Bamboo product processing waste biomass energy conversion system and method

Abstract

The invention discloses a bamboo product processing waste biomass energy conversion system and method, and relates to the technical field of biomass energy utilization. The system comprises a grading pretreatment unit, a carbon dioxide regulation and control double-reactor unit, a product refining unit and an energy circulation unit. According to the method, bamboo product processing waste is subjected to dehydration, graded crushing and activation through the graded pretreatment unit, bio-oil, coke and synthesis gas are generated through segmented conversion of the carbon dioxide regulation and control double-reactor unit, purification and modification are conducted through the product refining unit, and waste heat and by-products are recycled and reused through the energy circulation unit. The method solves the problems of poor product quality, high energy consumption and low utilization rate in the prior art, realizes full-component efficient conversion of the bamboo product processing waste, improves the added value of the product, is stable in operation, low in consumption and wide in adaptability, and has remarkable economic and ecological benefits.

Description

Technical Field

[0001] This invention relates to the field of biomass energy, specifically to a biomass energy conversion system and method for bamboo product processing waste. Background Technology

[0002] The bamboo product processing industry is large-scale, generating a significant amount of processing waste, including bamboo joints, bamboo strips, bamboo powder, bamboo filaments, and bamboo carving scraps. This waste accounts for over 80% of the total raw materials. Currently, the disposal methods for bamboo product processing waste are relatively limited, with some materials being incinerated or landfilled. This not only wastes biomass resources but also causes ecological problems such as air, soil, and water pollution, which does not meet the requirements of green development.

[0003] Existing biomass energy conversion technologies for bamboo product processing waste mostly rely on single pyrolysis or gasification processes, which have many technical bottlenecks. Single pyrolysis processes produce bio-oil with high water content and low calorific value, and the coke has insufficient porosity, making it difficult to meet the product quality requirements of practical applications. Gasification processes have poor operational stability, easily generate a large amount of tar, and tar removal is difficult and costly. At the same time, acidic gases can easily corrode equipment, increasing maintenance costs.

[0004] Furthermore, existing technologies lack targeted graded pretreatment stages, making them unsuitable for bamboo product processing waste of varying particle sizes and compositions. This results in low cellulose conversion rates and insufficient waste utilization. Simultaneously, the independent nature of each process step, coupled with the absence of energy recycling design, leads to high energy consumption, hindering the large-scale application of the technology. In conclusion, there is an urgent need for a highly efficient, stable, and low-consumption biomass energy conversion system and method for bamboo product processing waste to address the shortcomings of existing technologies. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the above-mentioned technology and provide a biomass energy conversion system and method for bamboo product processing waste.

[0006] To address the aforementioned technical problems, the present invention provides a biomass energy conversion system and method for bamboo product processing waste: A biomass energy conversion system for bamboo product processing waste includes a graded pretreatment unit, a carbon dioxide-controlled dual-reactor unit, a product refining unit, and an energy recycling unit, with each unit working in synergy to form a closed-loop operating system. The graded pretreatment unit consists of a screw extruder dewatering machine, a graded pulverizer, and an alkali-salt pretreatment tank, used for dewatering, grading, pulverizing, and activating the bamboo product processing waste. The carbon dioxide-controlled dual-reactor unit comprises a pyrolysis reactor and a gasification reactor connected in series, with a corrosion-resistant lining design, used to achieve segmented conversion reactions of the bamboo product processing waste. The product refining unit includes a tar catalytic cracking module, a syngas purification module, and a coke modification module, used for purifying and modifying the conversion products. The energy recycling unit is used to recover waste heat and by-products generated during system operation, reused in various units of the system to reduce energy consumption.

[0007] As an improvement, the grading pulverizer is used to separate bamboo product processing waste after dehydration by the screw extrusion dewatering machine into fine and coarse materials according to particle size. The fine and coarse materials are respectively adapted to the reaction paths of the pyrolysis reactor and the gasification reactor. The alkali salt pretreatment tank is filled with alkaline pretreatment liquid to break down the lignin-carbohydrate complex in the bamboo product processing waste.

[0008] As an improvement, the pyrolysis reactor is used to introduce a mixed atmosphere of carbon dioxide and nitrogen, and a catalyst is added to control the reaction process. The gasification reactor adopts a dual-flow bed structure and uses air and steam as gasifying agents to carry out a deep gasification reaction on the pyrolysis residue.

[0009] As an improvement, the tar catalytic cracking module uses activated carbon as a catalyst to remove tar, the syngas purification module enriches carbon monoxide and hydrogen in the syngas through membrane separation technology, and the coke modification module uses pyrolysis byproducts to activate the coke produced by pyrolysis.

[0010] As an improvement, the energy recycling unit can recover the waste heat generated by the gasification reactor to heat the staged pretreatment unit, while purifying the carbon dioxide in the exhaust gas from bio-oil combustion and recycling it to the pyrolysis reactor. Furthermore, the catalyst can be recovered and recycled through water leaching.

[0011] A method for biomass energy conversion of bamboo product processing waste includes the following steps: First, the bamboo product processing waste is pre-treated by grading. After dehydration by a screw extruder, it is separated into fine and coarse materials by a grading crusher. The fine and coarse materials are then fed into an alkaline salt pretreatment tank, where an alkaline pretreatment solution is added and reacted. After filtration and drying, activated bamboo material is obtained. Subsequently, a two-stage conversion reaction is carried out. The activated fine material is fed into a pyrolysis reactor, where bio-oil and coke are generated under a mixed atmosphere and catalyst. The activated coarse material and pyrolysis residue are fed into a gasification reactor to generate syngas. The products are then refined. Finally, the waste heat and by-products are recovered and reused through an energy recycling unit, thus completing the biomass energy conversion of bamboo product processing waste.

[0012] As an improvement, during the graded pretreatment process, the degree of dehydration of the bamboo product processing waste needs to be controlled to ensure that the moisture content of the dehydrated bamboo product processing waste meets the requirements of subsequent crushing and activation treatment. The alkaline pretreatment liquid is mixed with the bamboo product processing waste at a specific solid-liquid ratio and reacted under optimized conditions to improve the cellulose conversion rate.

[0013] As an improvement, in the two-stage conversion process, the pyrolysis reactor generates high-aromatic bio-oil and porous coke in a directional manner by controlling the reaction temperature and residence time, and the gasification reactor achieves deep conversion of pyrolysis residue through oxidation-reduction reaction, and the dual-fluid bed structure can reduce tar yield.

[0014] As an improvement, in the product refining process, the syngas can be directly used for power generation or synthetic fuel after purification, the bio-oil can be dehydrated and deacidified to increase its calorific value, and the coke can be activated and modified to be used as an adsorbent or energy carrier.

[0015] As an improvement, the recovered waste heat from gasification during the energy cycle process can meet most of the energy consumption requirements of the staged pretreatment unit, and the carbon dioxide recovery rate and catalyst recycling rate are both at a high level, achieving a significant improvement in the system's energy self-sufficiency rate.

[0016] The advantages of this invention compared to existing technologies are as follows: First, it achieves efficient utilization of all components of bamboo product processing waste. A graded pretreatment unit processes various types of bamboo product processing waste in stages, while an alkali-salt pretreatment tank enhances the convertibility of cellulose. The pyrolysis reactor and gasification reactor in a carbon dioxide-controlled dual-reactor unit operate in series, leaving no waste residue and completely solving the problems of low utilization and incomplete treatment in existing technologies. Second, it improves product quality and added value. The pyrolysis reactor generates high-value bio-oil, the gasification reactor, combined with a product refining unit, purifies syngas, and the coke, after activation by a coke modification module, can be used as an adsorbent, realizing the conversion of a single waste material into multiple high-value products. Third, it constructs a closed-loop recycling system. The energy recycling unit recovers waste heat for use in the graded pretreatment unit, purified carbon dioxide is reused in the pyrolysis reactor, and the catalyst is recovered and recycled, significantly reducing energy consumption and operating costs, and adapting to the needs of bamboo product processing plants of different sizes. Fourth, it is stable and environmentally friendly. The corrosion-resistant design of the carbon dioxide-controlled dual reactor unit extends the equipment's lifespan, is compatible with various types of waste, and can replace traditional incineration and landfill methods, reducing pollution and greenhouse gas emissions. It helps the bamboo industry form a circular economy model, is easy to promote, and has broad industrialization prospects. Attached Figure Description

[0017] Figure 1 This is a system architecture diagram of a biomass energy conversion system and method for bamboo product processing waste according to the present invention.

[0018] Figure 2 This is a diagram of a graded pretreatment unit for a biomass energy conversion system and method for bamboo product processing waste according to the present invention.

[0019] Figure 3 This is a schematic diagram of a carbon dioxide-controlled dual-reactor unit of a biomass energy conversion system and method for bamboo product processing waste according to the present invention.

[0020] Figure 4 This is a product refining unit diagram of a biomass energy conversion system and method for bamboo product processing waste according to the present invention.

[0021] Figure 5 This is a flowchart illustrating the core process of a biomass energy conversion system and method for bamboo product processing waste according to the present invention. Detailed Implementation

[0022] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0023] Referring to the accompanying drawings, a biomass energy conversion system and method for bamboo product processing waste is disclosed. The system includes a graded pretreatment unit, a carbon dioxide-controlled dual-reactor unit, a product refining unit, and an energy recycling unit. These units work in synergy to form a closed-loop operating system. The graded pretreatment unit consists of a screw extruder dewatering machine, a graded pulverizer, and an alkali-salt pretreatment tank, used for dewatering, grading, pulverizing, and activating the bamboo product processing waste. The carbon dioxide-controlled dual-reactor unit comprises a pyrolysis reactor and a gasification reactor connected in series, featuring a corrosion-resistant lining design, used to achieve segmented conversion reactions of the bamboo product processing waste. The product refining unit includes a tar catalytic cracking module, a syngas purification module, and a coke modification module, used for purifying and modifying the conversion products. The energy recycling unit recovers waste heat and byproducts generated during system operation, reusing them in various units of the system to reduce energy consumption.

[0024] The grading pulverizer is used to separate bamboo product processing waste into fine and coarse materials according to particle size after dehydration by the screw extrusion dewatering machine. The fine and coarse materials are respectively adapted to the reaction paths of the pyrolysis reactor and the gasification reactor. The alkali salt pretreatment tank is filled with alkaline pretreatment liquid, which is used to destroy the lignin-carbohydrate complex in the bamboo product processing waste.

[0025] The pyrolysis reactor is used to introduce a mixed atmosphere of carbon dioxide and nitrogen, and a catalyst is added to control the reaction process. The gasification reactor adopts a dual-flow bed structure and uses air and steam as gasifying agents to carry out a deep gasification reaction on the pyrolysis residue.

[0026] The tar catalytic cracking module uses activated carbon as a catalyst to remove tar, the syngas purification module enriches carbon monoxide and hydrogen in the syngas through membrane separation technology, and the coke modification module uses pyrolysis byproducts to activate the coke produced by pyrolysis.

[0027] The energy recycling unit can recover the waste heat generated by the gasification reactor to heat the staged pretreatment unit, while purifying the carbon dioxide in the exhaust gas from the bio-oil combustion and recycling it to the pyrolysis reactor. Furthermore, the catalyst can be recovered and recycled through water leaching.

[0028] A method for biomass energy conversion of bamboo product processing waste includes the following steps: First, the bamboo product processing waste is pre-treated by grading. After dehydration by a screw extruder, it is separated into fine and coarse materials by a grading crusher. The fine and coarse materials are then fed into an alkaline salt pretreatment tank, where an alkaline pretreatment solution is added and reacted. After filtration and drying, activated bamboo material is obtained. Subsequently, a two-stage conversion reaction is carried out. The activated fine material is fed into a pyrolysis reactor, where bio-oil and coke are generated under a mixed atmosphere and catalyst. The activated coarse material and pyrolysis residue are fed into a gasification reactor to generate syngas. The products are then refined. Finally, the waste heat and by-products are recovered and reused through an energy recycling unit, thus completing the biomass energy conversion of bamboo product processing waste.

[0029] During the graded pretreatment process, the degree of dehydration of bamboo product processing waste needs to be controlled to ensure that the moisture content of the dehydrated bamboo product processing waste meets the requirements of subsequent crushing and activation treatment. The alkaline pretreatment liquid is mixed with bamboo product processing waste at a specific solid-liquid ratio and reacted under optimized conditions to improve the cellulose conversion rate.

[0030] In the dual-stage conversion process, the pyrolysis reactor generates high-aromatic bio-oil and porous coke by controlling the reaction temperature and residence time, while the gasification reactor achieves deep conversion of the pyrolysis residue through oxidation-reduction reaction, and the dual-fluid bed structure can reduce tar yield.

[0031] During the product refining process, the syngas is purified and can be directly used for power generation or synthetic fuel, the bio-oil is dehydrated and deacidified to increase its calorific value, and the coke is activated and modified to be used as an adsorbent or energy carrier.

[0032] During the energy cycle, the recovered waste heat from gasification can meet most of the energy consumption requirements of the staged pretreatment unit. The carbon dioxide recovery rate and catalyst recycling rate are both at a high level, achieving a significant improvement in the system's energy self-sufficiency rate.

[0033] Example 1: Waste Conversion Example from Small and Medium-Sized Bamboo Product Processing Plants

[0034] Raw material pretreatment:

[0035] This embodiment uses mixed waste materials of bamboo joints, bamboo chips, and bamboo powder generated by small and medium-sized bamboo product processing plants, which are first processed through the graded pretreatment unit described in claim 1. First, the mixed waste material is fed into a screw extruder for dewatering. After dewatering, the moisture content of the waste material is controlled. The moisture content is calculated according to the material balance formula: .in, The moisture content of the waste. This refers to the total mass of waste material before dehydration. This represents the total mass of the waste material after dehydration. This formula is used to precisely control the degree of dehydration and ensure the moisture content of the waste material after dehydration. The moisture content should be ≤15% to avoid excessive moisture affecting subsequent crushing and activation, while also preventing excessively low moisture content from increasing the brittleness of the waste and raising crushing energy consumption.

[0036] The dehydrated waste material is fed into a classifying pulverizer, where it is separated into fine (1-3 mm) and coarse (3-10 mm) particles. The fine and coarse particles are then separately fed into an alkaline-salt pretreatment tank. The pretreatment tank contains an alkaline pretreatment solution. During the pretreatment process, the solid-liquid ratio must be controlled. The formula for calculating the solid-liquid ratio is: .in, The solid-liquid ratio, To determine the dry basis weight of the bamboo product processing waste in the pretreatment tank, This refers to the volume of the alkaline pretreatment solution. In this embodiment, it is set... (Unit: kg / L) This parameter is determined by calculation using a formula. It ensures that the alkaline pretreatment solution fully wets the waste, breaking down the lignin-carbohydrate complexes, while avoiding reagent waste and increased load on subsequent treatments due to excessive pretreatment solution. After pretreatment, the material is filtered and dried to obtain activated bamboo. The cellulose conversion rate of the activated bamboo can be evaluated using a formula: .in, For cellulose conversion rate, The mass of cellulose in the waste before pretreatment. To determine the quality of convertible cellulose in the pretreated activated bamboo material, in this embodiment... It can reach over 85%.

[0037] Two-stage transformation reaction:

[0038] The activated fine material is fed into the pyrolysis reactor in the carbon dioxide-controlled dual-reactor unit as described in claim 1. The pyrolysis reactor is purged with a mixed atmosphere of carbon dioxide and nitrogen, and the volume ratio of the mixed atmosphere is calculated using a formula: .in, This represents the volume fraction of carbon dioxide in the mixed atmosphere. Let be the volume of carbon dioxide. This refers to the volume of nitrogen gas. This embodiment sets... This ratio can be precisely controlled via a formula, which can both utilize carbon dioxide to participate in the pyrolysis reaction to optimize product distribution and use nitrogen dilution to reduce reaction intensity and improve the stability of the pyrolysis process. Simultaneously, a catalyst is added to the pyrolysis reactor; the catalyst addition amount is calculated using the following formula: .in, This represents the mass fraction of the catalyst. For catalyst quality, In this embodiment, the mass of the fine material in the pyrolysis reactor is considered. By controlling the amount of catalyst using this formula, the pyrolysis reaction can be precisely controlled, resulting in the directional generation of high-aromatic hydrocarbon bio-oil and porous coke.

[0039] The activated crude material and the pyrolysis residue from the pyrolysis reactor are fed together into a series of gasification reactors. The gasification reactors employ a dual-flow bed structure, using air and steam as gasifying agents. The syngas yield is calculated using the following formula: .in, For syngas yield, To generate the standard volume of syngas, This refers to the total mass (dry basis) of the feedstock and pyrolysis residue fed into the gasification reactor. This formula is used to evaluate the gasification reaction efficiency; in this embodiment... Up to 2.8m 3 / kg, the dual-flow bed structure design reduces tar yield by more than 40%, effectively solving the problem of excessive tar content in existing technologies.

[0040] Product Refining and Energy Cycle:

[0041] The products from pyrolysis and gasification are sent to the product refining unit. The tar catalytic cracking module uses activated carbon as a catalyst to remove tar. The formula for calculating the tar removal rate is: .in, Tar removal rate, To ensure the quality of tar in the pre-refining products, To ensure the quality of the tar in the refined product, in this embodiment... ≥95%. The syngas purification module enriches carbon monoxide and hydrogen in the syngas using membrane separation technology, significantly increasing the calorific value of the purified syngas. The coke modification module utilizes pyrolysis byproducts to activate the coke produced by pyrolysis, increasing the specific surface area of ​​the activated coke to 300 m². 2 Amounts above / g can be used as adsorbent materials.

[0042] The energy recycling unit recovers the waste heat generated by the gasification reactor to supply heat to the staged pretreatment unit. The formula for calculating the waste heat utilization rate is as follows: .in, To improve waste heat utilization rate, To recover and reuse waste heat, In this embodiment, the total waste heat generated by the gasification reactor is... With a recovery rate of ≥80%, it can meet 80% of the energy consumption requirements of the staged pretreatment unit. At the same time, the carbon dioxide in the purified bio-oil combustion exhaust gas is recycled to the pyrolysis reactor, with a carbon dioxide recovery rate of ≥70%. The catalyst is recovered and recycled through water leaching, with a recycling rate of ≥90%, realizing closed-loop operation of the system and significantly reducing energy consumption and operating costs.

[0043] Example 2: Waste Conversion Example from Large Bamboo Board Processing Plant

[0044] Raw material pretreatment:

[0045] This embodiment uses a large quantity of bamboo scraps and bamboo fiber waste generated by a large bamboo board processing plant, with a total raw material volume of 500 kg / batch. It also employs a graded pretreatment unit, followed by dewatering using a screw extrusion dewatering machine, and then determines the moisture content using a formula... Controlling moisture content Compared to Example 1, the lower moisture content is suitable for the continuous operation of large-scale production lines, reducing fluctuations in subsequent processes. The classifying pulverizer separates the dewatered waste into fine materials (particle size 1-2mm) and coarse materials (particle size 4-10mm), with fine materials accounting for 60% and coarse materials accounting for 40%, making it suitable for the processing capacity of large-scale pyrolysis and gasification reactors.

[0046] The solid-liquid ratio of the alkaline pretreatment solution in the alkaline pretreatment tank is determined by the formula... Set as (Unit: kg / L) A higher liquid-to-solid ratio can improve the uniformity of activation in large-scale batch processing, ensuring sufficient breakdown of the lignin-carbohydrate complex. After pretreatment, the cellulose conversion rate is calculated using the formula... Evaluate, It can reach 90%, providing high-quality activated bamboo material for subsequent two-stage conversion reactions.

[0047] Two-stage transformation reaction:

[0048] The volume fraction of carbon dioxide in the mixed atmosphere of the pyrolysis reactor is determined by the formula... Set as A higher carbon dioxide content can further optimize the quality of bio-oil and increase the content of aromatic hydrocarbons. The catalyst addition amount is determined by the formula... Set as It is adapted to the reaction scale of large reactors, ensuring full contact between the catalyst and fine materials, and improving pyrolysis efficiency. After the pyrolysis reaction is completed, the generated bio-oil and coke are separated by a separation device, and the coke is temporarily stored for subsequent gasification and modification treatment.

[0049] In the gasification reactor, the syngas yield is determined by the formula... Evaluation, in this embodiment 3 Compared to Example 1, the syngas yield is further improved due to the improved compatibility of raw materials and optimized parameters. During the gasification process, the ratio of air to steam is controlled to ensure that the oxidation-reduction reaction proceeds fully, and the conversion rate of pyrolysis residue is ≥98%, thus achieving full utilization of waste materials.

[0050] Product Refining and Energy Cycle:

[0051] In the product refining unit, the tar removal rate is determined by the formula... Controlled After membrane separation and purification, the syngas contains carbon monoxide and hydrogen with a purity of ≥90%, and can be directly used for power generation in the factory's self-contained power plant or for the synthesis of liquid fuels. The activated coke has a specific surface area of ​​≥320 m². 2 In addition to being used as an adsorbent, / g can also be partially returned to the gasification reactor as auxiliary fuel, thereby improving energy utilization.

[0052] The waste heat utilization rate of the energy cycle unit is expressed by the formula Calculation reachable It fully meets the heating needs of the graded pretreatment unit and some workshops; the carbon dioxide recovery rate is ≥75%, the catalyst recycling rate is ≥92%, and the system energy self-sufficiency rate is increased to 68%, significantly reducing the external energy dependence of large factories.

[0053] Example 3: Example of converting mixed waste from a bamboo craft processing plant:

[0054] Raw material pretreatment:

[0055] This embodiment uses mixed waste materials generated by a bamboo craft processing plant, including bamboo fibers, bamboo powder, and bamboo carving scraps. The raw materials have complex compositions and significant particle size variations, with a batch processing capacity of 100 kg. In the grading pretreatment unit, a screw extruder dewaters the material using a moisture content formula... Controlling the moisture content after dehydration It is suitable for processing small batches of multi-component raw materials and avoids clumping of fine materials due to excessive moisture content.

[0056] The grading crusher separates waste materials into fine (1-3mm particle size) and coarse (3-8mm particle size) materials, with fine materials accounting for 70% and coarse materials accounting for 30%. It is suitable for raw materials with a high proportion of fine particles, such as bamboo fibers and bamboo powder. The solid-liquid ratio in the alkali-salt pretreatment tank is determined using the formula... Set as (Unit: kg / L) A lower liquid-to-solid ratio is suitable for small-batch processing, reducing reagent consumption. The cellulose conversion rate after pretreatment is obtained through the formula. As assessed This can both meet the needs of subsequent reactions and control processing costs.

[0057] Two-stage transformation reaction:

[0058] In a pyrolysis reactor, the volume fraction of carbon dioxide in the mixed atmosphere is determined by the formula... Set as A lower carbon dioxide content reduces the difficulty of gas conditioning for small-batch production while ensuring product quality. The catalyst addition amount is determined by the formula... Set as It is suitable for raw materials with a high proportion of fine particles, avoiding increased costs due to excessive catalyst.

[0059] In the gasification reactor, the syngas yield is determined by the formula... Calculated as 3 For raw materials with complex compositions, the dual-fluid bed structure effectively inhibits tar formation, reducing tar yield by 42%, and solving the problem of excessive tar content during the gasification of fine materials such as bamboo fibers and bamboo powder.

[0060] Product Refining and Energy Cycle:

[0061] In the product refining unit, the tar removal rate is determined by the formula... Controlled After purification, the syngas can be used to power small generator sets, meeting part of the electricity needs of handicraft processing plants; the activated coke has a specific surface area ≥290m². 2 / g can be used as an adsorbent for small-scale wastewater treatment, realizing the high-value utilization of the product.

[0062] The waste heat utilization rate of the energy cycle unit is expressed by the formula Calculated as It can meet the energy consumption requirements of the staged pretreatment unit; the carbon dioxide recovery rate is ≥68%, the catalyst recycling rate is ≥89%, and the system operating cost is reduced by 40% compared with the traditional process, making it suitable for the cost budget of small and medium-sized handicraft processing plants.

[0063] Summary of Implementation Examples:

[0064] The three embodiments described above are adapted to bamboo product processing plants of different sizes and with different raw material characteristics, and are all based on the biomass energy conversion system and method for bamboo product processing waste described in the claims of this invention. By adjusting pretreatment parameters and two-stage conversion reaction conditions, and by precisely controlling key indicators using various formulas, the efficient conversion of all components of bamboo product processing waste is achieved. The products include high-quality bio-oil, syngas, and modified coke. Simultaneously, closed-loop operation is achieved through an energy recycling unit, reducing energy consumption and costs. Compared with existing technologies, this invention has significant practicality and advancement. In each embodiment, the waste utilization rate reaches 100%, the system energy self-sufficiency rate is ≥65%, and the added value of the products is significantly improved. It can be widely applied to the resource utilization of waste from various bamboo product processing enterprises.

[0065] Beneficial effects:

[0066] This invention discloses a biomass energy conversion system and method for bamboo product processing waste. Compared with existing technologies for treating bamboo product processing waste and converting it into biomass energy, it possesses significant technical advantages, economic value, and ecological benefits. Each beneficial effect is achieved through the coordinated design of the overall system structure and method steps, as detailed below:

[0067] This invention achieves efficient resource utilization of all components of bamboo product processing waste, completely solving the problems of low utilization rate and incomplete treatment of bamboo product processing waste in existing technologies. The invention utilizes a graded pretreatment unit to specifically treat various types of bamboo product processing waste, such as bamboo joints, bamboo chips, bamboo powder, and bamboo filaments. The waste is graded into fine and coarse materials according to particle size and adapted to different conversion pathways. Combined with the destructive effect of the alkaline pretreatment liquid in the alkali-salt pretreatment tank on the lignin-carbohydrate complex, the convertibility of cellulose in the bamboo product processing waste is significantly improved. Then, through the series operation of the pyrolysis reactor and gasification reactor in the carbon dioxide-controlled dual-reactor unit, the fine materials are directionally converted into bio-oil and coke, while the coarse materials and pyrolysis residue are deeply gasified into syngas, leaving no waste residue. This achieves 100% conversion of all components of bamboo product processing waste, avoiding the shortcomings of traditional single-process technologies that can only treat specific types of waste and easily generate secondary waste, truly maximizing waste resource utilization.

[0068] This significantly improves the quality and added value of biomass conversion products, enhancing their market competitiveness. In the carbon dioxide-controlled dual-reactor unit, the pyrolysis reactor is circulated with a mixed atmosphere of carbon dioxide and nitrogen. Combined with the catalytic effect, it can directionally generate bio-oil with high aromatic hydrocarbon content. Compared with bio-oil produced by existing pyrolysis technologies, it has a higher calorific value and lower impurity content, and can be used for power generation or synthetic liquid fuels without complex post-processing. The gasification reactor adopts a dual-fluid bed structure, effectively reducing tar yield. Combined with the tar catalytic cracking module and syngas purification module in the product refining unit, the purity of carbon monoxide and hydrogen in the syngas is greatly improved, directly adapting to the needs of the plant's self-contained power plant or fuel synthesis. At the same time, the coke modification module activates the coke produced by pyrolysis through pyrolysis byproducts, increasing the specific surface area and adsorption performance of the coke. This allows the coke to be used not only as an energy carrier but also as a high-value-added adsorbent material, realizing the conversion of a single waste into multiple high-value products. Compared with the existing technology that can only produce a single energy product, this significantly improves the overall conversion benefit.

[0069] By constructing a closed-loop energy cycle system, this invention significantly reduces system energy consumption and operating costs, demonstrating outstanding economic practicality. The energy cycle unit in this invention enables the recycling of energy and materials within the system. Waste heat generated by the gasification reactor is recovered to heat the dehydration and activation processes in the staged pretreatment unit, significantly reducing the dependence on external energy sources for the pretreatment process, with a waste heat utilization rate exceeding 80%. Simultaneously, carbon dioxide from bio-oil combustion exhaust gas is purified and reused in the pyrolysis reactor as a reaction medium, reducing greenhouse gas emissions and the consumption of external gaseous raw materials. The catalyst is recovered and recycled through water leaching, achieving a recycling rate exceeding 90%, avoiding resource waste and increased costs associated with single-use catalysts. Compared to existing technologies with high energy consumption and large reagent and catalyst consumption, this system achieves an energy self-sufficiency rate of over 65%, reduces overall operating costs by 40%, and is suitable for the production needs of bamboo product processing plants of different sizes, particularly for low-cost transformation of small and medium-sized enterprises and large-scale application by large enterprises.

[0070] The system boasts strong operational stability, wide adaptability, and excellent ecological and environmental benefits. The carbon dioxide-controlled dual-reactor unit employs a corrosion-resistant lining design, effectively resisting corrosion from acidic gases during the gasification reaction, extending equipment lifespan, reducing maintenance costs, and solving the problems of easy corrosion and poor operational stability in existing gasification equipment. The grading and pulverizing unit's grading pretreatment unit can flexibly adapt to bamboo product processing waste of different particle sizes and compositions. Whether it's mixed waste from small and medium-sized bamboo product processing plants, bamboo scraps and bamboo fiber waste from large bamboo board processing plants, or complex waste such as bamboo shreds and bamboo carving scraps from bamboo handicraft processing plants, efficient conversion can be achieved by adjusting pretreatment parameters, demonstrating adaptability far exceeding that of existing single-process equipment. Meanwhile, this invention replaces traditional waste incineration and landfill methods by transforming bamboo product processing waste into resources, completely eliminating the emission of harmful gases from incineration and the soil and water pollution caused by landfill. The energy cycle and material reuse design reduces fossil energy consumption and greenhouse gas emissions, achieving coordinated development of environmental protection and energy production. It helps the bamboo product processing industry form a circular economy model of "raw materials-processing-waste-energy", which has both ecological value and industrial upgrading significance.

[0071] This invention boasts outstanding technological innovation, representing a significant advancement over existing technologies. It is easily applicable and has broad industrialization prospects. The invention pioneers a dual-reactor coupling process combining staged pretreatment and carbon dioxide regulation, overcoming the technical bottlenecks of existing single pyrolysis and gasification processes. Through the synergistic interaction of each unit, it achieves multiple optimizations in conversion efficiency, product quality, and energy consumption control. The technical solution requires no complex equipment modifications and can be upgraded and adapted to existing waste treatment facilities in bamboo product processing plants, keeping investment costs under control. Furthermore, the entire conversion process is simple to operate and parameters are easily adjustable. Precise control of key indicators such as moisture content, solid-liquid ratio, and catalyst dosage through various formulas ensures stable system operation. This makes it easy for companies with varying technical levels to master and apply, enabling rapid promotion within the bamboo product processing industry and driving the green and resource-based upgrading of the entire industry, demonstrating significant social benefits and industrial value.

[0072] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A biomass energy conversion system for bamboo product processing waste, characterized in that: The system comprises a staged pretreatment unit, a carbon dioxide-controlled dual-reactor unit, a product refining unit, and an energy recycling unit, all operating in a closed-loop system. The staged pretreatment unit consists of a screw extruder, a staged pulverizer, and an alkali-salt pretreatment tank, used for dehydrating, grading, pulverizing, and activating bamboo product processing waste. The carbon dioxide-controlled dual-reactor unit consists of a pyrolysis reactor and a gasification reactor connected in series, featuring a corrosion-resistant lining design, used to achieve staged conversion reactions of bamboo product processing waste. The product refining unit includes a tar catalytic cracking module, a syngas purification module, and a coke modification module, used for purifying and modifying the conversion products. The energy recycling unit recovers waste heat and byproducts generated during system operation, reusing them in other units to reduce energy consumption.

2. The bamboo product processing waste biomass energy conversion system according to claim 1, characterized in that: The grading pulverizer is used to separate bamboo product processing waste into fine and coarse materials according to particle size after dehydration by the screw extrusion dewatering machine. The fine and coarse materials are respectively adapted to the reaction paths of the pyrolysis reactor and the gasification reactor. The alkali salt pretreatment tank is filled with alkaline pretreatment liquid, which is used to destroy the lignin-carbohydrate complex in the bamboo product processing waste.

3. The bamboo product processing waste biomass energy conversion system according to claim 1, characterized in that: The pyrolysis reactor is used to introduce a mixed atmosphere of carbon dioxide and nitrogen, and a catalyst is added to control the reaction process. The gasification reactor adopts a dual-flow bed structure and uses air and steam as gasifying agents to carry out a deep gasification reaction on the pyrolysis residue.

4. The bamboo product processing waste biomass energy conversion system according to claim 1, characterized in that: The tar catalytic cracking module uses activated carbon as a catalyst to remove tar, the syngas purification module enriches carbon monoxide and hydrogen in the syngas through membrane separation technology, and the coke modification module uses pyrolysis byproducts to activate the coke produced by pyrolysis.

5. The bamboo product processing waste biomass energy conversion system according to claim 1, characterized in that: The energy recycling unit can recover the waste heat generated by the gasification reactor to heat the staged pretreatment unit, while purifying the carbon dioxide in the exhaust gas from the bio-oil combustion and recycling it to the pyrolysis reactor. Furthermore, the catalyst can be recovered and recycled through water leaching.

6. A method for converting bamboo product processing waste into biomass energy, characterized in that: The biomass energy conversion system based on any one of claims 1 to 5 for bamboo product processing waste includes the following steps: First, the bamboo product processing waste is pre-treated by grading. After dehydration by a screw extruder, it is separated into fine and coarse materials by a grading pulverizer. The fine and coarse materials are then fed into an alkaline salt pretreatment tank, where an alkaline pretreatment solution is added and reacted. After filtration and drying, activated bamboo material is obtained. Subsequently, a two-stage conversion reaction is carried out. The activated fine material is fed into a pyrolysis reactor, where bio-oil and coke are generated under a mixed atmosphere and catalyst. The activated coarse material and pyrolysis residue are fed into a gasification reactor to generate syngas. The products are then refined. Finally, the waste heat and by-products are recovered and reused through an energy recycling unit, thus completing the biomass energy conversion of bamboo product processing waste.

7. The method for converting bamboo product processing waste into biomass energy according to claim 6, characterized in that: During the graded pretreatment process, the degree of dehydration of bamboo product processing waste needs to be controlled to ensure that the moisture content of the dehydrated bamboo product processing waste meets the requirements of subsequent crushing and activation treatment. The alkaline pretreatment liquid is mixed with bamboo product processing waste at a specific solid-liquid ratio and reacted under optimized conditions to improve the cellulose conversion rate.

8. The method for converting bamboo product processing waste into biomass energy according to claim 6, characterized in that: In the dual-stage conversion process, the pyrolysis reactor generates high-aromatic bio-oil and porous coke by controlling the reaction temperature and residence time, while the gasification reactor achieves deep conversion of the pyrolysis residue through oxidation-reduction reaction, and the dual-fluid bed structure can reduce tar yield.

9. The method for converting bamboo product processing waste into biomass energy according to claim 6, characterized in that: During the product refining process, the syngas is purified and can be directly used for power generation or synthetic fuel, the bio-oil is dehydrated and deacidified to increase its calorific value, and the coke is activated and modified to be used as an adsorbent or energy carrier.

10. The method for converting bamboo product processing waste into biomass energy according to claim 6, characterized in that: During the energy cycle, the recovered waste heat from gasification can meet most of the energy consumption requirements of the staged pretreatment unit. The carbon dioxide recovery rate and catalyst recycling rate are both at a high level, achieving a significant improvement in the system's energy self-sufficiency rate.

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