A system for carbonizing biomass based on boiler flue gases
The boiler flue gas carbonization biomass system utilizes the heat from boiler flue gas for staged drying and carbonization of biomass raw materials, solving the problems of high energy consumption and environmental pollution associated with traditional biomass carbonization, and achieving efficient energy utilization and environmental protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NORTHEAST ELECTRIC POWER DESIGN INST CO LTD OF CHINA POWER ENG CONSULTING GRP
- Filing Date
- 2025-06-03
- Publication Date
- 2026-06-02
AI Technical Summary
Traditional biomass carbonization processes are energy-intensive, increase production costs, and cause serious environmental pollution, while also resulting in low efficiency in utilizing boiler flue gas thermal energy.
Design a biomass carbonization system based on boiler flue gas, including a carbonization furnace, a biomass dryer, and a boiler, which are connected by high-temperature and medium-temperature flue gas ducts. The system utilizes the heat from the boiler flue gas to perform staged drying and carbonization of biomass raw materials, recovers the heat from volatile matter, and combines electrostatic dust removal and desulfurization tower to purify the flue gas.
It improves energy efficiency, reduces production costs, reduces environmental pollution, and achieves efficient carbonization of biomass raw materials and gradient utilization of thermal energy. The resulting biochar can be used for agricultural soil improvement or as solid fuel.
Smart Images
Figure CN224313457U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a system for biomass carbonization using boiler flue gas, and in particular to a technology for carbonizing biomass raw materials by recovering the heat from boiler flue gas, belonging to the field of energy efficiency utilization and environmental protection technology. Background Technology
[0002] Biomass carbonization technology is the process of converting biomass raw materials into biochar through a high-temperature pyrolysis reaction. Traditional biomass carbonization processes require external heat sources (such as natural gas or electricity), resulting in high energy consumption, increased production costs, and environmental impact. Coal-fired power plants, during operation, emit large amounts of high-temperature flue gas containing abundant thermal energy, traditionally considered waste and causing environmental pollution.
[0003] Existing technologies have attempted to utilize waste heat for biomass carbonization, but due to imperfect technology, the efficiency of waste gas heat utilization is low, resulting in energy waste and pollution problems. Utility Model Content
[0004] The purpose of this invention is to provide a system for carbonizing biomass raw materials by recovering heat from boiler flue gas. This technology can effectively improve the comprehensive utilization rate of energy, reduce production costs, and reduce environmental pollution.
[0005] To achieve the above objectives, this utility model proposes a system for carbonizing biomass based on boiler flue gas, comprising a boiler, economizer, air preheater, biomass dryer, pellet collector, carbonization furnace, electrostatic precipitator, desulfurization tower, exhaust flue of the desulfurization tower, and chimney. The system is characterized in that: the carbonization furnace and the boiler are connected via a high-temperature flue at the inlet of the carbonization furnace; the biomass dryer and the carbonization furnace are integrated; a medium-temperature flue leading from the boiler connects to the biomass dryer; the lower outlet of the biomass dryer connects to the pellet collector; one outlet of the pellet collector connects to the carbonization furnace; and the other outlet is connected to the medium-temperature flue via a cold flue fan, electrostatic precipitator, induced draft fan, and induced draft fan outlet recirculation flue; the carbonization furnace is also connected to the boiler via a carbonization furnace outlet exhaust flue.
[0006] The advantages and beneficial effects of this utility model are as follows:
[0007] First, the high-temperature flue gas introduced from the boiler into the high-temperature flue gas at the inlet of the carbonization furnace provides a heat source for biomass carbonization, realizing the physical isolation between biomass ash and the boiler system, eliminating the risk of increased furnace slagging rate and poisoning of boiler SCR (selective catalytic reduction) denitrification catalyst caused by alkali metal (K / Na) enrichment.
[0008] Secondly, the integrated design of the biomass dryer and carbonization furnace, through the coordinated operation of the medium-temperature flue and the cold flue fan, enables the gradient utilization of thermal energy in biomass drying. The aim is to utilize the waste heat from the boiler flue gas in stages for pre-drying of the raw materials in the medium-temperature section (150-100℃), overcoming the problems of agglomeration and low thermal efficiency during carbonization caused by the high initial moisture content of biomass raw materials in traditional processes. This design reduces the moisture content of biomass raw materials from 40% to below 15%, meeting the moisture control requirements of the carbonization process.
[0009] Third, the exhaust gas duct of the carbonization furnace is coupled to the boiler combustion system, allowing the volatile gases produced by pyrolysis to be injected back into the boiler furnace. This secondary combustion of hydrocarbon gases compensates for system heat losses caused by the carbonization process, maintaining the stability of the flue gas temperature gradient. The volatile heat value that is not utilized in traditional carbonization processes can be recovered, thereby reducing production costs and improving the overall energy efficiency of the system.
[0010] Fourth, by utilizing flue gas to carbonize biomass, the fly ash and waste gas generated during the carbonization process are purified through the boiler's original flue gas treatment system, which effectively reduces air pollution compared to conventional biomass carbonization processes. Simultaneously, the resulting biochar can be used for agricultural soil improvement or as solid fuel, offering significant environmental benefits. Attached Figure Description
[0011] Figure 1 This is a flow chart of the boiler flue gas carbonization biomass system provided by this utility model.
[0012] Among them, 1-boiler; 2-economizer; 3-air preheater; 4-medium temperature flue; 5-induced draft fan outlet recirculation flue; 6-biomass dryer; 7-cold flue fan; 8-biomass dryer outlet; 9-particle collector; 10-dust collector front flue; 11-carbonization furnace outlet exhaust gas flue; 12-carbonization furnace inlet high temperature flue; 13-carbonization furnace; 14-electrostatic precipitator; 15-dust collector outlet flue; 16-induced draft fan; 17-induced draft fan outlet flue; 18-desulfurization tower; 19-desulfurization tower outlet flue; 20-chimney; 21-carbonization furnace outlet biomass oil pipeline; 22-carbonization furnace discharge port; 23-biomass raw material feed pipeline. Detailed Implementation
[0013] To enable those skilled in the art to better understand the technical solution of this utility model, the preferred embodiments of this utility model are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.
[0014] like Figure 1 As shown, this utility model discloses a system for carbonizing biomass based on boiler flue gas, including: a boiler 1, an economizer 2, an air preheater 3, a biomass dryer 6, a pellet collector 9, a carbonization furnace 13, an electrostatic precipitator 14, an induced draft fan 16, a desulfurization tower 18, and a chimney 20. A high-temperature flue duct 12 at the inlet of the carbonization furnace 13 is also provided between the carbonization furnace 13 and the boiler 1 to transfer heat. The biomass dryer 6 and the carbonization furnace 13 are integrated, and a medium-temperature flue duct 4 drawn from the boiler 1 is connected to the biomass dryer. The biomass dryer 6 is connected to a pellet collector 9 via its outlet 8. One outlet of the pellet collector 9 is connected to the carbonization furnace 13, and the other outlet is connected to a medium-temperature flue duct 4 via a cold flue fan 7, an electrostatic precipitator 14, an induced draft fan 16, and an induced draft fan outlet recirculation flue 5. The medium-temperature flue duct 4 and the cold flue fan 7 operate in tandem to achieve gradient thermal energy utilization during biomass drying. The cold flue fan 7 provides power to transport the low-temperature flue gas after drying the biomass through a pipeline to the flue duct 10 before the dust collector. One outlet of the carbonization furnace is connected to the boiler 1 via a carbonization furnace outlet exhaust flue 11. The volatile gases generated during the carbonization process in the carbonization furnace 13 are returned to the boiler 1 for continued combustion. The carbonization furnace 13 carbonizes the biomass raw materials at high temperatures, converting them into biochar, oil, and gas. The dust collector outlet flue duct 15 connects the electrostatic precipitator 14 and the induced draft fan 16 to discharge the purified flue gas. The outlet of the induced draft fan 16 is connected to the induced draft fan outlet flue 17. The biomass oil pipeline 21 at the outlet of the carbonization furnace sends the biomass oil produced by the carbonization furnace 13 back to the boiler 1 for combustion, and the carbonized biomass char is sent out through the carbonization furnace discharge port 22. The outlet flue of the electrostatic precipitator is connected to the chimney 20 via the induced draft fan, one path passing through the desulfurization tower 18 and the desulfurization tower outlet flue 19, and the other path passing through the cold flue 17 at the outlet of the induced draft fan and the recirculation flue 5 at the outlet of the induced draft fan to the medium-temperature flue 4, transporting low-temperature flue gas.
[0015] During operation, biomass is fed into the biomass dryer 6 through the biomass feed pipe 23. High-temperature flue gas from the boiler 1 is guided to the biomass dryer 6 for preliminary drying through the medium-temperature flue 4. After the moisture in the biomass feedstock is evaporated, it enters the carbonization furnace 13 through the biomass dryer outlet 8. A cold flue fan 7 is connected to the pellet collector 9 via a pipe. The cold flue fan 7 extracts the low-temperature flue gas from the outlet of the biomass dryer 6 and discharges it to the flue 10 before the dust collector. The boiler 1 transfers heat to the carbonization furnace 13 through the high-temperature flue 12 at the carbonization furnace inlet, causing the biomass material to undergo a pyrolysis reaction at high temperatures, converting it into biochar, oil, and gas. The exhaust flue 11 at the carbonization furnace outlet returns the volatile gases generated during carbonization to the boiler 1 for continued combustion. Biomass oil is collected through the biomass oil pipe 21 at the carbonization furnace outlet and sent back to the boiler 1 for combustion. The carbonized biochar is sent out through the biochar conveying pipe 22 at the carbonization furnace outlet and can be further processed or sold directly.
Claims
1. A system for carbonizing biomass using boiler flue gas, comprising a boiler, economizer, air preheater, biomass dryer, pellet collector, carbonization furnace, electrostatic precipitator, desulfurization tower, exhaust flue of the desulfurization tower, and chimney, characterized in that: The carbonization furnace and the boiler are connected via a high-temperature flue at the inlet of the carbonization furnace; the biomass dryer and the carbonization furnace are integrated; a medium-temperature flue leading from the boiler is connected to the biomass dryer; the lower outlet of the biomass dryer is connected to a particle collector; one outlet of the particle collector is connected to the carbonization furnace; the other outlet is connected to the medium-temperature flue via a cold flue fan, an electrostatic precipitator, an induced draft fan, and an induced draft fan outlet recirculation flue; the carbonization furnace is also connected to the boiler via a carbonization furnace outlet exhaust flue.
2. The system for carbonizing biomass based on boiler flue gas according to claim 1, characterized in that: The biomass oil pipeline at the outlet of the carbonization furnace is connected to the boiler.
3. The system for carbonizing biomass based on boiler flue gas according to claim 1, characterized in that: The exhaust flue of the induced draft fan connects the induced draft fan and the desulfurization tower.
4. The system for carbonizing biomass based on boiler flue gas according to claim 1, characterized in that: Biomass is fed into the biomass dryer through the biomass feed pipe.