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CN-122012129-A - Airflow control method and system for high-temperature carbonization of biomass

CN122012129ACN 122012129 ACN122012129 ACN 122012129ACN-122012129-A

Abstract

The invention belongs to the technical field of biomass carbonization, and particularly relates to an airflow control method for biomass high-temperature carbonization, which comprises the steps of loading and sealing, namely loading biomass raw materials into a kiln body and sealing, drying, namely starting a combustion heating device, conveying thermal mass airflow to the kiln body, closing other regulating valves, opening regulating valves corresponding to induced draft fans, discharging water vapor and carbon dioxide, carbonizing, namely controlling negative pressure anaerobic environment ranging from-10 kPa to-1 kPa in the kiln body, closing the regulating valves corresponding to the thermal mass gas through the kiln body, and cracking gas utilization, namely opening the regulating valves of a cracking gas conveying pipe after biomass generates cracking gas in the carbonization process, and introducing the cracking gas into the combustion heating device to maintain the negative pressure of a combustion chamber to be lower than the air pressure in the kiln. The method and the system can realize high-efficiency stable biomass carbonization and fully utilize pyrolysis gas.

Inventors

  • HU JINBO

Assignees

  • 湖南中新锬能源科技有限公司

Dates

Publication Date
20260512
Application Date
20251230

Claims (10)

  1. 1. A gas flow control method for high-temperature carbonization of biomass is characterized in that the negative-pressure biomass high-temperature carbonization device comprises a kiln body, a combustion heat supply device, an induced draft fan, a thermal mass gas flow transmission pipeline and an electric control center, wherein the combustion heat supply device is communicated with the bottom of the kiln body through the thermal mass gas flow transmission pipeline, a pyrolysis gas transmission pipe is arranged at the top of the kiln body and is communicated with the top of the combustion heat supply device, a branch pipeline of the thermal mass gas flow transmission pipeline and the pyrolysis gas transmission pipe are provided with regulating valves, the induced draft fan is connected with one of the branch pipelines and is controlled to be opened and closed through the corresponding regulating valve, a plurality of temperature sensors are arranged in the kiln body, a gas flow sensor is further arranged in the thermal mass gas flow transmission pipeline, a pressure sensor is arranged in the kiln body and the combustion heat supply device, the electric control center is electrically connected with each part and is used for regulating the working states of the kiln body, the combustion heat supply device and the thermal mass gas flow transmission pipeline, The airflow control method for high-temperature carbonization of biomass comprises the following steps: Charging and sealing, namely charging biomass raw materials into a kiln body and sealing; drying, namely starting a combustion heat supply device, conveying thermal mass airflow to the kiln body, closing other regulating valves, opening regulating valves corresponding to the induced draft fan, and discharging water vapor and carbon dioxide; Carbonizing treatment, namely after controlling the negative pressure anaerobic environment in the kiln body to be-10 kPa to-1 kPa, closing a regulating valve corresponding to the heat mass gas through kiln body; and (3) utilizing the pyrolysis gas, namely opening a regulating valve of a pyrolysis gas conveying pipe after the pyrolysis gas is generated by biomass in the carbonization treatment process, and introducing the pyrolysis gas into a combustion heating device, so that the negative pressure of a combustion chamber is maintained to be lower than the air pressure in a kiln.
  2. 2. The method of claim 1 wherein the temperature of the thermal mass airflow in the kiln is 80 ℃ to 300 ℃ during the drying process, the airflow velocity of the thermal mass airflow in the thermal mass airflow transmission pipeline is 10 to 20 m/s, the air pressure in the kiln is maintained between-5 kPa and-1 kPa, and the drying process causes the moisture content of the biomass in the kiln to be lower than 5%.
  3. 3. The gas flow control method of claim 1, wherein the thermal mass gas flow temperature during the carbonization treatment is 300 ℃ to 900 ℃, the gas flow speed of the thermal mass gas flow in the thermal mass gas flow transmission pipeline is 20 to 40 m/s, and the gas pressure in the kiln body is maintained between-10 kPa and-1 kPa.
  4. 4. A method of controlling a flow of gas according to claim 3 wherein when the temperature at the top of the kiln body is greater than 200 ℃, the thermal mass flow is raised to above 900 ℃ and the velocity of the thermal mass flow in the thermal mass flow transfer conduit is increased to 30 m/s to 40m/s.
  5. 5. The gas flow control method according to claim 1, wherein the gas pressure of the combustion heating device is maintained at-30 kPa to-10 kPa and lower than the gas pressure in the kiln by at least 2kPa when the pyrolysis gas is treated.
  6. 6. The method of controlling gas flow according to claim 3, wherein the step of reducing the supply amount of the external gas source of the combustion heating device until the supply of the external gas source is closed after the opening of the regulating valve of the pyrolysis gas supply pipe.
  7. 7. The gas flow control method according to claim 6, wherein when the amount of the pyrolysis gas supplied to the combustion heating means is insufficient, the gas supply is switched back to the external gas source for combustion.
  8. 8. The method according to claim 1, wherein after the carbonization treatment is completed, the combustion heating device is turned off, and the kiln body is kept in a state of slight negative pressure and no oxygen, and is naturally cooled.
  9. 9. The gas flow control method of claim 1 wherein the thermal mass gas flow transfer conduit is a square conduit having a cross-sectional area of >100mm x 100mm or a circular conduit having a diameter of >100 mm.
  10. 10. A control system for implementing the method of any one of claims 1-9, comprising: The temperature sensor is arranged at the top of the kiln body, the thermal mass inlet, the outlet and the exhaust port; a gas flow sensor disposed in the thermal mass gas flow transfer conduit; The pressure sensor is arranged in the kiln body and the combustion chamber; And the electric control center is used for receiving the signals of the sensors and controlling the operation of the regulating valve, the burner and the induced draft fan.

Description

Airflow control method and system for high-temperature carbonization of biomass Technical Field The invention belongs to the technical field of biomass carbonization, and particularly relates to an airflow control method and system for biomass high-temperature carbonization. Background The conventional biomass firing of earth kilns, pit kilns and the like usually ignites biomass (such as wood, straw and rice hulls) in the kiln, and after the fire, oxygen supply is limited by covering soil, sandy soil or closing a vent and the like, so that the biomass is thermally cracked at high temperature to generate biochar and volatile gas pyrolysis gas. However, the existing modern methods are greatly improved in the traditional biomass firing process, but the problems of high equipment investment, high requirement on the process condition of adding inert gas in production and limited cracking of part of the process still exist. More importantly, neither conventional nor modern biomass char production has focused on the control of the thermal mass flow and the return combustion of the pyrolysis gases. Disclosure of Invention The invention aims to solve the technical problems and overcome the defects and shortcomings in the background art, and provides an airflow control method and an airflow control system for high-temperature carbonization of biomass, which can realize high-efficiency and stable carbonization of biomass and fully utilize pyrolysis gas. The technical scheme of the invention is that the airflow control method for high-temperature carbonization of biomass comprises the following steps: A gas flow control method for high-temperature carbonization of biomass is characterized in that the negative-pressure biomass high-temperature carbonization device comprises a kiln body, a combustion heat supply device, an induced draft fan, a thermal mass gas flow transmission pipeline and an electric control center, wherein the combustion heat supply device is communicated with the bottom of the kiln body through the thermal mass gas flow transmission pipeline, a pyrolysis gas transmission pipe is arranged at the top of the kiln body and is communicated with the top of the combustion heat supply device, a branch pipeline of the thermal mass gas flow transmission pipeline and the pyrolysis gas transmission pipe are provided with regulating valves, the induced draft fan is connected with one of the branch pipelines and is controlled to be opened and closed through the corresponding regulating valve, a plurality of temperature sensors are arranged in the kiln body, a gas flow sensor is further arranged in the thermal mass gas flow transmission pipeline, a pressure sensor is arranged in the kiln body and the combustion heat supply device, the electric control center is electrically connected with each part and is used for regulating the working states of the kiln body, the combustion heat supply device and the thermal mass gas flow transmission pipeline, The airflow control method for high-temperature carbonization of biomass comprises the following steps: Charging and sealing, namely charging biomass raw materials into a kiln body and sealing; drying, namely starting a combustion heat supply device, conveying thermal mass airflow to the kiln body, closing other regulating valves, opening regulating valves corresponding to the induced draft fan, and discharging water vapor and carbon dioxide; Carbonizing treatment, namely after controlling the negative pressure anaerobic environment in the kiln body to be-10 kPa to-1 kPa, closing a regulating valve corresponding to the heat mass gas through kiln body; and (3) utilizing the pyrolysis gas, namely opening a regulating valve of a pyrolysis gas conveying pipe after the pyrolysis gas is generated by biomass in the carbonization treatment process, and introducing the pyrolysis gas into a combustion heating device, so that the negative pressure of a combustion chamber is maintained to be lower than the air pressure in a kiln. In one embodiment, the temperature of the thermal mass airflow in the kiln body is 80-300 ℃ during the drying treatment, the airflow speed of the thermal mass airflow in the thermal mass airflow transmission pipeline is 10-20 m/s, the air pressure in the kiln body is maintained between-5 kPa and-1 kPa, and the moisture content of the biomass in the kiln body is lower than 5% during the drying treatment. In one embodiment, the temperature of the thermal mass airflow is 300-900 ℃ during the carbonization treatment, the airflow speed of the thermal mass airflow in the thermal mass airflow transmission pipeline is 20-40 m/s, and the air pressure in the kiln body is maintained between-10 kPa and-1 kPa. In one embodiment, when the temperature at the top of the kiln body is greater than 200 ℃, the temperature of the thermal mass airflow is raised to be more than 900 ℃, and the airflow speed of the thermal mass airflow in the thermal mass airflow transmission pipelin