Device and method for online self-heating pyrolysis reforming hydrogen production assisted by waste lithium battery positive electrode material

Abstract

The invention discloses a waste lithium battery positive electrode material assisted online self-heating pyrolysis reforming hydrogen production device. Relates to the field of waste material reforming hydrogen production, and comprises a raw material supply and control system I, a pyrolysis reduction reaction system II and a reforming reaction system III, the raw material supply and control system I comprises a nitrogen cylinder, a flowmeter, an air compressor, a water pump, a stock bin, a primary feeder, a secondary feeder and the like; the pyrolysis reduction reaction system II comprises a pyrolyzer, a lower-section combustor, a heating furnace, a lower-section thermocouple and the like, and the reforming reaction device III comprises an upper-section thermocouple, a reformer, an upper-end combustion furnace and the like. Meanwhile, the metal oxide obtained through reduction has a bond pre-breaking effect on the biomass, then generated micromolecule pyrolysis gas is reformed to prepare high-purity hydrogen, and heat in the pyrolysis reduction stage and heat in the reforming stage are provided by biomass pyrolytic carbon so as to achieve self-maintenance of the system.

Description

Technical Field

[0001] The present invention belongs to the fields of waste lithium battery recycling and renewable energy hydrogen production, and particularly relates to a device and method for auxiliary online self-heating pyrolysis reforming hydrogen production using waste lithium battery cathode materials. Background Art

[0002] With the annual increase in the market share of new energy vehicles, the demand for lithium batteries is constantly increasing, and the scrapping and recycling of batteries have become an important issue. Waste lithium batteries contain a large amount of toxic electrolytes. More importantly, the cathode materials of waste lithium-ion batteries contain a large amount of transition metals such as nickel, cobalt, manganese, copper, etc., making them have great recycling value.

[0003] Among the existing publicly disclosed patent technologies for recycling metal elements from waste lithium battery cathode materials, pyrometallurgy is simple and efficient and easy to industrialize, but pyrometallurgy needs to be carried out under high-temperature conditions (such as CN202210528271.9, CN201910085003.2, CN201711338938.4, etc.); hydrometallurgy has a high recovery rate, but a large amount of waste liquid generated needs to be treated (such as CN202310229422.5, CN202211506605.9, CN202111175610.1, etc.); in some technologies, the transition metals obtained after lithium extraction have complex components and do not consider their possible future application scenarios, such as a high-value recycling method for waste lithium iron phosphate / sodium iron phosphate battery cathode materials disclosed in publication number CN202211296996.6, and a comprehensive recycling method for lithium iron phosphate cathode materials disclosed in publication number CN202211334349.X.

[0004] Based on the analysis of the existing related recycling and utilization technologies for waste lithium battery cathode materials, it can be seen that the current recycling technologies for waste lithium batteries generally have problems such as high energy consumption, large pollution, and unclear product target orientation. Therefore, the present invention designs a device and method for auxiliary online self-heating pyrolysis reforming hydrogen production using waste lithium battery cathode materials. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems in the prior art and propose a logistics transportation and sorting device.

[0006] A device for auxiliary online self-sustaining pyrolysis reforming hydrogen production using waste lithium battery cathode materials, the device comprising a raw material supply and control system I, a pyrolysis reaction system II, and a reforming reaction system III;

[0007] The raw material supply and control system I includes a nitrogen cylinder, a flowmeter, an air compressor, a water pump, a silo, a primary feeder, a secondary feeder, and a temperature controller. Among them, the nitrogen cylinder is connected to the flowmeter, the flowmeter is connected to the silo, the silo is connected to the primary feeder, and the primary feeder and the secondary feeder are arranged crosswise;

[0008] The pyrolysis reaction system II includes a pyrolyzer, a lower burner, a heating furnace, a lower thermocouple, a separator, a recovery bin, a connecting pipe, and a distributor. Among them, the primary feeder is connected to the secondary feeder, the secondary feeder is connected to the pyrolyzer, the lower burner wraps the upper part of the pyrolyzer, the heating furnace wraps the lower part of the pyrolyzer, the temperature controller is connected to the thermocouple, the separator is connected to the pyrolyzer and the recovery bin, and the distributor is connected to the connecting pipe;

[0009] The reforming reaction device III includes an upper thermocouple, a reformer, and an upper burner. Among them, the reformer is connected to the pyrolyzer, and the upper burner wraps the reformer.

[0010] In the above device, the upper burner and the lower burner are provided with 3 to 5 turns of spiral structures, and the spiral angle is 15° to 20°.

[0011] In the above device, the primary feeder is arranged horizontally, the secondary feeder is arranged at an inclination of 15° to 30°, and the primary feeder and the secondary feeder are arranged vertically with staggered floors.

[0012] In the above device, the distributor is assembled in the middle section of the connecting pipe. The left side of the distributor is connected to the lower burner through a pipeline, and the upper side of the distributor is connected to the upper burner through a connecting pipe. The distributor is responsible for regulating the material ratio entering the lower burner and the upper burner.

[0013] The present invention also discloses a method using the device, including the following steps:

[0014] S1: Pyrolysis reduction reaction. Biomass and the positive electrode material of waste lithium batteries are mixed in proportion and fall into the pyrolyzer through the primary feeder and the secondary feeder. The biomass is first heated and pyrolyzed to produce biochar. At the same time, the biochar reduces the positive electrode material of the waste lithium battery, and the obtained metal complex pre-cleaves the fresh biomass, promoting the further cleavage of large molecules of the biomass pyrolysis gas;

[0015] S2: Fuel recovery and distribution. The biomass pyrolysis carbon and the metal complex enter the separator obliquely. Among them, the metal complex falls into the recovery bin after magnetic separation, flotation, etc. The biomass pyrolysis carbon enters the connecting pipe under the action of secondary air. Under the regulation of the distributor, part enters the lower burner and part enters the upper burner;

[0016] S3: Reforming hydrogen production reaction. The small molecules of biomass with pre-broken bonds generated in the pyrolyzer enter the reformer and come into full contact with the catalyst to produce a hydrogen-rich mixed gas.

[0017] In the above method, in step S1, the waste lithium battery cathode material is selected from one or more of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickel cobalt manganate, and lithium iron phosphate, and the biomass is selected from one or more of straw, bagasse, and pine. The ratio between the two is selected from 0.2 to 1.

[0018] In the above method, the carrier gas flow rate at the lower end inlet of the pyrolyzer is 1 - 2 L / min, and the working temperature is 350 - 650 °C.

[0019] In the above method, in step S2, the secondary air flow rate of the connecting pipe is 0.5 - 2 L / min, and the distributor regulates the biomass in the left and upper connecting pipes. The pyrolytic carbon ratio is selected from 0.25 to 0.66.

[0020] In the above method, in step S3, the working temperature of the reformer is 550 - 750 °C, and the catalyst is selected from one or more of Ni / CeO2 - Al2O3, Ni / Al2O3, and Ni / red mud.

[0021] In the above method, in step S1 and step S3, the air flow rate of the upper burner 19 and the lower burner 10 is 0.1 - 0.5 L / min.

[0022] Compared with the existing technology, the advantages of the present invention are as follows:

[0023] 1. Using biomass pyrolytic carbon as fuel, a large amount of heat is generated by combustion to supply the thermal reduction and reforming reactions. Therefore, the energy consumption of this device is extremely low and the economy is good.

[0024] 2. Continuous feeding of biomass and waste lithium battery cathode material, and continuous discharging of biomass pyrolytic carbon and metal complex. Therefore, the recovery amount of biomass and waste lithium battery cathode material is large, and this device meets the industrial requirements of mass treatment.

[0025] 3. The three processes of primary biomass pyrolysis, thermal reduction of biomass pyrolytic carbon, and pre-broken bond of metal complex biomass pyrolysis gas are organically coupled. While recovering the transition metals of waste lithium batteries, pyrolysis gas small molecules that are more easily reformed are obtained. Therefore, this method has the advantage of simple process.

[0026] 4. Using biomass and waste lithium battery cathode material as raw materials, a hydrogen-rich syngas is produced through self-sustaining on-line pyrolysis reforming, that is, "turning waste into treasure". The reactants and catalysts are all solid wastes, meeting the requirements of circular economy development. Description of the Drawings

[0027] Figure 1 This is a schematic diagram of the device for auxiliary on-line self-sustaining pyrolysis reforming of waste lithium battery cathode materials to produce hydrogen in the present invention.

[0028] Figure 2 XRD spectra of the recovered metal complexes for Examples 1, 2, and 3.

[0029] Figure 3 Schematic diagrams of the gas yields for Examples 1, 2, and 3.

[0030] Figure 4 Schematic diagrams of the gas proportions for Examples 1, 2, and 3.

[0031] Among them, 1 - nitrogen cylinder, 2 - flowmeter, 3 - air compressor, 4 - water pump, 5 - silo (5), 6 - primary feeder, 7 - secondary feeder, 8 - temperature controller, 9 - pyrolyzer, 10 - lower burner, 11 - heating furnace, 12 - lower thermocouple, 13 - separator, 14 - recovery bin, 15 - connecting pipe, 16 - distributor, 17 - upper thermocouple, 18 - reformer, 19 - upper burner. Detailed implementation manners

[0032] As Figures 1-4 shown, a device for auxiliary on-line self-sustaining pyrolysis reforming of waste lithium battery cathode materials to produce hydrogen, the device includes a raw material supply and control system I, a pyrolysis reaction system II, and a reforming reaction system III;

[0033] The raw material supply and control system I includes a nitrogen cylinder 1, a flowmeter 2, an air compressor 3, a water pump 4, a silo 5, a primary feeder 6, a secondary feeder 7, and a temperature controller 8, where the nitrogen cylinder 1 is connected to the flowmeter 2, the flowmeter 2 is connected to the silo 5, the silo 5 is connected to the primary feeder 6, and the primary feeder 6 and the secondary feeder 7 are arranged crosswise; the primary feeder 6 and the secondary feeder 7 adopt a unique crosswise staggered arrangement. So that the raw materials output from the primary feeder 6 can be fully and evenly mixed with the raw materials output from the secondary feeder 7 before entering the pyrolyzer.

[0034] The pyrolysis reaction system II includes a pyrolyzer 9, a lower burner 10, a heating furnace 11, a lower thermocouple 12, a separator 13, a recovery bin 14, a connecting pipe 15, and a distributor 16, where the primary feeder 6 is connected to the secondary feeder 7, the secondary feeder 7 is connected to the pyrolyzer 9, the lower burner 10 wraps the upper part of the pyrolyzer 9, the heating furnace 11 wraps the lower part of the pyrolyzer 9, the temperature controller 8 is connected to the thermocouple 12, and the thermocouple 12 monitors the temperature change inside the pyrolyzer 9 in real time, the separator 13 is connected to the pyrolyzer 9 and the recovery bin 14, and the distributor 16 is connected to the connecting pipe 15;

[0035] The reforming reaction device III includes an upper-section thermocouple 17, a reformer 18, and an upper-end combustor 19. Among them, the reformer 18 is connected to the pyrolyzer 9, and the upper-end combustor 19 wraps the reformer 18. Its main function is to provide a necessary high-temperature environment for the reformer 18, meet the heat conditions required for the reforming reaction, and promote the efficient progress of the reforming reaction.

[0036] Among them, the upper-section combustor 19 and the lower-section combustor 10 are provided with 3 to 5 turns of spiral structures, and the spiral angle is 15° to 20°.

[0037] The primary feeder 6 is horizontally arranged, the secondary feeder 7 is inclined at 15° to 30°, and the primary feeder 6 and the secondary feeder 7 are arranged vertically with staggered floors.

[0038] The distributor 16 is assembled in the middle section of the connecting pipe 15. The left side of the distributor is connected to the lower-section combustor 10 through a connecting pipe, and the upper side of the distributor is connected to the upper-section combustor 19 through a connecting pipe. The distributor 16 is responsible for regulating the material ratio entering the lower-section combustor 10 and the upper-section combustor 19.

[0039] Moreover, the present invention discloses a method of using the above device, including the following steps:

[0040] The first step is the pyrolysis reduction reaction: The biomass and the waste lithium battery cathode material are accurately conveyed into the pyrolyzer 9 according to a specific ratio by means of the primary feeder 6 and the secondary feeder 7. In this device, the biomass undergoes a pyrolysis reaction under suitable temperature conditions to generate biochar. At the same time, the generated biochar plays a reducing role to transform the waste lithium battery cathode material. The metal complex generated during the reaction has a unique function. It can perform a pre-bond-breaking operation on the subsequently newly added biomass raw material, causing the originally larger molecular structure in the biomass pyrolysis gas to further break, thereby forming smaller molecular substances that are more conducive to subsequent reactions. In the first step, the waste lithium battery cathode material is selected from one or more of lithium cobaltate, lithium nickelate, lithium manganate, ternary materials of lithium cobalt nickel manganate, and lithium iron phosphate, and the biomass is selected from one or more of straw, bagasse, and pinewood. The ratio between the two is selected from 1 / 10 to 1 / 1; the carrier gas flow rate at the lower-end inlet of the pyrolyzer 9 is 1 to 2 L / min, and the operating temperature of the pyrolyzer 9 is 350 to 650 °C;

[0041] Second-step fuel recovery and distribution: After the pyrolysis stage ends, the produced biomass pyrolysis carbon and metal complex tilt into the separator 13 together. In the separator, the metal complex is effectively separated from other substances through a series of professional separation techniques such as magnetic separation and flotation, and finally falls into the recovery bin 14, achieving efficient resource recovery. The biomass pyrolysis carbon, under the strong push of the secondary air, smoothly enters the connecting pipe 15. Subsequently, under the precise regulation of the distributor 16, this biomass pyrolysis carbon is reasonably distributed to different paths. Part of it enters the lower burner 10, and the other part enters the upper burner 19, thereby realizing the reasonable utilization of fuel in different parts. The secondary air flow rate in the connecting pipe is 0.5 - 2 L / min, and the proportion of biomass pyrolysis carbon in the left and upper connecting pipes regulated by the distributor is selected from 2 / 8 to 4 / 6..

[0042] Third-step reforming hydrogen production reaction: The biomass small molecules formed after the pre-bond-breaking treatment in the pyrolyzer 9 enter the reformer 18 in an orderly manner. Inside the reformer, these small molecules come into full contact with the catalyst and undergo a series of complex chemical reactions. After this key link, a hydrogen-rich mixed gas is finally successfully produced. The working temperature of the reformer 18 is 550 - 750 °C, and the catalysts are Ni / CeO2 - Al2O3, Ni / Al2O3, and Ni / red mud.

[0043] Among them, the air flow rate of the upper burner 19 and the lower burner 10 in the first step and the third step is 0.1 - 0.5 L / min.

[0044] Example 1:

[0045] Using the cathode material of waste nickel cobalt manganese acid lithium battery and corn straw as the mixed feed, with a ratio of 1 / 2, the carrier gas flow rate at the inlet of the pyrolyzer is 1 L / min, the working temperature of the pyrolyzer is 450 °C, the secondary air flow rate is 0.5 L / min, and the ratio on the left and upper sides of the distributor is 1 / 10; the temperature of the reformer is 700 °C, and the catalyst selected is Ni / CeO2 - Al2O3.

[0046] Example 2:

[0047] The ratio of the cathode material of waste nickel cobalt manganese acid lithium battery to corn straw is 3 / 10, and the others are the same as in Example 1.

[0048] Example 3:

[0049] The ratio of the cathode material of waste nickel cobalt manganese acid lithium battery to corn straw is 5 / 10, and the others are the same as in Example 1.

[0050] Example 4:

[0051] The ratio of the cathode material of waste nickel cobalt manganese acid lithium battery to corn straw is 7 / 10, and the others are the same as in Example 1.

[0052] The cathode material of the nickel cobalt manganese acid lithium battery in Example 1 was directly mixed with biomass. A reduction reaction occurred between the ternary lithium material and biomass charcoal, generating nickel oxide. Nickel oxide has a strong catalytic effect on biomass pyrolysis, resulting in a large change in the distribution of the final liquid-phase products.

[0053] The ternary lithium cathode material in Examples 1, 2, 3, and 4 was directly mixed with biomass according to different mass ratios. When the mass ratio increases, since the content of nickel oxide can be increased, the catalytic effect on biomass pyrolysis is stronger. The bond-breaking and deoxidation effect of nickel converts macromolecular compounds into small-molecular compounds. And small-molecular compounds are more likely to undergo reforming reactions to generate hydrogen. Finally, when Example 1 was used, the hydrogen production reached a maximum value of 19.5 mmol / g.

[0054] The final hydrogen production obtained in Example 1 was 14.2 mmol / g. As the mass ratio increased, the hydrogen production reached 19.5 mmol / g in Example 3. Further increasing the mass ratio, the hydrogen production in Example 4 remained almost unchanged.

[0055] As is known by common technical knowledge, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and are not the only ones. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. An apparatus for auxiliary on-line self-sustaining pyrolytic reforming of spent lithium battery cathode materials to produce hydrogen, characterized in that: The device includes a raw material supply and control system I, a pyrolysis reaction system II, and a reforming reaction system III; The raw material supply and control system I includes a nitrogen cylinder (1), a flow meter (2), an air compressor (3), a water pump (4), a silo (5), a primary feeder (6), a secondary feeder (7), and a temperature controller (8). Among them, the nitrogen cylinder (1) is connected to the flow meter (2), the flow meter (2) is connected to the silo (5), the silo (5) is connected to the primary feeder (6), and the primary feeder (6) and the secondary feeder (7) are arranged crosswise; The pyrolysis reaction system II includes a pyrolyzer (9), a lower burner (10), a heating furnace (11), a lower thermocouple (12), a separator (13), a recovery bin (14), a connecting pipe (15), and a distributor (16). Among them, the primary feeder (6) is connected to the secondary feeder (7), the secondary feeder (7) is connected to the pyrolyzer (9), the lower burner (10) wraps the upper part of the pyrolyzer (9), the heating furnace (11) wraps the lower part of the pyrolyzer (9), the temperature controller (8) is connected to the thermocouple (12), the separator (13) is connected to the pyrolyzer (9) and the recovery bin (14), and the distributor (16) is connected to the connecting pipe (15); The reforming reaction device III includes an upper thermocouple (17), a reformer (18), and an upper burner (19). Among them, the reformer (18) is connected to the pyrolyzer (9), and the upper burner (19) wraps the reformer (18).

2. The auxiliary online self-sustaining pyrolytic reforming hydrogen production device for the cathode material of waste lithium batteries according to claim 1, wherein: The upper burner (19) and the lower burner (10) are provided with 3 - 5 turns of spiral structures, and the spiral angle is 15° - 20°.

3. The auxiliary on-line self-sustaining pyrolytic reforming hydrogen production device for the cathode material of waste lithium batteries according to claim 1, wherein: The primary feeder (6) is arranged horizontally, the secondary feeder (7) is arranged at an inclination of 15° - 30°, and the primary feeder (6) and the secondary feeder (7) are arranged vertically with staggered floors.

4. The auxiliary online self-sustaining pyrolysis reforming hydrogen production device for the positive electrode material of waste lithium batteries according to claim 1, characterized in that: The distributor (16) is assembled in the middle section of the connecting pipe (15). The left side of the distributor (16) is connected to the lower burner (10) through a pipeline, the upper side of the distributor is connected to the upper burner (19) through the connecting pipe (15), and the distributor (16) is responsible for regulating the material ratio entering the lower burner (10) and the upper burner (19).

5. A method using the device according to any one of the above claims 1-4, characterized in that, It includes the following steps: S1: Pyrolysis reduction reaction. Biomass and the positive electrode material of waste lithium batteries are mixed in proportion, and fall into the pyrolyzer (9) through the primary feeder (6) and the secondary feeder (7). The biomass is first heated and pyrolyzed to produce biochar. At the same time, the biochar reduces the positive electrode material of waste lithium batteries, and the obtained metal complex pre - breaks the bonds of fresh biomass, promoting the further breakage of large - molecule pyrolysis gas of biomass; S2: Fuel recovery and distribution. Biomass pyrolysis carbon and metal complex enter the separator (13) obliquely. Among them, the metal complex falls into the recovery bin (14) after magnetic separation, flotation, etc. Biomass pyrolysis carbon enters the connecting pipe (15) under the action of secondary air. Under the regulation of the distributor (16), part enters the lower burner (10), and part enters the upper burner (19); S3: Reforming hydrogen production reaction. The small molecules of biomass with pre-broken bonds generated in the pyrolyzer (9) enter the reformer (18) and come into full contact with the catalyst to produce a hydrogen-rich mixed gas.

6. The method for auxiliary on-line self-sustaining pyrolytic reforming of waste lithium battery cathode materials to produce hydrogen according to claim 5, characterized in that, In step S1, the waste lithium battery cathode material is selected from one or more of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickel cobalt manganate, and lithium iron phosphate, and the biomass is selected from one or more of straw, bagasse, and pine. The ratio between the two is selected from 0.2 to 1.

7. The method for auxiliary online self-sustaining pyrolytic reforming of waste lithium battery cathode materials to produce hydrogen according to claim 5, characterized in that In step S1, the carrier gas flow rate at the lower end inlet of the pyrolyzer (9) is 1 - 2 L / min, and the working temperature is 350 - 650 °C.

8. The method for auxiliary on-line self-sustaining pyrolytic reforming of spent lithium battery cathode materials to produce hydrogen according to claim 5, characterized in that, In step S2, the secondary air flow rate of the connecting pipe (15) is 0.5 - 2 L / min. The distributor (16) regulates the biomass in the left and upper connecting pipes (15), and the pyrolytic carbon ratio is selected from 0.25 to 0.

66.

9. The method for auxiliary online self-sustaining pyrolytic reforming of waste lithium battery cathode materials to produce hydrogen according to claim 5, characterized in that In step S3, the working temperature of the reformer (18) is 550 - 750 °C, and the catalyst is selected from one or more of Ni / CeO2 - Al2O3, Ni / Al2O3, and Ni / red mud.

10. The method for auxiliary on-line self-sustaining pyrolytic reforming of waste lithium battery cathode materials to produce hydrogen according to claim 5, characterized in that, In steps S1 and S3, the air flow rate of the upper burner (19) and the lower burner (10) is 0.1 - 0.5 L / min.

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