CN115108546A - System and method for continuously preparing carbon material co-hydrogen from organic solid waste high polymer - Google Patents

Abstract

The invention relates to a system and method for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers. Carbon product collection unit and catalyst regeneration unit. The method includes heating and melting waste plastic into a pyrolysis device, the generated pyrolysis gas is passed into a vapor deposition device, and the residual gas after the reaction is separated and stored by hydrogen; the conveyor belt substrate is circulated in the device, and the vapor deposition reaction is carried out and then cooled, Reloading and drying of the catalyst is carried out after the carbon product recovery is carried out, and the next reaction is carried out after recycling. The invention forms a system for continuously preparing high-performance carbon materials and co-producing hydrogen from plastic waste, and partially supplies energy to the system through the combustible gas generated in the process of pyrolysis and vapor deposition, and solves the problem that the traditional pyrolysis method has low product yield and low product yield. The technical problem of high energy consumption has greatly improved the energy utilization rate.

Description

A system and method for continuous preparation of carbon materials and co-production of hydrogen from organic solid waste polymers

technical field

The invention relates to the technical field of pyrolysis, in particular to a system and method for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers.

Background technique

Plastics are considered to be one of the most refractory substances in nature. More than 60% of waste plastics in the world are disposed of by extensive incineration and landfill methods. The problems of water, air, soil pollution and land occupation cannot be ignored. How to realize the clean and high-value utilization of waste plastics has become the key to waste plastics recycling. Plastic products are rich in carbon and hydrogen. Common polyolefin and polystyrene plastics contain carbon elements as high as 80-93wt.% and hydrogen content of 8-16wt.%. Hydrocarbons generated from the cracking of waste plastics can be used as cheap carbon sources to synthesize carbon nanotubes.

In recent years, the use of small-molecule carbon-containing gases produced by pyrolysis of waste plastics at high temperatures to synthesize graphene, carbon nanotubes and other high-value carbon nanomaterials to co-produce hydrogen has gradually developed into an advanced and economical utilization technology. Graphene and carbon nanotubes have high electron mobility, low resistivity, and excellent thermal conductivity and permeability, and are used in energy storage and conversion, water splitting, nanodevices, environmental and green chemistry, catalysis, biosensors, and biotherapeutics. There are broad application prospects.

In the prior art, the preparation methods of carbon nanotubes mainly include arc discharge, laser ablation and vapor deposition. Among them, the carbon nanotubes prepared by the arc method and the laser method are of low purity, and the morphology of the raw materials is required. Higher, waste plastics are not a conventional source of carbon-containing raw materials for the preparation of carbon nanotubes by this method. However, the pyrolysis method in the traditional vapor deposition method has complicated steps, and it is difficult to continuously prepare high-performance carbon nanotubes and other carbon materials.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a system and method for continuously preparing carbon materials and co-producing hydrogen based on the defects of the prior art. The method steps are complicated and the continuous preparation is difficult, so that the high-performance carbon material can be continuously prepared online while ensuring the quality of the carbon product.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:

A system for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers is characterized in that: it comprises a melting feeding device, a pyrolysis device, a chemical vapor deposition device and a pyrolysis gas purification and utilization device which are connected in sequence, and the chemical The vapor deposition device includes a vapor deposition furnace, a conveyor belt and a carbon product cooling device, the vapor deposition furnace is provided with a conveyor belt inlet and a conveyor belt outlet, the carbon product cooling device is connected with the conveyor belt outlet, and the conveyor belt is based on stainless steel foil , which is loaded with a catalyst, the conveyor belt can enter the vapor deposition furnace and the carbon product cooling device in turn from the conveyor belt inlet and continuously drive forward, and the pyrolysis gas purification and utilization device includes a centrifuge, a compressor, a hydrogen gas A purification device and a hydrogen storage tank, the gas outlet on the vapor deposition furnace is sequentially connected to the centrifuge, the compressor, the hydrogen purification device and the hydrogen storage tank.

Further, the carbon product cooling device includes a cooling chamber, a fan and a condenser, the cooling chamber is communicated with the outlet of the conveyor belt, the cooling chamber is provided with a cooling medium inlet and a cooling medium outlet, and the cooling medium outlet is sequentially connected to the outlet. Describe the condenser, fan and cooling medium inlet.

Further, it also includes a carbon product collecting device, the carbon product collecting device is arranged downstream of the carbon product cooling device, the conveyor belt passes through the carbon product collecting device, and the carbon product collecting device can fall off and collect the carbon product on the conveyor belt .

Further, the carbon product collection device adopts an ultrasonic cleaning device.

Further, a catalyst regeneration device is arranged downstream of the carbon product collection device, and the conveyor belt passes through the catalyst regeneration device.

Further, it also includes a gas device, the gas device includes an air-fuel ratio controller, a small burner, a first vacuum pump and a second vacuum pump, and the melt feeding device includes an inner cylinder and an outer cylinder arranged outside the inner cylinder. and a screw conveying mechanism arranged inside the inner cylinder, the inner cylinder is provided with a feed port and a discharge port, the discharge port is connected with the inlet of the pyrolysis device, and the hydrogen purification device is connected in turn The first vacuum pump, the air-fuel ratio controller, the small burner and the flue gas inlet on the outer cylinder, and the second vacuum pump is connected with the air-fuel ratio controller.

A method for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers, utilizing the above-mentioned system for continuously preparing carbon materials and co-producing hydrogen, is characterized in that, comprising the following steps:

Step 1: Put the waste plastic into the melting feeding device from the feeding port for heating and melting;

Step 2: the melted material is pushed into the pyrolysis device through the screw conveying mechanism for pyrolysis reaction, the gas product generated after pyrolysis enters the vapor deposition furnace, and carbon nanotubes are formed on the conveyor belt substrate;

Step 3: After cooling the conveyor belt from the vapor deposition furnace, using ethanol as a medium, the carbon nanotubes on the conveyor belt substrate are cleaned and separated into the ethanol medium, and separated by suction filtration to collect the generated carbon nanotubes;

Step 4: replenish and dry the catalyst on the conveyor belt substrate, and then send it to the vapor deposition furnace again for reaction;

Step 5: extracting the residual gas after the reaction in the vapor deposition furnace, and purifying and separating to obtain hydrogen and other combustible gases;

Step 6: Pass the high temperature flue gas generated by the combustion of the combustible gas into the melting feeding device to provide a heat source for the melting of the waste plastic in the step 1.

Further, the melting temperature of the waste plastics in the step 1 is 150°C to 200°C, the pyrolysis reaction temperature of the pyrolysis device in the step 2 is 500°C to 800°C, and the reaction temperature in the vapor deposition furnace is 800°C. , the temperature of the high-temperature flue gas generated by the combustion of the combustible gas in the step 6 is 300°C to 400°C.

Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The system for continuously melting and feeding waste plastics and coupling pyrolysis-vapor deposition to prepare high-quality carbon nanotube fibers in the present invention can produce high-quality carbon nanotube fibers. At the same time, by-product gases including hydrogen, methane, carbon monoxide, etc. can also be generated, and the hydrogen can be separated and purified to achieve the purpose of co-production of hydrogen. 2. After the by-product gas produced by this system is separated and purified to produce hydrogen, there are still combustible gases such as methane and carbon monoxide. The system of co-producing hydrogen with materials greatly improves the energy utilization rate and achieves the purpose of energy saving and emission reduction. 3. The present invention proposes a two-stage continuous online pyrolysis-vapor deposition reactor for preparing carbon nanotube materials. The pyrolysis and vapor deposition steps are respectively placed in two-stage reaction furnaces, and carbon nanotubes are integrated in the form of a conveyor belt substrate. The process of material generation, cooling, collection and substrate reuse realizes the continuous online preparation of carbon nanomaterials, which greatly simplifies the operation steps.

Description of drawings

1 is a schematic structural diagram of a system for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers according to the present invention;

Among them: 1-screw conveying mechanism; 2-melting feeding device; 3-feeding port; 4-first vacuum pump; 5-small burner; 6-air-fuel ratio controller; 7-hydrogen storage tank; 8-hydrogen purification device; 9-compressor; 10-centrifuge; 11-gas outlet; 12-conveyor; 13-second vacuum pump; 14-catalyst regeneration device; 15-carbon product collection device; 16-fan; 17-condenser; 18 - cooling chamber; 19 - vapor deposition furnace; 20 - pyrolysis device; 21 - discharge port.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be described in further detail below with reference to the accompanying drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

Figure 1 shows a specific embodiment of a system for continuously preparing carbon materials and co-producing hydrogen from organic solid waste polymers, including:

The melting feeding device 2 is used for heating and melting waste plastics;

The pyrolysis device 20 is used for catalytic pyrolysis of the molten waste plastic, and is provided with a material inlet, a pyrolysis gas outlet and a slag discharge port. The degassing outlet is connected to a flow pipe, leading to the vicinity of the base of the conveyor belt 12 in the vapor deposition furnace 19;

The vapor deposition device includes a vapor deposition furnace 19, a conveyor belt 12 and a carbon product cooling device. The vapor deposition furnace 19 is provided with a conveyor belt inlet and a conveyor belt outlet. The carbon product cooling device is connected to the conveyor belt outlet. The conveyor belt 12 is based on stainless steel foil, on which Loaded with catalyst, the conveyor belt 12 can sequentially enter the vapor deposition furnace 19 and the carbon product cooling device from the conveyor belt inlet and continuously drive forward. For carbon nanotubes, the traveling direction of the conveyor belt 12 is opposite to the direction of the pyrolysis gas flow, so as to improve the reaction rate;

The carbon product cooling device includes a cooling chamber 18, a fan 16 and a condenser 17. The cooling chamber 18 is communicated with the outlet of the conveyor belt. The cooling chamber 18 is provided with a cooling medium inlet and a cooling medium outlet, and the cooling medium outlet is sequentially connected to the condenser 17 and the fan 16. and the cooling medium inlet, the carbon product cooling device is used for cooling the generated carbon nanotube product, using nitrogen as the cooling medium, circulating through the fan 16, and cooling the cooling medium with the condenser 17;

The pyrolysis gas purification and utilization device includes a centrifuge 10, a compressor 9, a hydrogen purification device 8 and a hydrogen storage tank 7, and the gas outlet of the vapor deposition furnace 19 is connected to the centrifuge 10, the compressor 9, the hydrogen purification device 8 and the storage tank in sequence. The hydrogen tank 7 is used for hydrogen purification and combustible gas separation for the residual gas after the vapor deposition reaction;

The gas device includes an air-fuel ratio controller 6, a small burner 8, a first vacuum pump 4 and a second vacuum pump 13, and the combustible gas (mainly methane, carbon monoxide, etc.) obtained after separation by the hydrogen purification device 8 is used as fuel, and will burn The generated high-temperature flue gas is sent to the melting feeding device 2, which is used as a heat source for the melting of waste plastics;

The carbon product collecting device 15 is arranged downstream of the carbon product cooling device, the conveyor belt 12 coming out of the carbon product cooling device passes through the carbon product collecting device 15, and the carbon product collecting device 15 can fall off and collect the carbon product deposited on the conveyor belt 12;

The catalyst regeneration device 14, the conveyor belt 12 from the carbon product collection device 15 passes through the catalyst regeneration device 14, and is used to reload and dry the catalyst on the conveyor belt 12 substrate after cleaning and stripping the carbon product.

The structure of the melting feeding device 2 includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder. , a flue gas flow channel is formed between the outer cylinder and the inner cylinder; the inner cylinder is provided with a screw conveying mechanism 1, specifically a helical auger, one end of which is driven by a motor. The melt feeding device 2 has a double-layered tube (tube)-like structure. High-temperature flue gas flows between the outer tube and the inner tube, and the material is transported in the inner tube. The waste plastic and the flue gas transfer heat indirectly through the wall of the tube.

The structure of the vapor deposition furnace 19 also includes an insulation layer and a flow pipe, which is used to directly transport the pyrolyzed gas product to the vicinity of the base of the conveyor belt 12. The insulation layer can ensure the self-maintenance of the carbon deposition reaction temperature.

The carbon product collecting device 15 is an ultrasonic cleaning device with openings at both ends. Using ethanol as a medium, the conveyed conveyor belt 12 is subjected to ultrasonic vibration cleaning to make the carbon product fall off the substrate, and then the carbon product is separated from the medium by suction filtration.

As shown in Figure 1, the hydrogen purification device 8 is provided with a gas inlet, an upper outlet for separating high-purity hydrogen, and a lower outlet for separating residual pyrolysis gas, the upper outlet is connected to the hydrogen storage tank 7, and the lower outlet passes through the air The fuel ratio controller 6 is connected to the small burner 5 . The pyrolysis gas inlet of the hydrogen purification device 8 is connected to the gas outlet 11 of the vapor deposition furnace 19 , and the connecting pipeline is connected with a centrifuge 10 and a compressor 9 in sequence. The hydrogen purification device 8 is provided with three outlets, upper, middle and lower, and the uppermost outlet is the separated high-purity hydrogen outlet, which is connected to the hydrogen storage tank 7; the middle and lower outlets are used to discharge residual pyrolysis gas to the air-fuel ratio controller 6, And the exhaust pipeline is provided with a first vacuum pump 4, a compressor 9 and the first vacuum pump 4 to ensure the effect of hydrogen separation and purification.

The two inlets of the air-fuel ratio controller 6 are respectively connected to the residual gas outlet of the hydrogen purification device and the air, and the combustible gas and air are respectively passed into the air-fuel ratio controller 6 through the first vacuum pump 4 and the second vacuum pump 13, and the air-fuel ratio controller 6 It is connected in series with the small burner 5 to control the ratio of air and combustible gas.

The catalyst in the vapor deposition furnace 19 is preferably a powder catalyst, which is prepared by mixing inexpensive transition metal salts with an alcohol solution, drying, and annealing at high temperature in an air atmosphere. Inexpensive transition metals include but are not limited to one or more of iron, cobalt, and nickel; the annealing temperature ranges from 800°C to 850°C.

Preferably, a thermal insulation layer is provided outside the melt feeding device 2 , the vapor deposition furnace 19 and the catalyst regeneration device 14 .

The method for continuously preparing carbon material for co-production of hydrogen using the organic solid waste polymer of this embodiment includes the following steps:

Step 1: The waste plastic raw material is put into the melting and feeding device 2 from the feeding port 3 for heating and melting. The heat source required by the melting and feeding device 2 is indirectly generated by the high-temperature flue gas generated by the combustion of methane, carbon monoxide and other gases in the small burner 5. The heat transfer method is provided, and the melting temperature of waste plastics is 150℃～200℃;

Step 2: The melted material is pushed into the pyrolysis device 20 by the screw conveying mechanism 1 for pyrolysis reaction. This step does not require a catalyst, and the required heat source is provided in the form of electric heating, and the pyrolysis temperature is 500°C to 800°C; The gas product generated after the solution is passed into the vapor deposition furnace 19 for reaction near the base of the conveyor belt 12 through the circulation pipe, and the reaction temperature is 800 ° C. Since the deposition reaction of carbon nanotubes is an exothermic reaction, and the outside of the vapor deposition furnace 19 is provided with Insulation layer, so this step does not require a heat source, and the temperature can be self-maintained; the catalyst is pre-loaded on the surface of the base of the conveyor belt 12, and the solid product generated after the reaction accounts for about 40% wt of the input material, and the amount of hydrogen in the residual non-condensable gas is The ratio is about 70%;

Step 3: The reacted conveyor belt 12 immediately enters the carbon product cooling device for cooling, and is cooled by air cooling, the cooling medium is nitrogen, and the cooling medium is indirectly cooled by means of an external condenser 17, and the temperature of the cooled carbon product is 50- 100° C.; the generated carbon nanotubes are transported to the carbon product collection device 15 for collection and utilization, and the carbon product collection device 15 utilizes ultrasonic vibration to separate and collect the carbon products from the base of the conveyor belt 12;

Step 4: The conveyor belt 12 after vibrating and cleaning enters the catalyst regeneration device 14 to reload the catalyst, and then enters the vapor deposition furnace 19 to react again after drying;

Step 5: The residual gas in the vapor deposition furnace 19 enters the hydrogen purification device 8 after passing through the centrifuge 10 and the compressor 9 to separate high-purity hydrogen and stores it in the hydrogen storage tank 7;

Step 6: The combustible gas (mainly including methane and carbon monoxide) in the remaining gas is adjusted by the air-fuel ratio controller 6 and then enters the small burner 5 for combustion, and the discharged high-temperature flue gas is passed from the flue gas inlet to the melting inlet. The space between the inner cylinder and the outer cylinder of the feeding device 2 is used as a heat source for heating and melting, and the temperature of the high-temperature flue gas is 300°C to 400°C.

The above embodiment builds a spiral melting continuous feeding, a continuous preparation process of pyrolysis and vapor deposition coupling method, adopts high temperature flue gas to melt waste plastics, and a system for preparing carbon nanotubes in stages by pyrolysis and vapor deposition reaction, so as to continuously and efficiently prepare carbon nanotubes. Nanotubes can realize high-value recycling of waste plastics.

The above-mentioned specific embodiments are only to illustrate the technical concept and structural features of the present invention, and the purpose is to enable relevant persons who are familiar with the technology to implement them accordingly, but the above content does not limit the scope of protection of the present invention, and any Any equivalent changes or modifications substantially made shall fall within the protection scope of the present invention.

Claims (8)

1. A system for continuously preparing carbon material hydrogen-coproduced by organic solid waste high polymer is characterized in that: including consecutive melting feed arrangement (2), pyrolysis device (20), chemical vapor deposition device and pyrolysis gas purification utilization device, chemical vapor deposition device includes vapour deposition stove (19), conveyer belt (12) and carbon product cooling device, be provided with conveyer belt entry and conveyer belt export on vapour deposition stove (19), carbon product cooling device with conveyer belt exit linkage, conveyer belt (12) use the stainless steel foil as the base, and it has the catalyst to load on it, conveyer belt (12) can be followed the conveyer belt entry enters into in proper order vapour deposition stove (19) and carbon product cooling device and continuous forward drive, pyrolysis gas purification utilization device includes centrifuge (10), compressor (9), hydrogen purification device (8) and hydrogen storage tank (7), the gas outlet on vapour deposition stove (19) connects gradually centrifuge (10), A compressor (9), a hydrogen purification device (8) and a hydrogen storage tank (7).

2. The system for continuously preparing carbon material co-produced hydrogen from organic solid waste high polymer as claimed in claim 1, wherein: carbon product cooling device includes cooling chamber (18), fan (16) and condenser (17), cooling chamber (18) with conveyer belt export intercommunication is provided with coolant entry and coolant export on cooling chamber (18), the coolant export connects gradually condenser (17), fan (16) and coolant entry.

3. The system for continuously preparing carbon material co-produced hydrogen from organic solid waste high polymer as claimed in claim 1, wherein: the carbon product cooling device is characterized by further comprising a carbon product collecting device (15), wherein the carbon product collecting device (15) is arranged at the downstream of the carbon product cooling device, the conveying belt (12) penetrates through the carbon product collecting device (15), and the carbon product collecting device (15) can fall off and collect carbon products on the conveying belt (12).

4. The system for continuously preparing carbon material co-produced hydrogen from organic solid waste high polymer as claimed in claim 3, wherein: the carbon product collecting device (15) adopts an ultrasonic cleaning device.

5. The system for continuously preparing carbon material co-produced hydrogen from organic solid waste high polymer as claimed in claim 3, wherein: a catalyst regeneration device (14) is arranged downstream of the carbon product collection device (15), and the conveyor belt (12) passes through the catalyst regeneration device (14).

6. The system for continuously preparing carbon material co-produced hydrogen from organic solid waste high polymer as claimed in claim 5, wherein: still include gas combustion apparatus, gas combustion apparatus includes air-fuel ratio controller (6), small-size combustor (5), first vacuum pump (4) and second vacuum pump (13), melting feed arrangement (2) are in including inner tube, setting the outside urceolus of inner tube is in with the setting the inside screw conveyor (1) of inner tube, be provided with feed inlet (3) and discharge gate (21) on the inner tube, discharge gate (21) with the access connection of pyrolysis device (20), hydrogen purification device (8) connect gradually the flue gas entry on first vacuum pump (4), air-fuel ratio controller (6), small-size combustor (5) and the urceolus, second vacuum pump (13) are connected with air-fuel ratio controller (6).

7. The method for continuously preparing carbon material co-produced hydrogen by using organic solid waste high polymer, which utilizes the system for continuously preparing carbon material co-produced hydrogen in claim 6, is characterized by comprising the following steps:

step 1: waste plastics are put into a melting and feeding device (2) from a feeding hole (3) to be heated and melted;

step 2: the melted materials are pushed by a screw conveying mechanism (1) to enter a pyrolysis device (20) for pyrolysis reaction, gas products generated after pyrolysis enter a vapor deposition furnace (19), and carbon nano tubes are generated on a base of a conveying belt (12);

and step 3: cooling a conveyor belt (12) coming out of a vapor deposition furnace (19), cleaning and separating the carbon nanotubes on the substrate of the conveyor belt (12) into an ethanol medium by taking ethanol as the medium, and collecting the generated carbon nanotubes after suction filtration and separation;

and 4, step 4: replenishing and drying the catalyst on the substrate of the conveyor belt (12), and then feeding the catalyst into the vapor deposition furnace (19) again for reaction;

and 5: extracting residual gas after reaction in the vapor deposition furnace (19), and purifying and separating to obtain hydrogen and other combustible gases;

step 6: and (3) introducing high-temperature flue gas generated by combustion of the combustible gas into a melting and feeding device (2) to provide a heat source for melting the waste plastics in the step (1).

8. The method for continuously preparing carbon material co-production hydrogen from organic solid waste high polymer as claimed in claim 7, wherein: the melting temperature of the waste plastics in the step 1 is 150-200 ℃, the pyrolysis reaction temperature of the pyrolysis device (20) in the step 2 is 500-800 ℃, the reaction temperature in the vapor deposition furnace (19) is 800 ℃, and the temperature of high-temperature flue gas generated by combustion of combustible gas in the step 6 is 300-400 ℃.

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