CN116948705A

CN116948705A - Biomass fluidized bed high-temperature gasification and biomass activated carbon co-production device and system method

Info

Publication number: CN116948705A
Application number: CN202311012803.4A
Authority: CN
Inventors: 董惠文; 董春波
Original assignee: Jiangsu Wotu Agricultural Development Co ltd
Current assignee: Jiangsu Wotu Agricultural Development Co ltd
Priority date: 2023-08-12
Filing date: 2023-08-12
Publication date: 2023-10-27

Abstract

In order to solve the technical problems in the existing biomass combustion technology, the invention provides a biomass fluidized bed high-temperature gasification and biomass activated carbon co-production device and a system method, which solve the problem of high-moisture material combustion, can enable the utilization rate of the whole biomass to reach more than 96%, basically has no residue emission in the whole process, does not stop working all the year round, can reach the ultra-low emission standard without other environmental protection facilities, and mainly can co-produce high-quality biomass activated carbon while producing high-temperature fuel gas.

Description

Biomass fluidized bed high-temperature gasification and biomass activated carbon co-production device and system method

Technical Field

The invention belongs to the field of new biomass energy, and relates to a device and a system method for high-temperature gasification of a biomass fluidized bed and co-production of biomass activated carbon, which relate to the preparation of combustible gas and biomass activated carbon by biomass. Generating high-temperature combustible gas flow through a biomass fluidized bed gasifier and a precipitation layer at the lower part of the cyclone separator, and conveying the gas flow to a gas boiler or kiln of the next working section for combustion under the action of weak positive pressure; in the process, semicoke is piled up at the bottom of the cyclone separator, and combustible gas is generated at the same time to upwards flow along with the gas, and is directly discharged at the bottommost part of the separator through the closed air cooling conveyor, so that high-quality biomass activated carbon is generated.

Background

The biomass fuel is a renewable resource, and responds to the global 'double carbon' policy, and the invention uses the fluidized bed technology, so that high-quality biomass activated carbon is generated while high-temperature fuel gas is generated, the biomass fuel is completely consumed, no waste residue is discharged basically, and the utilization rate of the whole biomass reaches over 96 percent.

At present, pruning matters and crop straws of forestry and fruit trees are main stream raw materials for biomass energy, the natural moisture of the pruning matters and crop straws is about 40% and 30%, the combustion efficiency of a common chain grate furnace can only reach 75%, and a circulating fluidized bed boiler can reach 83% -85%, because high moisture and residues can take away certain energy, the gasification agents with the height of Wen Shuiqi and the like are effectively utilized to promote biomass to generate hot gas, and semicoke and coke formed at high temperature (700-800 ℃) in a fluidized bed gasification furnace are washed at high temperature, and the process is an activation process, so that biomass carbon generated under the device of the invention has the specific surface area and the inner surface area washed by high-temperature steam, and is actually biomass activated carbon.

Along with the implementation of the national ultra-low emission environment-friendly policy, jiangsu province further requires that direct combustion of biomass needs to use a formed fuel, otherwise, a gasification technology is used, the invention generates high-temperature hot gas, the hot gas is directly combusted and supplied to a boiler or a kiln of the next section, the used fluidizer is hot air flow heated by waste heat of equipment, the hot gas is formed by combustion of a fluidized bed gasifier, and the secondary high-temperature low-nitrogen combustion of the next section effectively reduces nitrogen oxides and sulfides, and can reach the ultra-low emission standard even if the desulfurization and denitrification technology is not used any more.

All biomass direct-fired boilers face an insurmountable problem of pollution of the boiler overheat surfaces and the flues, so that the overheat efficiency is low, the flues are blocked, the boiler is shut down and cleaned in 180 days in an ideal state, and the boiler is shut down and cleaned seriously every week. The cleaning work is difficult and the equipment is injured. The equipment of the invention is high-temperature gas combustion, and can work without stopping the machine all the year round.

Disclosure of Invention

In order to achieve the technical effects, the invention adopts the following technical scheme:

the invention aims to provide a biomass fluidized bed high-temperature gasification and biomass activated carbon co-production device, which comprises a fluidized bed gasification furnace device, a strong wind feeding component, a cyclone separator component (the components comprise a cyclone gas-solid separation component, a high-temperature combustible gas positive pressure conveying component, a semicoke/coke discharging component, a stacking and anoxic secondary carbonization component, a generated activated carbon closed wind cooling conveying component), a main fan, a waste heat preheating air component and an intelligent control component.

The device of the invention is divided into a small movable device and a large fixed device, the device with 600 ten thousand cards as the boundary of heat energy output and devices below 600 ten thousand cards adopts the scheme of figure 1, and the device above 600 ten thousand cards adopts the scheme of figure 2. The main difference is the different preheating modes of the fluidizer.

The feeding assembly comprises a feeding bin, the feeding bin is quantitatively closed and fed to the feeder, and the feeding high-pressure fan blows the material of the feeder to the middle of the fluidized bed gasification furnace in real time and in an oriented manner.

The fluidized bed gasification furnace device has small bottom, large middle and small top, hot gasifying agent blows from bottom to top, and the working temperature in the furnace is limited to 650-1000 ℃. The gasification furnace has small lower space and ensures large lower wind power. The raw materials are added into the middle part of the gasification furnace through a feeder and mixed with semicoke fluidized at high temperature, and newly-entered materials with larger water content sink to the bottom of a hearth and are combusted and gasified with the gasifying agent; semi-coke particles with extremely low moisture rise to the upper part of the hearth, absorb heat from the bottom and carry out gasification reaction with carbon dioxide, steam and the like to generate hot fuel gas; the mixture of the hot fuel gas and the semicoke is normally boiled, fluidized, burned and gasified in the gasifier, when the self-temperature of the semicoke reaches about 700 ℃, the moisture is completely evaporated, and the semicoke is naturally blown to the cyclone separator from the smooth top under the action of wind power. Heavy impurities such as stones and iron fall on the lower part of the fluidized bed gasification furnace and are discharged through a wind-blocking slag discharging system. All components of the fluidized bed gasifier body are made of wear-resistant and high-temperature-resistant (1100℃) materials, for example, equipment below 600 kilocalories adopts 310S-06Cr25Ni20 stainless steel, and the movable device is a movable device; the equipment above 600 ten thousand cards adopts refractory heat-resistant material to integrally cast, and is a fixed and immovable device.

The automatic control system of the fluidized bed gasifier device is a part of an ARM core control system, an I/O station consists of a plurality of temperature, pressure, flow, gas analyzers and valve type execution mechanisms with RS-485 output, and the temperature in the gasifier is ensured to be uniformly maintained at a specified temperature according to different materials by uniformly arranging fluidizing gas, so that the coupling balance point is ensured to be reached in ash melting point, carbonization and gasification, and nitrogen in the air is ensured not to be oxidized; the temperature in the gasification furnace is in semiautomatic linkage with the feeding system, and the system reminds a boiler worker whether to increase or decrease feeding according to the temperature in the gasification furnace and other relevant indexes. The air inlet and the intensity of the fluidizing agent are controlled by an ARM core control system to control the main fan frequency converter, and manual or automatic modes can be adopted for fine control.

The cyclone separator assembly comprises a high-temperature combustible gas positive pressure conveying assembly, a blanking, stock and anoxic secondary carbonization assembly and a generated active carbon closed air conveying assembly. The mixture of hot fuel gas and semicoke which is conveyed to the cyclone separator by positive pressure of the fluidized bed gasifier is subjected to gas-solid separation under the action of the cyclone separator, and then high-temperature combustible gas is conveyed to a downstream section combustion boiler by the top of the separator by positive pressure. Under the action of the cyclone separator, biomass semi-coke and coke sink to the bottom of the separator to form a certain stacking layer, under the state, the biomass semi-coke and coke are further carbonized, and associated combustible gas is upwards and enters a downstream section combustion boiler along with high-temperature combustible gas. The shorter the cyclone hot gas outlet duct, the better, the maximum length supporting 120 meters.

The lower part of the cyclone separator component is a stacking layer, limit control is arranged, the upper warning line is reached, and the ARM core control system automatically informs the wind-closing conveying device through the I/O station to convey the activated carbon outwards; when reaching the lower warning line, the ARM core control system I/O station automatically stops working the wind-blocking conveying device.

The main fan and the waste heat preheating air component can adopt the scheme of figure 1 according to the device below 600 kilowatt-hour cards, the fluidized bed gasification furnace and the cyclone separator are both made of 310S materials, and the main fan distributes air at multiple points according to the air flow principle, so that heat recovery is realized, gasifying agent is successfully preheated, the closed waste heat preheating shell adopts 304+ heat-resistant cotton, and the integration and portability of equipment are ensured. The device above 600 ten thousand cards adopts the scheme of fig. 2, the preheating component can adopt the mode of fig. 2, a special air preheater is used, a corresponding fluidized bed gasifier and a cyclone separator adopt refractory heat-resistant material for integrated pouring, and a fixed device is installed on site.

The ignition is carried out for the first time or after stopping, a proper amount of dried wood chips (moisture is lower than 13%) with oil of the same specification are added through a seeding machine, after the limit is reached, an electric heating ignition system is started manually, after open fire exists, a proper amount of air intake of a main fan is started, and after the fire is big, the operation is carried out according to a normal fluidization flow.

The control system adopts an ARM core control system and a remote I/O station for control, and comprises the following functions: the system has the functions of operation process data acquisition and processing, process control detection, total loop control, picture appearance, detail display, alarm group display, motor operation state monitoring, yield analysis system, anti-drowsiness system, process operation trend record, shift report, daily report, accident recall and the like. In order to realize multi-level management, the system has a local/remote/two-place operation mode and a remote scattered alarm and audit monitoring function.

The device below 600 ten thousand big cards adopts the scheme of figure 1, and the device above 600 ten thousand big cards adopts the scheme of figure 2. The main difference is the different preheating modes of the fluidizer.

Drawings

Fig. 1 is a schematic diagram of a biomass fluidized bed high-temperature gasification and biomass activated carbon co-production device according to an embodiment of the invention. Fig. 1 is a small mobile device, mainly supporting a device with a thermal energy output below 600 kilo-kilo cards.

Fig. 2 is a high-temperature gasification and biomass activated carbon co-production device of a biomass fluidized bed provided by the specific embodiment of the invention. Fig. 2 is a small mobile device, mainly supporting a device with a thermal energy output of 600 ten thousand cards or more.

In the figure: 1-a fluidized bed gasifier; a 2-cyclone separator; 3-a pipeline for the high-temperature combustible gas to enter a combustion boiler of a downstream working section; 4-an active carbon wind-closing cooling conveyor; 5-a storage bin; 6-a feeder; 7, a seeding fan; 8-a fluidizer inlet; 9-closing an air cooling slag extractor; 10-a preheating system or a traditional air preheater; 11-a main fan; 12-a wind distributor; A. b, C, D, E, F, G and the like are multipoint air distribution pipelines; 13-uniform air distribution plates; 14-a feed belt; 15-an activated carbon stacking layer; 16-an air preheater; 17-a main fan; 18-to the boiler combustion.

The summary of the invention does not represent or limit the scope of the claims, which are entitled to protection.

Description of the embodiments

For a better illustration of the present invention, and to facilitate an understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

raw materials: after the pine is processed by a chipper, the length of the wood chip is 15-35 mm, the thickness is 2-3mm, and the water content is about 35-45%. After iron removal, impurity removal and screening, pure wood chips are formed. The material is conveyed to a feed bin through a feeding belt, the feed bin quantitatively closes the wind and discharges the material to a feeder, a material sowing high-pressure fan blows the material of the feeder to the middle part of a fluidized bed gasification furnace in real time and in a directional manner, the material is mixed with semicoke wood chips fluidized at high temperature, the newly-entered material with high water content sinks towards the bottom of a hearth, and the material is combusted and gasified with a gasifying agent; the semicoke chips with extremely low moisture rise to the upper part of the hearth, absorb heat from the bottom and carry out gasification reaction with carbon dioxide, steam and the like to generate hot fuel gas; the mixture of the hot fuel gas and the semicoke chips is normally boiled, fluidized, burned and gasified in the gasifier, when the self-temperature of the semicoke reaches about 700 ℃, the moisture is completely evaporated, and the semicoke is naturally blown to the cyclone separator from the smooth top under the action of wind power. Heavy impurities such as stones and iron fall on the lower part of the fluidized bed gasification furnace and are discharged through a wind-blocking slag discharging system. After gas-solid separation of the mixture of hot fuel gas and semicoke under the action of the cyclone separator, the high-temperature combustible gas is conveyed into a downstream section combustion boiler from the top of the separator under positive pressure. Under the action of the cyclone separator, the biomass semi-coke is sunk to the bottom of the separator to form a certain stacking layer, under the state, the biomass carbon is further carbonized, and the associated combustible gas is upwards and enters a downstream section combustion boiler along with the high-temperature combustible gas. The stacking layer is provided with limit control, reaches an upper warning line, and the ARM core control system automatically informs the wind-blocking conveying device through the I/O station to convey the activated carbon outwards; when reaching the lower warning line, the ARM core control system I/O station automatically stops working the wind-blocking conveying device. The main fan and the waste heat preheating air component adopt the mode of fig. 1, and the main fan distributes air according to the air flow principle by sealing the fluidized bed gasification furnace and the cyclone separator shell, thereby realizing heat recovery and successfully preheating gasifying agent. Aiming at fresh wood chips as raw materials, the invention has the following technical indexes in the working process: the operating temperature of the gasifier is 800 ℃; the time from the entry of the wood chips into the gasifier to the formation of semicoke is about 1-3 minutes, at which time the semicoke or coke temperature is about 700 ℃; after entering the separator, the temperature of the stacking layer is about 600-800 ℃; the calorific value of the hot gas is 1200Kcal/Nm3; the hot gas outbound pressure is about 5kPaG; the hot gas outbound temperature is 750 ℃; no tar is separated out in the whole process; most of the activated carbon just discharged from the furnace is small in blocks and particles, the water content is about 1.6%, the ash content is 0.8%, the average carbon content is about 90%, and the calorific value is 8000 kcal.

The invention is not limited to the particular embodiments disclosed, as long as it does not depart from the spirit of the invention, as the shape of the various devices, other applications of the non-body portion, etc., may vary depending upon the actual circumstances.

Claims

1. The utility model provides a living beings fluidized bed high temperature gasification and living beings active carbon coproduction device which characterized in that, the system device includes fluidized bed gasifier, strong wind feed subassembly, cyclone subassembly, main fan and waste heat preheating air subassembly, intelligent control subassembly. The device of the invention is divided into a small movable device and a large fixed device, the device with 600 ten thousand cards as the boundary of heat energy output and devices below 600 ten thousand cards adopts the scheme of figure 1, and the device above 600 ten thousand cards adopts the scheme of figure 2.

2. The fluidized bed gasification furnace apparatus according to claim 1, wherein the fluidized bed gasification furnace is characterized in that the hot gasifying agent is blown from bottom to top, uniformly distributed, the working temperature in the furnace is limited to 650-1000 ℃, and the optimal temperature is uniformly controlled to 800 ℃. The gasification furnace has small lower space and ensures strong lower wind power. The raw materials are added into the middle part of the gasification furnace through a feeder and mixed with semicoke fluidized at high temperature, and newly-entered materials with larger water content sink to the bottom of a hearth and are combusted and gasified with the gasifying agent; semi-coke particles with extremely low moisture rise to the upper part of the hearth, absorb heat from the bottom and carry out gasification reaction with carbon dioxide, steam and the like to generate hot fuel gas; the mixture of the hot fuel gas and the semicoke is boiled, fluidized, burned and gasified in the gasifier, when the temperature in the gasifier reaches 800 ℃, the self-temperature of the semicoke reaches about 700 ℃, the moisture is basically evaporated, and under the action of bottom wind power and sowing air inlet, the semicoke and the coke meeting the conditions are naturally blown to the cyclone separator from the smooth top of the gasifier. Heavy impurities such as stones and iron fall on the lower part of the fluidized bed gasification furnace and are discharged through a closed air cooling slag discharging system.

3. The fluidized bed gasification furnace according to claim 2 has a smooth structure at the upper part, a small structure at the lower part, a medium structure at the middle part, and the like, which can achieve the best effects of fluidized bed boiling, gasification, carbonization and directional guiding transportation, and the claims are not limited to changing the shape, and are also considered as the disclosure of the invention as long as the concept of the invention is not violated.

4. The strong wind material sowing assembly according to claim 1, wherein the bin is quantitatively fed to the feeder, the material of the feeder is blown into the middle part of the fluidized bed gasification furnace in real time and in a directional manner by the material sowing high-pressure fan, and the material and the strong wind of the material are discharged from the top of the fluidized bed gasification furnace in a parabolic manner, and the material can be sowed into the gasification furnace and collide with the rising hot fire of semicoke, heat transfer and ignition, so that the purpose of quick semicoke is achieved. Under the combined action of the sowing wind and the gasifying agent, semicoke and coke which meet the requirements are naturally blown to the cyclone separator from the smooth top of the gasifying furnace. The air pressure of the high-pressure seeding fan is larger than the upward fluidization air pressure at the bottom, so that the strong air flow sealing effect is achieved.

5. The cyclone separator assembly according to claim 1, wherein the cyclone separator assembly comprises cyclone gas-solid separation, high temperature combustible gas positive pressure conveying pipeline, semicoke/coke blanking, stacking and anoxic secondary carbonization layer, and generated active carbon closed air cooling conveying assembly.

6. The small mobile device of claim 1, wherein the implementation is in accordance with the scheme of fig. 1. The fluidized bed gasifier and the cyclone separator are both made of 310S-06Cr25Ni20 stainless steel, a closed sealing box is made of 304 stainless steel outside the two components of the fluidized bed gasifier and the cyclone separator, a high-temperature-resistant light flame-retardant heat-insulating material is used outside the 304 box, and the outermost layer is packaged by a thin steel plate. The main fan adopts a multi-point uniform air distribution scheme according to the principle of wind, positive pressure air uniformly dissipates heat for the 310S steel body, the process is also an air preheating process, the temperature uniformity of the whole bellows is ensured, and finally the bellows is blown into the fluidized bed gasifier through the bottom of the fluidized bed gasifier. The process can automatically or manually control the temperature, pressure and the like of the gas through interaction of the I/O station and the ARM core control system.

7. The large mobile device of claim 1, wherein the implementation is in accordance with the scheme of fig. 2. The fluidized bed gasifier and the cyclone separator are integrally cast by adopting refractory heat-resistant materials, and are large fixed and immovable devices. The main fan is conveyed to the preheater in a positive pressure mode, and after the temperature and the wind pressure reach the standards (according to different materials and different indexes), the air is blown into the fluidized bed gasification furnace through the bottom of the fluidized bed gasification furnace. The process can automatically or manually control the temperature, pressure and the like of the gas through interaction of the I/O station and the ARM core control system.

8. The lower stack of claim 5 wherein the cyclone separator assembly has a lower stack with limit control to reach an upper guard, ARM core control system automatically informing the shut-off conveyor via I/O station to deliver activated carbon outwardly; when reaching the lower warning line, the ARM core control system I/O station automatically stops working the wind-blocking conveying device.

9. The process and product of claim 2 and claim 5, wherein the process and product are characterized by the following technical specifications: the temperature of the lower stacking layer of the separator is about 600-800 ℃; the calorific value of the output hot gas is about 1200Kcal/Nm3; the hot gas outbound pressure is about 5kPaG; the outlet temperature of the hot gas is 700-850 ℃; no tar is separated out in the whole process.

10. The intelligent control assembly of claim 1, wherein the control system employs an ARM core control system plus a remote I/O station for control, including but not limited to the following functions: the system has the functions of operation process data acquisition and processing, process control detection, total loop control, picture appearance, detail display, alarm group display, motor operation state monitoring, yield analysis system, anti-drowsiness system, process operation trend record, shift report, daily report, accident recall and the like. In order to realize multi-level management, the system has a local/remote/two-place operation mode and a remote scattered alarm and audit monitoring function.