Biomass gas making furnace

Abstract

The utility model belongs to the field of combustible gas production, and particularly relates to a biomass gas production technology. The gas making furnace sequentially comprises a straight cylinder section I, a conical section and a straight cylinder section II from bottom to top, and the section area of the straight cylinder section I is larger than that of the straight cylinder section II; a metal and slag melting pool is arranged in the straight cylinder section I; a slag hole communicated with the slag layer is formed in the side wall of the straight cylinder section I; a biomass particle spray gun is mounted on the side wall of the straight cylinder section I and is used for blowing biomass particles into the molten pool; the biomass particle spray gun also sprays a solvent into the furnace to form a slag layer with good fluidity; a gas spray gun is mounted on the top and / or the side wall of the gas making furnace; an outlet of the gas spray gun is positioned above or in the slag layer; the gas spray gun sprays oxygen-containing gas as a gasifying agent of the gas making furnace; the biomass gasification furnace has the advantages that the biomass is gasified at high temperature, and various biomass can be well gasified; the synthesis gas generated by gasification does not contain tar, so that the coal gas purification process is simple, the synthesis gas does not contain methane, and a methane reforming link is omitted.

Description

Technical Field

[0001] The invention belongs to the field of gasification from combustible materials, and specifically relates to a biomass gasification technology. Background Art

[0002] Biomass is the most widespread substance on Earth. It includes all animals, plants, and microorganisms, as well as the organic matter derived, excreted, and metabolized by these living things. Each type of biomass possesses a certain amount of energy. The energy generated by biomass, using biomass as a carrier, is biomass energy. Biomass energy is a form of energy derived directly or indirectly from photosynthesis of plants, derived from the storage of solar energy in the form of chemical energy within living organisms.

[0003] The main sources of biomass include wood waste, agricultural straw, fruit shells, waste residues from sugar and winemaking, and aquatic plants. These organic combustible materials are heated in the absence of oxygen, causing complex chemical reactions and energy conversion. This process essentially transforms the atoms of elements such as carbon, hydrogen, and oxygen in the organic combustible materials into combustible gas molecules such as carbon monoxide, methane, and hydrogen under the reaction conditions, transferring most of the energy in the organic combustible materials to these gases.

[0004] Numerous methods exist for converting biomass into clean gases, liquid fuels, or biochar, including combustion, chemical, biochemical, physical, and thermochemical methods. Among these, biomass thermochemical conversion technology offers advantages such as strong adaptability to feedstocks and ease of scalable application. Biomass gasification to produce syngas (primarily hydrogen and carbon monoxide) and subsequently to synthesize liquid fuels (methanol, ethanol, etc.) is the most promising biomass energy conversion and utilization pathway within thermochemical conversion technology. This has garnered unprecedented attention from both domestic industry and academia, with significant investment in related research and development.

[0005] The core equipment in the biomass gasification process for producing syngas is the gasification unit. The unit's form, structure, and operating parameters directly impact the quality of the resulting syngas. Currently, biomass gasification units (gasifiers, gasifiers) can be broadly categorized into three types: fixed-type, entrained-flow, and fluidized-bed.

[0006] Fixed-bed gasification furnaces have simple structures, low investment, low gas heat loss, and flexible operating modes (divided into updraft, downdraft, horizontal suction, and open-center types). They do not have high requirements for the type and particle size of raw materials, but they are inconvenient to feed, have small production scales, poor continuous operation capabilities, uneven temperatures in the furnace, and poor heat exchange effects. The synthesis gas contains methane, and the exported synthesis gas is prone to carry volatile substances such as tar and steam.

[0007] The operating temperature of the entrained flow furnace is high and the temperature inside the furnace is uniform, but the entrained flow furnace has high requirements for the particle size of the raw materials, which poses a challenge to the grinding of biomass raw materials containing a large amount of fiber. In addition, the synthesis gas contains methane, and the exported synthesis gas is prone to carry tar. In addition, the entrained flow furnace has strict requirements on biomass, and most biomass is not suitable for entrained flow gasification.

[0008] The fluidized bed has a high heat capacity, can process materials with high water content, and has a fast heat and mass transfer rate. However, it is very sensitive to the physical properties and flammability of the raw materials, is difficult to control, has a low operating temperature, and contains methane in the outlet synthesis gas. Subsequent equipment is generally required to deal with tar and reform the synthesis gas, making the gasification system and equipment more complicated.

[0009] Increasing the concentration of syngas, reducing the tar in syngas, improving the adaptability of gasification equipment to raw materials, and optimizing the gasification process control have become the main directions of development of new biomass gasification equipment. Summary of the Invention

[0010] The purpose of the utility model is to provide a biomass gasification furnace to overcome the defects of the existing biomass gasification technology.

[0011] The utility model is realized through the following technical solutions:

[0012] A biomass gasification furnace, wherein the gasification furnace body is a steel container, which comprises, from bottom to top, a straight section I, a conical section, and a straight section II, wherein the area of ​​the straight section I is greater than the area of ​​the straight section II; a cooling wall and refractory material are installed on the inner side of the gasification furnace body;

[0013] There is a molten pool in the straight section I, the lower layer of the molten pool is molten iron, and the upper layer of the molten pool is slag; a slag outlet connected to the slag layer is installed on the side wall of the straight section I, and a liquid level detection device connected to the iron layer is installed on the side wall of the straight section I;

[0014] At least one biomass particle spray gun is installed on the side wall of the straight cylinder section I to spray biomass particles into the molten pool; the biomass particle spray gun also sprays solvent into the furnace;

[0015] The liquid level detection device is a U-shaped tube connected to the bottom of the molten pool iron layer, the outer side of the U-shaped tube is a steel shell and the inner side is a refractory material;

[0016] The tapered section connects the straight section I and the straight section II;

[0017] There is a gas outlet for the gasifier on the straight section II;

[0018] At least one gas lance is installed on the top and / or side wall of the gasification furnace, and the outlet of the gas lance is located above the slag layer or in the slag layer; the gas lance sprays oxygen-containing gas, and the oxygen-containing gas serves as a gasifying agent for the gasification furnace;

[0019] The coal gas produced by the gasification furnace is discharged from the coal gas outlet of the gasification furnace.

[0020] Preferably, the biomass particle spray gun sprays biochar particles with a particle size of ≤3 mm made by carbonizing and crushing biomass particles into the slag layer in the furnace; the biomass particles can be replaced by coke powder, blue charcoal powder, and anthracite.

[0021] Preferably, the biomass particle spray gun also sprays iron-containing materials into the slag layer to replenish the iron loss in the molten pool;

[0022] Preferably, the gas spray gun can also spray steam and / or biomass particles into the space above the molten pool in the furnace. The steam spraying is used to adjust the H2 content in the coal gas; the biomass particles sprayed by the gas spray gun can reduce the CO2 content in the coal gas.

[0023] Preferably, the gas lance can also spray oxygen-containing gas into the molten pool in the furnace, with the angle between the gas lance and the horizontal line being -45° to +45°, and the spraying position being within the slag layer.

[0024] Preferably, the conveying gas for spraying the biomass particles with the biomass particle spray gun is one of CO2, O2-containing gas, and synthesis gas.

[0025] Preferably, the oxygen content of the oxygen-containing gas is ≥90%.

[0026] Preferably, the oxygen content of the oxygen-containing gas is ≥99%.

[0027] Preferably, the biomass particles are produced from biomass through a biomass particle processing system, the biomass particles have a particle size of ≤10 mm, and the water content of the biomass particles is ≤15%.

[0028] Preferably, the section area of ​​the straight tube section I / the section area of ​​the straight tube section II is ≥2.5.

[0029] Preferably, the height of the straight section II is ≥10m, so as to reduce the CO2 content in the coal gas.

[0030] Preferably, the slag outlet is used to discharge the slag in the gasification furnace to maintain a certain slag surface height.

[0031] Preferably, the solvent is a substance containing CaO and / or a substance containing MgO, so as to form a slag layer with good fluidity, and the CaO / SiO2 in the slag is greater than 0.8.

[0032] Preferably, the biomass particle spray gun sprays iron-containing materials into the furnace to replenish the iron loss in the molten pool.

[0033] Preferably, the liquid level detection device is provided with an electromagnetic induction heating device to keep the liquid level detection device warm.

[0034] Preferably, the liquid level detection device is used to determine the liquid level height of the molten pool in the furnace.

[0035] Preferably, the liquid level detection device can be used as a device for filling molten iron into the smelting furnace when the furnace is started.

[0036] Preferably, the coal gas produced by the gasification furnace is discharged from the coal gas outlet of the gasification furnace, and becomes purified synthesis gas after being processed by dust removal, waste heat utilization, and coal gas composition adjustment devices. The main components of the synthesis gas are CO, H2, and CO2. The synthesis gas and green hydrogen enter the methanol synthesis tower to produce green methanol; or the synthesis gas enters the synthesis tower to produce green methanol after decarbonization and adjustment of the H / C ratio.

[0037] The beneficial effects of the present invention are:

[0038] The utility model adopts high-temperature gasification of biomass, has good adaptability to biomass raw materials, and can gasify various biomasses well; the tar produced in the gasification process is further cracked, and the coal gas does not contain tar, which makes the coal gas purification process simple, and the synthesis gas basically does not contain methane, eliminating the methane reforming link. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of biomass gasification furnace

[0040] Figure 2 This is a schematic diagram of the installation of gas spray guns in the vertical section II of the biomass gasification furnace

[0041] Figure 3 Schematic diagram of gas spray gun installed in the cone section of biomass gasification furnace

[0042] Figure 4 Biomass gasification flow chart

[0043] Legend Marker

[0044] 1 Gasifier, 2 Vertical Section I, 3 Cone Section, 4 Vertical Section II, 5 Cooling Wall, 6 Refractory Material,

[0045] 7 iron layer, 8 slag layer, 9 slag outlet, 10 liquid level detection device, 11 gas spray gun, 12 biomass particle spray gun, 13 gas outlet. Specific embodiments

[0046] Example 1:

[0047] The following is attached Figure 1 , Attachment Figure 4 For reference, the implementation of the present invention is described in detail so that ordinary technicians in the field can easily implement it. The present invention can be embodied in many different forms and is not limited to this description.

[0048] The gasification furnace 1 is a steel container, which comprises, from bottom to top, a straight section I2, a conical section 3, and a straight section II4. The area of ​​the straight section I2 / the area of ​​the straight section II3 is greater than 2.5. A cooling wall 5 and refractory material 6 are installed on the inner side of the gasification furnace 1.

[0049] There is a molten pool in the straight section I2, with an iron layer 7 at the bottom and a slag layer 8 at the top. A slag port 9 connected to the slag layer is installed on the side wall of the straight section I2, and a liquid level detection device 10 connected to the iron layer is installed on the side wall of the straight section I2.

[0050] Two biomass particle spray guns 12 are installed on the side wall of the straight cylinder section I2 to spray biomass particles into the molten pool; the biomass particle spray guns 12 also spray solvent into the furnace;

[0051] The liquid level detection device 10 is a U-shaped tube connected to the bottom of the molten pool iron layer 7, with a steel shell on the outside and refractory material on the inside. The liquid level detection device 10 uses electromagnetic induction for heating and heat preservation.

[0052] The tapered section connects the straight section I2 and the straight section II4;

[0053] There is a gas furnace gas outlet 13 on the straight section II2;

[0054] A gas lance 11 is provided on the top of the gasification furnace 1, and the outlet of the gas lance 11 is located above or within the slag layer 8; the gas lance 11 sprays oxygen-containing gas, which serves as a gasifying agent for the gasification furnace;

[0055] The coal gas produced by the gasification furnace 1 is discharged from the coal gas outlet 13 of the gasification furnace 1 .

[0056] The biomass is collected and stored, then crushed, dried, and pelletized. The biomass is dried to a moisture content of less than 15% and pelletized to a particle size of ≤10mm. The biomass pellets are transported to the biomass pellet silo of the biomass pellet injection system and pneumatically conveyed to the biomass pellet injection lance 12 via the serial tank injection system. The biomass pellet injection lance 12 is then sprayed into the slag layer 8 of the molten pool. The biomass pellet injection lance 12 forms an angle of approximately 45° with the centerline of the gasification furnace. The biomass pellets are carried by the high-speed conveying gas through the slag layer 8 and impact into the iron layer 7. The conveying gas is syngas and / or oxygen-containing gas and / or nitrogen and / or CO2.

[0057] The solvent (CaO and / or MgO) is pneumatically conveyed and sprayed into the gasification furnace 1 through the biomass particle spray gun 12 to form a slag with good fluidity (the basicity of the slag is about 1.1) containing about 5% FeO.

[0058] The iron-containing material is pneumatically conveyed and sprayed into the gasification furnace 1 through the biomass particle spray gun 12 to replenish the loss of molten iron.

[0059] The biomass particles are carbonized and granulated (particle size ≤ 3 mm), and then injected into the gasification furnace 1 through the injection system and the biomass particle injection gun 12 to ensure that a certain amount of carbon particles exist in the slag and control the degree of foamy slag.

[0060] Oxygen is injected into the gasification furnace 1 through a gas lance 11. The oxygen outlet is located above the molten pool and is ejected at a velocity of >100 m / s. The biomass particles injected into the molten pool decompose, releasing CO and H₂. Fe in the molten pool oxidizes to produce FeO. Biochar from biomass decomposition dissolves into the molten iron. [C] reacts with FeO to produce CO. The CO and H₂ combust with the oxygen above the molten pool, with a secondary combustion rate of CO of approximately 35%. This combustion releases a significant amount of heat, heating the molten pool and providing heat for the gasification of the biomass particles. The coal gas generated in the gasification furnace 1 undergoes cyclonic dust removal and purification. The waste heat is recovered in a waste heat boiler to produce steam and reduce the gas temperature. The gas is then subjected to fine dust removal, dechlorination, and desulfurization, and its composition is adjusted to produce syngas of appropriate composition. The syngas and green hydrogen enter the methanol synthesis tower to produce green methanol.

[0061] The gas spray gun 11 sprays oxygen with an oxygen content of >99%. Oxygen is used as a gasifying agent. A certain amount of steam can be added to the oxygen to adjust the H2 content in the coal gas.

[0062] The coal gas generated in the gasification furnace 1 has a (CO+H2) content of ≥65%.

[0063] The slag formed during the production process of the gasification furnace 1 is discharged regularly through the slag outlet 9 and is processed into slag by the slag-water granulation system. The slag is used in the building materials industry.

[0064] The liquid level detection device 10 measures the height h2 of the liquid level in the liquid level detection device 10, and the iron layer height h is obtained by calculation:

[0065] Height of iron layer in furnace h=(h2*ρ2-HP) / (ρ 2_ -ρ1)

[0066] Pressure of space above molten pool: P

[0067] The height from the center line of the slag hole to the bottom of the molten iron: H, H is known

[0068] Slag layer height: h1, h1 is the height from the center line of the slag mouth to the top surface of the iron layer in the furnace; slag density ρ1; h1 = Hh liquid level detection device 10 liquid level height h2, molten iron density ρ2

[0069] The height of the iron layer in the furnace h, the density of the molten iron ρ2

[0070] Example 2:

[0071] The following is attached Figure 2 For reference, the difference from Example 1 is that:

[0072] Two gas lances 11 are mounted on the side wall of the gasification furnace 1 in a symmetrical arrangement, with the angle between the gas lances 11 and the horizontal line being 0°. Oxygen-containing gas is injected into the slag layer 8 of the molten pool of the gasification furnace 1 through the gas lances.

[0073] Example 3

[0074] The following is attached Figure 3 For reference, the difference from Example 1 is that:

[0075] The conical section 3 of the gasification furnace 1 is provided with four gas lances 11, which are evenly arranged and have an angle of 50° with the horizontal line. Oxygen is injected into the space above the molten pool of the gasification furnace 1 through the gas lances.

[0076] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A biomass gasification furnace, characterized in that: The gasification furnace body is a steel container, which consists of straight section I, conical section, and straight section II from bottom to top. The area of ​​straight section I is greater than that of straight section II. The inner side of the gasification furnace body is equipped with cooling wall and refractory materials. There is a molten pool in the straight section I, the lower layer of the molten pool is molten iron, and the upper layer of the molten pool is slag; The side wall of the straight section I is equipped with a slag port connected to the slag layer, and the side wall of the straight section I is equipped with a liquid level detection device connected to the iron layer; The liquid level detection device is a U-shaped tube connected to the bottom of the molten pool iron layer, the outer side of the U-shaped tube is a steel shell and the inner side is a refractory material; At least one biomass particle spray gun is installed on the side wall of the straight cylinder section I to spray biomass particles into the molten pool; the biomass particle spray gun also sprays solvent into the furnace; The tapered section connects the straight section I and the straight section II; There is a gas outlet for the gasifier on the straight section II; At least one gas lance is installed on the top and / or side wall of the gasification furnace, and the outlet of the gas lance is located above the slag layer or in the slag layer; the gas lance sprays oxygen-containing gas, and the oxygen-containing gas serves as a gasifying agent for the gasification furnace; The coal gas produced by the gasification furnace is discharged from the coal gas outlet of the gasification furnace.

2. The biomass gasification furnace according to claim 1, characterized in that: The biomass particle spray gun sprays biomass charcoal particles with a particle size of ≤3mm, which are made by carbonizing and crushing biological particles, into the slag layer in the furnace; the biomass particles can be replaced by coke powder, blue charcoal powder, and anthracite.

3. The biomass gasification furnace according to claim 1, characterized in that: The biomass particle spray gun also sprays iron-containing materials into the slag layer.

4. The biomass gasification furnace according to claim 1, characterized in that: The gas lance injects steam and / or biomass particles.

5. The biomass gasification furnace according to claim 1, characterized in that: The gas spray gun can also spray oxygen-containing gas into the molten pool in the furnace, and the angle between the gas spray gun and the horizontal line is -45° to +45°.

6. The biomass gasification furnace according to claim 1, characterized in that: The conveying gas for spraying biomass particles with the biomass particle spray gun is one of CO2, O2-containing gas and synthesis gas.

7. The biomass gasification furnace according to claim 1, characterized in that: The section area of ​​the straight tube section I / the section area of ​​the straight tube section II is ≥2.

5.

8. The biomass gasification furnace according to claim 1, characterized in that: The height of the straight section II is ≥10m, which is conducive to reducing the CO2 content in the gas composition.

9. The biomass gasification furnace according to claim 1, characterized in that: The slag outlet is used to discharge the slag in the biomass gasification furnace and maintain a certain slag surface height.

10. The biomass gasification furnace according to claim 1, characterized in that: The biomass particle spray gun sprays iron-containing materials into the furnace to supplement the loss of iron in the molten pool.

11. The biomass gasification furnace according to claim 1, characterized in that: The liquid level detection device is provided with an electromagnetic induction heating device.

12. The biomass gasification furnace according to claim 1, characterized in that: The liquid level detection device is used to determine the liquid level of the molten pool in the furnace.

13. The biomass gasification furnace according to claim 1, characterized in that: The gas making furnace is connected with the cyclone dust collector, the waste heat boiler, the synthesis gas and the methanol synthesis tower at one time.

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