Biomass fluidized bed gasification system suitable for green hydrogen coupling

Abstract

The utility model discloses a biomass fluidized bed gasification system suitable for green hydrogen coupling. The biomass fluidized bed gasification system comprises a fluidized bed gasification furnace, a first cyclone separator, an oxidation cracking furnace, a waste heat boiler, a second cyclone separator, a dust remover and a water scrubber, the fluidized bed gasification furnace, the first cyclone separator, the oxidation cracking furnace, the waste heat boiler, the second cyclone separator, the dust remover and the water scrubber are sequentially connected along the flow direction of synthesis gas to form a synthesis gas flow path; the system disclosed by the utility model is very suitable for a green-hydrogen coupled biomass gasification device, the heat recovery rate exceeds 98%, the unit effective gas yield is about 1t steam, and the energy consumption is greatly saved; however, the heat recovery rate of the traditional gasification technology adopting a chilling process is only about 75%. A large amount of high-grade heat with the temperature higher than 1000 DEG C is directly chilled by cooling water to meet the requirement of a follow-up conversion device, and serious waste is caused.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of biomass fluidized bed gasification systems suitable for green hydrogen coupling. BACKGROUND

[0002] The content of alkali metal K and halogen CL in biomass is relatively high, which leads to low ash melting point of biomass, and easily causes problems such as slagging, blocking and corrosion fouling.

[0003] Methane existing in biomass synthesis gas is useless vent gas for subsequent chemical synthesis, and the existence of methane increases raw material consumption and power consumption.

[0004] For the device that exists electrolysis water preparation green hydrogen coupling biomass gasification, since the variable unit is cancelled, the downstream device has no corresponding technical requirements for the water vapor ratio of the gasification device, which leads to serious energy waste in the original quenching process. UTILITY MODEL CONTENT

[0005] The utility model solves the technical problems that the existing electrolysis water preparation hydrogen coupling biomass gasification system has quenching process leading to energy waste, and provides a biomass fluidized bed gasification system suitable for green hydrogen coupling, and the system has high heat recovery rate.

[0006] The utility model solves the above technical problems through the following technical solutions:

[0007] A biomass fluidized bed gasification system suitable for green hydrogen coupling comprises a fluidized bed gasification furnace, a first cyclone separator, an oxidative cracking furnace, a waste heat boiler, a second cyclone separator, a dust collector and a water washing tower.

[0008] The fluidized bed gasification furnace comprises a gasification furnace body and a distribution plate arranged at the bottom of the gasification furnace body.

[0009] The gasification furnace body is provided with a feed inlet, the feed inlet is located above the distribution plate, and the end of the feed inlet towards the slag discharge port is inclined.

[0010] In the utility model, it can be understood that the fluidized bed gasifier is a gasifier for generating synthetic gas by gasification of biomass raw materials in the prior art, wherein the synthetic gas generally mainly comprises H2, CO, CO2, methane and some hydrocarbons.

[0011] It can be understood that when the distribution plate of the utility model is installed in the fluidized bed gasifier, the distribution plate is placed upside down at the bottom of the fluidized bed gasifier, that is, the end with a larger diameter of the distribution plate faces upward, and the end with a smaller diameter of the distribution plate faces downward.

[0012] The fluidized bed gasifier of the utility model improves the reaction temperature by arranging the fluidizing agent port at the side of the distribution plate and arranging the gasification agent ports around the slag discharge port, forms a central high-temperature area, eliminates tar, expands the range of the central high-temperature area of the gasifier, and reduces the problem of easy slagging in the central high-temperature area while eliminating tar; meanwhile, the fluidizing agent port inclined toward the slag discharge port is arranged below the feed inlet, on the one hand, the material quickly enters the high-temperature area in the center of the gasifier for reaction, and the tar above is brought into the high-temperature area to quickly gasify the tar, and on the other hand, the fluidizing agent port arranged downward plays a certain flushing effect on the distribution plate, which can effectively prevent the agglomeration of slag blocks to form large slag blocks to block the slag discharge port.

[0013] In the utility model, the inclination angle A1 of the feed inlet relative to the horizontal plane is preferably 30-80°, for example, 45° or 60°.

[0014] In the utility model, preferably, the inclination angle A1 of the feed inlet and the inclination angle A4 of the conical surface of the distribution plate relative to the horizontal plane are the same. If the inclination angle (namely A1) of the feed inlet is too small, the large particles of the feed will fall in a parabolic manner and hit the distribution plate, and most of the particles cannot accelerate to reach the center. If the inclination angle (namely A1) of the feed inlet is too large, the feed particles will increase the wear of the distribution plate.

[0015] In the utility model, the distance Hf between the lower edge of the feed inlet and the upper edge of the distribution plate is preferably 0-Di, for example, 0.48Di or 0.072Di, and Di refers to the inner diameter of the gasifier.

[0016] In the utility model, preferably, the axis of the feed inlet intersects the central axis of the gasifier body, so that the feeding direction is directly opposite the central direction of the gasifier.

[0017] In the utility model, the inclination angle A2 of the fluidizing agent port inclined toward the slag discharge port relative to the horizontal plane is preferably 0-30°, and does not include 0°, for example, 15°.

[0018] In the utility model, can understand, in addition to all the fluidizing agent mouth located directly below the feed inlet, the axis of the rest of the fluidizing agent mouth can be inclined to one end of the residue discharge port, can also be inclined to the end away from the residue discharge port, can also be along the horizontal direction. Preferably, the axis of the rest of the fluidizing agent mouth is inclined to the end away from the residue discharge port or along the horizontal direction;Further, the chord length L2 of the area formed by all the fluidizing agent mouths inclined to one end of the residue discharge port is L1~10L1, and L1 is the diameter of the feed inlet. If the width of the feed acceleration zone is too narrow, it cannot guarantee that all the feed can be accelerated, and if it is too wide, not only the feed is accelerated, but also the surrounding ash enters the center high-temperature zone, competes for the gasifying agent, and leads to incomplete gasification.

[0019] The distribution plate is divided into a feed acceleration zone and a bed fluidization zone along its circumference, all the fluidizing agent mouths inclined to one end of the residue discharge port are located in the feed acceleration zone, and the chord length of the feed acceleration zone is L2.

[0020] Further, the inclination angle A3 of the rest of the fluidizing agent mouths relative to the horizontal plane is 0~45°, for example 0°, and the inclination angle A3 refers to the angle between the axis of the fluidizing agent mouth and the horizontal plane, and the positive angle refers to the horizontal upward.

[0021] In the utility model, preferably, the plurality of fluidizing agent mouths are uniformly distributed on the distribution plate.

[0022] The number and distribution of the fluidizing agent mouths are optimized according to the gasification feed scale, and generally 5-10 layers of the fluidizing agent mouths are sequentially distributed along the top to the bottom of the distribution plate, each layer includes a plurality of fluidizing agent mouths equally spaced along the circumference of the distribution plate;The spacing of the adjacent two layers of the fluidizing agent mouths along the axial direction of the distribution plate is preferably 100-300mm.

[0023] In the utility model, preferably, the axis of the first gasifying agent mouth is parallel to the central axis of the distribution plate. The gasifying agent is sprayed out of the first gasifying agent mouth, pushes the high-speed turbulent flow of the bubbling fluidized bed region, and strengthens the mass transfer, heat transfer and high-temperature reaction processes in the central region and the upper bubbling fluidization region.

[0024] In the utility model, preferably, the first gasifying agent mouth is uniformly distributed with a plurality of, for example 3, along the circumference of the residue discharge port. The distance between the axis of the first gasifying agent mouth and the axis of the residue discharge port is preferably 200-500mm, for example 300mm. If the distance is too small, the gas sprayed out of the first gasifying agent mouth will hinder the falling ash from entering the residue discharge port, leading to poor residue discharge;If the distance is too large, the unreacted carbon-containing ash will enter the residue discharge port, leading to high carbon content of the discharged residue, and waste of raw materials.

[0025] The diameter of the first gasification agent port is preferably 10-200mm, for example 80mm.

[0026] The utility model discloses a preferably still set up a gas inlet pipe in the deslagging port, the gas inlet pipe forms a second gasification agent port, and an annular area for deslagging is arranged between the gas inlet pipe and the deslagging port. When the second gasification agent port is not arranged in the deslagging port, the outer wall of the gas inlet pipe no longer contacts the high-temperature ash and slag, thereby eliminating the problem of wear of the gas inlet pipe.

[0027] Preferably, the diameter of the second gasification agent port accounts for 30-70% of the diameter of the deslagging port, and more preferably, the diameter of the second gasification agent port is 100-200mm, for example 150mm, and the diameter of the deslagging port is 200-300mm, for example 250mm.

[0028] Preferably, the pore size of the fluidization agent port is 2-10mm, for example 5mm or 7mm.

[0029] Preferably, the inclination angle A4 of the conical surface of the distribution plate with respect to the horizontal plane is 30-80°, for example 45° or 60°.

[0030] The fluidization agent port is used for introducing fluidization agent, and the first gasification agent port is used for introducing gasification agent.

[0031] Preferably, the material of the distribution plate is metal and / or non-metallic refractory material.

[0032] Preferably, a leakage prevention assembly is arranged on the fluidization agent port, which is used for preventing the ash and slag in the furnace from being reversely threaded to the outside of the distribution plate. The leakage prevention assembly preferably comprises a connecting portion and a leakage prevention portion, one end of the connecting portion is connected with the leakage prevention portion, the outer diameter of the other end of the connecting portion matches the pore size of the fluidization agent port, a porous structure for passing fluidization agent is arranged on the leakage prevention portion, the pore size of the porous structure is 0.1-500μm, and a hole structure for passing fluidization agent is arranged on the connecting portion. The porous structure is only used for passing gasification agent, and it is difficult for ash and slag to pass through, thereby preventing the ash and slag from being reversely threaded to the outside of the distribution plate. The other end of the connecting portion is inserted into the fluidization agent port, thereby realizing the connection between the leakage prevention assembly and the fluidization agent port.

[0033] Preferably, the leakage prevention portion is a block-shaped body, the porous structure is arranged on the block-shaped body, and the block-shaped body is processed from one or more of a metal mesh, metal fibers, metal powder and ceramic.

[0034] The pore size of the porous structure is preferably 0.1-120 μm, for example 5-25 μm. If the pore size of the porous structure is too large, the ash will be blocked in the porous structure, and if the pore size is too small, the fluidization effect of the fluidizing agent will be affected.

[0035] The hole structure on the connecting part can be conventional in the art, for example a through hole or a mesh hole.

[0036] The connecting part preferably comprises a first support and a sleeve, the first support is provided with a support groove, the groove bottom of the support groove is provided with a first through hole, the leakage prevention part is arranged in the support groove, one end of the sleeve is provided with a flange, the outer diameter of the flange is greater than the hole diameter of the fluidizing agent port and less than the inner diameter of the support groove, the flange is located in the support groove, and the outer diameter of the other end of the sleeve matches the hole diameter of the fluidizing agent port. In the preferred scheme, the first through hole and the pipe hole of the sleeve form a hole structure for the fluidizing agent to pass through. When the leakage prevention assembly is assembled in the fluidizing agent port, the other end of the sleeve is inserted into the fluidizing agent port, and the flange is clamped on the outer periphery of the fluidizing agent port. The gasification agent enters the furnace body through the second through hole, the porous structure in the leakage prevention part and the first through hole.

[0037] More preferably, the connecting part further comprises a second support, the second support is a sleeve structure, the second support is sleeved outside the flange, and the first support is connected outside the second support through threads. During installation, the end of the second support can be fixed to the back of the distribution plate through welding, and the first support is connected with the second support through threads, so that the leakage prevention assembly is convenient to disassemble and assemble.

[0038] More preferably, the leakage prevention assembly further comprises a first support and a second support, the first support, the leakage prevention part and the second support are sequentially arranged in the support groove from top to bottom, and the first support and the second support are both metal mesh structures. The hole diameter of the metal mesh structure is preferably 0.1-1 mm. The first support and the second support are arranged to prevent the leakage prevention part from being deformed due to extrusion.

[0039] In the utility model, preferably, the biomass fluidized bed gasification system coupled with green hydrogen further comprises a first water inlet pipeline and a heat exchanger, the first water inlet pipeline is connected with a steam drum of the waste heat boiler, and the heat exchanger is connected with a connecting pipeline of the dust remover and the water washing tower and the first water inlet pipeline. The heat exchanger exchanges heat in the connecting pipeline and the first water inlet pipeline, and further utilizes the waste heat in the synthesis gas. The first water inlet pipeline is used for feeding water into the steam drum.

[0040] The heat exchanger is conventional in the art, and the heat exchanger generally comprises a first port and a second port, the first port is connected with the first water inlet pipeline, and the second port is connected with the connecting pipeline.

[0041] In the utility model, it can be understood that the fluidized bed gasification furnace is generally provided with a synthetic gas outlet, a fly ash return port and a slag discharge port, the synthetic gas outlet is connected with the synthetic gas inlet of the cyclone separator, and the fly ash return port is connected with the fly ash discharge port of the cyclone separator.

[0042] Preferably, the synthetic gas outlet is arranged at the top of the fluidized bed gasification furnace, and the slag discharge port is preferably arranged at the bottom of the fluidized bed gasification furnace.

[0043] In the utility model, it can be understood that the cyclone separator is conventional in the art and is used for separating gas, solid and liquid parts in the synthetic gas from the fluidized bed gasification furnace. The first cyclone separator is generally provided with a synthetic gas inlet, a synthetic gas outlet and a fly ash discharge port.

[0044] Preferably, the fly ash discharge port is arranged at the bottom of the first cyclone separator, the synthetic gas inlet is arranged at the upper side of the first cyclone separator, and the synthetic gas outlet is arranged at the top of the first cyclone separator.

[0045] Preferably, the bottom of the first cyclone separator is provided with a leg device, the leg device is connected between the fly ash discharge port of the first cyclone separator and the fly ash return port of the fluidized bed gasification furnace, and is used for returning fly ash to the fluidized bed gasification furnace for secondary reaction. The leg device is conventional in the art.

[0046] In the utility model, it can be understood that the oxidative cracking furnace is conventional in the art and is used for oxidizing and cracking methane and some hydrocarbons in the synthetic gas into CO and H2, so that the content of effective gas (H2 and CO) can be increased.

[0047] It can be understood that the oxidative cracking furnace of the utility model is generally not provided with a quenching zone.

[0048] The oxidative cracking furnace is generally provided with a synthetic gas inlet and a synthetic gas outlet, the synthetic gas inlet is connected with the synthetic gas outlet of the cyclone separator, and the synthetic gas outlet is connected with the gas inlet of the waste heat boiler.

[0049] Preferably, the synthetic gas inlet and the synthetic gas outlet are arranged at the top and the bottom of the oxidative cracking furnace respectively.

[0050] The oxidizing cracking furnace is preferably a non-catalytic oxidizing cracking furnace, which can reduce catalyst deactivation or plugging caused by H2S and fly ash in the crude synthesis gas compared to a catalytic conversion furnace.

[0051] In the utility model, it can be understood that the waste heat boiler is a device for recovering heat of synthesis gas from the oxidizing cracking furnace in the prior art. For example, the waste heat boiler comprises a steam drum, an evaporator and a superheater, and the evaporator and the superheater are connected with the steam drum. The waste heat of high-temperature synthesis gas is converted into steam or hot water by heating water in the waste heat boiler by the evaporator, and the steam or hot water is further heated by the superheater, so that the temperature and pressure of the steam are improved, the steam can reach a higher temperature and pressure, and different process requirements are met.

[0052] The waste heat boiler is generally provided with a synthesis gas inlet and a synthesis gas outlet for the inlet and outlet of synthesis gas.

[0053] Preferably, the synthesis gas inlet and the synthesis gas outlet are arranged at the top and the bottom of the waste heat boiler respectively.

[0054] Preferably, the waste heat boiler is a fire tube boiler, which is conventional in the prior art. The high-temperature gas in the fire tube has a high flow rate, and fly ash and alkali metals are not easy to deposit, so that the waste heat boiler can effectively resist alkali metal fouling and corrosion. The material of the furnace tube of the waste heat boiler is preferably 20G steel, which can resist chloride ion corrosion well.

[0055] Preferably, the bottom of the steam drum is further connected with a blowdown device for discharging deposits at the bottom of the steam drum.

[0056] In the utility model, it can be understood that the second cyclone separator is a device for separating gas and solid in the synthesis gas from the waste heat boiler in the prior art. The second cyclone separator is generally provided with a synthesis gas inlet, a synthesis gas outlet and a fly ash outlet. The synthesis gas inlet of the second cyclone separator is connected with the synthesis gas outlet of the waste heat boiler, and the synthesis gas outlet of the second cyclone separator is connected with the gas inlet of the dust collector.

[0057] Preferably, the fly ash outlet is arranged at the bottom of the second cyclone separator, the synthesis gas inlet is arranged at the upper side of the second cyclone separator, and the synthesis gas outlet is arranged at the top of the second cyclone separator.

[0058] The utility model discloses, can understand, the dust remover is the conventional device for further dust removal of the synthetic gas from the second cyclone separator in the field, the synthetic gas import of the dust remover is connected with the synthetic gas export of the second cyclone separator, and the synthetic gas export of the dust remover is connected with the air inlet of the water scrubbing tower.

[0059] Wherein, the fly ash discharge port preferably is arranged at the bottom of the dust remover, the synthetic gas import preferably is arranged at the lower side of the dust remover, and the synthetic gas export preferably is arranged at the upper side of the dust remover.

[0060] The utility model discloses, the biomass fluidized bed gasification system suitable for green hydrogen coupling preferably still includes fly ash return pipeline, one end of fly ash return pipeline is connected fly ash export of second cyclone separator and fly ash export of dust remover, and the other end of fly ash return pipeline is connected return port of fluidized bed gasification furnace, and the fly ash collected in second cyclone separator and dust remover is returned to fluidized bed gasification furnace, and carbon conversion rate is improved.

[0061] Wherein, the fly ash return pipeline preferably further is provided with return powder device. The return powder device includes the buffer hopper, the lock hopper and the sending hopper that are connected in sequence.

[0062] The utility model discloses, can understand, the water scrubbing tower is the conventional device for further washing of synthetic gas in the field. The water scrubbing tower generally is provided with air inlet, air outlet, ash water export and water inlet, and the air inlet is connected with the synthetic gas export of the dust remover.

[0063] Wherein, the air outlet and the ash water export preferably are arranged at the top and bottom of the water scrubbing tower respectively, the air inlet and the ash water circulation return port preferably are arranged at the lower side of the water scrubbing tower, and the water inlet preferably is arranged at the upper side of the water scrubbing tower.

[0064] Wherein, the biomass fluidized bed gasification system suitable for green hydrogen coupling preferably further includes ash water return pipeline, and both ends of the ash water return pipeline are connected with the ash water export of the water scrubbing tower and the water inlet of the water scrubbing tower respectively, for returning the ash water in the water scrubbing tower to the water inlet and recycling. Wherein, the ash water return pipeline is provided with a pump.

[0065] Wherein, the water inlet of the water scrubbing tower can be further provided with a second water inlet pipeline, and the second water inlet pipeline is used for passing the industrial water into the water scrubbing tower.

[0066] The biomass fluidized bed gasification system suitable for green hydrogen coupling of the utility model can be used for gasification of biomass, and the gasification method specifically includes the following steps:

[0067] The biomass raw material is introduced through the feeding port, the fluidizing agent is introduced through the fluidizing agent port, and the gasification agent is introduced through the first gasification agent port, and a gasification reaction is carried out, and the obtained crude synthesis gas is sequentially subjected to treatment through the first cyclone separator, the oxidative cracking furnace, the waste heat boiler, the second cyclone separator, the dust remover and the water washing tower.

[0068] The utility model discloses when still including aforementioned second gasification agent port, through the second gasification agent port, gasification agent is introduced.

[0069] The utility model discloses when adopting aforementioned first water inlet pipeline and heat exchanger, in the processing, the heat in the connecting pipeline and the first water inlet pipeline is exchanged through the heat exchanger.

[0070] The utility model discloses the biomass raw material is the power conventional, for example wood, straw, rice husk, bamboo cane etc.

[0071] The utility model discloses the biomass raw material is the power conventional, for example wood, wheat, corn straw, rice husk, bamboo cane one or more combinations.

[0072] The utility model discloses the biomass raw material particle's maximum particle size is preferably < 10mm.

[0073] The utility model discloses can understand, the fluidizing agent and the gasification agent are the power conventional.

[0074] The fluidizing agent can be oxygen or a mixture of oxygen and steam, or a mixture of oxygen, steam and nitrogen, or a mixture of oxygen, steam and carbon dioxide.

[0075] The gasification agent can be oxygen or a mixture of oxygen and steam.

[0076] The feeding speed of the fluidizing agent and the gasification agent can be adjusted according to actual working conditions.

[0077] The temperature of the gasification reaction is conventional in the art, for example, 700-1300℃, for example, 820℃.

[0078] The pressure in the fluidized bed gasifier is conventional in the art, for example 0.5-80 barg, for example 40 barg.

[0079] The positive progress effect of the utility model lies in:

[0080] (1) the system of the utility model cancels the downstream shift device because the downstream device has no requirement for the steam ratio of the gasification system when coupled with green hydrogen, and the system of the utility model improves the heat recovery rate.

[0081] (2) the heat recovery rate of the system of the utility model is more than 98%, and the unit effective gas production is about 1t steam, which greatly saves energy consumption; the heat recovery rate of the traditional gasification technology using quenching process is only about 75%, and a large amount of high-grade heat greater than 1000 DEG C is directly quenched by cooling water for the needs of the subsequent shift device, which causes serious waste.

[0082] (3) the system of the utility model can completely digest the fly ash returned to the fluidized bed gasifier from the dust remover and the second cyclone separator due to the high temperature zone of the fluidized bed gasifier, and the entire gasification device has no fly ash discharge, the carbon conversion rate can reach more than 99%, and the environmental protection problem is solved; the carbon conversion rate of the traditional biomass gasification technology is only about 80% due to no setting, which not only causes large biomass consumption, but also fly ash is difficult to handle as hazardous waste.

[0083] (4) the fluidized bed gasifier in the system of the utility model has a high-temperature oxidation zone, can fully decompose tar, effectively reduces the tar content at the outlet of the fluidized bed gasifier or makes the outlet of the fluidized bed gasifier have no tar, the effective gas in the synthesis gas can reach more than 65%, and the yield of the effective gas of the biomass gasification is greatly improved; for the traditional biomass gasification technology, the gasification temperature cannot be improved due to the influence of the gasifier slag, the tar is 50-100g / Nm 3 , the methane is more than 10%, and the effective gas content in the synthesis gas is low, less than 50%. BRIEF DESCRIPTION OF DRAWINGS

[0084] Figure 1 It is a structural schematic view of the biomass gasification system according to the embodiment 2 of the utility model.

[0085] Figure 2 It is a structural schematic view of the distribution plate according to the embodiment 1 of the utility model.

[0086] Figure 3 It is a partial structural schematic view of the fluidized bed gasifier according to the embodiment 1 of the utility model.

[0087] Figure 4Is the position relation diagram of the first gasification agent port and the slag discharge port in the fluidized bed gasification furnace according to embodiment 1 of the utility model.

[0088] Figure 5 Is the structure diagram of the leakage prevention assembly according to embodiment 1 of the utility model.

[0089] Mark explanation:

[0090] Fluidized bed gasification furnace 1

[0091] Gasification furnace shaft 101

[0092] Feed inlet 1011

[0093] Distribution plate 102

[0094] Fluidizing agent port 1021

[0095] First gasification agent port 1022

[0096] Slag discharge port 1023

[0097] Second gasification agent port 1024

[0098] Feed acceleration zone S1

[0099] Bed fluidization zone S2

[0100] Leakage prevention assembly 103

[0101] First support 1031

[0102] First through hole 10311

[0103] Limiting step surface 10312

[0104] Second support 1032

[0105] Sleeve 1033

[0106] First support piece 1034

[0107] Second support piece 1035

[0108] Leakage prevention part 1036

[0109] First cyclone separator 2

[0110] Oxidative cracking furnace 3

[0111] Waste heat boiler 4

[0112] Steam drum 41

[0113] Second cyclone separator 5

[0114] Dust remover 6

[0115] Water scrubbing tower 7

[0116] First water inlet pipeline 8

[0117] Heat exchanger 9

[0118] Fly ash return pipeline 10

[0119] Powder return device 11

[0120] Leg device 12

[0121] Second water inlet pipeline 13

[0122] Ash water return pipeline 14

[0123] Pump 15

[0124] Blowdown device 16 DETAILED DESCRIPTION

[0125] The utility model will be further illustrated by the following examples, but the utility model is not limited in the scope of the examples.

[0126] Example 1

[0127] This embodiment discloses a fluidized bed gasification furnace, as shown in the figure, which comprises a gasification furnace body 101 and a distribution plate 102 in the gasification furnace body 101. Figures 2-5

[0128] The two feed inlets 1011 are arranged on the gasification furnace body 101, and the axis of the feed inlet 1011 intersects with the central axis of the gasification furnace body 101, so that the feeding direction is directly opposite the central direction of the gasification furnace body 101.

[0129] The feed inlet 1011 is located above the distribution plate 102, and the distance Hf between the lower edge of the feed inlet 1011 and the upper edge of the distribution plate 102 is 0.18 m, the inner diameter Di of the gasification furnace body 101 is 3.3 m, and the total height is 25 m. The axis of the feed inlet 1011 is inclined towards one end of the slag discharge port 1023, and the inclination angle A1 of the feed inlet 1011 relative to the horizontal plane is 45°.

[0130] The inclination angle A4 of the conical surface of the distribution plate 102 relative to the horizontal plane is 45°, and the material of the distribution plate 102 is metal or non-metal refractory material.

[0131] The distribution plate 102 is provided with a plurality of fluidizing agent ports 1021, first gasification agent ports 1022 and slag discharge ports 1023, the first gasification agent port 1022 is provided with a pipeline, the inner diameter of the pipeline is 80 mm, and the pore size of the fluidizing agent port 1021 is 5 mm;

[0132] ​The distribution plate 102 is conical, and 5 layers of fluidizing agent ports 1021 are distributed on the distribution plate. The distance between two adjacent layers along the axial direction of the distribution plate is 300 mm. The number of fluidizing agent ports in each layer from top to bottom is 82, 71, 52, 44 and 22 respectively. The fluidizing agent ports in each layer are equidistantly distributed along the circumferential direction of the distribution plate 102.

[0133] The distribution plate 102 is divided into a feed accelerating zone S1 and a bed fluidizing zone S2 along the circumferential direction thereof. Each feed port 1011 corresponds to a feed accelerating zone S1 below. The diameter L1 of the feed port 1011 is 100 mm, and the chord length L2 of the feed accelerating zone S1 is 300 mm. The axis of the fluidizing agent port 1021 located in the feed accelerating zone S1 is inclined towards one end of the slag discharge port 1023, and the inclination angle A2 is 15°. The axis of all fluidizing agent ports 1021 located in the bed fluidizing zone S2 is inclined at an angle A3 of 0° with respect to the horizontal direction, i.e. along the horizontal direction.

[0134] The slag discharge port 1023 is arranged at the bottom of the distribution plate 102, and the diameter of the slag discharge port is 250 mm. The first gasifying agent port 1022 has three, which are equidistantly arranged around the four sides of the slag discharge port 1023. The distance between the axis of the first gasifying agent port 1022 and the axis of the slag discharge port is 300 mm. The axis of the first gasifying agent port 1022 is parallel to the axis of the distribution plate 102, and both are in the vertical direction. A gasifying agent feeding pipe is arranged in each first gasifying agent port 1022. A slag discharge pipe is arranged in the slag discharge port 1023, and a gasifying agent feeding pipe is sleeved in the slag discharge pipe as a second gasifying agent port 1024. The diameter of the pipe is 150 mm. The annular gap between the slag discharge pipe and the gasifying agent feeding pipe is the slag discharge area.

[0135] The fluidizing agent port 1021 is provided with a leakage prevention assembly 103, which is located on the back of the distribution plate 102. The leakage prevention assembly 103 includes a leakage prevention part 1036 and a connecting part. The leakage prevention part 1036 is a plate structure made of metal fibers, and a porous structure for passing fluidizing agent is arranged on the plate. The pore size of the porous structure is 5-25 μm. A hole structure for passing fluidizing agent is arranged on the connecting part.

[0136] The connecting part comprises a first support 1031, a second support 1032, a sleeve 1033, a first support piece 1034 and a second support piece 1035. The first support 1031 is provided with a support groove, the groove bottom of the support groove is provided with a first through hole 10311, and the first support piece 1034, the leakage prevention part 1036 and the second support piece 1035 are sequentially arranged in the support groove from top to bottom. One end of the sleeve 1033 is provided with a flange, the outer diameter of the flange is greater than the hole diameter of the fluidizing agent port 1021 and less than the inner diameter of the support groove, the flange is located in the support groove, and the outer diameter of the other end of the sleeve 1033 matches the hole diameter of the fluidizing agent port 1021. The second support 1032 is a sleeve structure and is made of metal, the second support 1032 is sleeved outside the flange, and the first support 1031 is threadedly connected outside the second support 1032.

[0137] A limiting step surface 10312 is arranged on the inner side wall of the support groove, which is used for limiting the rotation depth of the second support 1032 in the first support 1031, so as to avoid excessive rotation and extrusion of the leakage prevention part 1036.

[0138] The depth of the support groove of the first support 1031 is equal to the sum of the thicknesses of the first support piece 1034, the leakage prevention part 1036, the second support piece 1035 and the flange of the sleeve 1033.

[0139] The sleeve 1033 is a ceramic sleeve with a length of 100 mm and an inner diameter of 5.0 mm, and the wall thickness of the end of the sleeve 1033 without the flange is 1.5 mm.

[0140] The first support piece 1034 and the second support piece 1035 are both steel wire mesh structures, the hole diameter of the steel wire mesh is about 0.5 mm, and the skeleton steel wire diameter of the steel wire mesh is 0.2 mm.

[0141] During installation, the first support piece 1034, the leakage prevention part 1036 and the second support piece 1035 are arranged in the support groove of the first support 1031; the end of the second support 1032 is fixed to the back of the distribution plate 102 by welding, the end with a smaller outer diameter of the sleeve 1033 is inserted into the fluidizing agent port 1021, and the flange of the sleeve 1033 is clamped on the distribution plate 102 at the outer periphery of the fluidizing agent port 1021, and the first support 1031 is connected with the second support 1032 by threading. The gasifying agent enters the furnace body through the second through hole 10311, the porous structure in the leakage prevention part and the pipe hole of the sleeve 1033.

[0142] Embodiment 2

[0143] The embodiment discloses a biomass fluidized bed gasification system suitable for green hydrogen coupling, which comprises a furnace body, a distribution plate 102, a connecting part and a gasification agent inlet 101. Figure 1As shown, it comprises: a fluidized bed gasifier 1, a first cyclone 2, an oxidative cracking furnace 3, a waste heat boiler 4, a second cyclone 5, a dust collector 6, a water washing tower 7, a first water inlet pipeline 8, a heat exchanger 9, a fly ash return pipeline 10, a powder returning device 11, a second water inlet pipeline 13 and an ash water return pipeline 14.

[0144] The fluidized bed gasifier 1 is the fluidized bed gasifier described in Embodiment 1.

[0145] The gasifier body 101 is further provided with a syngas outlet, a fly ash return port and a slag discharge port. The syngas outlet is arranged at the top of the gasifier body 101, the slag discharge port is arranged at the bottom of the gasifier body 101, and the fly ash return port is arranged at the lower side of the gasifier body 101.

[0146] The first cyclone 2 is used to separate the gas and solid parts in the syngas out of the fluidized bed gasifier; wherein the first cyclone 2 is provided with a syngas inlet, a syngas outlet and a fly ash discharge port. The fly ash discharge port is arranged at the bottom of the cyclone 2, the syngas inlet is arranged at the upper side of the first cyclone 2, and the syngas outlet is arranged at the top of the first cyclone 2.

[0147] The bottom of the first cyclone is provided with a leg device 12, which is connected between the fly ash discharge port of the cyclone 2 and the fly ash return port of the gasifier body 101, for returning the fly ash to the fluidized bed gasifier 1 for secondary reaction.

[0148] The oxidative cracking furnace 3 is used to oxidize the methane and some hydrocarbons in the syngas to make it crack into CO and H2. The oxidative cracking furnace 3 is a non-catalytic oxidative cracking furnace, and there is no quenching zone in the oxidative cracking furnace 3. The oxidative cracking furnace 3 is provided with a syngas inlet and a syngas outlet. The syngas inlet is arranged at the top of the oxidative cracking furnace 3, and the syngas outlet is arranged at the lower side of the oxidative cracking furnace 3.

[0149] The waste heat boiler 4 is used to recover the heat of the syngas out of the oxidative cracking furnace. The waste heat boiler is a fire tube boiler, and the tube material is 20G steel. The waste heat boiler comprises a steam drum, an evaporator and a superheater, and the evaporator and the superheater are connected with the steam drum. The waste heat boiler 4 is provided with a syngas inlet and a syngas outlet for the inlet and outlet of the syngas. The syngas inlet and the syngas outlet are arranged at the top and the bottom of the waste heat boiler respectively.

[0150] The second cyclone separator 5 is used to separate gas and solid in the synthesis gas from the waste heat boiler 4. The second cyclone separator 5 is a low-temperature cyclone separator. The second cyclone separator 5 is provided with a synthesis gas inlet, a synthesis gas outlet and a fly ash outlet, the fly ash outlet is arranged at the bottom of the second cyclone separator 5, the synthesis gas inlet is arranged at the upper side of the second cyclone separator 5, and the synthesis gas outlet is arranged at the top of the second cyclone separator 5.

[0151] The dust collector 6 is used to further remove dust from the synthesis gas from the second cyclone separator 5. The dust collector 6 is provided with a synthesis gas inlet, a synthesis gas outlet and a fly ash outlet, the fly ash outlet is arranged at the bottom of the dust collector 6, the synthesis gas inlet is arranged at the lower side of the dust collector 6, and the synthesis gas outlet is arranged at the upper side of the dust collector 6.

[0152] The water washing tower 7 is used to further wash the synthesis gas. The water washing tower 7 is provided with an air inlet, an air outlet, a grey water outlet and a water inlet, the air outlet and the grey water outlet are arranged at the top and the bottom of the water washing tower 7 respectively, the air inlet is arranged at the lower side of the water washing tower 7, and the water inlet is arranged at the upper side of the water washing tower 7. The water inlet of the water washing tower 7 is provided with a second water inlet pipeline 13, and the second water inlet pipeline 13 is used to introduce industrial water into the water washing tower 7.

[0153] The synthesis gas outlet of the gasifier furnace body 101 is connected with the synthesis gas inlet of the first cyclone separator 2, the synthesis gas outlet of the first cyclone separator 2 is connected with the synthesis gas inlet of the oxidative cracking furnace 3, the synthesis gas outlet of the oxidative cracking furnace 3 is connected with the synthesis gas inlet of the waste heat boiler 4, the synthesis gas inlet of the waste heat boiler 4 is connected with the synthesis gas inlet of the second cyclone separator 5, the synthesis gas outlet of the second cyclone separator 5 is connected with the air inlet of the dust collector 6, and the synthesis gas outlet of the dust collector 6 is connected with the air inlet of the water washing tower 7, thereby forming a synthesis gas flow route.

[0154] The first water inlet pipeline 8 is connected with the steam drum 41 of the waste heat boiler 4, and is used to introduce boiler water into the steam drum 41. The bottom of the steam drum 41 can also be connected with a blowdown device 16 for discharging the sediment at the bottom of the steam drum.

[0155] The heat exchanger 9 comprises a first port and a second port, the first port is connected with the first water inlet pipeline 8, and the second port is connected with a connecting pipeline of the dust collector 6 and the water washing tower 7. The heat exchanger 9 exchanges heat in the connecting pipeline and the first water inlet pipeline 8.

[0156] One end of the fly ash return pipeline 10 is connected with the fly ash outlet of the second cyclone separator 5 and the fly ash outlet of the dust collector 6, and the other end of the fly ash return pipeline 10 is connected with the return port of the gasifier body 101, so as to return the fly ash collected by the second cyclone separator 5 and the dust collector 6 to the fluidized bed gasifier. The fly ash return pipeline is further provided with a powder returning device 11, which comprises a buffer hopper, a lock hopper and a sending hopper connected in sequence.

[0157] The two ends of the ash water return pipeline 14 are connected with the ash water outlet of the water washing tower 7 and the water inlet of the water washing tower 7 respectively, so as to return the ash water in the water washing tower 7 to the water inlet for recycling. The ash water return pipeline 14 is provided with a pump 15.

[0158] Embodiment 3

[0159] The embodiment discloses a biomass fluidized bed gasification method suitable for green hydrogen coupling, which is carried out by using the biomass fluidized bed gasification system suitable for green hydrogen coupling described in embodiment 2.

[0160] The gasification method specifically comprises the following steps:

[0161] The biomass raw material is introduced through the feeding port 1011, the fluidizing agent is introduced through the fluidizing agent port 1021, and the gasification agent is introduced through the first gasification agent port 1022 and the second gasification agent port 1024, so as to carry out a gasification reaction, and the obtained crude synthetic gas is sequentially treated by the first cyclone separator 2, the oxidative cracking furnace 3, the waste heat boiler 4, the second cyclone separator 5, the dust collector 6 and the water washing tower 7.

[0162] In the treatment process, the heat in the connecting pipeline of the dust collector 6 and the water washing tower 7 and the first water inlet pipeline 8 is exchanged by the heat exchanger 9.

[0163] The raw material is a granular material after biomass granulation, the biomass is bamboo, the maximum particle size of the granular material is <10 mm, and the external water is <4%. The feeding amount is 50 t / h, the feeding is at room temperature, the gasification pressure is 40 barg, and the gasification temperature is 820 DEG C. The fluidizing agent and the gasification agent are both mixed gas of oxygen and steam, wherein the oxygen content in the gasification agent is 40%, the feeding speed of the gasification agent is 60 m / s, the oxygen content in the fluidizing agent is 10%, the feeding speed of the fluidizing agent is 0.3 m / s, and the sum of the total flow of the gasification agent and the total flow of the fluidizing agent is 15 t / h. The total flow of the gasification agent is 8.6 t / h, the total flow of the fluidizing agent is 6.4 t / h, and the volume of the gasifier body is 220 m 3 .

[0164] The system of the embodiment is operated for 200 days.

[0165] Implementation effect:

[0166] The residence time of the biomass particles in the gasifier shaft 101 is > 20 s, and the outlet of the gasifier shaft 101 is free of tar.

[0167] The composition of the synthesis gas leaving the water scrubber 7 is monitored, and the effective gas content of the synthesis gas is > 65%.

[0168] The overall heat recovery of the system is > 98%, and the carbon conversion is > 98%.

Claims

1. A biomass fluidized bed gasification system suitable for green hydrogen coupling, characterized in that, It comprises a fluidized bed gasifier, a first cyclone separator, an oxidative cracking furnace, a waste heat boiler, a second cyclone separator, a dust collector and a water washing tower; the fluidized bed gasifier, the first cyclone separator, the oxidative cracking furnace, the waste heat boiler, the second cyclone separator, the dust collector and the water washing tower are sequentially connected along a synthetic gas flow direction to form a synthetic gas flow route. The fluidized bed gasifier comprises a gasifier body and a distribution plate arranged at the bottom of the gasifier body; the distribution plate is in the shape of a conical hopper, and a plurality of fluidizing agent ports, first gasification agent ports and a slag discharge port are arranged on the distribution plate; the fluidizing agent ports are arranged at the side of the distribution plate, the slag discharge port is arranged at the bottom of the distribution plate, and the first gasification agent ports are arranged around the slag discharge port and closer to the slag discharge port than the fluidizing agent ports; the pore diameter of the first gasification agent ports is larger than that of the fluidizing agent ports. The gasifier body is provided with a feed inlet above the distribution plate, and the feed inlet is inclined toward one end of the slag discharge port; all the fluidizing agent ports directly below the feed inlet are inclined toward one end of the slag discharge port.

2. The biomass fluidized bed gasification system suitable for green hydrogen coupling according to claim 1, wherein, The fluidized bed gasifier satisfies one or more of the following conditions: ① The inclination angle A1 of the feed inlet relative to the horizontal plane is 30-80°; ② The inclination angle A1 of the feed inlet relative to the horizontal plane is the same as the inclination angle A4 of the conical surface of the distribution plate relative to the horizontal plane; ③ The distance Hf between the lower edge of the feed inlet and the upper edge of the distribution plate is 0-Di, and Di refers to the inner diameter of the gasifier body; ④ The axis of the feed inlet intersects the central axis of the gasifier body; ⑤ The inclination angle A2 of the fluidizing agent ports inclined toward one end of the slag discharge port relative to the horizontal plane is 0-30°, and 0° is not included; ⑥ The slag discharge port is further provided with an air inlet pipe forming a second gasification agent port, and an annular area for discharging slag is arranged between the air inlet pipe and the slag discharge port; the diameter of the second gasification agent port accounts for 30-70% of the diameter of the slag discharge port, and the diameter of the second gasification agent port is 100-200 mm; ⑦ The chord length L2 of the area formed by all the fluidizing agent ports inclined toward one end of the slag discharge port is L1-10L1, and L1 is the diameter of the feed inlet; ⑧ Except for all the fluidizing agent ports directly below the feed inlet, the axes of the remaining fluidizing agent ports are inclined away from one end of the slag discharge port or in the horizontal direction; the inclination angle A3 of the remaining fluidizing agent ports relative to the horizontal plane is 0-45°.

3. The biomass fluidized bed gasification system suitable for green hydrogen coupling according to claim 1, wherein, The fluidized bed gasifier satisfies one or more of the following conditions: ① The pore diameter of the fluidizing agent ports is 2-10 mm; ② The plurality of fluidizing agent ports are uniformly distributed on the distribution plate; 5-10 layers of fluidizing agent ports are sequentially distributed from the top to the bottom of the distribution plate, and each layer of fluidizing agent ports comprises a plurality of fluidizing agent ports equally spaced along the circumferential direction of the distribution plate; the axial spacing between adjacent two layers of fluidizing agent ports is 100-300 mm; ③ The axes of the first gasification agent ports are parallel to the central axis of the distribution plate; 4. The diameter of the first gasifying agent port is 10-200 mm; 5. The first gasifying agent ports are uniformly distributed along the circumference of the slag discharge port; the distance between the axis of the first gasifying agent port and the axis of the slag discharge port is 200-500 mm; 6. The inclination angle A4 of the conical surface of the distribution plate relative to the horizontal plane is 30-80°.

4. The biomass fluidized bed gasification system suitable for green hydrogen coupling according to any one of claims 1-3, characterized in that, The fluidizing agent port is provided with a leakage prevention assembly, which comprises a connecting part and a leakage prevention part, one end of the connecting part is connected with the leakage prevention part, the outer diameter of the other end of the connecting part matches the hole diameter of the fluidizing agent port, the leakage prevention part is provided with a porous structure for the passage of fluidizing agent, the pore size of the porous structure is 0.1-500 μm, and the connecting part is provided with a hole structure for the passage of fluidizing agent.

5. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 4, wherein, The leakage prevention assembly meets one or more of the following conditions:

1. The leakage prevention part is a block, and the block is provided with the porous structure; 2. The pore size of the porous structure is 0.1-120 μm.

6. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 4, wherein, The connecting part comprises a first support and a sleeve, the first support is provided with a support groove, the groove bottom of the support groove is provided with a first through hole, the leakage prevention part is arranged in the support groove, one end of the sleeve is provided with a flange, the outer diameter of the flange is greater than the hole diameter of the fluidizing agent port and less than the inner diameter of the support groove, the flange is located in the support groove, the outer diameter of the other end of the sleeve matches the hole diameter of the fluidizing agent port, and the first through hole and the tube hole of the sleeve form the hole structure.

7. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 6, wherein, The connecting part further comprises a second support, which is a sleeve structure, the second support is sleeved outside the flange, and the first support is threadedly connected outside the second support; The leakage prevention assembly further comprises a first support and a second support, the first support, the leakage prevention part and the second support are sequentially arranged in the support groove from top to bottom, and the first support and the second support are both metal mesh structures; the hole diameter of the metal mesh structure is 0.1-1 mm.

8. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 1, wherein, The biomass fluidized bed gasification system suitable for green hydrogen coupling meets one or more of the following conditions:

1. The bottom of the first cyclone separator is provided with a leg device, which is connected between the fly ash discharge port of the first cyclone separator and the fly ash return port of the fluidized bed gasification furnace, for returning fly ash to the fluidized bed gasification furnace; 2. The waste heat boiler is a fire tube boiler.

9. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 1, wherein, The biomass fluidized bed gasification system suitable for green hydrogen coupling further comprises a first water inlet pipeline and a heat exchanger, the first water inlet pipeline is connected with the steam drum of the waste heat boiler, the heat exchanger is connected with the connecting pipeline of the dust remover and the water washing tower and the first water inlet pipeline, and the heat exchanger exchanges heat in the connecting pipeline and the first water inlet pipeline.

10. The biomass fluidized bed gasification system suitable for green hydrogen coupling of claim 1, wherein, The biomass fluidized bed gasification system suitable for green hydrogen coupling meets one or more of the following conditions: The biomass fluidized bed gasification system suitable for green hydrogen coupling further comprises a fly ash return pipeline, one end of the fly ash return pipeline is connected with a fly ash outlet of the second cyclone separator and a fly ash outlet of the dust collector, and the other end of the fly ash return pipeline is connected with a return port of the fluidized bed gasification furnace. The biomass fluidized bed gasification system suitable for green hydrogen coupling further comprises an ash water return pipeline, two ends of the ash water return pipeline are respectively connected with an ash water outlet of the water washing tower and a water inlet of the water washing tower, and the ash water return pipeline is used for returning ash water in the water washing tower to the water inlet for recycling.

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