Production process for producing charcoal from biomass

Abstract

The invention relates to a production process for biomass carbonization, a production system for biomass carbonization comprises a plurality of carbonization furnaces, and the production process comprises the following steps: in the production process, one carbonization furnace is in a standby mode, and the other carbonization furnaces are in a production mode; one carbonization furnace which is in the production mode and needs to be shut down for maintenance is set as a target shut down furnace, the carbonization furnace in the standby mode is a target starting furnace, and then mode switching between the target shut down furnace and the target starting furnace is carried out; in the mode switching process, combustible gas generated in the blowing-out process of the target blowing-out furnace is transferred into a heating system of the target starting furnace to be combusted, and heat is provided for starting of the target starting furnace; after mode switching is completed, the target shutdown furnace is in the standby mode, the target starting furnace is in the production mode, a torch can not be arranged in a biomass charcoal production place, the requirement of a production system for the place is reduced, and when one carbonization furnace needs to be shut down for daily cleaning and maintenance, continuous production of biomass charcoal is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass carbonization, and in particular to a production process for producing carbon from biomass. Background Art

[0002] For carbonization furnaces for carbonizing biomass, the method of anaerobic dry distillation pyrolysis is usually adopted to achieve biomass carbonization. Combustible gas is generated during the pyrolysis process of biomass to produce carbon. A specific proportional form of the components of the combustible gas is: the content of CO is 29.20%, the content of H2 is 24.74%, the content of CH4 is 7.3%, and the content of H2O is 32.30%. In order to reduce the dependence on external energy, the combustible gas is usually introduced into the combustion chamber to provide continuous heat source for the carbonization furnace.

[0003] However, in order to ensure the normal operation of the production system, when starting the carbonization furnace, the combustion chamber is ignited and started by the fuel oil system. The system is stable within 2 - 3 hours after startup, and the fuel supply is stopped after stabilization; during the startup process, the amount of combustible gas generated by the carbonization furnace gradually increases from less to more, and after being led out by the gas blower, it is sent to the burner on the combustion chamber for combustion. In actual production, the phenomenon of coking and furnace shutdown of the carbonization furnace often occurs. The shutdown time of the carbonization furnace is 2 - 3 hours. During this period, the high-temperature gas generated is sent to the torch for combustion and finally discharged into the atmosphere.

[0004] In actual operation, due to reasons such as gas volume changes during furnace shutdown, the combustion of the torch is unstable, and the torch needs to have a safety distance from the building structure, occupying a large area. When the production site does not meet the conditions for building a torch, the design, construction, and commissioning of the biomass carbonization system cannot be realized. Summary of the Invention

[0005] The applicant of the present invention aims at the above-mentioned disadvantages in the existing production technology and provides a production process for producing carbon from biomass, so that a torch can be not set in the production site of biomass carbonization, the requirements for the site of the production system can be reduced, and when a carbonization furnace needs to be shut down for daily cleaning and maintenance, the continuous production of biomass carbonization can be ensured.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A production process for producing carbon from biomass, the production system for biomass carbonization adopted includes multiple carbonization furnaces, and the production process includes the following steps:

[0008] During the production process, one carbonization furnace is in the standby mode, and the remaining carbonization furnaces are in the production mode;

[0009] Set one carbonization furnace that is in the production mode and needs to be shut down for maintenance as the target deactivated furnace, and the carbonization furnace in the standby mode as the target activated furnace, and then perform the mode switching between the target deactivated furnace and the target activated furnace;

[0010] During the mode switching process, the combustible gas generated during the shutdown process of the target deactivated furnace is transferred to the heating system of the target activated furnace for combustion, providing heat for the startup of the target activated furnace.

[0011] After the mode switching is completed, the target deactivated furnace is in the standby mode, and the target activated furnace is in the production mode.

[0012] As a further improvement of the above technical solution:

[0013] During the mode switching process,

[0014] gradually reduce the feed rate of the target deactivated furnace and simultaneously increase the transfer ratio of the combustible gas generated by the target deactivated furnace.

[0015] While gradually reducing the feed rate of the target deactivated furnace, gradually increase the feed rate of the target activated furnace so that the combustible gas temperatures at the exhaust ports of the target deactivated furnace and the target activated furnace are both the process exhaust temperature.

[0016] During the mode switching process, the sum of the feed rates of the target deactivated furnace and the target activated furnace is equal to the feed rate of one carbonization furnace in the production mode during the production process.

[0017] The number of carbonization furnaces is greater than or equal to three;

[0018] Set the maintenance cycles of each carbonization furnace to be the same, and stagger the maintenance time points so that the time interval between adjacent maintenance time points is greater than or equal to the shutdown time of each carbonization furnace.

[0019] The production system includes a heating system corresponding to each carbonization furnace, a gas self-supply pipeline system connecting the exhaust port of the carbonization furnace and the heating system, and a gas transfer pipeline system connecting all the gas self-supply pipeline systems;

[0020] During the mode switching process, the gas transfer pipeline system connects the gas self-supply pipeline systems of the target deactivated furnace and the target activated furnace, and the gas blower of the gas self-supply pipeline system sends the combustible gas into the heating system;

[0021] Adjust the transfer ratio by adjusting the air volume of the gas blower corresponding to the target deactivated furnace.

[0022] The gas transfer pipeline system includes a connecting pipeline and a first stop valve provided on the connecting pipeline;

[0023] The gas self - supply pipeline system further includes a gas pipeline connecting the exhaust port and the heating system. A gas blower is arranged in the gas pipeline. The gas pipeline on one side of the gas blower is connected to the communication pipeline to form a tee connection point. The corresponding gas pipeline is connected by adjusting the opening and closing of the first stop valve. A regulating valve is arranged on the gas pipeline on the other side of the gas blower. A check valve is arranged on the gas pipeline between the tee connection point and the exhaust port. The transfer ratio is adjusted by adjusting the opening and closing degree of the regulating valve corresponding to the target deactivated furnace.

[0024] The heating system includes a combustion chamber and a blower connected to the combustion chamber. The flue of the combustion chamber is connected to the heating chamber of the carbonization furnace. After the combustible gas at the exhaust port of the target deactivated furnace reaches normal pressure, the blower is used to cool the heating chamber of the target deactivated furnace.

[0025] The heating system is provided with an external fuel pipeline for supplying external energy to the combustion chamber.

[0026] A burner connected to the gas pipeline is arranged on the combustion chamber.

[0027] The beneficial effects of the present invention are as follows:

[0028] The structure of the present invention is compact, reasonable and easy to operate. Adding a carbonization furnace to the production system makes one carbonization furnace as a standby furnace. The combustible gas generated during the shutdown process of the carbonization furnace that needs to be shut down for maintenance is supplied to the standby carbonization furnace for startup, improving the utilization rate of gas. It is not necessary to set up a flare at the biomass carbonization production site, reducing the requirements for the production site. At the same time, continuous production of biomass carbonization is realized through the switching between the two carbonization furnace modes during the shutdown process.

[0029] At the same time, the present invention also has the following advantages:

[0030] (1) By adjusting the feed rate of the target deactivated furnace and the combustion amount of the combustible gas, gradually reducing the feed rate and making the temperature of the generated combustible gas at the process exhaust temperature, ensuring the stable quality of the product. Transfer the excess combustible gas to the target activated furnace to realize the heat distribution between the target activated furnace and the target deactivated furnace during the mode switching process, and realize the switching of the production capacity of the two carbonization furnaces and the continuous stability of the production system.

[0031] (2) The process system adopting the N - use - one - standby scheme (N≥2) is safer, more reliable and easier to control than the one - use - one - standby scheme, making the production capacity of the entire production system more stable. Description of the Drawings

[0032] Figure 1 It is a schematic diagram during the production processes of Embodiment 1 and Embodiment 2 of the present invention.

[0033] Figure 2Schematic diagram of the mode switching process in Embodiments 1 and 2 of the present invention.

[0034] Figure 3 Schematic diagram after the mode switching in Embodiments 1 and 2 of the present invention is completed.

[0035] Figure 4 Schematic diagram during the production process in Embodiment 3 of the present invention.

[0036] Figure 5 Schematic diagram of the mode switching process in Embodiment 3 of the present invention.

[0037] Figure 6 Schematic diagram of the mode switching process in Embodiment 3 of the present invention (supply state).

[0038] Figure 7 Schematic diagram after the mode switching in Embodiment 3 of the present invention is completed.

[0039] Wherein:

[0040] 1. Carbonization furnace; 11. Exhaust port; 12. Flue gas outlet; 13. Flue gas inlet;

[0041] 2. Heating system; 21. Flue; 22. Combustion chamber; 23. Burner; 24. External fuel pipeline; 25. Blower;

[0042] 4. Gas self - supply pipeline system; 41. Gas pipeline; 42. Second stop valve; 43. Check valve; 44. Flowmeter; 45. Gas monitor; 46. Gas blower; 47. Third stop valve; 48. Regulating valve;

[0043] 5. Gas transfer pipeline system; 51. Connecting pipeline; 511. Main pipe; 512. Branch pipe; 52. First stop valve; 53. Three - way connection point. Specific embodiments

[0044] The following combines with the attached drawings to illustrate the specific embodiments of the present invention.

[0045] Embodiment 1:

[0046] As Figures 1 - 3 shown, the production process of biomass carbonization in this embodiment, the production system for biomass carbonization includes multiple carbonization furnaces 1, and the production process includes the following steps:

[0047] During the production process, one carbonization furnace 1 is in the standby mode, and the rest of the carbonization furnaces 1 are in the production mode;

[0048] Set one carbonization furnace 1 that is in the production mode and needs to be shut down for maintenance as the target shutdown furnace, and the carbonization furnace 1 in the standby mode as the target startup furnace, and then perform the mode switching between the target shutdown furnace and the target startup furnace;

[0049] During the mode switching process, the combustible gas generated during the shutdown process of the target deactivated furnace is transferred to the heating system 2 of the target activated furnace for combustion, providing heat for the startup of the target activated furnace.

[0050] After the mode switching is completed, the target deactivated furnace is in standby mode, and the target activated furnace is in production mode.

[0051] After the mode switching is completed, the entire production system resumes normal production. One carbonization furnace 1 is in standby mode, and the remaining carbonization furnaces 1 are in production mode.

[0052] In this embodiment, the carbonization furnace 1 is a continuous carbonization furnace, such as a horizontal rotary core carbonization furnace. To meet the temperature conditions required for biomass carbonization in the carbonization furnace 1, the carbonization furnace 1 is equipped with a heating system 2, and the heating system 2 includes a combustion chamber 22. To reduce dependence on external energy, the exhaust port 11 of the carbonization furnace 1 is connected to a gas self-supply pipeline system 4 to supply the combustible gas generated during the carbonization process to the heating system 2 for self-heating of the carbonization furnace 1.

[0053] Each carbonization furnace 1 in the production system has the same specifications, that is, parameters such as the structural form and rated output are the same, and the supporting heating system 2 and gas self-supply pipeline system 4 have the same specifications, ensuring the same production, shutdown, startup time, and process parameters for each carbonization furnace 1.

[0054] Adding one carbonization furnace 1 to the production system, using one carbonization furnace 1 as a standby furnace, supplying the combustible gas generated during the shutdown process of the carbonization furnace 1 that needs to be shut down for maintenance to the standby carbonization furnace 1 for startup, improving the utilization rate of gas, not setting up a torch at the biomass carbonization production site, reducing the requirements of the production system for the site, and realizing continuous production of biomass carbonization through the mode switching between the two carbonization furnaces 1 during the shutdown process.

[0055] Embodiment 2:

[0056] On the basis of Embodiment 1, further improve the production process of biomass carbonization. During the mode switching process, gradually reduce the feed rate of the target deactivated furnace, and simultaneously increase the transfer ratio of the combustible gas generated by the target deactivated furnace. While gradually reducing the feed rate of the target deactivated furnace, gradually increase the feed rate of the target activated furnace, so that the temperature of the combustible gas at the exhaust port 11 of the target deactivated furnace and the target activated furnace is the process exhaust temperature. During the mode switching process, gradually increase the transfer ratio of the combustible gas until the combustible gas at the exhaust port 11 of the target deactivated furnace is at atmospheric pressure, and the transfer ratio of the combustible gas generated by the target deactivated furnace is 100%.

[0057] During the mode switching process, the sum of the feed rates of the target deactivated furnace and the target activated furnace is equal to the feed rate of one carbonization furnace 1 in the production mode during the production process.

[0058] The process exhaust temperature is the required temperature for the combustible gas discharged from the carbonization furnace 1 during the production process. By matching the heat provided by the heating system 2 with the feed rate of the carbonization furnace 1, the relative constancy of the flue gas temperature in the flue 21 of the heating system 2 is maintained. The flue gas temperature is the process heating temperature, which maintains a stable carbonization reaction, thereby ensuring that the combustible gas discharged from the exhaust port 11 is also within the range of the process exhaust temperature, ensuring the stability of the products of the carbonization reaction, and thus guaranteeing the quality of the products.

[0059] The carbonization reaction is still ongoing inside the target deactivated furnace that has stopped feeding, consuming the internal materials. During this process, part of the combustible gas generated inside the target deactivated furnace is used for its own heating, and part is transferred to the combustion chamber 22 of the target activated furnace. When the combustible gas at the exhaust port 11 of the target deactivated furnace is at atmospheric pressure, the transfer ratio of the combustible gas generated by the target deactivated furnace is 100%. At this time, the target deactivated furnace stops producing charcoal, and the target activated furnace fully utilizes the combustible gas generated by itself for carbonization, that is, the mode switching is completed.

[0060] By adjusting the feed rate of the target deactivated furnace and the combustion amount of the combustible gas, gradually reducing the feed rate and making the temperature of the generated combustible gas within the process exhaust temperature range, the quality stability of the products is ensured. The excess combustible gas is transferred to the target activated furnace to achieve the heat distribution between the target activated furnace and the target deactivated furnace during the mode switching process, and to achieve the switching of the production capacity of the two carbonization furnaces 1 and the continuous stability of the production system.

[0061] In a specific production condition of the carbonization furnace 1 in an exemplary embodiment: the biomass is cotton stalks, the feed rate of each carbonization furnace 1 is 1.5 - 2 t / h, and the flow rate of the combustible gas is 1275 Nm 3 / h - 1900 Nm 3 / h, the process exhaust temperature is 450 °C - 500 °C, and the process heating temperature is 900 - 950 °C. The feed rate needs to meet the feed requirements of the carbonization furnace 1. Generally, the feed rate of the carbonization furnace 1 needs to meet not less than 30% of the maximum feed rate.

[0062] The number of carbonization furnaces 1 is two. As Figures 1 - 3 shown, that is, when adding one carbonization furnace 1 on the basis of one carbonization furnace 1 without using a torch, the amount of charcoal generated by the carbonization furnace 1 during the furnace shutdown process gradually decreases, and the amount of charcoal generated by the standby furnace during the furnace startup process gradually increases. During the mode switching process, the total output of the production system can be maintained higher than the charcoal output during the shutdown process of a single carbonization furnace 1, and the relative stability of the overall charcoal output of the production system can be ensured.

[0063] Figure 1 It indicates that during the production process, Carbonization Furnace 1#1 is in the production mode, and Carbonization Furnace 2#1 is in the standby mode.

[0064] Figure 2 It represents the mode switching process, where Carbonization Furnace 1#1 is the target furnace to be stopped, and Carbonization Furnace 2#1 is the target furnace to be started.

[0065] In the initial stage of mode switching, when the feed rate of Carbonization Furnace 1#1 (the target furnace to be stopped) is 70%, the feed rate of Carbonization Furnace 2#1 (the target furnace to be started) is 30%. The opening degree of the regulating valve 48 of Carbonization Furnace 1#1 is reduced, so that part of the combustible gas during the shutdown process of Carbonization Furnace 1#1 is used for its own heating, and part is used for the startup of Carbonization Furnace 2#1. The regulating valve 48 of Carbonization Furnace 2#1 is in the fully open state;

[0066] In the middle stage of mode switching, when the feed rate of Carbonization Furnace 1#1 (the target furnace to be stopped) is 50%, the feed rate of Carbonization Furnace 2#1 (the target furnace to be started) is 50%. The opening degree of the regulating valve 48 of Carbonization Furnace 1#1 is continuously reduced. Compared with the initial stage of mode switching, the proportion of the combustible gas generated by Carbonization Furnace 1#1 transferred to Carbonization Furnace 2#1 increases;

[0067] In the later stage of mode switching, when the feed rate of Carbonization Furnace 1#1 (the target furnace to be stopped) is 30%, the feed rate of Carbonization Furnace 2#1 (the target furnace to be started) is 70%. The proportion of the combustible gas generated by Carbonization Furnace 1#1 transferred to Carbonization Furnace 2#1 is further increased;

[0068] At the end of mode switching, Carbonization Furnace 1#1 (the target furnace to be stopped) stops feeding, and the feed rate of Carbonization Furnace 2#1 is 100%. When the combustible gas at the exhaust port 11 of Carbonization Furnace 1#1 is at atmospheric pressure, the regulating valve 48 of Carbonization Furnace 1#1 is closed. At this time, Carbonization Furnace 1#1 stops producing carbon and can be cooled for maintenance. Carbonization Furnace 2#1 is in the production state. As Figure 3 shown, after the mode switching is completed, Carbonization Furnace 1#1 is in the standby mode, and Carbonization Furnace 2#1 is in the production mode.

[0069] The mode switching process takes about 2 - 3 hours, which is the furnace shutdown time.

[0070] Embodiment 3:

[0071] Different from Embodiments 1 and 2, the number of carbonization furnaces 1 is greater than or equal to three;

[0072] It is set that the maintenance cycles of each carbonization furnace 1 are the same, and the maintenance time points are staggered to avoid each other, and the time interval between adjacent maintenance time points is greater than or equal to the furnace shutdown time of each carbonization furnace 1.

[0073] Figure 4It indicates that during the production process, carbonization furnace 1 of No. 1 and No. 2 is in the production mode, and carbonization furnace 1 of No. 3 is in the standby mode.

[0074] Figure 5 It indicates the mode switching process. Carbonization furnace 1 of No. 1 is the target furnace to be stopped, carbonization furnace 1 of No. 3 is the target furnace to be started, and carbonization furnace 1 of No. 2 is in the production mode.

[0075] Figure 7 It indicates that after the mode switching is completed, carbonization furnace 1 of No. 1 is in the standby mode, and carbonization furnaces 1 of No. 2 and No. 3 are in the production mode.

[0076] The process system adopting the N - use - one - standby scheme (N≥2) is safer, more reliable, easier to control than the one - use - one - standby scheme, and makes the production capacity of the whole production system more stable.

[0077] Figure 6 It indicates a state during the mode switching process. During the mode switching process, according to the control requirements of the process exhaust temperature, at least one carbonization furnace 1 in the production mode supplies combustible gas to the target furnace to be started.

[0078] Supply means intermittent supply according to the demand. By monitoring parameters such as temperature during the start - up process of the target furnace to be started, it can be judged whether the heating conditions after the transfer of combustible gas meet the heat demand for starting the target furnace to be started. If not, the combustible gas of carbonization furnace 1 of No. 2 during the production process can be supplied to the combustion chamber 22 of carbonization furnace 1 of No. 3 (the target furnace to be started). For the distribution of the combustible gas volume in the whole production system, it is easier to achieve the balance of physical and chemical quantities between heat and material quantity. The process fluctuation of the whole production system is small, and the quality of carbon products is reliably guaranteed.

[0079] As Figures 1 - 7 shown, the production system includes a heating system 2 corresponding to each carbonization furnace 1, a gas self - supply pipeline system 4 connecting the exhaust port 11 of the carbonization furnace 1 and the heating system 2, and a gas transfer pipeline system 5 connecting all gas self - supply pipeline systems 4;

[0080] During the mode switching process, the gas transfer pipeline system 5 connects the gas self - supply pipeline systems 4 of the target furnace to be stopped and the target furnace to be started, and the gas blower 46 of the gas self - supply pipeline system 4 sends the combustible gas into the heating system 2;

[0081] The transfer ratio is adjusted by regulating the air volume of the gas blower 46 corresponding to the target furnace to be stopped.

[0082] The heating system 2 includes a combustion chamber 22, and a burner 23 communicating with the inner cavity of the combustion chamber 22 is arranged on the combustion chamber 22. The gas blower 46 is a high-temperature and high-pressure supercharging blower, which introduces the combustible gas generated in the carbonization furnace 1 into the burner 23, and after ignition, it burns in the combustion chamber 22. A flue 21 communicating with the flue gas inlet 13 of the heating chamber of the carbonization furnace 1 is arranged on the combustion chamber 22. The high-temperature flue gas generated in the combustion chamber 22 enters the heating chamber of the carbonization furnace 1 through the flue 21 and is discharged from the flue gas outlet 12 of the carbonization furnace 1. An exhaust port 11 is arranged on the furnace chamber of the carbonization furnace 1, and the combustible gas generated during the biomass carbonization process is discharged from the exhaust port 11.

[0083] The heating system 2 includes a blower 25 connected to the combustion chamber 22. During the production process, the carbonization furnace 1 supplies the combustible gas generated by carbonization to itself for heating through the gas self-supply pipeline system 4. In order to maintain the process exhaust temperature and the process heating temperature, usually, while the blower 25 supplies oxygen to the combustion chamber 22, it takes away a part of the flue gas heat to maintain the process heating temperature.

[0084] The gas transfer pipeline system 5 includes a connecting pipeline 51 and a first stop valve 52 arranged on the connecting pipeline 51.

[0085] As Figure 1 shown, when there are two carbonization furnaces 1, the connecting pipeline 51 is a single pipeline; as Figure 4 shown, when the number of carbonization furnaces 1 is greater than or equal to three, the connecting pipeline 51 includes a main pipe 511 and a plurality of branch pipes 512 communicating with the main pipe 511. The branch pipes 512 correspond to the carbonization furnaces 1 one by one, and a first stop valve 52 is arranged on each branch pipe 512.

[0086] The gas self-supply pipeline system 4 further includes a gas pipeline 41 connecting the exhaust port 11 and the heating system 2. The gas blower 46 is arranged in the gas pipeline 41. The gas pipeline 41 on one side of the gas blower 46 is connected to the connecting pipeline 51 and forms a tee connection point 53. By adjusting the opening and closing of the first stop valve 52, the corresponding gas pipeline 41 is connected. A regulating valve 48 is arranged on the gas pipeline 41 on the other side of the gas blower 46. A check valve 43 is arranged on the gas pipeline 41 between the tee connection point 53 and the exhaust port 11. The transfer ratio is adjusted by adjusting the opening and closing degree of the regulating valve 48 corresponding to the target deactivated furnace. The connecting pipeline 51 or the branch pipe 512 is connected to the gas pipeline 41 to form a tee connection point 53, and the tee connection point 53 is a tee pipe fitting for connecting pipelines.

[0087] A tee connection point 53 is arranged on the gas pipeline 41 corresponding to each carbonization furnace 1. The tee connection points 53 are connected through the connecting pipeline 51. By opening the first stop valve 52, the gas pipeline 41 of the corresponding carbonization furnace 1 is connected, and the transfer of the combustible gas at the tee connection point 53 is realized. The check valve 43 is used to prevent the combustible gas from entering the carbonization furnace 1 from the exhaust port 11.

[0088] A second shut-off valve 42 and a third shut-off valve 47 are provided on the gas pipeline 41 between the tee connection point 53 and the heating system 2. The second shut-off valve 42 is located on the inlet side of the gas blower 46 and is used for pressure buildup before the gas blower 46 is started. The third shut-off valve 47 is located on the outlet side of the gas blower 46 and is a pneumatic quick-closing valve, which is used for quickly cutting off the combustible gas in case of emergency.

[0089] A flowmeter 44 is provided upstream of the gas blower 46 to detect the flow rate of the combustible gas entering the heating system 2. A concentration sensor for detecting the concentration of the combustible gas entering the heating system 2 can also be provided. By detecting the concentration and flow rate of the combustible gas and precisely controlling the flow rate, the feeding amount of the carbonization furnace 1 is matched, so that the heating system 2 maintains a relatively constant process heating temperature, and at the same time, the process exhaust gas temperature is controlled, thereby ensuring the quality of the product during the furnace shutdown process.

[0090] The air volume of the gas blower 46 can be adjusted by using a frequency converter, thereby adjusting the transfer ratio. When a regulating valve 48 is provided on the gas pipeline 41 to adjust the transfer ratio, the regulating valve 48 of the target enabled furnace is in the fully open state, and the regulating valve 48 of the target disabled furnace controls the transfer ratio of the combustible gas generated by the target disabled furnace by adjusting the opening and closing conditions.

[0091] During the mode switching process, according to the control requirement of the process exhaust gas temperature, when at least one carbonization furnace 1 in the production mode supplies combustible gas to the target enabled furnace, the gas pipelines 41 of at least three carbonization furnaces 1 are connected, as Figure 6 shown. The supply of combustible gas can be achieved by reducing the opening degree of the regulating valve 48 corresponding to the carbonization furnace 1 in the production mode and simultaneously opening the first shut-off valve 52 corresponding to the carbonization furnace 1 in the production mode. After the supply is completed, the first shut-off valve 52 corresponding to the carbonization furnace 1 in the production mode can be closed, and the corresponding regulating valve 48 can be fully opened.

[0092] The heating system 2 includes a combustion chamber 22 and a blower 25 connected to the combustion chamber 22. The flue 21 of the combustion chamber 22 is connected to the heating chamber of the carbonization furnace 1. After the combustible gas at the exhaust port 11 of the target disabled furnace is at normal pressure, the blower 25 is used to cool the heating chamber of the target disabled furnace.

[0093] A gas monitor 45 is provided at the exhaust port 11 of the carbonization furnace 1 to monitor the pressure and temperature of the combustible gas; the fact that the combustible gas at the exhaust port 11 of the target disabled furnace is at normal pressure indicates that the carbonization furnace 1 stops carbonization; after the target disabled furnace is cooled down, furnace shutdown maintenance can be carried out, such as cleaning coking.

[0094] The blower 25 is a conventional accessory of the combustion chamber 22. While providing the oxygen required for fuel combustion, it controls the temperature of the flue gas in the flue 21 of the combustion chamber 22 to ensure a stable process heating temperature.

[0095] The amount of feedstock into the carbonization furnace 1 is directly proportional to the heat of the combustible gas. By controlling the matching of the feedstock amount and the gas amount, the stable matching of process conditions is achieved, ensuring product quality. The specific control method can adopt an automatic control using a PLC or DCS system. This method is prior art and will not be elaborated in detail here.

[0096] The heating system 2 is provided with an external fuel pipeline 24 for supplying external energy to the combustion chamber 22.

[0097] A burner 23 connected to the gas pipeline 41 is provided on the combustion chamber 22.

[0098] When the external fuel provided by the external fuel pipeline 24 is fuel oil, the burner 23 can be a dual-purpose gas and oil type. While the burner 23 is connected to the gas pipeline 41, it is also connected to the external fuel pipeline 24.

[0099] When the production equipment is put into production, external energy is used to start up all the carbonization furnaces 1 that need to be in the production mode.

[0100] In the production system of this embodiment, another production mode of increasing production capacity can also be realized. The number of carbonization furnaces 1 is N, N is greater than or equal to three, the rated gas production of the carbonization furnace 1 is Q, and the rated combustion amount of each burner 23 is q, q is greater than or equal to N×Q / (N - 1). When the number of carbonization furnaces 1 is four, three burners 23 can burn the combustible gas generated by the four carbonization furnaces 1. While achieving the maximum production, a certain carbonization furnace 1 can be shut down for maintenance. The rated combustion amount of q is the rated combustion amount of the burner 23.

[0101] In the above embodiments, if all the carbonization furnaces 1 need to be shut down, they can be shut down one by one. For the last carbonization furnace 1, excessive cold air is introduced into the combustion chamber 22 through the blower 25 to reduce the temperature of the flue gas discharged from the combustion chamber 22, reduce the heating of the carbonization furnace 1, thereby reducing the temperature of the materials in the carbonization furnace 1 and reducing the gas production rate to achieve shutdown.

[0102] For the production system using biomass to produce carbon, in the case of not setting up a flare, a gas storage tank can be set up for emergency storage of the combustible gas generated by shutting down the carbonization furnace 1.

[0103] The above description is an explanation of the present invention, not a limitation of the invention. The scope defined by the present invention can be seen in the claims. Any form of modification can be made within the protection scope of the present invention.

Claims

1. A biomass charcoal production process, characterized in that: The production system for biomass charcoal production comprises a plurality of carbonization furnaces (1), and the production process comprises the following steps: During the production process, one carbonization furnace (1) is in standby mode, and the other carbonization furnaces (1) are in production mode; A carbonization furnace (1) in production mode and requiring shutdown for maintenance is set as a target shutdown furnace, and a carbonization furnace (1) in standby mode is set as a target activation furnace, and then the modes of the target shutdown furnace and the target activation furnace are switched; During the mode switching process, the combustible gas generated during the shutdown process of the target deactivated furnace is transferred to the heating system (2) of the target activated furnace for combustion, thereby providing heat for the startup of the target activated furnace; After the mode switching is completed, the target deactivated furnace is in standby mode and the target activated furnace is in production mode.

2. The process for producing charcoal from biomass according to claim 1, characterized in that: During mode switching, Gradually reduce the feed rate of the target shutdown furnace and simultaneously increase the transfer ratio of the combustible gas generated by the target shutdown furnace. The feed rate of the target deactivated furnace is gradually reduced while the feed rate of the target activated furnace is gradually increased, so that the combustible gas temperatures at the exhaust ports (11) of the target deactivated furnace and the target activated furnace are both equal to the process exhaust temperature.

3. The process for producing charcoal from biomass as claimed in claim 2, characterized in that: During the mode switching process, the sum of the feed amount of the target deactivated furnace and the feed amount of the target activated furnace is equal to the feed amount of a carbonization furnace (1) in the production mode during the production process.

4. The process for producing charcoal from biomass according to claim 1, characterized in that: The number of carbonization furnaces (1) is greater than or equal to three; The maintenance cycle of each carbonization furnace (1) is set to be the same, and the maintenance time points are staggered and avoided, and the time interval between adjacent maintenance time points is greater than or equal to the shutdown time of each carbonization furnace (1).

5. The process for producing charcoal from biomass according to claim 1, characterized in that: The production system comprises a heating system (2) corresponding to each carbonization furnace (1), a gas self-sufficient pipeline system (4) connecting the exhaust port (11) of the carbonization furnace (1) and the heating system (2), and a gas transfer pipeline system (5) connecting all the gas self-sufficient pipeline systems (4); During the mode switching process, the gas transfer pipeline system (5) connects the gas self-sufficient pipeline system (4) of the target deactivated furnace and the target activated furnace, and the gas blower (46) of the gas self-sufficient pipeline system (4) delivers the combustible gas into the heating system (2); The transfer ratio is adjusted by adjusting the air volume entering the gas blower (46) corresponding to the target deactivated furnace.

6. The process for producing charcoal from biomass as claimed in claim 5, characterized in that: The gas transfer pipeline system (5) comprises a connecting pipeline (51) and a first stop valve (52) arranged on the connecting pipeline (51); The gas self-sufficient pipeline system (4) also includes a gas pipeline (41) connecting the exhaust port (11) and the heating system (2); a gas fan (46) is arranged in the gas pipeline (41); the gas pipeline (41) on one side of the gas fan (46) is connected to the connecting pipeline (51) to form a three-way connection point (53); the corresponding gas pipelines (41) are connected by adjusting the opening and closing of the first stop valve (52); a regulating valve (48) is arranged on the gas pipeline (41) on the other side of the gas fan (46); a check valve (43) is arranged on the gas pipeline (41) between the three-way connection point (53) and the exhaust port (11); and the transfer ratio is adjusted by adjusting the opening and closing degree of the regulating valve (48) corresponding to the target deactivated furnace.

7. The process for producing charcoal from biomass as claimed in claim 5, characterized in that: The heating system (2) comprises a combustion chamber (22) and a blower (25) connected to the combustion chamber (22); the flue (21) of the combustion chamber (22) is connected to the heating chamber of the carbonization furnace (1); after the combustible gas at the exhaust port (11) of the target deactivated furnace reaches normal pressure, the blower (25) is used to cool the heating chamber of the target deactivated furnace.

8. The process for producing charcoal from biomass according to claim 7, characterized in that: The heating system (2) is provided with an external fuel pipeline (24) for supplying external energy to the combustion chamber (22).

9. The process for producing charcoal from biomass according to claim 7, characterized in that: The combustion chamber (22) is provided with a burner (23) connected to the gas pipeline (41).

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