilization of dedusting ash solid waste, but also can form a combined supply and production coupling system with coke oven gas, flexibly regulate and control the carbon-hydrogen ratio of synthesis gas, realize the "hydrogen-carbon complementation" between coal coking and coal gasification, and is an important development direction of future coal coking integration.

[0004] Chinese patent CN111454738A discloses a dry quenching coke powder gasification method, and the generated synthesis gas is used as a circulating cooling gas to replace inert gas for coke cooling. However, the system is complex, the synthesis gas as a cooling medium seriously affects the quality of the coke, and the high temperature (800-900℃) of the synthesis gas is easy to explode in the dry quenching furnace or pipeline, which has the safety hazard of explosion. Chinese patent 105001914A discloses a method for coking dedusting ash mixed coal co-gasification, which can improve the gasification effect of dedusting ash to a certain extent, but the mixing ratio is low (<20%), and the mixed coal needs to be purchased from outside, which increases the operation cost. Compared with coal, coking dedusting ash has complex composition and variable composition, poor reactivity, high ash melting point, high slag viscosity, and poor high-temperature rheological property, and belongs to unconventional gasification raw material, so the existing mature coal gasification technology is difficult to meet the application requirements of dedusting ash gasification. SUMMARY

[0005] In view of the environmental pollution problem caused by long-term stacking of coking fly ash, the application provides a gasification method and device suitable for low-reactivity, high-ash-melting-point unconventional carbon-containing raw materials, and realizes resourceization and high-value utilization of coking fly ash solid waste.

[0006] In view of the characteristics of low volatile matter, poor reactivity, high ash melting point, high slag viscosity and poor high-temperature rheological property of coking fly ash, the application provides a gasification method and device for coking fly ash solid waste, adopts a multi-reaction-zone coupling principle, creates a local high-temperature zone (> 2500 DEG C) in the gasification furnace through material deployment and reactor structure design, accelerates the gasification reaction rate, and improves the adaptability of the gasification raw material; through the partition combination of high-temperature gasification, slag solidification and quenching slagging, the requirements of the traditional gasification furnace on the viscosity-temperature characteristics of the molten slag are overcome, the material fluctuation resistance of the gasification furnace is improved, the slagging risk of the slagging port is reduced, the efficient gasification of the unconventional carbon-containing raw material of coking fly ash is realized, the CO-rich gasification gas and the H2-rich coke oven gas are co-supplied and co-produced, the carbon-hydrogen ratio of the synthesis gas is flexibly adjusted, the hydrogen-carbon complementary of the coal coking and coal gasification between systems is realized, the energy efficiency of the coupled system is improved, and the carbon dioxide emission is reduced.

[0007] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme: A gasification device for coking fly ash solid waste, comprising a gasification furnace, the reaction zone of the gasification furnace is divided into a high-temperature gasification zone, a shift hydrogen production zone and a molten slag quenching zone from top to bottom; The top of the high-temperature gasification zone is provided with a gasification nozzle and a flame detector for ignition, start-up and process raw material feeding and flame monitoring; the bottom outlet of the high-temperature gasification zone is provided with a cooling water coil necking portion, which is beneficial to uniform slag hanging; the high-temperature gasification zone is connected with the shift hydrogen production zone through an expanding section; the circumference of the conical surface of the expanding section is symmetrically provided with atomizing nozzles for supplying spraying water or low-temperature steam or organic wastewater; The bottom of the shift hydrogen production zone is connected with a quenching downcomer through a necking section, and the outlet of the quenching downcomer extends into the lower part of the molten slag quenching zone; The bottom of the molten slag quenching zone is provided with a slagging port, and the side wall is provided with a synthesis gas outlet; a membrane water cooling wall is arranged between the gasification furnace cavity and the gasification furnace shell, and the inner side of the membrane water cooling wall is cast with a refractory material.

[0008] Further, the gasification nozzle is a combined gasification nozzle, which is a multilayer annular sleeve structure, and sequentially comprises an ignition channel, a fuel gas channel, a combustion-supporting gas channel, an oxygen and steam channel and a coking fly ash channel from inside to outside, and cooling jackets are arranged between adjacent channels and outside the nozzle. An ignition controller is arranged at the top of the ignition channel, the fuel gas channel is provided with a fuel gas inlet, the combustion-supporting gas channel is provided with a combustion-supporting gas inlet, the oxygen and steam channel is provided with an oxygen / steam inlet, and the coking fly ash channel is provided with a coking fly ash inlet.

[0009] Further, the circumferential direction of the gasification nozzle is provided with several flame detectors, and the angle between the flame detector and the axis of the gasification nozzle is 5~30 ° . The flame detector is provided with a shut-off valve and a protective gas inlet.

[0010] Further, the atomizing nozzle is a ring sleeve structure, and the inside is an atomizing gas channel and the outside is a cooling medium channel, and the atomizing gas channel is recessed by 5~30mm compared to the cooling medium channel.

[0011] The coking dedusting ash gasification furnace is a membrane water cooling wall structure, allowing the use temperature to be ≤1700℃, the pressure strength to be ≥60MPa, and the furnace body to be sequentially composed of a shell, a water cooling wall, and a refractory material from the outside to the inside.

[0012] Further, a plurality of bubble-breaking baffles are arranged between the inner wall of the molten slag chilling zone and the outer wall of the downcomer, and circulating slag water flows between the baffles; the side of the molten slag chilling zone is also respectively provided with a chilling water inlet and a chilling water outlet, the chilling water inlet is higher than the height of the bubble-breaking baffles, and the chilling water outlet is located between the bottom layer of bubble-breaking baffles and the second layer of bubble-breaking baffles.

[0013] Further, the circumferential direction of the cone surface of the flared section is provided with atomizing nozzles, which are uniformly and symmetrically distributed, the number is 2~20, and the angle with the horizontal plane is 0~90 ° .

[0014] Further, the diameter ratio of the high-temperature gasification zone to the shift hydrogen production zone is 1:1~2; the height ratio is 1:0.2~2.

[0015] Further, the high-temperature gasification zone and the shift hydrogen production zone are connected by a flared section, and the vertex angle of the cone is 40~120 ° .

[0016] Further, the bubble-breaking baffles are a louver structure composed of multiple rows of horizontally inclined blades with an inclination of 20~75 ° .

[0017] A gasification method for coking dedusting ash solid waste, comprising the following steps: Step 1, qualified coking dedusting ash with a particle size of less than 100μm is transported to a dedusting ash bin, and then sequentially passes through a lock hopper and a feeding tank before being pneumatically transported to the gasification nozzle at the top of the gasification furnace; the coking dedusting ash enters the gasification furnace from the coking dedusting ash inlet of the gasification nozzle; Step 2, the gasification agent is injected into the gasification furnace along the vertical direction from the gasification agent channel of the gasification nozzle, the reaction temperature, the reaction pressure, and the gas-solid contact time of the high-temperature gasification zone are controlled, so that the dedusting ash and the gasification agent perform high-temperature gasification reaction to generate synthesis gas rich in CO and H2; Step 3, the gas and molten slag in the high-temperature gasification zone enter the shift hydrogen production zone through the flared section, the cooling medium is introduced into the shift hydrogen production zone from the atomizing nozzle located in the flared section, and the temperature of the shift hydrogen production zone is controlled to make part of the molten ash solidify, and part of the CO is converted into H2 through the high-temperature steam shift reaction; Step 4, the gas carrying ash descends into the molten slag quenching zone through the quenching downpipe, the gas flows back upward after reaching the bottom of the molten slag quenching zone, is cooled and washed by the circulating slag water through the multi-layer bubble-breaking baffle, and is cooled to 100-350℃, and then is discharged from the syngas outlet of the gasification furnace; the ash is captured by the circulating slag water and is discharged from the bottom of the slag discharge port and sent to the ash water system for treatment; Step 5, the crude syngas discharged from the gasification furnace enters the washing tower, and the dust and acid gases entrained in the syngas are further removed in the washing tower, and the temperature of the syngas at the outlet of the washing tower is controlled to be lower than 100℃; Step 6, the purified syngas after washing enters the drying tower and the drying agent regeneration tower for further dehydration and drying, and the dew point temperature of the syngas at the outlet of the drying tower is controlled to be lower than -40℃; Step 7, the dried purified syngas enters the turbine generator to convert the residual pressure into electric energy, and the pressure of the syngas is reduced to 10-50KPa; Step 8, the syngas after pressure reduction is sampled and analyzed by using a coal gas analyzer, and the qualified syngas with an oxygen content of less than 0.5% enters the coke oven gas pipe network, and the unqualified syngas is discharged.

[0018] Further, the reaction temperature of the high-temperature gasification zone is 1200-1650℃, the reaction pressure is 0.1-8.0MPa, and the gas-solid contact time is 5-20s; the temperature of the shift hydrogen production zone is 700-1000℃, and the residence time of the gas in the shift hydrogen production zone is 5-20s.

[0019] Further, the gasification agent is oxygen, steam, carbon dioxide and nitrogen (O2 / H2O / CO2 / N2), the jet velocity of the gasification agent is 80-120m / s; the oxygen consumption ratio to the coking dust removal ash is 0.6-1.0Nm 3 / kg; the steam consumption ratio to the coking dust removal ash is 0-0.4Nm 3 / kg; the carbon dioxide consumption ratio to the coking dust removal ash is 0-0.4Nm 3 / kg; the nitrogen consumption ratio to the coking dust removal ash is 0-0.3Nm 3 / kg; the volume percentage of oxygen in the gasification agent is 70-100%, the volume percentage of steam is 0-30%, the volume percentage of carbon dioxide is 0-30%, and the volume percentage of nitrogen is 0-20%.

[0020] Further, the dust removal ash jet velocity at the outlet of the gasification nozzle is 5-20m / s.

[0021] Further, the pressure difference between the feeding tank and the gasifier during the conveying of the fly ash is kept at 0.2-1.0 MPa, and the ratio of the conveying gas to the fly ash is 0.08-1 Nm 3 kg of fly ash, so as to ensure the continuous and stable conveying of the coking fly ash.

[0022] Further, the cooling medium sprayed through the atomizing nozzle into the hydrogen production area by shift conversion is one or more of the following: coal gas washing water at 20-60 ℃, industrial tap water, industrial soft water or boiler saturated water at 100-200 ℃, and the amount is 0.25-0.7 kg of water per kg of fly ash, or low-temperature steam at 100-250 ℃, and the amount is 0.5-1.8 kg of water vapor per kg of fly ash.

[0023] Further, preferably, a grinding and powdering unit is arranged before the fly ash enters the ash bin, so as to control the particle size of the fine powder of the fly ash to be less than 100 μm.

[0024] Compared with the prior art, the present application has the following advantages: (1) Good adaptability to raw materials. Through the combination of high-temperature gasification, slag solidification and quenching and slagging in different zones, the gasifier can be applied to unconventional gasification raw materials with high ash melting point and low reaction activity, such as anthracite, coking fly ash and petroleum coke.

[0025] (2) The reaction zones of high-temperature gasification and hydrogen production by shift conversion in the gasifier are coupled, so that the sensible heat of the raw gas can be fully utilized, the hydrogen content in the raw gas is increased, the CO shift load is reduced, and the gasification effect is improved.

[0026] (3) The lower injection quenching process and the self-adaptive slagging technology can reduce the requirement of the traditional gasifier on the viscosity-temperature characteristics of the molten slag, improve the resistance of the gasifier to raw material fluctuations, reduce the risk of slag blocking in the slagging port of the gasifier, and improve the operation stability and reliability of the gasifier.

[0027] (4) The process flow is simple, and the equipment investment is reduced. Compared with the similar entrained-flow gasification technology, the investment is reduced by 30%.

[0028] (5) Through the overall coupling and optimization integration of coal gasification and coal coking across systems, the hydrogen and carbon in the gasified coal gas and the coke oven gas are complementary, which is beneficial to reduce energy consumption, reduce CO2 emissions, increase production, and improve the economic benefits of the coking enterprise. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic view of a gasification device for coking fly ash solid waste according to the present application; Figure 2 is a structural schematic view and assembly mode of a combined gasification nozzle and flame detector in the present application; Figure 3 is a process flow diagram for gasification of coking fly ash solid waste to produce synthetic gas. BRIEF DESCRIPTION OF DRAWINGS 1 - gasifier, 2 - gasification nozzle, 3 - flame detector, 4 - gasifier shell, 5 - membrane water wall, 6 - flared section, 7 - atomizing nozzle, 8 - constricted section, 9 - water wall cooling water inlet, 10 - syngas outlet, 11 - quench water outlet, 12 - slag tap, 13 - quench downcomer, 14 - bubble breaker baffle, 15 - quench water inlet, 16 - cooling water coil constricted section 17 - water wall cooling water outlet, 18 - ignition controller, 19 - fuel gas inlet, 20 - combustion air inlet, 21 - cooling jacket, 22 - gasification agent passage, 23 - coking dedusting ash inlet, 24 - shut-off valve, 25 - protective gas inlet, 26 - dedusting filter, 27 - dedusting ash bin, 28 - lock hopper, 29 - feed tank, 30 - slag lock hopper, 31 - slag pool, 32 - scrubbing tower, 33 - drying tower, 34 - drying agent regeneration tower, 35 - turbine generator, 36 - coal gas analyzer. DETAILED DESCRIPTION

[0030] For a further understanding of the present application, we will now describe it in further detail. However, the present application has various implementations, and is not limited to the specific examples listed herein. The presentation of these examples is intended to deepen the overall understanding of the disclosure of the present application.

[0031] As shown in Figure 1 , 2 , the present application provides a gasification device for coking dedusting ash solid waste, including a gasifier 1, wherein the outer wall of the gasifier 1 is a cylindrical shell 4, and the inside is a membrane water wall 5, and the space between the shell and the membrane water wall is an annular cavity filled with nitrogen balance gas; the inside of the gasifier 1 forms a hollow reaction zone, which is divided into a high-temperature gasification zone, a shift hydrogen production zone and a molten slag quenching zone from top to bottom; The top of the high-temperature gasification zone is provided with a gasification nozzle 2 and a flame detector 3 for ignition, start-up and process raw material feeding and flame monitoring; in order to make the membrane water-cooled wall surface uniformly hang slag, a cooling water coil necking 16 is arranged at the bottom outlet of the high-temperature gasification zone; the high-temperature gasification zone is connected with the shift hydrogen production zone through an expanding section 6, and an atomizing nozzle 7 is arranged on the conical surface of the expanding section 6 in the circumferential direction, which can spray liquid water or high-concentration organic wastewater; the atomizing nozzle 7 is horizontally or obliquely downward symmetrically arranged, which is used for rapid cooling of gas and molten ash; a water-cooled wall cooling water inlet 9 and a water-cooled wall cooling water outlet 17 are further arranged at the top of the high-temperature gasification zone and the bottom of the shift hydrogen production zone respectively; the outlet of the shift hydrogen production zone is connected with a quenching downpipe 13 through a contraction section 8, the bottom of the quenching downpipe 13 extends into the lower part of the molten slag quenching zone, and a plurality of bubble breaking baffles 14 are arranged between the inner wall of the molten slag quenching zone and the outer wall of the downpipe above the lower end of the quenching downpipe 13; a slag discharge port 12 is arranged at the bottom of the molten slag quenching zone, a synthesis gas outlet 10 is arranged on the upper wall of the molten slag quenching zone, and a quenching water inlet 15 and a quenching water outlet 11 are further arranged on the opposite two side walls of the molten slag quenching zone respectively; the quenching water inlet 15 is higher than the height of the bubble breaking baffle 14, and the quenching water outlet 11 is located between the bottom bubble breaking baffle and the second bubble breaking baffle.

[0032] The dome center of the gasification furnace 1 is provided with one or more combined gasification nozzles 2, the gasification nozzle 2 is a multi-layer annular sleeve structure, and from inside to outside, it is sequentially provided with an ignition channel, a fuel gas channel, a combustion supporting gas channel, an oxygen and steam channel, and a dedusted ash channel, and a cooling jacket 21 is arranged between adjacent channels and the outside of the nozzle for protection; an ignition controller 18 is arranged at the top of the ignition channel, the fuel gas channel is provided with a fuel gas inlet 19, the combustion supporting gas channel is provided with a combustion supporting gas inlet 20, the oxygen and steam channel is provided with a gasification agent channel 22, and the dedusted ash channel is provided with a coking dedusted ash inlet 23.

[0033] A plurality of flame detectors 3 are arranged in the circumferential direction of the gasification nozzle 2, and the inclination angle between the flame detector 3 and the axis of the gasification nozzle 2 is 10~30 o . A cut-off valve 24 and a protective gas inlet 25 are arranged on the flame detector 3.

[0034] The diameter ratio of the high-temperature gasification zone to the shift hydrogen production zone is 1:1~2, and the height ratio is 1:0.2~2.

[0035] The high-temperature gasification zone and the shift hydrogen production zone are connected through an expanding section 6, and the cone top angle of the expanding section is 40~120 o .

[0036] The conical surface of the expanding section 6 is provided with atomizing nozzles in the circumferential direction, and the arrangement mode is uniformly and symmetrically distributed, the number is 2~20, and the included angle between the atomizing nozzle and the horizontal plane is 0~90 o .

[0037] Wherein, the high temperature gasifier 1 is provided with a vertical suspension membrane water cooling wall 5, allowing the use of temperature ≤ 1700 ℃, pressure strength ≥ 60 MPa, and the inside of the water cooling wall is cast with 10-100 mm refractory material.

[0038] Wherein, the material of the membrane water cooling wall 5 can use chromium molybdenum alloy, high carbon steel or nickel-based alloy.

[0039] Wherein, the bubble breaking baffle 14 is a louver type structure composed of multiple rows of horizontally inclined 20-80 o Leaf blades.

[0040] Wherein, the number of layers of the bubble breaking baffle 14 in the molten slag chilling section is 2-20 layers.

[0041] A gasification method for coking dust ash solid waste, comprising the following steps: Step 1, qualified coking dust ash with particle size less than 100 μm is transported to the dust ash bin 27, and then sequentially passes through the lock hopper 28 and the feeding tank 29, and is transported by air to the gasification nozzle 2 at the top of the gasifier; the coking dust ash enters the gasifier 1 from the dust ash inlet 23 of the gasification nozzle 2; Step 2, the gasification agent is vertically sprayed into the gasifier 1 from the gasification agent channel 22 of the gasification nozzle 1, the temperature of the high temperature gasification zone is controlled to be 1200-1650 ℃, the pressure is controlled to be 0.1-8.0 MPa, and the gas-solid contact time is controlled to be 5-20 s, so that the coking dust ash and the gasification agent are subjected to high temperature gasification reaction to generate CO and H2 rich synthesis gas; Step 3, the gas and molten slag in the high temperature gasification zone flows downward, enters the shift hydrogen production zone through the flared section 6, the cooling medium is sprayed into the shift hydrogen production zone of the gasifier from the atomizing nozzle 7 located on the flared section 6, the temperature of the shift hydrogen production zone is controlled to be 700-1000 ℃, the molten slag is rapidly solidified, and part of the CO is converted to H2 by high temperature steam shift reaction, and the gas stays in the shift hydrogen production zone for 5-20 s; Step 4, the gas carrying ash and slag enters the molten slag chilling zone through the chilling downpipe 13, the circulating slag water enters from the chilling water inlet 15 and is discharged from the chilling water outlet 11 (after filtration and water replenishment, it enters the chilling water inlet 15 again to form a cycle), the gas flows back upward after reaching the bottom of the molten slag chilling zone, is cooled and washed by the circulating slag water through the multiple layers of bubble breaking baffles 14, and is cooled to 100-350 ℃, and is discharged from the synthesis gas outlet 10 to the gasifier 1, and is sent to the subsequent system for purification treatment; the ash and slag are captured by the circulating slag water and periodically discharged from the bottom of the slag discharge port 12 into the slag lock hopper 30 and the slag pool 31, and the slag water is sent to the ash water system for treatment.

[0042] Step 5, the crude synthesis gas discharged from the gasifier 1 enters the washing tower 32, and the dust and pickling gas entrained in the synthesis gas are further removed in the washing tower 32, and the dust content of the synthesis gas at the outlet of the washing tower is controlled to be less than 50 mg / Nm3 , the temperature is lower than 100℃.

[0043] Step 6, the purified synthesis gas after washing enters the drying tower 33 and the drying agent regeneration tower 34 for further dehydration and drying, and the dew point temperature of the synthesis gas at the outlet of the drying tower is controlled to be less than -40℃.

[0044] Step 7, the dried purified synthesis gas enters the turbine generator 35 to convert the residual pressure into electric energy, and at the same time, the pressure of the synthesis gas is reduced to 10-50KPa.

[0045] Step 8, the synthesis gas after pressure reduction is sampled and analyzed by using the coal gas analyzer 36, and the qualified synthesis gas with oxygen content less than 0.5% enters the coke oven gas pipe network, and the unqualified synthesis gas is discharged.

[0046] Among them, step (1) is to ensure the continuous and stable conveying of coking dust, and the pressure difference between the feeding tank 29 and the gasifier 1 is controlled to be 0.2-1.0MPa, and the ratio of conveying gas to dust is 0.08-1Nm 3 / kg.

[0047] Among them, the volume percentage of oxygen in the gasification agent of step (2) is 70-100%, the volume percentage of water vapor is 0-30%, the volume percentage of carbon dioxide is 0-30%, and the volume percentage of nitrogen is 0-20%.

[0048] Among them, the jet velocity of the dust at the outlet of the gasification nozzle of step (2) is 5-20m / s; the jet velocity of oxygen and water vapor is 80-120m / s.

[0049] Among them, the consumption ratio between oxygen and coking dust in step (2) is 0.6-1.0Nm 3 of oxygen / kg of dust.

[0050] Among them, the consumption ratio between water vapor and coking dust in step (2) is 0-0.4Nm 3 of water vapor / kg of dust.

[0051] Among them, the consumption ratio between carbon dioxide and coking dust in step (2) is 0-0.4Nm 3 of carbon dioxide / kg of dust.

[0052] Among them, the consumption ratio between nitrogen and coking dust in step (2) is 0-0.3Nm 3 of nitrogen / kg of dust.

[0053] The cooling medium of the step (3) sprayed into the shift hydrogen production area through the atomizing nozzle 7 can be coal gas washing water at 20-60℃, industrial tap water, industrial soft water or boiler saturated water at 100-200℃, and the flow rate is 0.25-0.7 kg water / kg coking dedusting ash; or low-temperature steam at 100-250℃, and the usage amount is 0.5-1.8 kg water steam / kg dedusting ash.

[0054] The dry coal gas composition at the outlet of the gasification furnace of the step (4) is as follows: H2 volume content 25-45%, CO volume content 35-50%, CO2 volume content 5-15%, and the volume content of the rest of the gas 5-20%.

[0055] The following several examples make the present application more specific for those skilled in the art.

[0056] Example 1

[0057] The total height of the coking dedusting ash gasification device is 15250 mm. The height of the high-temperature gasification area is 5300 mm, the inner diameter is 1300 mm, and the outer diameter is 2400 mm; the height of the shift hydrogen production area is 4200 mm, the inner diameter is 1800 mm, and the outer diameter is 3200 mm, and the height of the molten slag quenching area is 5750 mm, and the inner diameter is 3200 mm. A combined gasification nozzle 2 and two flame detectors 3 are arranged at the top center of the gasification furnace, and the included angle between the flame detector 3 and the axis of the gasification nozzle 2 is 10°. The taper top angle of the flared section 6 between the high-temperature gasification area and the shift hydrogen production area is 90°, and four atomizing nozzles 7 are arranged horizontally symmetrically along the taper surface of the flared section 6. Three layers of bubble-breaking baffles 14 are arranged in the molten slag quenching area, and the blade of the bubble-breaking baffle 14 is at an angle of 30° with the horizontal direction. o o

[0058] The coking dedusting ash is used as the raw material, and the industrial analysis and element analysis of the environmental dedusting ash are shown in Table 1, and the ash melting point of the environmental dedusting ash is shown in Table 2. According to the gasification method described in the present application, the pressure difference between the feeding tank 29 and the gasification furnace 1 is adjusted to 0.5 MPa, the ratio of carbon dioxide to dedusting ash is 0.2 Nm 3 ​​ / kg, the environmental fly ash with particle size less than 100 μm is sprayed into the gasifier 1 from the coking fly ash inlet 23, the gasification agent composed of 90% oxygen and 10% water vapor is injected into the gasifier 1 from the high-speed gasification nozzle 2, the temperature of the high-temperature gasification zone is controlled to be 1250°C, the pressure is 1.0 MPa, and the generated high-temperature gas and molten ash and slag flow downward into the shift hydrogen production zone; the 4 atomizing nozzles 7 are horizontally symmetrically arranged in the flared section 6 between the high-temperature gasification zone and the shift hydrogen production zone, and the industrial wastewater is introduced at 30-40°, the water amount is adjusted to control the temperature of the shift hydrogen production zone to be 800°C, the quenching water is evaporated into water vapor, part of CO in the high-temperature gas reacts with the water vapor to generate H2 through the water gas shift reaction, and the molten ash and slag are cooled and solidified; the gas and the ash and slag continue to flow downward through the downcomer 13 into the molten slag quenching zone, the gas is deflected upward through the bubble breaking baffle 14 to be in countercurrent contact with the circulating quenching water, and the ash and slag are washed and captured by the circulating slag water; the circulating quenching water enters the molten slag quenching zone from the quenching water inlet 15 and is discharged from the gasifier from the quenching water outlet 11, and the temperature of the molten slag quenching zone is controlled to be 230°C; the cooled gas is discharged from the gasifier from the syngas outlet 10 in the side wall of the molten slag quenching zone, and the ash and slag are discharged from the slag outlet 12 at the bottom of the gasifier to further enter the slag lock hopper 30 and the slag pool 31 and be treated by the ash water system. The generated crude syngas is sequentially subjected to further purification and drying in the washing tower 32, the drying tower 32 and the regenerator 34, the dust content of the syngas at the outlet of the drying tower 32 is controlled to be less than 10 mg / Nm 3 , and the dew point temperature is controlled to be less than -40°C; the purified syngas is sent to the turbine generator 35 to generate electricity, and the pressure is reduced to 40 KPa; the gasification syngas is sampled and analyzed by using the coal gas analyzer 36, the qualified gas with oxygen content less than 0.5% is sent to the coke oven gas pipe network, and the unqualified gas is discharged. The main operating parameters and the gasification indexes of the coking fly ash gasification furnace are shown in Table 3.

[0059] Example 2

[0060] The total height of the coking fly ash gasification device is 15250 mm. Among them, the height of the high-temperature gasification zone is 6000 mm, the inner diameter is 1300 mm, and the outer diameter is 2400 mm; the height of the shift hydrogen production zone is 3500 mm, the inner diameter is 1800 mm, and the outer diameter is 3200 mm, and the height of the molten slag quenching zone is 5750 mm, and the inner diameter is 3200 mm. A combined gasification nozzle 2 and two flame detectors 3 are arranged at the center of the top of the gasifier, and the included angle between the flame detector 3 and the axis of the gasification nozzle 2 is 20°. The cone top angle of the flared section 6 between the high-temperature gasification zone and the shift hydrogen production zone is 60°, and 6 atomizing nozzles 7 are horizontally symmetrically arranged along the cone surface of the flared section 6. Five layers of bubble breaking baffles 14 are arranged in the molten slag quenching zone, and the included angle between the baffle blade and the horizontal plane is 60°. The coking fly ash high-temperature gasification furnace is the same as example 1.

[0061] The industrial analysis and element analysis of the coke oven coal preparation dust are shown in Table 1, and the ash melting point of the coke oven coal preparation dust is shown in Table 2. According to the gasification method, the pressure difference between the feeding tank 29 and the gasification furnace 1 is adjusted to 0.6 MPa, the ratio of carbon dioxide to dust is 0.3 Nm 3 / kg, the coke oven coal preparation dust with a particle size less than 100 μm is sprayed into the gasification furnace 1 from the coke oven dust inlet 23, the gasification agent composed of 90% oxygen and 10% water vapor is injected into the gasification furnace 1 at high speed from the gasification agent channel 22, the temperature of the high-temperature gasification zone is controlled to 1300℃, the pressure is 2.0 MPa, the industrial tap water at 20℃ is sprayed into the shift hydrogen production zone from the atomizing nozzle 7, the temperature of the shift hydrogen production zone is adjusted to 850℃, the temperature of the molten slag quenching zone is 160℃, and the rest is the same as in Example 1. The main operating parameters and gasification indexes of the coke oven coal preparation dust high-temperature gasification furnace are shown in Table 3 below.

[0062] Example 3

[0063] The total height of the coke oven coal preparation dust gasification device is 15250 mm. Among them, the high-temperature gasification zone has a height of 6500 mm, an inner diameter of 1300 mm, and an outer diameter of 2400 mm; the shift hydrogen production zone has a height of 3200 mm, an inner diameter of 1800 mm, and an outer diameter of 3200 mm, and the molten slag quenching zone has a height of 5550 mm and an inner diameter of 3200 mm. A combined gasification nozzle 2 and two flame detectors 3 are arranged at the center of the top of the gasification furnace, and the included angle between the flame detector 3 and the axis of the gasification nozzle 2 is 20°. The taper top angle of the flared section 6 between the high-temperature gasification zone and the shift hydrogen production zone is 45°, and the atomizing nozzles 7 are uniformly arranged on the taper surface of the flared section at an angle of 45° horizontally downward. Three layers of defoaming baffles 14 are arranged in the molten slag quenching zone, and the included angle between the defoaming baffle blades and the horizontal plane is 45°. The rest of the coke oven coal preparation dust high-temperature gasification furnace is the same as in Example 1.

[0064] The coke oven coke side dust is used as raw material, the industrial analysis and element analysis of the coke side dust are shown in Table 1, and the ash melting point of the coke side dust is shown in Table 2. According to the gasification method, the pressure difference between the feeding tank 29 and the gasification furnace 1 is adjusted to 0.6 MPa, the ratio of carbon dioxide to dust is 0.2 Nm 3 / kg, the coke side dust with a particle size less than 100 μm is sprayed into the gasification furnace 1 from the coke oven dust inlet 23, the gasification agent composed of 90% oxygen and 10% carbon dioxide is injected into the gasification furnace 1 at high speed from the gasification agent channel 22, the temperature of the high-temperature gasification zone is controlled to 1350℃, the pressure is 3.0 MPa, the industrial tap water at 20℃ is sprayed into the shift hydrogen production zone from the atomizing nozzle 7, the temperature of the shift hydrogen production zone is adjusted to 850℃, the temperature of the molten slag quenching zone is 120℃, and the rest is the same as in Example 1. The main operating parameters and gasification indexes of the coke oven coal preparation dust high-temperature gasification furnace are shown in Table 3 below.

[0065] Example 4

[0066] The total height of the coking dedusting ash gasification device is 15250mm. Among them, the height of the high-temperature gasification zone is 6500mm, the inner diameter is 1300mm, and the outer diameter is 2400mm; the height of the hydrogen production by transformation zone is 3200mm, the inner diameter is 1800mm, and the outer diameter is 3200mm, the height of the molten slag quenching zone is 5550mm, and the inner diameter is 3200mm. A combined gasification nozzle 2 and two flame detectors 3 are arranged at the center of the top of the gasification furnace, and the included angle between the flame detector 3 and the axis of the gasification nozzle 2 is 20°. The cone top angle of the flared section 6 between the high-temperature gasification zone and the hydrogen production by transformation zone is 45°, and 8 atomizing nozzles 7 are uniformly arranged along the conical surface of the flared section, which are oppositely arranged horizontally downward at an angle of 60°. Three layers of bubble breaking baffles 14 are arranged in the molten slag quenching zone, and the included angle between the baffle blade and the horizontal plane is 45°. The coking dedusting ash high-temperature gasification furnace is the same as example 1.

[0067] The industrial analysis and element analysis of the coke screening dedusting ash are shown in table 1, and the ash melting point of the coke screening dedusting ash is shown in table 2. According to the gasification method described in the application, the pressure difference between the feeding tank 29 and the gasification furnace 1 is adjusted to 1.0MPa, the ratio of carbon dioxide to dedusting ash is 0.25Nm 3 / kg, the coke screening dedusting ash with a particle size less than 100μm is sprayed into the gasification furnace 1 from the coke screening dedusting ash inlet 23, the gasification agent composed of 95% oxygen and 5% carbon dioxide is injected into the gasification furnace 1 at high speed from the gasification agent channel 22, the temperature of the high-temperature gasification zone is controlled to be 1350℃, the pressure is 4.0MPa, the industrial tap water at 20℃ is sprayed into the hydrogen production by transformation zone from the atomizing nozzle 7, the temperature of the hydrogen production by transformation zone is adjusted to be 900℃, the temperature of the molten slag quenching zone is 230℃, and the rest is the same as example 1. The main operation parameters and gasification indexes of the coking dedusting ash high-temperature gasification furnace are shown in the following table 3.

[0068] Table 1 is the industrial analysis and elemental analysis of the coking fly ash used in Examples 1-4. Table 2 is the ash melting point of the coking fly ash used in Examples 1-4. Table 3 is the test conditions and test results of the coking fly ash solid waste high-temperature gasification for synthesis gas in Examples 1-4. It can be found that under the working conditions of high-temperature gasification zone temperature 1250-1500℃, and shift hydrogen production zone temperature 800-1000℃, efficient gasification of coking fly ash solid waste with low reactivity and high ash melting point can be realized, the effective gas (CO+H2) content in the gasification synthesis gas is greater than 74%, the carbon conversion rate and cold gas efficiency are up to 97.3% and 79.2% respectively, and the oxygen consumption, steam consumption and fly ash consumption per unit of effective synthesis gas are all lower than those of the existing industrialized pulverized coal gas flow bed gasifier. Moreover, the introduction of H2O in the shift hydrogen production zone can promote the CO water gas shift to generate H2, increase the H2 content in the raw coal gas, and greatly improve the economy of the coking fly ash solid waste gasification process. The gasification method and device for coking fly ash solid waste of the present application exhibit excellent gasification effect, realize the resourceization and high-value utilization of coking fly ash solid waste, and solve the gasification problem of unconventional carbon-containing raw materials with low reactivity and high ash melting point.

[0069] Table 1 Industrial analysis and elemental analysis of coking fly ash

[0070] Table 2 Ash melting point of coking fly ash

[0071] Table 3 Test results of coking fly ash solid waste high-temperature gasification

[0072] The contents not described in detail in the specification of the present application belong to the prior art known to those skilled in the art. Although the above describes the specific embodiments of the present application in order to facilitate those skilled in the art to understand the present application, it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

Claims

1. A gasification apparatus for coking fly ash solid waste, characterized by: The gasification furnace 1 comprises a reaction zone which is divided into a high-temperature gasification zone, a shift hydrogen production zone and a molten slag quenching zone from top to bottom; The top of the high-temperature gasification zone is provided with a gasification nozzle 2 and a flame detector 3 for ignition, start-up and process raw material feeding and flame monitoring; the bottom outlet of the high-temperature gasification zone is provided with a cooling water coil necking 16 to facilitate uniform slag hanging; the high-temperature gasification zone is connected with the shift hydrogen production zone through an expanding section 6; the circumferential direction of the tapered surface of the expanding section 6 is symmetrically provided with atomizing nozzles 7 for supplying spraying water or low-temperature steam or organic waste water; The bottom of the shift hydrogen production zone is connected with a quenching downcomer 13 through a necking section 8, and the outlet of the quenching downcomer 13 extends into the lower part of the molten slag quenching zone; The bottom of the molten slag quenching zone is provided with a slag discharge port 12, and the side wall surface is provided with a synthesis gas outlet 10; a membrane water cooling wall 5 is arranged between the gasification furnace cavity and the gasification furnace shell 4, and the inner side of the membrane water cooling wall 5 is cast with refractory material.

2. The gasification apparatus for coking dedusting ash solid waste according to claim 1, characterized in that: The gasification nozzle 2 is a combined gasification nozzle and has a multi-layer annular sleeve structure, which comprises, from inside to outside, an ignition channel, a fuel gas channel, a combustion-supporting gas channel, an oxygen and steam channel and a dedusting ash channel, and cooling jackets 21 are arranged between adjacent channels and on the outside of the nozzle.

3. The gasification apparatus for coking dedusting ash solid waste according to claim 1, characterized in that: The atomizing nozzle 7 has an annular sleeve structure, which comprises, from inside to outside, an atomizing gas channel and a cooling medium channel, and the atomizing gas channel is recessed by 5-30 mm compared with the cooling medium channel.

4. The gasification apparatus for coking dedusting ash solid waste according to claim 1, characterized in that: A plurality of bubble-breaking baffles 14 are arranged between the inner wall of the molten slag quenching zone and the outer wall of the downcomer, and circulating slag water flows between the baffles; the side surface of the molten slag quenching zone is further provided with a quenching water inlet 15 and a quenching water outlet 11, the quenching water inlet 15 is higher than the height of the bubble-breaking baffles 14, and the quenching water outlet 11 is located between the bottommost bubble-breaking baffle and the second bubble-breaking baffle.

5. A gasification process for coking fly ash solid waste, characterized by: The method comprises the following steps: Step 1: qualified coking dedusting ash with a particle size of less than 100 μm is conveyed to a dedusting ash bin 27, and then sequentially passes through a lock hopper 28 and a feeding tank 29 and is pneumatically conveyed to the gasification nozzle 2 at the top of the gasification furnace; the coking dedusting ash enters the gasification furnace 1 from the coking dedusting ash inlet 23 of the gasification nozzle 2; Step 2: the gasification agent is vertically sprayed into the gasification furnace 1 from the gasification agent channel 22 of the gasification nozzle 1 to control the reaction temperature, reaction pressure and gas-solid contact time of the high-temperature gasification zone, so that the dedusting ash and the gasification agent are subjected to high-temperature gasification reaction to generate synthesis gas rich in CO and H2; Step 3: the gas and molten slag in the high-temperature gasification zone enter the shift hydrogen production zone through the expanding section 6, the cooling medium is introduced into the shift hydrogen production zone from the atomizing nozzle 7 located in the expanding section 6, and the temperature of the shift hydrogen production zone is controlled to rapidly solidify the molten ash slag, and part of the CO is converted into H2 through high-temperature steam shift reaction; Step 4: the gas carrying ash and slag enters the molten slag quenching zone through the quenching downcomer 13, the gas flows back upward after reaching the bottom of the molten slag quenching zone, is cooled and washed by the circulating slag water through the plurality of bubble-breaking baffles 14, is cooled to 100-350 ℃, and is then discharged from the synthesis gas outlet 10 of the gasification furnace 1; the ash and slag are captured by the circulating slag water and are discharged from the bottom slag discharge port 12 to be treated by an ash water system. Step 5, the crude synthesis gas from the gasification furnace 1 enters the scrubbing tower 32, in which the dust and acid gas entrained in the synthesis gas are further removed, and the temperature of the synthesis gas at the outlet of the scrubbing tower is controlled to be lower than 100℃; Step 6, the purified synthesis gas after scrubbing enters the drying tower 33 and the drying agent regeneration tower 34 through a pipeline, and is further dehydrated and dried, and the dew point temperature of the synthesis gas at the outlet of the drying tower is controlled to be lower than -40℃; Step 7, the dried purified synthesis gas enters the turbine generator 35, and the residual pressure is converted into electric energy, and the pressure of the synthesis gas is reduced to 10~50KPa; Step 8, the synthesis gas after pressure reduction is sampled and analyzed by using the coal gas analyzer 36, and the qualified synthesis gas with oxygen content less than 0.5% enters the coke oven gas pipeline network, and the unqualified synthesis gas is discharged.

6. The method of claim 5, wherein the coking dedusting ash solid waste is gasified by the method. The reaction temperature in the high-temperature gasification zone is 1200~1650℃, the reaction pressure is 0.1~8.0MPa, and the gas-solid contact time is 5~20s; the temperature in the shift hydrogen production zone is 700~1000℃, and the residence time of the gas in the shift hydrogen production zone is 5~20s.

7. The method of claim 5, wherein the coking dedusting ash solid waste is gasified by using a fluidized bed gasification technology. The gasification agent is oxygen, water vapor, carbon dioxide and nitrogen, the jet velocity of the gasification agent is 80-120 m / s; the consumption ratio of oxygen to coking fly ash is 0.6-1.0 Nm 3 / kg; the consumption ratio of water vapor to coking fly ash is 0-0.4 Nm 3 / kg; the consumption ratio of carbon dioxide to coking fly ash is 0-0.4 Nm 3 / kg; the consumption ratio of nitrogen to coking fly ash is 0-0.3 Nm 3 / kg; the volume percentage of oxygen in the gasification agent is 70-100%, the volume percentage of water vapor is 0-30%, the volume percentage of carbon dioxide is 0-30%, and the volume percentage of nitrogen is 0-20%.

8. The method of claim 5, wherein the coking dedusting ash solid waste is gasified by the method. The dust removal ash jet velocity at the outlet of the gasification nozzle is 5~20m / s.

9. The method of claim 5, wherein the coking dedusting ash solid waste is gasified by using a fluidized bed gasification technology. The pressure difference between the feeding tank 29 and the gasification furnace 1 during the conveying of the dedusting ash is 0.2-1.0 MPa, and the ratio of the conveying gas to the dedusting ash is 0.08-1 Nm 3 conveying gas / kg dedusting ash, which is used to ensure the continuous and stable conveying of the coking dedusting ash.

10. The method of claim 5, wherein the coking dedusting ash solid waste is gasified. The cooling medium sprayed into the shift hydrogen production zone through the atomizing nozzle 7 is any one or more of 20~60℃ coal gas scrubbing water, industrial tap water, industrial soft water or 100~200℃ boiler saturated water, and the amount is 0.25~0.7kg water / kg dust removal ash, or 100~250℃ low-temperature steam, and the amount is 0.5~1.8kg water steam / kg dust removal ash.

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