Garbage hydrogen production and carbon sequestration system comprising plasma cracking furnace

Abstract

The utility model discloses a garbage hydrogen production and carbon sequestration system comprising a plasma cracking furnace. Comprising a cracking furnace and provides high-temperature energy by using a plasma torch system so as to deeply crack the pyrolysis gas; the purification module is used for separating carbon dust and purifying hydrogen until the hydrogen is high in purity; the boiler module is used for recovering waste heat of the system; and the electrical control module is used for integral control. According to the cracking furnace, through the technical path of combining pyrolysis and plasma high-temperature cracking, waste garbage can be efficiently converted into hydrogen with the purity reaching 99.999%, meanwhile, carbon elements in raw materials are mainly captured in the form of solid carbon dust instead of generating carbon dioxide, and therefore greenhouse gas emission is remarkably reduced, the gas purification process is simplified, and the energy consumption is reduced. And the energy utilization efficiency and the resource value of wastes are improved.

Description

Technical Field

[0001] This utility model relates to the field of waste treatment and resource utilization technology, and in particular to a waste-to-hydrogen and carbon fixation system including a plasma pyrolysis furnace. Background Technology

[0002] Converting waste plastics into high-value energy products (such as hydrogen) and materials (such as carbon materials) is an important direction in chemical recycling. Among existing technologies, pyrolysis and gasification are common processing methods.

[0003] Traditional pyrolysis technology typically decomposes plastics under anaerobic or oxygen-deficient conditions, with the main products being pyrolysis oil, pyrolysis gas, and solid residue (carbon black). The pyrolysis gas contains hydrogen, methane, olefins, etc., but its composition is complex, the hydrogen content is relatively low, and the pyrolysis process may still produce some tar and pollutants.

[0004] Traditional gasification technologies typically utilize a gasifying agent (such as air, oxygen, or water vapor) to react with plastics at high temperatures (often >700°C) to produce syngas, primarily composed of hydrogen (H2) and carbon monoxide (CO). If air is used as the gasifying agent, a large amount of nitrogen is introduced into the product gas, resulting in low hydrogen concentration and difficulties in subsequent separation and purification. While using oxygen or water vapor can increase hydrogen concentration, it requires an additional oxygen or steam supply system, increasing energy consumption and cost. More importantly, regardless of the gasification method, carbon primarily exists in gaseous CO or CO2 forms. This not only increases the difficulty of hydrogen purification (such as CO conversion and CO2 removal) but also fails to prevent the final carbon dioxide emissions. Furthermore, the gasification process usually requires high reaction temperatures, placing high demands on equipment materials and energy supply.

[0005] In the field of hydrogen production from plastics, researchers have begun to explore technologies that directly decompose hydrocarbons (the main components of plastic pyrolysis products) into hydrogen and solid carbon at high temperatures in order to improve hydrogen yield and reduce carbon oxide generation. However, achieving efficient decomposition requires extremely high temperatures (typically >1000°C), and traditional heating methods (such as combustion) are not only inefficient but also introduce combustion products, generating CO2 emissions.

[0006] Therefore, existing technologies for producing hydrogen from waste plastics generally suffer from the following technical problems:

[0007] Traditional pyrolysis gasification processes convert most of the carbon into CO or CO2, increasing the burden of subsequent gas purification and leading to higher greenhouse gas emissions, making it difficult to achieve effective carbon fixation.

[0008] In addition to hydrogen, the product gas also contains various components such as CO, CO2, CH4, and N2 (if air is used), requiring a complex and costly separation and purification system to obtain high-purity hydrogen.

[0009] To reach the required reaction temperature, a large amount of fuel or energy is often required; if pure oxygen or steam is used for gasification, an oxygen or steam generation system is also required.

[0010] In conclusion, there is an urgent need to develop a new waste plastic treatment technology that can efficiently convert plastics into high-purity hydrogen, capture carbon in an environmentally friendly solid form, and reduce the system's energy consumption and complexity, in order to solve the aforementioned problems of existing technologies. Summary of the Invention

[0011] The technical problem this invention aims to solve is: addressing the existing problems in waste-to-hydrogen production technologies, such as high carbon dioxide emissions, difficulty in effectively solidifying carbon, low hydrogen content and purity in the product gas, complex and costly gas purification systems, and high energy consumption and system complexity due to reliance on combustion or external gasifying agents. This invention provides a waste-to-hydrogen and carbon fixation system including a plasma pyrolysis furnace, which aims to efficiently produce high-purity hydrogen while capturing most of the carbon in solid form, reducing carbon emissions, simplifying the purification process, and improving energy efficiency.

[0012] The technical solution adopted by this utility model to solve its technical problem is:

[0013] A waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace includes:

[0014] The pre-processing module is used to break down waste into particles of regular size;

[0015] The pyrolysis module is used to pyrolyze the particles to generate pyrolysis gas and solid slag;

[0016] The pyrolysis module includes a pyrolysis furnace and a plasma torch system. The pyrolysis furnace receives pyrolysis gas and pyrolyzes it at a high temperature of 1300°C to generate hydrogen and solid carbon dust. The plasma torch system includes a hydrogen plasma torch and an air plasma torch. The hydrogen plasma torch provides the pyrolysis temperature during system operation, while the air plasma torch is used for system startup and shutdown. Through the pyrolysis of the pyrolysis module, the carbon elements in the plastic are converted into solid carbon dust instead of gaseous CO or CO2.

[0017] The purification module is used to sequentially remove dust, wash and purify the cracked gas by pressure swing adsorption to obtain hydrogen with a purity of ≥99.999%.

[0018] Boiler module, used to recover waste heat from pyrolysis and pyrolysis modules to generate steam;

[0019] The electrical control module is used to control the coordinated operation of all modules.

[0020] Preferably, the hydrogen plasma torch and the air plasma torch are powered by the same power system.

[0021] Preferably, the design parameters of the pyrolysis furnace include:

[0022] Capacity 1000 Nm³ / h, rated operating temperature 1300℃, air volume 800 Nm³ / h, outlet dust content 300 g / Nm³, design withstand temperature 1500℃, pyrolysis gas inlet capacity 1000 Nm³ / h, design dust removal capacity 300 kg / h.

[0023] Preferably, the pyrolysis module further includes a gas cooling and scrubbing system, which includes:

[0024] Economizer, used for preliminary cooling of hydrogen cracking gas rich in carbon dust;

[0025] Bag filters are used to collect carbon dust from gases;

[0026] A scrubbing tower is used to clean and remove residual dust and cool the gas to below 70°C. The liquid in the circulation loop of the scrubbing tower is water or sodium hydroxide solution.

[0027] Preferably, the purification module includes:

[0028] A gas compression and purification device is used to compress and pretreat hydrogen.

[0029] Pressure swing adsorption (PSA) hydrogen purification system is used to purify hydrogen.

[0030] Hydrogen compression system, used to compress hydrogen gas into a high-pressure storage tank;

[0031] The gas storage system includes a temporary hydrogen-rich gas tank, a temporary exhaust gas tank, a 0.8MPa hydrogen tank, and a 45MPa hydrogen tank.

[0032] Preferably, the boiler module includes a waste heat boiler, an economizer, a water-cooled wall, a superheater, and an air preheater, and generates steam with parameters of 180°C and 0.8 MPa.

[0033] Preferably, it also includes auxiliary modules, which include a plasma torch start-up air compressor, an instrument air compressor, a nitrogen system air compressor, a nitrogen generator, a closed-loop water tank, a circulating pump, an air-water cooler, pipes, valves, and instruments.

[0034] The beneficial effects that this utility model can achieve include the following:

[0035] By using a plasma torch to provide energy for high-temperature pyrolysis, the carbon in waste is mainly converted into easily collectable solid carbon dust, rather than the large amounts of gaseous CO or CO2 produced by traditional gasification or incomplete pyrolysis. This significantly reduces greenhouse gas emissions and simplifies the carbon capture and management process.

[0036] This two-stage pyrolysis-pyrolysis process, especially the plasma pyrolysis step, directly generates gas with a high hydrogen concentration and significantly reduces the generation of impurities such as CO and CH4. During operation, the use of a hydrogen plasma torch avoids the introduction of nitrogen, making the gas composition entering the purification module relatively simple, reducing the load and complexity of subsequent purification units such as pressure swing adsorption (PSA), and enabling the economical and efficient acquisition of hydrogen with a purity of up to 99.999%.

[0037] Plasma torches can efficiently convert electrical energy into high-temperature heat energy required for pyrolysis, avoiding some energy loss and dependence on external gasifying agents (such as oxygen and steam) that are common in traditional combustion heating. At the same time, the sensible heat of pyrolysis flue gas and pyrolysis gas is recovered and utilized in multiple stages through boiler modules (including economizers, waste heat boilers, etc.) to generate steam, which improves the overall energy efficiency of the system. The modular design of each function facilitates integrated control and improves the stability and reliability of system operation. Attached Figure Description

[0038] Figure 1 This is a system schematic diagram of a waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace in Example 1. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these specific embodiments do not limit the scope of protection of the present invention in any way. Example

[0040] As shown in the figure, a waste-to-hydrogen and carbon fixation system including a plasma pyrolysis furnace is designed to convert plastic waste into high-purity hydrogen through pyrolysis and pyrolysis processes, while capturing solid carbon in the process to achieve carbon dioxide emission reduction. The system consists of eight main parts: a pretreatment module, a pyrolysis module, a pyrolysis module, a purification module, a boiler module, a water supply module, an auxiliary module, and an electrical control module. These modules are closely connected through pipelines, cables, and a control system to form a complete operational process system.

[0041] In this embodiment, the pretreatment module is a raw material crushing and conveying system. Its function is to process raw materials that are usually input in the form of 1-meter cubic packages, to decompose the packaging, and to break plastic waste of different shapes into small particles of regular size to adapt to the subsequent feeding system and help to improve the rate of pyrolysis reaction.

[0042] In this embodiment, the pyrolysis module includes a pyrolysis furnace and a combustion furnace system. Plastic particles, crushed by the pretreatment module, are fed into the pyrolysis furnace through a storage tank valve (not shown in the figure). Pyrolysis occurs inside the furnace at approximately 850°C, generating pyrolysis gas and solid slag. The slag mainly consists of fixed carbon and ash from the raw materials and accumulates in the slag furnace (bottom area of ​​the pyrolysis furnace). The pyrolysis module is connected to a discharge system, which discharges the slag into portable containers via a slag discharger, which are then transported to other storage locations.

[0043] In this embodiment, the pyrolysis module includes a pyrolysis furnace, a gas cooling and scrubbing system, and a pyrolysis feeding system (a system that introduces pyrolysis gas into the pyrolysis furnace). After entering the pyrolysis furnace, the pyrolysis gas undergoes further pyrolysis at a high temperature of approximately 1300°C, generating carbon dust and hydrogen. The key design parameters of the pyrolysis furnace are as follows: capacity 1000 Nm³ / h; rated operating values ​​1300°C, 800 Nm³ / h gas flow rate, and 300 g / Nm³ dust content at the outlet; design withstand temperature 1500°C; design pyrolysis gas inlet capacity 1000 Nm³ / h; design dust removal capacity 300 kg / h. The high temperature and energy required for pyrolysis are provided by a hydrogen plasma torch on the pyrolysis furnace. The system is equipped with two 150 kWe hydrogen plasma torches (one in use and one on standby), and two 150 kWe air plasma torches, the latter dedicated to the system startup and shutdown processes.

[0044] The carbon-dust-rich hydrogen cracking gas exiting the pyrolysis furnace is first cooled by an economizer (serving as a gas cooler in this case) to facilitate subsequent carbon dust collection. Next, the gas flows through a bag filter, where carbon dust is collected. Subsequently, the gas enters a scrubbing tower for cleaning to remove remaining dust and is cooled to below 70°C. The treated gas is then pumped by a vacuum pump into a temporary hydrogen-rich gas tank. It is worth noting that during system startup and shutdown, the gas extracted by the vacuum pump is directly connected to the flue gas treatment system. The loop liquid in the scrubbing tower can be water; if the feedstock contains polyvinyl chloride or salts, potentially resulting in hydrochloric acid in the cracked gas, a sodium hydroxide solution can be used as the scrubbing liquid to absorb the hydrochloric acid.

[0045] In this embodiment, the purification module is responsible for hydrogen purification and consists of a gas compression purification system, a hydrogen purification system, and a hydrogen compression system. Cold, clean hydrogen-rich gas stored in a temporary hydrogen-rich gas tank is introduced into the compressor. After undergoing dry cooling, dehumidification, and filtration dust removal, it enters the absorption tank according to the pressure swing adsorption (PSA) purification sequence. Through the PSA process, hydrogen with a purity of up to 99.999% is obtained and stored in a 0.8 MPa hydrogen tank. The hydrogen stored in the 0.8 MPa hydrogen tank is then compressed by the hydrogen compression system and input into a 45 MPa hydrogen tank. The exhaust gas generated during the PSA process is temporarily stored in a waste gas tank, and the exhaust gas in the waste gas tank is then sent to the gas burner for secondary combustion.

[0046] In this embodiment, the boiler module includes a waste heat boiler and an associated feedwater system for recovering system heat and generating steam. High-temperature flue gas from the pyrolysis module, along with some heat recovered by the economizer in the pyrolysis module, is used to heat and superheat water in the waste heat boiler, ultimately producing steam with a specification of 180°C and 0.8 MPa, which is supplied through a conventional heat pipe system. Deionized water from the feedwater module is pumped to the economizer (water-side preheating) and water-cooled walls in the boiler module via a main feed pump. Saturated steam separated in the steam drum is further heated to the target temperature in the superheater. Furthermore, the waste heat boiler also integrates an air preheater for heating the combustion air supplied to the gas burner in the pyrolysis module's combustion furnace.

[0047] In this embodiment, the water supply module includes a flue gas treatment system and a water treatment system. The flue gas treatment system is responsible for treating the flue gas from the waste heat boiler, removing acidic gases and dust, before discharging it through a chimney. This system includes a bag filter, an induced draft fan, a chimney, and related flue ducts and valves. The dust content of the flue gas generated by the gas burner is typically less than 50 mg / m³, and the NOx content is approximately 150-200 mg / m³. The water treatment system is responsible for producing the deionized water required by the system. It filters and deionizes tap water from the municipal water supply system to remove particles and ions from the water. The treated deionized water is stored in the main water tank of the boiler module. This tank not only supplies water to the boiler but also provides makeup water to the scrubbing tower of the pyrolysis module and replenishes the closed-loop circulating water system in the auxiliary module.

[0048] In this embodiment, the auxiliary module integrates the necessary public engineering units to support the operation of the system, including (not shown in the figure, which are conventional technical means): a plasma torch start-up air compressor system. This system is directly connected to the air inlet of the air plasma torch in the pyrolysis module through a dedicated air pipeline, a flow control valve and a safety valve. Its function is to provide sufficient compressed air that meets the pressure requirements to the air plasma torch during the start-up and shutdown phases of the pyrolysis furnace system.

[0049] The instrument air compressor produces clean, dry compressed air, which is connected to numerous pneumatic actuators, some sensors, and pneumatic components of the control system installed on all modules (including pretreatment, pyrolysis, pyrolysis, purification, boiler, feedwater, auxiliary modules themselves, and emission systems) through an instrument air pipeline network that is distributed throughout the system. It provides a stable and reliable power source or signal medium to drive valve switching, regulate valve opening, and ensure the normal operation of some instruments in the automated control system.

[0050] The nitrogen system air compressor generates compressed air, which is directly delivered to the air inlet of the nitrogen generator through pipelines, specifically providing raw material air for the nitrogen generator.

[0051] The nitrogen generator receives raw air from the air compressor of the nitrogen system, separates it into nitrogen, and then connects it to various locations within the system that require nitrogen through a nitrogen pipeline network to produce and supply high-purity nitrogen. As an inert gas, nitrogen is mainly used for: purging equipment and pipelines with nitrogen before system startup, after shutdown, or in emergencies to replace internal air or combustible gases and prevent the formation of explosive mixtures; or, in certain operating or standby states, filling equipment with nitrogen to create a protective atmosphere and prevent material oxidation or undesirable reactions.

[0052] The system also includes a closed-loop cooling water system (not shown in the diagram, a conventional technology) for equipment cooling, comprising a closed-loop water tank, a circulating pump, and an air-water cooler. All these units are connected and operated via necessary pipes, valves, and instruments. The circulating pump draws water from the closed-loop water tank and delivers it to the equipment requiring cooling via cooling water supply pipes. This equipment mainly includes: the plasma torch of the pyrolysis module, the compressor of the purification module, part of the power supply cabinet of the electrical control module, the furnace jacket or cooling elements of the pyrolysis furnace and pyrolysis furnace, and other heat-generating equipment. After absorbing heat, the cooling water returns through the cooling water return pipe, flows through the air-water cooler to dissipate the heat into the atmosphere, and the cooled water flows back to the closed-loop water tank, completing the cycle. The system also includes a water replenishment pipe (connected to the deionized water system), a drain valve, and temperature and pressure monitoring instruments.

[0053] In this embodiment, the electrical control module is equipped with all necessary electrical control devices, responsible for the power distribution, automation control, data monitoring, and communication of the entire system. This includes (not shown in the figure, but a conventional technical means) a low-voltage circuit breaker cabinet, which receives low-voltage power from the factory's main substation or dedicated transformer, and distributes the power to all equipment using standard low-voltage electricity within the system via power cables through internal circuit breakers, contactors, relays, thermal overload protection, and other components.

[0054] The plasma DC power supply cabinet receives high-voltage AC power (which may come directly from the medium-voltage power grid and be stepped down by a dedicated transformer, or stepped up from the main low-voltage system). Internally, it converts the AC power into high-energy, high-current DC power through high-power rectification, filtering, current stabilization / voltage stabilization circuits.

[0055] The PLC control cabinet houses the core programmable logic controller and its input / output modules. The PLC is connected via signal cables to field sensors and actuators distributed throughout all process modules.

[0056] The data acquisition cabinet is connected to the PLC and / or field intelligent instruments via a communication network or a direct signal line;

[0057] And fiber optic communication cabinets.

[0058] In addition, the system explicitly includes an emission system and a gas storage system. The emission system includes a slag discharge device, which is directly installed at the slag discharge port at the bottom of the pyrolysis furnace in the pyrolysis module and is responsible for handling the slag discharge;

[0059] The ash discharge device is installed at the lower ash hopper outlet of the bag filter in the gas cooling and scrubbing system of the pyrolysis module to discharge ash (including carbon dust and flue gas ash), and at the lower ash hopper outlet of the bag filter (used to treat pyrolysis combustion flue gas) in the flue gas treatment system of the feedwater module.

[0060] The wastewater discharge includes the scrubbing tower drain of the pyrolysis module, the drain of the boiler module, and the water treatment system of the auxiliary module. The gas storage system includes tanks for gas storage and buffering: a temporary hydrogen-rich gas tank, a temporary exhaust gas tank, a 0.8MPa hydrogen tank, and a 45MPa hydrogen tank.

[0061] The working principle and method of the above-mentioned waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace are as follows:

[0062] Step 1, Raw Material Receiving and Pre-processing Stage: First, the collected waste is transported to the front end of the system.

[0063] Raw materials enter the pretreatment module, where they are processed into small particles or lumps of relatively uniform size that are suitable for the feeding system through physical methods such as crushing and screening, in order to improve the efficiency and uniformity of the subsequent pyrolysis reaction.

[0064] Step 2, pyrolysis stage: The pretreated plastic granules are fed into the pyrolysis furnace through the feeding system.

[0065] Meanwhile, the combustion air is preheated by the air preheater using the waste heat of the subsequent flue gas, and then sent to the gas burner in the pyrolysis furnace. The burner provides the basic heat required for the initial and maintenance of the pyrolysis process.

[0066] Inside the pyrolysis furnace, the material is heated to approximately 850°C in an oxygen-free or oxygen-deficient environment. At this temperature, the plastic undergoes a pyrolysis reaction, breaking down its macromolecular chains and producing:

[0067] The pyrolysis gas mainly contains various hydrocarbon gases and small amounts of CO, H2, etc. This gas stream is used as the main intermediate product and is then discharged to the next stage.

[0068] Slag is a solid residue, mainly composed of fixed carbon, ash and inorganic impurities from the raw materials. The slag accumulates at the bottom of the pyrolysis furnace and is discharged periodically or continuously through the slag discharge system for subsequent treatment or disposal.

[0069] The high-temperature flue gas generated by the gas burner is extracted and sent to a waste heat boiler for energy recovery.

[0070] Step 3, High-temperature pyrolysis stage: Pyrolysis gas exported from the pyrolysis furnace enters the pyrolysis furnace.

[0071] Inside the pyrolysis furnace, a plasma torch is installed. During normal operation, a portion of the produced H2 is used as the working plasma gas; during system startup or shutdown, air may be used as the working gas. The plasma torch generates an extremely high-temperature (approximately 1300°C or higher) plasma jet, providing the necessary high-energy and high-temperature environment for the pyrolysis reaction.

[0072] Under the high temperature of plasma, hydrocarbon molecules in the pyrolysis gas undergo deep cracking (chain breaking) reactions, mainly transforming into hydrogen and carbon dust (fine solid carbon particles). The resulting gas flow is a high-temperature cracked gas rich in H2 and carrying a large amount of carbon dust.

[0073] Step four, gas cooling and primary purification stage: The high-temperature pyrolysis gas first enters the economizer. Here, part of the sensible heat of the pyrolysis gas is recovered and used to preheat the feedwater (deionized water) entering the waste heat boiler, and the temperature of the pyrolysis gas itself is initially reduced.

[0074] The cooled pyrolysis gas then passes through a bag filter, which effectively captures most of the carbon dust in the gas stream using filter bags. The captured carbon dust is periodically discharged and collected from the bottom of the filter.

[0075] The pyrolysis gas, after dust removal, enters the scrubbing tower. Inside the tower, the gas comes into full contact with sprayed deionized water (or an alkaline solution such as sodium hydroxide, depending on the raw material, to absorb any acidic gases such as HCl). This process further cools the gas to approximately 70°C and washes away residual trace dust and soluble impurities.

[0076] Step 5, Gas Transportation and Buffer Storage Stage: The clean hydrogen-rich gas, after cooling and washing, is extracted by a vacuum pump and transported to a temporary hydrogen-rich gas tank for buffer storage.

[0077] In addition, when the system starts up, stops, or operates abnormally, the gas extracted by the vacuum pump may not be qualified hydrogen-rich gas. In this case, the gas flow may be switched to the temporary exhaust gas tank or directly introduced into the flue gas treatment system to avoid contaminating the subsequent purification unit.

[0078] Step Six, Hydrogen Refining and Purification Stage:

[0079] The gas stored in the hydrogen-rich temporary gas tank is fed into a gas compression and purification system, specifically a hydrogen purification system. This system utilizes the difference in selective adsorption capacity of the adsorbent for H2 and other impurity gases (such as CO, CH4, N2, etc.) under different pressures to separate high-purity H2 (target purity 99.999%) from the mixed gas. The separated high-purity H2 is then sent to a 0.8MPa hydrogen tank for storage. Impurity gases that are not adsorbed or released during the desorption phase form waste gas / tail gas, which is collected in a temporary waste gas tank and can be used as fuel for the system's own use (such as supplemental burners) or subjected to further treatment.

[0080] Step 7, High-Pressure Hydrogen Storage Stage: As needed, some of the H2 stored in the 0.8MPa hydrogen tank can be further pressurized through a hydrogen compression system and stored in a 45MPa hydrogen tank to meet the requirements for high-pressure storage or external transportation.

[0081] Step 8, Energy Recovery and Steam Production Stage:

[0082] The high-temperature flue gas discharged from the pyrolysis furnace burner enters the waste heat boiler. After being preheated by the economizer, the deionized water enters the heat exchange tube bundle of the waste heat boiler. The flue gas flows through the waste heat boiler tube bundle, transferring its heat to the working fluid (water) inside the tubes to generate steam with the required parameters (such as 180°C, 0.8MPa). The cooled flue gas leaves the waste heat boiler and enters the flue gas treatment system.

[0083] Step Nine, Flue Gas Treatment and Emission Stage:

[0084] Flue gas from waste heat boilers, along with non-H2 gases that may originate from vacuum pumps, enter the flue gas treatment system. This system typically includes units for dust removal, desulfurization, and denitrification to ensure the removal of pollutants (dust, SOx, NOx, etc.) from the flue gas, meeting emission standards.

[0085] Step 10: The treated clean flue gas is finally discharged into the atmosphere through a chimney (not shown in the figure) via an induced draft fan (not shown in the figure).

[0086] Before entering the treatment system, some of the heat from the flue gas is used in the air preheater to preheat the combustion air entering the pyrolysis furnace burner, thus achieving further energy recovery.

[0087] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any innovative improvements or substitutions based on this utility model should fall within the scope of the claims of this utility model. Furthermore, the parameters, materials, and processes mentioned in the above embodiments are not unique. Without departing from the technical essence of this utility model, those skilled in the art can make various alternative choices, and these alternative solutions should also be considered to fall within the scope of protection of this utility model.

Claims

1. A waste-to-hydrogen and carbon sequestration system comprising a plasma pyrolysis furnace, characterized in that, include: The pre-processing module is used to break down waste into particles of regular size; The pyrolysis module is used to pyrolyze the particles to generate pyrolysis gas and solid slag; The pyrolysis module includes a pyrolysis furnace and a plasma torch system. The pyrolysis furnace receives pyrolysis gas and pyrolyzes it at a high temperature of 1300°C to generate hydrogen and solid carbon dust. The plasma torch system includes a hydrogen plasma torch and an air plasma torch. The hydrogen plasma torch provides the pyrolysis temperature during system operation, while the air plasma torch is used for system startup and shutdown. Through the pyrolysis of the pyrolysis module, the carbon elements in the plastic are converted into solid carbon dust instead of gaseous CO or CO2. The purification module is used to sequentially remove dust, wash and purify the cracked gas by pressure swing adsorption to obtain hydrogen with a purity of ≥99.999%. Boiler module, used to recover waste heat from pyrolysis and pyrolysis modules to generate steam; The electrical control module is used to control the coordinated operation of all modules.

2. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, The hydrogen plasma torch and the air plasma torch are powered by the same power system.

3. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, The design parameters of the pyrolysis furnace include: Capacity 1000 Nm³ / h, rated operating temperature 1300℃, air volume 800 Nm³ / h, outlet dust content 300 g / Nm³, design withstand temperature 1500℃, pyrolysis gas inlet capacity 1000 Nm³ / h, design dust removal capacity 300 kg / h.

4. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, The pyrolysis module further includes a gas cooling and scrubbing system, which includes: Economizer, used for preliminary cooling of hydrogen cracking gas rich in carbon dust; Bag filters are used to collect carbon dust from gases; A scrubbing tower is used to clean and remove residual dust and cool the gas to below 70°C. The liquid in the circulation loop of the scrubbing tower is water or sodium hydroxide solution.

5. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, The purification module includes: A gas compression and purification device is used to compress and pretreat hydrogen. Pressure swing adsorption (PSA) hydrogen purification system is used to purify hydrogen. Hydrogen compression system, used to compress hydrogen gas into a high-pressure storage tank; The gas storage system includes a temporary hydrogen-rich gas tank, a temporary exhaust gas tank, a 0.8MPa hydrogen tank, and a 45MPa hydrogen tank.

6. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, The boiler module includes a waste heat boiler, an economizer, a water-cooled wall, a superheater, and an air preheater, producing steam with parameters of 180℃ and 0.8MPa.

7. The waste-to-hydrogen and carbon sequestration system including a plasma pyrolysis furnace according to claim 1, characterized in that, It also includes auxiliary modules, including a plasma torch start-up air compressor, an instrument air compressor, a nitrogen system air compressor, a nitrogen generator, a closed-loop water tank, a circulating pump, an air-water cooler, pipes, valves, and instruments.

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