Process and device for deep processing of biomass and synergistic treatment of solid wastes from multiple fields

Abstract

The present invention belongs to the field of the treatment of solid waste, and relates to a process and device for the deep processing of biomass and the synergistic treatment of solid wastes from multiple fields. By means of the technical route of "recovering multiple metals by means of pre-reduction with biochar and melt separation by using green electricity coupled with biogas" and on the basis of the mechanisms of "component characteristic matching and energy structure optimization", a pyrolyzing furnace is used to pyrolyze biomass raw materials and organic solid and hazardous wastes so as to prepare biochar and fuel gases (H2 and CO), which are supplied to a primary reduction furnace as a reducing agent and a heat source, respectively; generated metallic flue gas is subjected to a flue gas treatment and enrichment to form lead-zinc dust; generated metallized materials, residual carbon and metallic solid wastes in the raw materials are charged into a secondary reduction furnace for deep reduction; high-temperature flue gas generated in the secondary reduction furnace supplies heat for primary reduction, thereby achieving flue gas recirculation and energy recovery; a high-temperature molten alloy is ultimately generated, and high-temperature molten slag is subjected to slag injection and granulation to prepare mineral wool. The process can produce high-end advanced materials such as green steel, a zinc-rich powder and mineral wool, has the technical characteristics of a large treatment capacity, a fast reduction speed, a high energy utilization rate, good adaptability to raw materials, etc., and has wide implementation and application prospects.

Description

Process and equipment for deep processing of biomass and coordinated management of solid waste in multiple fields Technical Field

[0001] The present invention belongs to the field of solid waste treatment, and relates to a process and device for deep processing of biomass and coordinated management of solid waste in multiple fields. Background Art

[0002] my country has stored rich, high-quality and huge biomass resources. According to statistics, there are more than 5 billion tons of biomass resources above the surface, including garden waste wood and crop straw, various solid and hazardous wastes from industry and cities, etc. Most of the current management methods are direct incineration, discharge or storage, which causes environmental pollution and extremely low energy utilization rate. Therefore, there is an urgent need to carry out secondary integration and full utilization of a large amount of biomass resources to improve the comprehensive utilization rate and market promotion from the energy and product dimensions.

[0003] At the same time, my country's industrial production and processing byproducts, such as low-grade tailings, metallurgical slag, construction waste, sludge, and dust, generate a massive amount of solid waste, exceeding 6 billion tons. However, the comprehensive utilization rate is less than 40%, leaving significant room for improvement. Annual emissions of municipal solid and hazardous waste exceed 200 million tons, with a complex composition that includes kitchen waste, hazardous medical waste, scrap metal, broken glass, and ceramic fragments. The harmless treatment and resource utilization of these industrial and municipal solid and hazardous wastes are major concerns across all industries.

[0004] At present, the disposal process for biomass materials and industrial-urban solid waste is mainly based on pyrolysis. Mature technologies include rotary hearth furnaces, rotary kilns, waste incinerators, melting furnaces and other technologies and equipment. The advantage is that the processes and equipment of each system are relatively mature, but each has its own defects, such as low energy utilization rate, poor raw material adaptability, strong dependence on energy media, high comprehensive energy consumption of each process, limited product application and market value, and pollutant (dioxin) emissions. Therefore, the market urgently needs a new process characterized by resource coupling, raw material synergy, energy complementarity and product diversity, to design new solutions for industrial and urban environmental governance and build a new situation of multi-field, cross-professional and multi-channel solid waste governance.

[0005] Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a process and device for the coordinated management of multi-field solid waste by deep processing of biomass using the technical route of "biochar pre-reduction + green electricity coupled biogas melting to recover multi-metals".

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A process for deep processing of biomass and collaborative management of solid waste in multiple fields, comprising the following steps:

[0009] Classification: Classify solid waste into metals, metal oxides, and organics;

[0010] Pyrolysis: Mix organic solid waste with biomass and pyrolyze it to generate biochar and gas;

[0011] Primary reduction: Use biomass carbon to reduce metal oxide solid waste to generate high-temperature flue gas and metallized materials;

[0012] Secondary reduction: Mixing metallic solid waste with metallized materials and then reducing them to generate high-temperature flue gas, slag and liquid metal;

[0013] Flue gas treatment: The high-temperature flue gas generated in the "primary reduction" is subjected to dust reduction and heat exchange to obtain low-temperature coal gas and lead-zinc dust.

[0014] Optionally, the low-temperature coal gas obtained after the "flue gas treatment" is used for "secondary reduction".

[0015] Optionally, the low-temperature coal gas obtained after the "flue gas treatment" is used to perform "slag conditioning" on the slag obtained after the "secondary reduction", and the slag is blown into silk and granulated to produce mineral wool, which is then solidified in conjunction with CO2.

[0016] Optionally, oxygen-rich fresh air is introduced in the "secondary reduction" step for reduction.

[0017] Optionally, the high-temperature flue gas generated in the "secondary reduction" and the fuel gas generated in the "pyrolysis" are used for reduction in the "primary reduction" without introducing other heat sources.

[0018] Optionally, waste heat can be used to generate electricity using the heat exchange in the "flue gas treatment".

[0019] Optionally, part of the gas generated in the "pyrolysis" is used for municipal reuse, and part is introduced into the "primary reduction" step.

[0020] Optionally, the "flue gas treatment" step produces low-temperature flue gas, lead-zinc dust and metallized slag, and the produced metallized slag is mixed with metal solid waste and metallized materials to participate in "secondary reduction".

[0021] Optionally, broken glass and ceramic fragments can be used as slag forming agents for "slag tempering".

[0022] Optionally, the biomass source in the "pyrolysis" step is garden waste wood and crop straw and / or industrial and urban carbon-containing solid hazardous waste, providing reducing agent biomass charcoal and fuel gas for "primary reduction" and / or "secondary reduction".

[0023] Optionally, during the "secondary reduction" process, the reduction furnace introduces oxygen-rich fresh air and low-temperature coal gas generated during the "primary reduction" process through side blowing and / or bottom blowing to form molten pool stirring, combined with green electricity heating, and utilizes residual carbon in the metallized material for reduction.

[0024] Optional products of "primary reduction" include:

[0025] Volatile metals: Contains one or more of zinc, lead, cadmium, and indium, and is discharged with high-temperature flue gas;

[0026] Metallized materials: containing one or more of iron, nickel, copper and chromium, participating in "secondary reduction" in the form of metallized slag.

[0027] Optionally, a "batch and molding" step is provided between the "classification" and the "primary reduction" to batch and mold the metal oxide solid waste and the biochar according to their ingredients.

[0028] A device for deep processing of biomass and collaborative management of solid waste in multiple fields, wherein a pyrolysis section, a primary reduction section, and a secondary reduction section are sequentially arranged along the material flow direction; the flue gas outlet of the secondary reduction is backconnected to the flue gas inlet of the primary reduction; the flue gas outlet of the primary reduction furnace is connected to a heat exchanger and a dust removal device.

[0029] Optionally, the material inlet of the primary reduction furnace is connected to a batching machine and / or a pelletizing machine.

[0030] The beneficial effects of the present invention are:

[0031] The present invention proposes a technical route of "biochar pre-reduction + green electricity coupled biogas melting and recovery of multi-metals", using the biochar and fuel gas produced by the pyrolysis of biomass raw materials as reducing agents and fuel agents, and comprehensively planning, intelligent batching, coupled reduction, flue gas circulation and energy optimization of solid waste from multiple sources, multiple fields and multiple forms, so as to achieve full-scale management and resource utilization of various types of solid waste. In terms of energy media, it gets rid of the dependence on traditional fossil fuels and proposes the ultimate energy efficiency concept of "double synergy" + "deep reduction" + "flue gas circulation", that is, "organic solid waste + biomass + high-temperature flue gas" to prepare biochar and coordinate the primary reduction of metals, and "metallized slag (carbon-containing) + metal solid waste + low-temperature coal gas" to coordinate deep reduction to obtain alloy liquid, which significantly improves the application dimension and market value of the product, improves energy utilization, reduces the overall energy consumption of the system, and reduces carbon emissions. This technology involves the coordinated management of solid waste in multiple fields such as industry, agriculture and cities, and provides important guidance and reference for the coordinated management plans and methods for the harmlessness, reduction and resource utilization of various types of waste. It is a new process, technology and method with large processing capacity, fast reduction speed, high energy utilization rate, strong raw material adaptability and full quantitative management. It also produces high-end advanced materials such as green steel, zinc-rich powder, mineral rock wool, etc., creating multi-dimensional market application scenarios and high-value products. It has technical characteristics such as large processing capacity, fast reduction speed, high energy utilization rate, strong raw material adaptability, and has broad implementation and application prospects.

[0032] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0034] Figure 1 is a process roadmap. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0037] In the description of the present invention, it should be understood that if there are terms such as "up", "down", "left", "right", "front", and "back" indicating directions or positional relationships, they are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] Please refer to Figure 1. The present invention relates to a process and device for deep processing of biomass and coordinating the management of solid waste in multiple fields, and provides the following technical solutions:

[0039] S1. Classify multi-source solid waste according to its physical and chemical properties, feed biomass and organic hazardous waste into the pyrolysis furnace, and produce biochar and fuel gas through pyrolysis;

[0040] S2. Biochar is used as a reducing agent and mixed with the metal oxide solid waste to be reduced. After forming, it is sent to the first reduction furnace for pre-reduction. The pyrolysis furnace gas and the high-temperature reducing gas of the II reduction furnace are continuously introduced to provide heat during the process. The generated flue gas containing volatile metals is captured and recycled through a heat exchanger and dust collector. The resulting lead and zinc dust can be directly sold. The generated metallized slag and low-temperature coal gas are sent to the next stage process.

[0041] S3. The pre-reduced metallized slag and metallic solid waste are fed into a secondary reduction furnace for deep reduction. During the process, "low-temperature coal gas + oxygen-rich fresh air + green electricity" are introduced to form a molten pool for stirring and sufficient reaction. The produced molten metal is supplied to the upstream steelmaking process for reuse or cast into alloy iron blocks for direct external sale. The produced high-temperature reducing gas is combined with the biomass pyrolysis gas and blown back to the primary reduction furnace for pre-reduction and drying.

[0042] S4. Part of the coal gas produced by the primary reduction furnace is blown back to the high-temperature slag treatment section at the end of the process for slag blowing, silk making, granulation and other processes, and finally forms mineral rock wool, which is solidified in conjunction with CO2.

[0043] In step S1, a "component characteristic matching and energy structure optimization" mechanism is proposed, in which biomass and carbon-containing solid hazardous waste enter the pyrolysis furnace together, the generated biomass charcoal and metal oxide solid waste enter the primary reduction furnace for pre-reduction, and the generated metallized materials and metal solid waste enter the secondary reduction furnace for deep reduction. Broken glass and ceramic fragments are then used as slag-forming agents for slag tempering at the end of the process. The biomass pyrolysis furnace process described in step S1 involves the processing of raw materials in the fields of garden waste wood and crop straw, industrial and urban carbon-containing solid hazardous waste, etc., providing reducing agent biomass charcoal and fuel gas for the subsequent two-stage reduction furnace.

[0044] The products in step S2 include: (1) volatile metals such as zinc, lead, cadmium, and indium that are captured and enriched as lead-zinc-rich dust after heat exchange and dust collection in the flue gas system; (2) metal slag containing iron, nickel, copper, chromium, etc.; (3) treated coal gas, which is used for deep reduction in the secondary reduction furnace and blown back to the slag post-processing section for spraying, silk making, and granulation to synergistically fix CO2. The heating gas for the primary reduction furnace in step S2 comes from the gas (H2, CO, CH4, etc.) of the pyrolysis furnace and the high-temperature flue gas generated by the secondary reduction furnace. The process does not require the introduction of energy media outside the system, achieving energy self-sufficiency. The batching process in step S2 can be achieved by a batching machine, and the batching equipment can be selected according to the specific process. The molding can be achieved by a pelletizing machine, or other molding equipment can be selected according to the process.

[0045] The secondary reduction furnace in step S3 is a high-temperature melting furnace, and its main function is to perform deep reduction on the metallized materials and metal solid wastes produced by the primary reduction furnace, and finally realize slag-gold separation. The secondary reduction furnace described in step S3 blows the primary reduction furnace gas + oxygen-enriched fresh air into the melting reduction furnace by side blowing, bottom blowing, etc. to form a molten pool stirring, combines with green electricity to achieve rapid heating, and then uses the residual carbon in the metallized material to complete deep reduction. The high-temperature flue gas produced by the secondary reduction furnace is connected to the biomass pyrolysis gas to form the system gas control terminal, which is used to supply the reduction and heating of the primary reduction furnace on the one hand, and on the other hand, if there is a surplus, it is supplied to the municipal unified matching application.

[0046] The high-temperature slag produced by the secondary reduction furnace in step S4 is sprayed with part of the coal gas produced by the primary reduction furnace to form silk and granulate, and finally forms mineral wool as a high-value building material for sale or reuse in the factory, which cooperates with CO2 solidification to reduce carbon emissions.

[0047] The present invention integrates the characteristics and advantages of "waste treatment with waste, clean fuel, coordinated management and high-value products". It can treat solid waste in multiple fields such as industry, agriculture, and cities. The technology and equipment are highly compatible and scalable. In terms of furnace type and process selection, it can be connected to rotary hearth furnaces, rotary kilns, smelting furnaces, vertical furnaces, etc. In terms of the synergy of raw material management, based on the physical and chemical properties of raw materials, it can treat various solid wastes such as industrial dust and slag from steel, nonferrous metals, and chemicals, urban sludge, medical hazardous waste, etc., and produce high-end advanced materials such as green steel, zinc-rich powder, and rock wool, creating multi-dimensional market application scenarios and high-value products. It has technical characteristics such as large processing capacity, fast reduction speed, high energy utilization rate, and strong raw material adaptability, and has broad implementation and application prospects.

[0048] Example

[0049] A solid waste treatment center in a certain factory area was selected as a pilot platform. A rotary hearth furnace and a small melting furnace have been built in the factory. By adding a biomass pyrolysis furnace and renovating the platform loading system, transfer system and flue gas circulation system, the implementation and verification of the patent content of this invention can be realized.

[0050] Step 1: Industrial solid waste and domestic waste within the factory are sorted. Metal-containing tailings, wet leaching residue, dust removal ash, heavy metal sludge, etc. are mixed with biochar according to their composition and sent to the primary reduction furnace - rotary hearth furnace for pre-reduction; scrap metal parts and plate and pipe cutting waste are sent to the secondary reduction furnace - melting furnace for deep reduction; waste glassware and ceramic pieces are used as auxiliary materials for reuse in the slag granulation stage;

[0051] Step 2: Select reed bamboo and plant straw around the factory as biomass raw materials and send them into the pyrolysis furnace for pyrolysis at 500℃~600℃. The generated biomass charcoal and the metal-containing solid hazardous waste to be treated are pelletized and then sent to the rotary hearth furnace for pre-reduction. The process is heated to 1250℃ by the gas generated by the pyrolysis process. The system flue gas passes through the heat exchanger and dust collector to capture and recover volatile metals such as lead, zinc, and cadmium;

[0052] Step 3: The metallized slag produced by the rotary hearth furnace is hot-charged and sent to the melting furnace for deep reduction. The melting furnace is continuously heated to 1600°C using side-blown rotary hearth furnace gas + oxygen-enriched fresh air to achieve stirring and deep reduction. The produced molten metal is reused in the upstream off-furnace refining system, and the produced high-temperature flue gas is blown back to the rotary hearth furnace system for heating and reduction;

[0053] Step 4: The high-temperature slag produced by the melting furnace flows into the sedimentation-type electric furnace, and is tempered with auxiliary materials such as glassware and ceramic pieces. After the slag discharge conditions are met, the rotary hearth furnace gas is used for injection to produce rock wool, which synergistically solidifies the CO2 in the flue gas.

[0054] Sampling and analysis of the metallized slag of the product in this implementation case showed that its total iron content was >60%, the metallization rate was >80%, and the content of impurities such as Pb, Zn, and Cd was <0.5%.

[0055] Sampling and analysis of the lead-zinc dust of the product in this implementation case showed that the zinc content was about 65%, the lead content was about 8%, and the content of impurities such as K, Na, F, and Cl was about 10%.

[0056] Sampling and analysis of the molten metal and slag in this embodiment showed that the iron content in the molten metal was approximately 92%, and the iron content in the slag was approximately 5%.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A process for deep processing of biomass and collaborative management of solid waste in multiple fields, characterized by: The following steps are involved: Classification: Classify solid waste into metals, metal oxides, and organics; Pyrolysis: Mix organic solid waste with biomass and pyrolyze it to generate biochar and gas; Primary reduction: Use biomass carbon to reduce metal oxide solid waste to generate high-temperature flue gas and metallized materials; Secondary reduction: deep reduction of metallic solid waste and metallized materials to generate high-temperature flue gas, slag and molten metal; Flue gas treatment: The high-temperature flue gas generated in the "primary reduction" is subjected to dust reduction and heat exchange to obtain low-temperature coal gas and lead-zinc dust.

2. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: The low-temperature coal gas obtained after "flue gas treatment" is used for "secondary reduction".

3. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1 or 2, characterized in that: The low-temperature coal gas obtained after "flue gas treatment" is used to "temper the slag" obtained after "secondary reduction", and the slag is blown into silk and granulated to produce mineral wool, which is solidified in conjunction with CO2.

4. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: In the "secondary reduction" step, oxygen-rich fresh air is introduced to perform deep reduction of metals.

5. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: In the "primary reduction", the high-temperature flue gas generated in the "secondary reduction" and the fuel gas generated in the "pyrolysis" are used for reduction without introducing other heat sources.

6. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: Utilize heat exchange in "flue gas treatment" to generate electricity using waste heat.

7. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: Part of the gas generated in "pyrolysis" is used for municipal reuse, and part is introduced into the "primary reduction" step.

8. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: The "flue gas treatment" step produces low-temperature flue gas, lead-zinc dust and metallized slag. The generated metallized slag is mixed with metal solid waste and metallized materials to participate in "secondary reduction".

9. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 3, characterized in that: Use broken glass and ceramic fragments as slag-forming agents for "slag conditioning".

10. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: The biomass in the "pyrolysis" step comes from garden waste wood and crop straw and / or industrial and urban carbon-containing solid hazardous waste, providing reducing agents biomass charcoal and fuel gas for "primary reduction" and / or "secondary reduction".

11. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: During the "secondary reduction" process, the reduction furnace introduces oxygen-rich fresh air and low-temperature coal gas generated during the "primary reduction" process through side blowing and / or bottom blowing to form molten pool stirring. Combined with green electricity heating, the residual carbon in the metallized material is used for reduction.

12. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: The products of "primary reduction" include: Volatile metals: Contains one or more of zinc, lead, cadmium, and indium, and is discharged with high-temperature flue gas; Metallized materials: containing one or more of iron, nickel, copper, and chromium, participating in "secondary reduction" in the form of metallized slag.

13. The process for collaboratively managing multi-field solid waste through deep processing of biomass according to claim 1, characterized in that: The "batch and molding" step is set between "classification" and "primary reduction" to batch and mold the metal oxide solid waste and biochar according to their ingredients.

14. A device for deep processing of biomass and collaborative management of solid waste in multiple fields, characterized by: The pyrolysis section, the primary reduction section, and the secondary reduction section are arranged in sequence along the material flow direction; The flue gas outlet after the secondary reduction is connected back to the flue gas inlet of the primary reduction; The flue gas outlet of the primary reduction furnace is connected to a heat exchanger and a dust removal device.

15. The device for biomass deep processing and coordinated management of multi-field solid waste according to claim 14, characterized in that: The material inlet of the primary reduction furnace is connected to a batching machine and / or a pelletizing machine.

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