Biomass gas production method

Abstract

The invention discloses a biomass gas production method, belongs to the technical field of biomass gas, and aims to solve the problems of low treatment capacity and high energy consumption of a biomass gas production system in the prior art. The method comprises the following steps: starting a preheating burner, supplying flue gas into a carbonization furnace, and preheating the carbonization furnace; the method comprises the following steps: feeding biomass into a carbonization auger group, and carrying out initial carbonization on the biomass in the carbonization auger group to generate initial biomass gas; biomass fuel gas is ignited by a fuel gas burner to generate flue gas, and the flue gas is supplied to a heat storage buffer tank; and the flue gas in the heat storage buffer tank is fed into a carbonization furnace to carbonize the biomass in the carbonization auger group to generate biomass gas. The method can be used for producing biomass gas.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass gas, and in particular relates to a biomass gas production method. Background Art

[0002] Against the backdrop of global energy structure adjustment and increasing environmental awareness, the research and development and innovation of biomass gas production technology, as a clean and renewable energy source, are of great significance.

[0003] At present, the production of biomass gas mainly adopts carbonization technology, and the carbon in the biomass is converted into combustible gas through reaction.

[0004] However, the existing production of biomass gas mostly adopts a rotary kiln structure. On the one hand, since the rotary kiln relies on the rotation of the cylinder to achieve material turning and heat exchange, the heat transfer efficiency is low, resulting in slow heating and limited processing capacity. In order to maintain the reaction temperature, a large amount of external energy needs to be continuously consumed, especially when processing high-moisture content materials, the energy consumption cost increases sharply. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a biomass gas production method to solve the problems of low processing capacity and high energy consumption of biomass gas production systems in the prior art.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions.

[0007] The present invention provides a biomass gas production method, comprising the following steps:

[0008] Step 1: Turn on the preheating burner to supply flue gas into the carbonization furnace to preheat the carbonization furnace;

[0009] Step 2: The biomass is fed into the carbonizing auger group, and the biomass in the carbonizing auger group is initially carbonized to generate initial biomass gas;

[0010] Step 3: The biomass gas is ignited by the gas burner to generate flue gas, which is then fed into the heat storage buffer tank;

[0011] Step 4: The flue gas in the heat storage buffer tank is supplied to the carbonization furnace to carbonize the biomass in the carbonization auger group to generate biomass gas.

[0012] Furthermore, in step 1, the preheating temperature of the carbonization furnace is 300°C to 400°C.

[0013] Furthermore, in step 4, the carbonization temperature of the biomass is 350°C to 420°C.

[0014] Furthermore, in step 4, the carbonization pressure of the biomass is -20Pa to 30Pa.

[0015] Furthermore, step 4 also includes the following steps:

[0016] During the biomass carbonization process, thermocouples are used to collect temperature data in the carbonization furnace in real time and transmit it to the controller;

[0017] The controller determines whether the temperature data exceeds the temperature threshold. If it exceeds, the flue gas release port on the heat storage buffer tank is opened to reduce the high-temperature flue gas supplied to the carbonization furnace.

[0018] Furthermore, the temperature threshold is 450°C.

[0019] Furthermore, step 4 also includes the following steps:

[0020] During the biomass carbonization process, a pressure sensor is used to collect real-time pressure data in the carbonization furnace and transmit it to the controller;

[0021] The controller determines whether the pressure data exceeds the pressure threshold. If so, it opens the flue gas release port on the heat storage buffer tank to reduce the high-temperature flue gas supplied to the carbonization furnace.

[0022] Furthermore, the pressure threshold is 0.05 MPa.

[0023] Furthermore, after step 4, the following steps are also included:

[0024] Step 5: The exhaust gas discharged from the carbonization furnace is dedusted and discharged through the chimney.

[0025] Furthermore, the biomass gas production method uses a biomass gas production system:

[0026] The biomass gas production system includes a carbonization furnace, a heat storage buffer tank, a gas burner, a cyclone separator and an exhaust dust removal box. The carbonization auger group is installed in the carbonization furnace.

[0027] The gas outlet of the carbonizing auger group is connected to the gas burner and the heat storage buffer tank in sequence, and the exhaust gas outlet of the carbonizing furnace is connected to the cyclone separator and the exhaust dust removal box in sequence.

[0028] Furthermore, the gas burner includes a combustible gas inlet pipe, an inner tube, an outer tube, a flue gas outlet pipe and an igniter.

[0029] Furthermore, the combustible gas inlet pipe, the inner tube and the flue gas outlet pipe are connected in sequence, the inner tube is arranged in the outer tube and is coaxially fixedly connected to the outer tube, the inner tube is provided with a central diffusion cone and cyclone blades coaxially arranged with the inner tube, there is a gap between the outer wall of the central diffusion cone and the inner wall of the inner tube, the cyclone blades are sleeved on the outer wall of the central diffusion cone, the inner end of the cyclone blades is fixedly connected to the central diffusion cone, the outer end of the cyclone blades is fixedly connected to the inner wall of the inner tube, and the cyclone blades are located in the gap between the outer wall of the central diffusion cone and the inner wall of the inner tube.

[0030] Furthermore, a plurality of cyclone holes are respectively provided on the side walls of the inner tube, a main air port is provided on the side walls of the outer tube, a gap is provided between the inner tube and the outer tube, the main air port, the gap between the inner tube and the outer tube and the cyclone holes constitute a cyclone channel, and the ignition end of the igniter extends into the inner tube.

[0031] Furthermore, the outer cylinder is a constant diameter cylinder structure.

[0032] Furthermore, the combustible gas inlet pipe and the flue gas outlet pipe are constant diameter pipes.

[0033] Furthermore, the inner tube includes an expanded diameter section, a reduced diameter section and a constant diameter section connected in sequence along the flow direction of the combustible gas, the central diffusion cone and the cyclone blades are both arranged in the expanded diameter section, the cyclone air holes are arranged on the side wall of the expanded diameter section, and are located on the side of the cyclone blades away from the combustible gas inlet pipe, and the igniter is located on the side of the cyclone blades away from the combustible gas inlet pipe.

[0034] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0035] A) In the biomass gas production method provided by the present invention, the combustion of the gas generated by biomass carbonization is used to achieve carbonization heat supply for the biomass in the carbonization furnace. Only a small amount of natural gas needs to be burned in the initial operation to generate the initial carbonization heat required for the biomass. Subsequent operation of the device can utilize the gas generated by itself to achieve heat self-sufficiency, reduce external energy consumption, lower operating costs, and save energy and protect the environment.

[0036] B) In the biomass gas production method provided by the present invention, due to the provision of the expanded diameter section and the constant diameter section of the outer cylinder, when air is supplied from the main air inlet into the gap between the inner and outer cylinders, the cross-section of the gap gradually decreases, causing the air flow rate to continuously increase, and the air flows through the cyclone holes to form a high-speed vortex of air that is supplied to the outer cylinder.

[0037] C) In the biomass gas production method provided by the present invention, due to the setting of the central diffusion cone, the flow cross-section of the combustible gas can also be reduced, the flow velocity of the combustible gas can be increased, and the increase in flow resistance caused by the setting of the cyclone blades can be reduced, so that the combustible gas can flow smoothly through the cyclone blades.

[0038] D) The biomass gas production method provided by the present invention utilizes a specifically designed outer and inner cylinder, as well as specific locations of the various components, to achieve a nested structure of the outer and inner cylinders while increasing the air and combustible gas flow rates. This allows for the formation of two high-speed swirls, achieving thorough mixing of the air and combustible gas.

[0039] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages will become apparent from the description or be understood through practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the embodiments of the description and the contents particularly pointed out in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0041] Figure 1 This is a flow chart of the biomass gas production method provided in Example 1 of the present invention;

[0042] Figure 2 This is a schematic structural diagram of a biomass gas production system in the biomass gas production method provided in Example 1 of the present invention;

[0043] Figure 3 This is a schematic structural diagram of another direction of the biomass gas production system in the biomass gas production method provided in Example 1 of the present invention;

[0044] Figure 4 A schematic structural diagram of a carbonizing auger group in the biomass gas production method provided in Example 1 of the present invention;

[0045] Figure 5 This is a schematic structural diagram of a gas burner in the biomass gas production method provided in Example 1 of the present invention.

[0046] Reference numerals:

[0047] 1-Carbonization tube body; 2-Carbonization auger blades; 3-Carbonization shaft; 4-Cyclone separator; 5-Exhaust dust removal box; 6-Pressure sensor; 7-Thermocouple; 8-Cooling tube body; 9-Cooling auger blades; 10-Cooling shaft; 11-Drive motor; 12-Reducer; 13-Carbonization furnace; 14-Heat storage buffer tank; 15-Gas burner; 151-Combustible gas inlet pipe; 152-Inner tube; 153-Outer tube; 154-Flue gas outlet pipe; 155-Igniter; 156-Central diffusion cone; 157-Cyclone blades; 158-Main air inlet; 159-Cyclone air hole. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0049] The present invention provides a method for producing biomass gas. Figure 1 , including the following steps:

[0050] Step 1: Turn on the preheating burner to supply high-temperature flue gas into the carbonization furnace 13 to preheat the carbonization furnace 13;

[0051] Step 2: feeding the biomass into the carbonizing auger group, where the biomass in the carbonizing auger group is initially carbonized to generate initial biomass fuel gas (e.g., carbon monoxide and / or hydrogen);

[0052] Step 3: The biomass gas is ignited by the gas burner 15 to generate high-temperature flue gas, which is supplied to the heat storage buffer tank 14;

[0053] Step 4: The high-temperature flue gas in the heat storage buffer tank 14 is supplied to the carbonization furnace 13 to carbonize the biomass in the carbonization auger group and continuously generate biomass gas.

[0054] Compared with the prior art, in the biomass gas production method provided by the present invention, the combustion of the gas generated by the carbonization of biomass is used to realize the carbonization heat supply of the biomass in the carbonization furnace 13. Only a small amount of natural gas combustion is required at the initial stage of operation to generate the initial carbonization heat required for the biomass. The subsequent operation of the device can utilize the gas generated by itself to achieve self-sufficiency in heat, reduce external energy consumption, reduce operating costs, and save energy and protect the environment.

[0055] For example, in order to fully initially carbonize the biomass, for example, in the above step 1, the preheating temperature of the carbonization furnace 13 is 300° C. to 400° C.

[0056] Accordingly, in order to achieve continuous and sufficient carbonization of the biomass, illustratively, in the above step 4, the carbonization temperature of the biomass is 350° C. to 420° C., and the carbonization pressure of the biomass is -20 Pa to 30 Pa.

[0057] In order to ensure the accuracy of controlling the carbonization parameters in the carbonization furnace 13, the above step 4 further includes the following steps:

[0058] During the biomass carbonization process, the temperature data in the carbonization furnace 13 is collected in real time using a thermocouple 7 and transmitted to the controller;

[0059] The controller determines whether the temperature data exceeds the temperature threshold;

[0060] If it exceeds, the flue gas release port on the heat storage buffer tank 14 is opened to reduce the high-temperature flue gas supplied to the carbonization furnace 13.

[0061] It should be noted that the above temperature threshold is 450°C.

[0062] Accordingly, in order to ensure the safety of biomass carbonization in the carbonization furnace 13, the above step 4 further includes the following steps:

[0063] During the biomass carbonization process, the pressure sensor 6 is used to collect the pressure data in the carbonization furnace 13 in real time and transmit it to the controller;

[0064] The controller determines whether the pressure data exceeds the pressure threshold;

[0065] If it exceeds, the flue gas release port on the heat storage buffer tank 14 is opened to reduce the high-temperature flue gas supplied to the carbonization furnace 13.

[0066] It should be noted that the above pressure threshold is 0.05 MPa.

[0067] In this way, by adopting the above method, the temperature and pressure in the carbonization furnace 13 can be monitored in real time, thereby ensuring the stable operation of the biomass carbonization, avoiding the dangers of over-temperature and over-pressure, and improving the overall safety of the method.

[0068] In order to process the exhaust gas discharged from the carbonization furnace 13, the following steps are further included after the above step 4:

[0069] Step 5: Dust removal is performed on the waste gas discharged from the carbonization furnace 13, and the waste gas after dust removal is discharged through the chimney.

[0070] For example, the above-mentioned biomass gas production method adopts a biomass gas production system with the following structure:

[0071] See also Figures 2 to 3 , including a carbonization furnace 13, a heat storage buffer tank 14, a gas burner 15, a cyclone separator 4 and an exhaust gas dust removal box 5, and the carbonization auger group is arranged in the carbonization furnace 13.

[0072] The gas outlet of the carbonizing auger group is connected to the gas burner 15 and the heat storage buffer tank 14 in sequence, and the exhaust gas outlet of the carbonizing furnace 13 is connected to the cyclone separator 4 and the exhaust dust removal box 5 in sequence.

[0073] For the structure of carbonized auger group, see Figure 4 , including multiple carbonization auger pipes arranged in parallel, the carbonization auger pipe includes a carbonization pipe body 1 and carbonization auger blades 2 and a carbonization shaft 3 arranged in the carbonization pipe body 1, the carbonization auger blades 2 are sleeved on the outer wall of the carbonization shaft 3, and multiple carbonization pipe bodies 1 are connected end to end to form a zigzag biomass conveying pipeline.

[0074] The spiral directions of two adjacent carbonizing auger blades 2 are opposite, and the carbonizing auger blades 2 are driven to rotate by the carbonizing shaft 3 to realize the transportation of biomass.

[0075] In order to cool the biomass after carbonization, the carbonization auger group further includes a cooling auger pipe, which is arranged in parallel with the carbonization auger pipe.

[0076] The cooling auger pipe includes a cooling pipe body 8 and cooling auger blades 9 and a cooling shaft 10 arranged in the cooling pipe body 8. The cooling auger blades 9 are sleeved on the outer wall of the cooling shaft 10. The feed end of the cooling pipe body 8 is connected to the discharge end of the last carbonization pipe body 1. The spiral direction of the cooling auger blades 9 is opposite to the spiral direction of the last carbonization auger blade 2. The carbonized biomass is cooled by the cooling auger pipe.

[0077] In order to simplify the structure of the carbonizing auger group and realize the rotation of multiple carbonizing shafts 3 and cooling shafts 10 at the same time, the carbonizing auger group further includes a drive motor 11, a reducer 12 and a synchronous pulley. The output shaft of the drive motor 11 is connected to the input end of the synchronous pulley through the reducer 12, and the output end of the synchronous pulley is respectively connected to the multiple carbonizing shafts 3 and the cooling shaft 10. In this way, the drive motor 11 drives the multiple carbonizing shafts 3 and the cooling shaft 10 to rotate synchronously through the reducer 12 and the synchronous pulley in turn, thereby realizing the transportation of biomass in the carbonizing auger group.

[0078] For the structure of the gas burner 15, see Figure 5 , including a combustible gas inlet pipe 151, an inner tube 152, an outer tube 153, a flue gas outlet pipe 154 and an igniter 155.

[0079] Among them, the combustible gas inlet pipe 151, the inner tube 152 and the flue gas outlet pipe 154 are connected in sequence, the inner tube 152 is arranged in the outer tube 153 and is coaxially fixedly connected to the outer tube 153, and the inner tube 152 is provided with a central diffusion cone 156 and a cyclone blade 157 coaxially arranged with the inner tube 152. There is a gap between the outer wall of the central diffusion cone 156 and the inner wall of the inner tube 152, and the cyclone blade 157 is sleeved on the outer wall of the central diffusion cone 156, the inner end of the cyclone blade 157 is fixedly connected to the central diffusion cone 156, and the outer end of the cyclone blade 157 is fixedly connected to the inner wall of the inner tube 152, and the cyclone blade 157 is located in the gap between the outer wall of the central diffusion cone 156 and the inner wall of the inner tube 152.

[0080] A plurality of cyclone holes 159 are respectively provided on the side walls of the inner tube 152, and a main air port 158 ​​is provided on the side walls of the outer tube 153. There is a gap between the inner tube 152 and the outer tube 153. The main air port 158, the gap between the inner tube 152 and the outer tube 153, and the cyclone holes 159 constitute a cyclone channel, and the ignition end of the igniter 155 extends into the inner tube 152.

[0081] It should be noted that the central diffusion cone 156 is set with its large end facing the flame direction, which can also block the flame and prevent the flame from flowing back to another layer of the central diffusion cone 156, thereby ensuring the combustion safety of the preheating burner and the gas burner 15.

[0082] Exemplarily, the outer cylinder 153 is a constant diameter cylinder structure.

[0083] The combustible gas inlet pipe 151 and the smoke gas outlet pipe 154 are constant diameter pipes.

[0084] The inner tube 152 includes an expanding diameter section, a reducing diameter section and a constant diameter section connected in sequence along the flow direction of the combustible gas. The central diffusion cone 156 and the cyclone blades 157 are both arranged in the expanding diameter section. The cyclone holes 159 are arranged on the side wall of the expanding diameter section and are located on the side of the cyclone blades 157 away from the combustible gas inlet pipe 151. The igniter 155 is located on the side of the cyclone blades 157 away from the combustible gas inlet pipe 151.

[0085] In this way, on the one hand, due to the setting of the expanded diameter section and the fact that the outer cylinder 153 is a constant diameter section, when air is supplied into the gap between the inner cylinder 152 and the outer cylinder 153 from the main air inlet 158, the cross-section of the gap gradually decreases, causing the air flow rate to increase continuously, and the air flows through the cyclone holes 159 to form a high-speed vortex of air that is supplied to the outer cylinder 153.

[0086] On the other hand, due to the setting of the central diffusion cone 156, the flow cross-section of the combustible gas can also be reduced, the flow velocity of the combustible gas can be increased, and the increase in flow resistance caused by the setting of the cyclone blades 157 can be reduced, so that the combustible gas can flow smoothly through the cyclone blades 157.

[0087] In summary, the use of the specific structure of the outer cylinder 153 and the inner cylinder 152 and the specific positions of the various components can increase the air flow rate and the combustible gas flow rate on the basis of realizing the nested structure of the outer cylinder 153 and the inner cylinder 152, thereby forming two high-speed swirls and achieving sufficient mixing of the air and the combustible gas.

[0088] It is worth noting that due to the generation of two high-speed swirls, the air pressure near the axis of the inner tube 152 may decrease, and the concentrations of combustible gas and air here are low, affecting the combustion uniformity in the inner tube 152.

[0089] Therefore, the gas burner 15 further includes a double-helical central gas supply pipe group.

[0090] Specifically, the central air supply pipe group is located in the inner tube 152 and is coaxially arranged with the inner tube 152. The central air supply pipe group includes a spiral combustible gas supply pipe and a spiral air supply pipe. The two are intertwined to form a double helix structure. A plurality of combustible gas spray holes are opened on the combustible gas supply pipe. The gas outlet direction of the combustible gas spray holes is perpendicular to the side wall of the combustible gas supply pipe. A plurality of air spray holes are opened on the air supply pipe. The gas outlet direction of the air spray holes is perpendicular to the side wall of the air supply pipe. The combustible gas sprayed from the combustible gas spray holes has the same swirl direction as the combustible gas flowing out of the cyclone blades 157, and the air sprayed from the air spray holes has the same swirl direction as the supply air flowing out of the cyclone holes 159.

[0091] In this way, the double-helix central air supply pipe group can effectively compensate for the problem of low concentration of combustible gas and air in the central area and improve combustion uniformity.

[0092] In addition, the combustible gas ejected from the combustible gas injection holes and the air ejected from the air injection holes still form two swirl flows, further enhancing the overall swirl flow of the airflow in the inner cylinder 152 .

[0093] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A biomass gas production method, characterized in that: The steps include: Step 1: Turn on the preheating burner to supply flue gas into the carbonization furnace to preheat the carbonization furnace; Step 2: feeding the biomass into the carbonizing auger group, where the biomass in the carbonizing auger group is initially carbonized to generate initial biomass gas; Step 3: The biomass gas is ignited by the gas burner to generate flue gas, which is then fed into the heat storage buffer tank; Step 4: The flue gas in the heat storage buffer tank is supplied to the carbonization furnace to carbonize the biomass in the carbonization auger group to generate biomass gas.

2. The biomass gas production method according to claim 1, characterized in that: In the step 1, the preheating temperature of the carbonization furnace is 300°C to 400°C.

3. The biomass gas production method according to claim 1, characterized in that: In the step 4, the carbonization temperature of the biomass is 350°C to 420°C.

4. The biomass gas production method according to claim 1, characterized in that: In the step 4, the carbonization pressure of the biomass is -20Pa to 30Pa.

5. The biomass gas production method according to claim 1, characterized in that: The step 4 further comprises the following steps: During the biomass carbonization process, thermocouples are used to collect temperature data in the carbonization furnace in real time and transmit it to the controller; The controller determines whether the temperature data exceeds the temperature threshold. If it exceeds, the flue gas release port on the heat storage buffer tank is opened to reduce the high-temperature flue gas supplied to the carbonization furnace.

6. The biomass gas production method according to claim 5, characterized in that: The temperature threshold is 450°C.

7. The biomass gas production method according to claim 1, characterized in that: The step 4 further comprises the following steps: During the biomass carbonization process, a pressure sensor is used to collect real-time pressure data in the carbonization furnace and transmit it to the controller; The controller determines whether the pressure data exceeds the pressure threshold. If so, it opens the flue gas release port on the heat storage buffer tank to reduce the high-temperature flue gas supplied to the carbonization furnace.

8. The biomass gas production method according to claim 7, characterized in that: The pressure threshold is 0.05 MPa.

9. The biomass gas production method according to claim 1, characterized in that: The step 4 further includes the following steps: Step 5: The exhaust gas discharged from the carbonization furnace is dedusted and discharged through the chimney.

10. The biomass gas production method according to any one of claims 1 to 9, characterized in that: The biomass gas production method adopts a biomass gas production system: The biomass gas production system includes a carbonization furnace, a heat storage buffer tank, a gas burner, a cyclone separator and an exhaust dust removal box, and the carbonization auger assembly is arranged in the carbonization furnace; The gas outlet of the carbonizing auger group is connected to the gas burner and the heat storage buffer tank in sequence, and the exhaust gas outlet of the carbonizing furnace is connected to the cyclone separator and the exhaust gas dust removal box in sequence.

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