Gasification furnace ignition fuel system based on biomass tar

Abstract

The invention discloses a gasification furnace ignition fuel system based on biomass tar. The system comprises a gasification furnace, the upper part of the gasification furnace is communicated with a cyclone separator, the top end of the cyclone separator is communicated with an electrical tar precipitator, the lower part of the electrical tar precipitator is communicated with a tar supply pump, and an outlet of the tar supply pump is communicated with a tar storage tank; the tar storage tank is communicated with a filter dryer, an outlet of the filter dryer is communicated with a tar delivery pump, an outlet of the tar delivery pump is communicated with a steam heater, an outlet of the steam heater is communicated with an on-bed oil gun, and an outlet of the on-bed oil gun is located above an air distribution plate of the gasification furnace. And a combustion fan is communicated with the interior of the gasification furnace air distribution plate. According to the invention, tar in the biomass synthesis gas is removed on the premise of not generating waste water, not reducing the calorific value of the gas and not using a catalyst; and the tar is recycled as fuel for ignition of the gasification furnace, so that the operation cost of the gasification furnace is saved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass gasification tar utilization, and in particular to a biomass tar-based gasifier ignition fuel system. Background Art

[0002] Promoting the development of renewable clean energy is one of the effective measures to save energy and reduce emissions. Biomass energy has abundant reserves and is the fourth largest energy source after coal, oil and natural gas. Biomass is increasingly valued as an alternative energy source to fossil fuels, and biomass gasification technology is one of the important technologies for biomass utilization.

[0003] Biomass gasification refers to the process of gasifying biomass fuels including bark, straw, rice husk, etc. with oxygen or water vapor to generate hydrogen and carbon monoxide, also known as synthesis gas. Since biomass is a low-level fuel, a lot of tar will be produced during the gasification process, causing blockage and contamination of subsequent pipelines and equipment. This is one of the problems that need to be solved in biomass gasification. Before using the synthesis gas from biomass gasification to generate electricity or synthesize liquid fuels, the tar is generally deeply removed. In the prior art, methods for removing tar include water washing method, high-temperature catalytic cracking method and other methods.

[0004] The water washing method is a commonly used tar removal method in large chemical plants. It uses water to wash the gas to quickly cool it down, thereby achieving tar condensation and falling with the droplets. This is usually achieved through the spray device of the cooling washing tower. However, the water washing method has the following technical problems: First, a large amount of wastewater is generated. Tar-containing wastewater includes a large amount of organic matter, inorganic acid and NH3, etc. Random discharge will cause serious pollution and require subsequent treatment, increasing the investment cost of environmental protection; second, the separation of tar from synthesis gas will reduce the calorific value of the gas, which will reduce the overall efficiency of gasification and cause energy waste.

[0005] High temperature catalytic cracking is also an effective means of removing tar. While removing tar, it also increases the content of combustible components such as H2 and CH4 in the synthesis gas, so it has received widespread attention. However, the technical problems of high temperature catalytic cracking are as follows: the catalyst is expensive, which increases the operating cost. Currently, there are few cases of applying high temperature catalytic cracking to tar. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention proposes a gasifier ignition fuel system based on biomass tar, which removes tar from biomass synthesis gas without generating wastewater, reducing the calorific value of the gas, and requiring no catalyst, thereby causing no burden on the environment; and the tar is recycled as fuel for ignition of the gasifier, saving the operating cost of the gasifier.

[0007] In order to achieve the above-mentioned object, the present invention is designed to provide a biomass tar-based gasifier ignition fuel system, comprising a gasifier for biomass gasification, wherein the upper portion of the gasifier is connected to a cyclone separator, and the particularity thereof is:

[0008] The top of the cyclone separator is connected to an electric tar collector for separating biomass tar and synthesis gas, the lower part of the electric tar collector is connected to a tar supply pump, and the outlet of the tar supply pump is connected to a tar storage tank;

[0009] The tar storage tank is connected to a filter dryer, the outlet of the filter dryer is connected to a tar delivery pump, the outlet of the tar delivery pump is connected to a steam heater, the outlet of the steam heater is connected to an oil gun on the bed, the outlet of the oil gun on the bed is located above the air distribution plate of the gasifier, and the inside of the air distribution plate of the gasifier is connected to a combustion-supporting fan;

[0010] The biomass coke output from the oil gun outlet on the bed is used as ignition fuel, and the gasifier is ignited in cooperation with the combustion-supporting fan.

[0011] Furthermore, a preheating heater for preheating the biomass char is provided inside the tar storage tank.

[0012] Furthermore, the outlet of the steam heater is connected to two on-bed oil guns, and the two on-bed oil guns are respectively located on both sides above the air distribution plate of the gasifier.

[0013] Furthermore, the oil gun outlet on the bed is located 1.5 to 2.5 m above the air distribution plate of the gasifier, and the oil gun outlet on the bed is arranged to be inclined downward, with an angle of 15 to 30 degrees with the horizontal plane.

[0014] Furthermore, the outlet of the steam heater is also connected to an oil return cooler, and the outlet of the oil return cooler is connected to a tar storage tank.

[0015] Furthermore, the gasifier is a fluidized bed gasifier.

[0016] The advantages of the present invention are:

[0017] 1. The present invention connects the electric tar collector to the top of the cyclone separator, and uses the electric tar collector to ionize the synthesis gas and tar particles. The synthesis gas rises in the electric tar collector, and the tar particles are negatively charged. They are adsorbed on the surface of the precipitation electrode along the direction of the electric line, and then release the charge to become medium-sized oil particles, which flow along the surface of the precipitation electrode to the bottom of the equipment, thereby completely removing the tar in the biomass synthesis gas, preventing the downstream transmission system and equipment of the synthesis gas from being contaminated and blocked by tar, and maintaining the long-term good operation of the whole system. The whole process does not generate wastewater, does not reduce the calorific value of the gas, does not require the use of catalysts, and does not cause a burden on the environment;

[0018] 2. The present invention utilizes the biomass tar recovered by the electric tar collector as the ignition fuel of the gasifier, which can reduce the diesel consumption during the ignition of the biomass gasifier and reduce the operating cost;

[0019] The biomass tar-based gasifier ignition fuel system of the present invention removes tar in biomass synthesis gas without generating waste water, reducing the calorific value of the fuel gas, and requiring no catalyst; and recycles the tar as a fuel for ignition of the gasifier, thereby saving the operating cost of the gasifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the arrangement of the present invention;

[0021] In the figure: gasifier 1, cyclone separator 1-1, electric tar collector 2, tar supply pump 3, tar storage tank 4, preheating heater 5, filter dryer 6, tar delivery pump 7, steam heater 8, return oil cooler 9, bed oil gun 10, combustion-supporting fan 11. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0023] In the description of the present invention, it is necessary to understand that the terms "length", "width", "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 the present invention and simplifying the description, rather than indicating or implying 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 the invention.

[0024] like Figure 1 As shown, the ignition fuel system of the gasifier based on biomass tar of the present invention comprises a gasifier 1 for biomass gasification, the upper portion of the gasifier 1 is connected to a cyclone separator 1-1, the top of the cyclone separator 1-1 is connected to an electric tar collector 2 for separating biomass tar and synthesis gas, the lower portion of the electric tar collector 2 is connected to a tar supply pump 3, and the outlet of the tar supply pump 3 is connected to a tar storage tank 4.

[0025] The present invention connects the electrostatic tar collector 2 to the top of the cyclone separator 1-1, and utilizes the electrostatic tar collector 2 to ionize the synthesis gas and tar particles. The synthesis gas rises inside the electrostatic tar collector 2, and the tar particles are negatively charged and adsorbed on the surface of the precipitation electrode along the direction of the electric line of force, and then release the charge to become medium-sized oil particles. The oil mist particles are continuously condensed on the surface of the electrode plate, and the particles increase in size and finally become oil droplets, which flow along the surface of the precipitation electrode to the bottom of the equipment, thereby completely removing the tar in the biomass synthesis gas, preventing the downstream transmission system and equipment of the synthesis gas from being contaminated and blocked by tar, and maintaining the long-term good operation of the entire system. The entire process does not generate wastewater, does not reduce the calorific value of the gas, does not require the use of catalysts, and does not cause a burden on the environment.

[0026] The liquid tar is pumped to the tar storage tank 4 for storage by the tar supply pump 3 .

[0027] In this embodiment, a gasification system with a biomass fuel processing capacity of 15 t / h is taken as an example. The type of biomass fuel is agricultural and forestry waste (including tree prunings, rice husks, sawdust, etc.), with a particle size of 5-20 mm, a moisture content not higher than 20%, and a lower calorific value not lower than 3200 kcal / kg.

[0028] The biomass fuel is gasified by the gasifier 1, and the gasification temperature is 700-800°C. At this temperature, the biomass gasification reaction rate is good, and it can run stably without coking. After gasification, the syngas flow rate is about 30000Nm 3 / h, the mass fraction of gasified tar in raw biomass fuel is about 3% to 5%. After passing through the electric tar collector 2, liquid tar is formed, which is transported to the tar storage tank 4 through the tar supply pump 3 for storage.

[0029] The tar storage tank 4 is connected to a filter dryer 6, the outlet of the filter dryer 6 is connected to a tar delivery pump 7, the outlet of the tar delivery pump 7 is connected to a steam heater 8, the outlet of the steam heater 8 is connected to a bed oil gun 10, the outlet of the bed oil gun 10 is located above the air distribution plate of the gasifier 1, and the air distribution plate of the gasifier 1 is connected to a combustion-supporting fan 11. The biomass coke output from the outlet of the bed oil gun 10 is used as an ignition fuel, and the gasifier 1 is ignited in cooperation with the combustion-supporting fan 11.

[0030] Before the gasifier 1 needs to be ignited, the tar delivery pump 7 is turned on, the tar passes through the filter dryer 6 to remove impurities and moisture, and then is heated to a suitable temperature by the steam heater 8, and is delivered to the bed oil gun 10 as an ignition fuel, and the gasifier is ignited in conjunction with the combustion-supporting fan 11.

[0031] Preferably, a preheating heater 5 for preheating biomass tar is provided inside the tar storage tank 4, and the heating temperature of the preheating heater 5 does not exceed 80° C. Tar is in liquid state at 80° C. Before the gasifier 1 is ignited, the preheating heater 5 of the tar storage tank 4 is turned on to preheat the tar so that the tar can smoothly enter the filter dryer 6 to remove impurities and moisture.

[0032] The outlet of the steam heater 8 is connected to two bed oil guns 10, which are respectively located on both sides above the air distribution plate of the gasifier 1. Specifically, the outlet of the bed oil gun 10 is located 1.5 to 2.5 meters above the air distribution plate of the gasifier 1, and the outlet of the bed oil gun 10 is arranged downwardly in an inclined manner, with an angle of 15 to 30 degrees with the horizontal plane.

[0033] Preferably, the outlet of the steam heater 8 is also connected to an oil return cooler 9 , and the outlet of the oil return cooler 9 is connected to the tar storage tank 4 , so as to recover the tar that has not entered the gasifier for combustion to the tar storage tank 4 .

[0034] Specifically, the gasifier 1 is a fluidized bed gasifier.

[0035] The biomass tar-based gasifier ignition fuel system of the present invention removes tar in biomass synthesis gas without generating waste water, reducing the calorific value of the fuel gas, and requiring no catalyst; and recycles the tar as a fuel for ignition of the gasifier, thereby saving the operating cost of the gasifier.

[0036] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A biomass tar-based gasifier ignition fuel system, comprising a gasifier (1) for biomass gasification, wherein the upper portion of the gasifier (1) is connected to a cyclone separator (1-1), characterized in that: The top of the cyclone separator (1-1) is connected to an electric tar collector (2) for separating biomass tar and synthesis gas, the lower part of the electric tar collector (2) is connected to a tar supply pump (3), and the outlet of the tar supply pump (3) is connected to a tar storage tank (4); The tar storage tank (4) is connected to a filter dryer (6), the outlet of the filter dryer (6) is connected to a tar delivery pump (7), the outlet of the tar delivery pump (7) is connected to a steam heater (8), the outlet of the steam heater (8) is connected to an on-bed oil gun (10), the outlet of the on-bed oil gun (10) is located above the air distribution plate of the gasifier (1), and the inside of the air distribution plate of the gasifier (1) is connected to a combustion-supporting fan (11); The biomass coke output from the outlet of the oil gun (10) on the bed is used as ignition fuel, and cooperates with the combustion-supporting fan (11) to ignite the gasifier (1).

2. The biomass tar-based gasifier ignition fuel system according to claim 1, characterized in that: A preheating heater (5) for preheating biomass char is arranged inside the tar storage tank (4).

3. The biomass tar-based gasifier ignition fuel system according to claim 2, characterized in that: The outlet of the steam heater (8) is connected to two bed oil guns (10), and the two bed oil guns (10) are respectively located on both sides above the air distribution plate of the gasifier (1).

4. The biomass tar-based gasifier ignition fuel system according to claim 3, characterized in that: The outlet of the oil gun (10) on the bed is located 1.5 to 2.5 m above the air distribution plate of the gasifier (1), and the outlet of the oil gun (10) on the bed is arranged to be inclined downward, with an angle of 15 to 30° with the horizontal plane.

5. The biomass tar-based gasifier ignition fuel system according to claim 1, characterized in that: The outlet of the steam heater (8) is also connected to an oil return cooler (9), and the outlet of the oil return cooler (9) is connected to a tar storage tank (4).

6. The biomass tar-based gasifier ignition fuel system according to claim 1, characterized in that: The gasifier (1) is a fluidized bed gasifier.

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