Fluidized bed and bubbling bed combined biomass gasification device

Abstract

The invention relates to a fluidized bed and bubbling bed combined biomass gasification device, which comprises a biomass gasification device, a fuel feeding system, an ignition system, a bed material supply system, a cyclone separator, a special biomass high-temperature gas boiler, an air blower, an induced draft fan and the like. Biomass gas is produced in a mode of combining a fluidized bed and a bubbling bed and is used by a special boiler. According to the device, an existing fixed bed gasification furnace cooling device is omitted, biomass high-temperature fuel gas is used as a medium, more heat is utilized in a rear fuel gas special boiler, and the water cooling jacket cooling loss of the fixed bed gasification furnace is reduced to a great extent. And meanwhile, steam generated by the rear-end boiler is fed into the bubbling bed to further gasify a by-product (charcoal) of fluidized bed gasification reaction, so that more heat energy is released, the biomass gasification efficiency is greatly improved, and the biomass energy is more fully utilized.

Description

Technical Field

[0001] The invention relates to a biomass gasification device combining a fluidized bed with a bubbling bed. Background Art

[0002] Biomass gasification is a thermochemical reaction that uses oxygen or oxygen-containing substances in the air as a gasifying agent to convert biomass energy into combustible gases (mainly hydrogen, carbon monoxide and methane) under high temperature conditions. Biomass gasification technology plays a positive role in treating large amounts of agricultural and forestry waste, reducing environmental pollution, replacing fossil energy and achieving carbon neutrality. At present, the more popular gasifiers in China are fixed bed upper suction type and fixed bed lower suction type, which have been widely used in food, textile, chemical industry and centralized heating in parks. However, there are two major technical pain points in fixed bed gasifiers. One is that a water cooling jacket is used to force cool the furnace wall in the gasification area, and the cooling water takes away a large amount of heat that cannot be effectively utilized. The other is that the gasification by-products (charcoal) are all discharged from the furnace in the form of slag discharge without further gasification, and even some devices discharge wet charcoal. These two technical pain points seriously reduce the efficiency of the gasifier.

[0003] The present invention proposes a new biomass gasification device combining a fluidized bed and a bubbling bed, which utilizes the characteristics of the fluidized bed, such as high heat transfer efficiency, uniform temperature, fast gas-solid mass transfer rate, and fast reaction speed, to improve the gasification efficiency of biomass materials. At the same time, the water cooling jacket is eliminated, and the high-temperature biomass fuel gas is used as a medium to utilize the lost heat in the rear gas boiler, which greatly improves the efficiency of the gasifier.

[0004] Different from conventional fluidized bed gasification devices, the patent of the present invention adds a bubbling bed and introduces steam into the bubbling bed to gasify the fluidized bed gasification by-product (charcoal) into combustible gas, further improving the gasification efficiency of the gasification device.

[0005] It can be foreseen that the implementation of this device will be a major breakthrough in biomass gasification technology, which can "make the most of" biomass energy and promote the utilization of biomass energy to a high level of efficiency, cleanliness and large-scale. Summary of the invention

[0006] The purpose of the present invention is to design a biomass gasification device combining a fluidized bed and a bubbling bed to improve the biomass gasification efficiency.

[0007] The solution adopted by the present invention to solve the technical problem is a biomass gasification device combining a fluidized bed and a bubbling bed, including a biomass gasification device, a fuel feeding system, an ignition system, a bed material supply system, a cyclone separator, a biomass high-temperature gas-fired boiler, a blower, an induced draft fan, etc. The biomass gasification device includes a fluidized bed and a bubbling bed. The biomass is fed into the fluidized bed through the biomass fuel feeding system for oxygen-deficient combustion. The blower is installed on the air inlet duct of the biomass gasification device. After the biomass is subjected to oxygen-deficient combustion in the fluidized bed, it is fed into the bubbling bed for further gasification with steam. The biomass high-temperature fuel gas generated by the fluidized bed and the bubbling bed is purified and fed into the biomass high-temperature gas-fired boiler for combustion.

[0008] Furthermore, in the fluidized bed area, the biomass completes drying, volatilization, oxidation reaction and partial reduction reaction.

[0009] Furthermore, in the bubbling bed area, the carbon particles after the fluidized bed reaction react with the introduced steam to further generate combustible gas.

[0010] Furthermore, the bed material supply system provides the bed material supply required during the initial startup and normal operation of the fluidized bed.

[0011] Furthermore, the cyclone separator recovers the unreacted carbon particles in the fuel gas and returns them to the bubbling bed to continue the reaction.

[0012] Furthermore, the boiler is a special biomass high-temperature gas boiler with stable combustion, easy to meet environmental protection indicators, and complete explosion-proof measures.

[0013] Compared with the prior art, the present invention has the following obvious effects: 1. Compared with the fixed bed, the fluidized bed has a faster gas-solid mass transfer rate, a more complete reaction and a higher gasification efficiency. 2. Compared with the water-cooled jacket, the adiabatic furnace recovers at least 17% of the heat. 3. The added bubbling bed system continues to gasify the byproduct (charcoal) of conventional gasification with steam, and the water molecules are cracked in a high-temperature environment to react with carbon to generate combustible gases such as carbon monoxide, hydrogen and methane. Under the control of the operating mechanism of the fluidized bed and the bubbling bed, the entire device can achieve stable operation, high gasification efficiency, no water-cooled jacket cooling loss, and no carbon discharge loss.

[0014] Combined with the integrated layout of the biomass high-temperature gas-fired boiler, the energy island has a compact structure, small footprint, short system flow, high efficiency, and can be scaled up to achieve cogeneration. It is foreseeable that the device will play a positive role in the country's dual carbon strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings.

[0016] Figure 1 A schematic diagram of the structure of the device.

[0017] In the figure: 1-Biomass gasification device; 1-1-fuel inlet system; 1-2-ignition system; 1-3-bed material supply system; 1-4-fluidized bed; 1-5-bubbling bed; 1-6-steam inlet; 1-7-cyclone separator; 2-biomass high-temperature gas-fired boiler; 2-1-boiler body; 2-2-air preheater; 2-3-high-temperature burner; 2-4-steam drum; 3-blower; 4-induced draft fan. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, a biomass gasification device combining a fluidized bed and a bubbling bed comprises a biomass gasification device, a fuel inlet system, an ignition system, a bed material supply system, a cyclone separator, a biomass high-temperature gas-fired boiler, a blower, an induced draft fan, etc. The biomass gasification device (1) comprises a fuel inlet system (1-1), an ignition system (1-2), a bed material supply system (1-3), a fluidized bed (1-4), a bubbling bed (1-5), a steam inlet (1-6) and cyclone separator (1-7), etc., the biomass enters the fluidized bed (1-4) from the fuel inlet system (1-1) for underoxygen combustion, and the biomass gasification device (1) needs to be ignited through the ignition system (1-2) when starting. The blower (3) is used to supply air to the bottom air inlet of the biomass gasification device (1), and the air supplied by the blower (3) first passes through the air preheater (2-2) of the biomass high-temperature gas-fired boiler (2) and then is sent to the fluidized bed (1-4). Part of the fuel enters the bubbling bed (1-5) after fluidized underoxygen combustion in the fluidized bed (1-4) and reacts with the steam sent to the bubbling bed (1-5). The inlet of the cyclone separator (1-7) is connected to the outlet of the biomass gasification device (1) to purify the generated biomass high-temperature fuel gas. The material separated by the cyclone separator (1-7) is returned to the bubbling bed (1-5) to continue the reaction. The outlet of the cyclone separator (3) is connected to the biomass fuel gas dedicated boiler (2). The biomass high-temperature fuel gas enters the high-temperature burner (2-3) of the biomass fuel gas dedicated boiler (2) through a pipeline for combustion. The flue gas is heat exchanged through the boiler body (2-1) to generate steam. After steam-water separation in the steam drum (2-4), qualified steam is drawn out for power generation and heating. The induced draft fan (4) is used for flue gas discharge of the biomass high-temperature fuel gas dedicated boiler (2).

[0020] In this embodiment, the source of the steam inlet (1-6) in the biomass gasification device (1) is the steam generated by the biomass high-temperature gas-fired boiler (2), and no other external energy input is required.

[0021] In this embodiment, the biomass gasification device (1) serves as a stable energy supply for the entire system. To ensure the normal operation of the biomass gas-fired boiler (2), auxiliary equipment such as the blower (3) and the induced draft fan (4) need to be operated separately.

[0022] In this embodiment, the bed material height needs to be controlled during the operation of the biomass gasification device (1). The bed material supply system (1-3) is located in the lower middle part of the biomass gasification device (1) to supply bed material to the fluidized bed.

[0023] Unless otherwise stated, any technical solution disclosed in the above patent, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range, and any technician in the field should understand that the preferred numerical range is only a numerical value with a more obvious or representative technical effect among many implementable numerical values. Since there are too many numerical values ​​to be exhaustive, the present invention discloses some numerical values ​​to illustrate the technical solution of the present invention, and the numerical values ​​listed above should not constitute a limitation on the protection scope of the present invention.

[0024] If this patent discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connected by bolts or screws), or as: a non-detachable fixed connection (for example, riveting, welding). Of course, the fixed connection can also be replaced by an integrated structure (for example, manufactured by a casting process) (except when it is obviously impossible to use an integrated forming process).

[0025] In the description of this patent, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the patent rather than to limit it; although the patent is described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the patent can still be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solution of the patent, they should all be included in the scope of the technical solution requested for protection by the patent.

Claims

1. A biomass gasification device combining a fluidized bed and a bubbling bed, characterized in that: It includes biomass gasification device, fuel supply system, ignition system, bed material supply system, cyclone separator, biomass high-temperature gas-fired special boiler, blower, induced draft fan, etc.

2. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The biomass gasification device comprises a fluidized bed and a bubbling bed, wherein the fluidized bed is arranged in the middle and the bubbling beds are arranged on both sides of the fluidized bed. The biomass fuel enters the fluidized bed of the biomass gasification device from the feed port, and air is fed in from the bottom of the fluidized bed. The char after fluidized and oxygen-deficient combustion in the fluidized bed enters the bubbling bed and undergoes pyrolysis and gasification reaction with the steam fed into the bubbling bed. The biomass high-temperature fuel gas generated by the biomass gasification device is fed to a dedicated boiler for biomass high-temperature fuel gas for combustion.

3. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 2, characterized in that: The fluidized bed device has the characteristics of fast gas-solid mass transfer rate, sufficient reaction and high gasification efficiency. The furnace wall of the gasification area is not provided with a water cooling jacket and is an insulated furnace.

4. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 2, characterized in that: The bubbling bed needs to be fed with steam to continue gasifying the byproduct (char) of pyrolysis gasification in the fluidized bed. In the high temperature environment, water molecules are cracked and react with carbon to generate combustible gases such as carbon monoxide, hydrogen and methane.

5. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The combustion medium in the biomass high-temperature gas-fired boiler is the biomass high-temperature gas produced by the gasification device. The boiler needs to be equipped with a high-temperature burner to adjust the combustion ratio of the biomass gas and air. The steam generated by the boiler can be used for power generation and heating.

6. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The air sent by the blower is introduced into the fluidized bed of the biomass gasification device after being preheated by the boiler heat exchanger. The induced draft fan is located at the boiler flue gas outlet pipe.

7. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The cyclone separator is located at the gas outlet of the biomass gasification device and is used to purify the biomass high-temperature gas. The materials separated by the cyclone separator are returned to the fluidized bed and the bubbling bed.

8. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The fuel inlet system is located in the lower middle part of the biomass gasification device, and the feed enters the fluidized bed for oxygen-deficient combustion.

9. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The bed material supply system is located in the lower middle part of the biomass gasification device and supplies bed material to the fluidized bed.

10. The biomass gasification device combining a fluidized bed and a bubbling bed according to claim 1, characterized in that: The ignition system is located at the bottom of the fluidized bed and is mainly used for ignition when the biomass gasification device is started.

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