High-valued treatment system and method for organic solid waste

Abstract

The invention relates to an organic solid waste high-valued treatment system and method. The system comprises a fluidization catalytic depolymerization reactor, a first cyclone separator, a waste heat recovery device, a steam generator, a three-phase separator and a working medium regeneration heater which are arranged in sequence. According to the system and the method, catalytic depolymerization of the organic solid wastes is realized through a fluidized catalytic reaction, cyclic utilization of reaction materials and energy is realized through a closed-loop process design, and various mixed organic solid wastes can be catalytically converted into high-added-value synthesis gas, low-carbon olefin, liquid oil and the like; graded cyclic utilization of organic solid waste and capacity is achieved to the maximum extent, complex procedures caused by sorting are effectively reduced, the cost is reduced, and the recycling process is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid waste resource high-value utilization, in particular to an organic solid waste high-value treatment system and method. BACKGROUND

[0002] Safe disposal and efficient recycling of organic solid waste have become a global problem. With the promotion of the "double carbon target" and the strategic goal of "circular economy", China has introduced a series of policies in recent years around the recycling of organic solid waste, and has put forward more stringent requirements for the disposal of organic solid waste, which has gradually reduced the proportion of traditional landfill disposal and incineration disposal. In terms of recycling of solid waste, physical recycling is currently the mainstream technology, but it requires organic solid waste to be sufficiently single and clean, and has high requirements for raw materials. However, after consumption, organic solid waste often exists in a mixed form, making it difficult for physical recycling strategies to be applicable and less universal. In addition, physical recycling technology is a kind of downgrading treatment, which essentially only delays the disposal time of organic solid waste, but its end fate is still disposal. Under the above background, it is urgent to develop a mixed organic solid waste recycling technology with high tolerance and strong universality. Compared with physical recycling technology, chemical recycling technology is expected to play a key role in the future field of organic solid waste recycling due to its flexibility and element recycling.

[0003] However, in order to achieve the goals of high-value utilization of organic solid waste, reduction of waste pollution and sustainable recycling development, simple, green, low-carbon and feasible technologies still need to be researched and developed. SUMMARY

[0004] In order to overcome the deficiencies of the prior art, the present application is dedicated to providing a simple, efficient and low-carbon organic solid waste high-value treatment system and method. The system realizes catalytic depolymerization of organic solid waste through fluidized catalytic reaction, and realizes recycling of reaction materials and energy through closed-loop process design, which can catalytically convert various mixed organic solid waste into high-value synthesis gas, low-carbon olefins and liquid oil, etc., maximize the graded recycling of organic solid waste and energy, effectively reduce the complex procedures caused by sorting, reduce costs and simplify the recycling process.

[0005] In order to achieve the above technical effects, the technical solutions provided by the present application are as follows:

[0006] An organic solid waste high-value treatment system, characterized in that the system comprises a fluidized catalytic depolymerization reactor, a first cyclone separator, a waste heat recovery device, a steam generator, a three-phase separator and a working medium regenerative heater arranged in sequence.

[0007] The organic solid waste is sent into a fluidized catalytic depolymerization reactor after being treated by melting, and a depolymerization reaction occurs under the action of a catalyst and a working medium;

[0008] The depolymerization products are separated by using a first cyclone separator, and the separated solid product is partially sent to the fluidized catalytic depolymerization reactor for recycling, and partially sent to a working medium regenerative heater for heating treatment; the separated high-temperature gas product is sent to a waste heat recovery device for waste heat recovery;

[0009] The gas after waste heat recovery is sent into a steam generator, and the generated steam is used as fluidizing gas of the fluidized catalytic depolymerization reactor;

[0010] The gas output from the steam generator is sent into a three-phase separator; the gas component separated by the three-phase separator is sent to the working medium regenerative heater as fuel gas for heating the solid product recovered from the first cyclone separator; the heated solid product is sent to the fluidized catalytic depolymerization reactor for recycling; the water separated by the three-phase separator is sent to the steam generator for recycling after being treated by water treatment.

[0011] Further, the system further comprises a conveying mechanism, preferably, the conveying mechanism is a screw conveying mechanism; further preferably, the conveying mechanism has a heating function for heating the organic solid waste to a molten state; preferably, the heating function is realized by microwave, photo-thermal, electromagnetic and the like;

[0012] Further, the system further comprises a second cyclone separator, the organic solid waste in a molten state is sent into the separator, liquid is sprayed into the fluidized catalytic depolymerization reactor from the bottom of the second cyclone separator, and gas is sent to the top of the fluidized catalytic depolymerization reactor from the top of the second cyclone separator;

[0013] Further, the system further comprises a working medium hopper for sending the mixed catalyst and working medium to the fluidized catalytic depolymerization reactor;

[0014] Further, the system further comprises a water treatment system, the water separated by the three-phase separator is sent to the water treatment device, and is sent to the steam generator for recycling after being treated by water treatment;

[0015] Further, the solid product separated from the first cyclone separator is partially sent to the working medium regenerative heater for heating treatment, and then is sent to the working medium hopper.

[0016] Further, the liquid oil component separated from the three-phase separator is stored in a storage tank, and byproducts including terephthalic acid, polyether polyol and the like are separated by water immersion, acidification and the like.

[0017] The waste heat recovery device is not particularly limited in the present application, and can be a generator commonly known in the prior art.

[0018] According to the technical scheme of the present application, the organic solid waste includes one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyurethane, nylon, rubber, waste tires, waste clothes, electronic waste, waste lubricating oil, or waste biomass.

[0019] According to the technical scheme of the present application, the working medium includes one or more of molten salt, sandstone, biochar, graphite carbon, amorphous carbon, zinc oxide, cerium oxide, indium oxide, or iron oxide.

[0020] According to the technical scheme of the present application, the catalyst is one or more of nickel, iron, cobalt, tungsten, magnesium, zinc, indium oxide, indium tin oxide, zirconium oxide, tungsten oxide, zinc oxide, aluminum oxide, molecular sieve, or graphite carbon.

[0021] Further, according to the technical scheme of the present application, when a two-component catalyst is used, the mass ratio between the components of the catalyst satisfies (0.01-100):(0.01-100); when a three-component catalyst is used, the mass ratio between the components satisfies (0.01-100):(0.01-100):(0.01-100), and so on.

[0022] The preparation method of the catalyst is as follows: after the catalyst components are uniformly mixed, the catalyst is prepared by calcining at a high temperature of 350-500°C for 3-10 hours.

[0023] According to the technical scheme of the present application, the working medium is used in combination with the catalyst. The working medium circulates and flows between the fluidized catalytic depolymerization reactors, so as to promote the chemical depolymerization reaction of the organic solid waste in the reactors.

[0024] According to the technical scheme of the present application, the mass ratio of the organic solid waste to the catalyst satisfies 1:(0.01-100).

[0025] The present application has the following beneficial effects:

[0026] The present application utilizes the fluidized catalytic depolymerization reaction to decompose the organic solid waste, adopts the catalytic depolymerization strategy, effectively converts the organic solid waste into high-value-added products such as synthesis gas, low-carbon olefins, and liquid oil, and the conversion rate of the organic components is more than 90%; and through a special process route, the closed-loop utilization of the depolymerization products and energy is realized. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The present application is an organic solid waste high-value treatment system schematic diagram.

[0028] Reference signs:

[0029] Fluidized catalytic depolymerization reactor 1; first cyclone 2; waste heat recovery device 3;

[0030] Steam generator 4; three-phase separator 5;

[0031] Working medium regenerative heater 6; conveying mechanism 7;

[0032] Second cyclone 8; working medium hopper 9; water treatment system 10; storage tank 11. DETAILED DESCRIPTION

[0033] The present application will now be further described in conjunction with the accompanying drawings, but the following embodiments do not constitute a limitation on the present application.

[0034] Example 1

[0035] The recycling of polyethylene, polypropylene, polystyrene mixed organic solid plastic is operated as follows:

[0036] 1) The collected polyethylene, polypropylene and polystyrene plastics are mixed in a certain mass ratio, and in this embodiment, the mass ratio is 10:13:1, which is added to the screw conveying mechanism 7 with heating function through the hopper, and heated to a molten state;

[0037] 2) The molten organic solid waste is conveyed to the separator 8, the liquid is injected from the bottom of the second cyclone 8 into the fluidized catalytic depolymerization reactor 1, and the gas is conveyed from the top of the second cyclone 8 to the top of the fluidized catalytic depolymerization reactor 1;

[0038] 3) A tungsten / alumina catalyst is used, sandstone is used as a heating working medium, the catalyst and the working medium are fully mixed, and then added to the fluidized catalytic depolymerization reactor 1 through the working medium hopper 9;

[0039] The preparation method of the tungsten / alumina catalyst is as follows: 10 parts of alumina is dispersed in 50 parts of deionized water, then 3 parts of tungsten chloride is added, and stirred at room temperature for 3 hours. Then, the deionized water is evaporated at 70°C, and the obtained solid species is calcined in an air atmosphere at 350°C for 3 hours to prepare the catalyst;

[0040] 4) The mass ratio of plastic to catalyst is 5:1; 60 parts of the mixture is added to the fluidized catalytic depolymerization reactor, and under the action of the catalyst, the plastic undergoes depolymerization reaction;

[0041] 5) the first cyclone separator 2 is used to separate the depolymerization products, and part of the solid products (i.e. catalyst and working medium) separated is transported to the fluidized catalytic depolymerization reactor 1 for recycling; part is transported to the working medium regenerative heater 6 for heating treatment; the high-temperature gas product separated is transported to the waste heat recovery device 3 for waste heat recovery;

[0042] The waste heat recovery device 3 is a generator; the gas after waste heat recovery enters the steam generator 4, and the steam generated is used as the fluidizing gas of the fluidized catalytic depolymerization reactor 1;

[0043] The gas output from the steam generator 4 enters the three-phase separator 5; the gas component separated by the three-phase separator 5 is sent to the working medium regenerative heater 6 and used as fuel gas for heating part of the catalyst and working medium recovered from the first cyclone separator 2, and after being heated to 350°C, is transported to the working medium hopper 9 and then to the fluidized catalytic depolymerization reactor 1 for recycling.

[0044] Further, the liquid oil component separated from the three-phase separator 5 is stored in the storage tank 11 and is separated into by-products through water immersion, acidification and other processes.

[0045] Further, the water component separated by the three-phase separator 5 is transported to the water treatment device 10 and is transported to the steam generator 4 for recycling after water treatment.

[0046] The present application adopts the catalytic depolymerization strategy to effectively convert organic solid waste into synthesis gas, low-carbon olefin and liquid oil and other high-value-added products, and the conversion rate of organic components is more than 90%; and through a special process route, the depolymerization products and energy are realized closed-loop utilization.

[0047] Example 2

[0048] The recycling of polyethylene and polypropylene mixed organic solid plastics is as follows:

[0049] 1) The collected polyethylene and polypropylene plastics are mixed in a certain mass ratio, and in this embodiment, the mass ratio is 2:1, and are added to the screw conveying mechanism 7 with heating function through the hopper and are heated to a molten state;

[0050] 2) The molten organic solid waste is transported to the separator 8, the liquid is sprayed into the fluidized catalytic depolymerization reactor 1 from the bottom of the second cyclone separator 8, and the gas is transported to the top of the fluidized catalytic depolymerization reactor 1 from the top of the second cyclone separator 8;

[0051] 3) The zirconium / molecular sieve catalyst is used, the sandstone is used as the heating working medium, the catalyst and the working medium are fully mixed, and then are added to the fluidized catalytic depolymerization reactor 1 through the working medium hopper 9;

[0052] The zirconium / molecular sieve catalyst is prepared as follows: 15 parts of molecular sieve is dispersed in 70 parts of deionized water, then 1 part of zirconium chloride is added, and stirred at room temperature for 2 hours. Then, the deionized water is rotary evaporated at 70°C, and the obtained solid species is calcined in an air atmosphere at 400°C for 4 hours, and finally the catalyst is prepared.

[0053] 4) 100 parts of the mixture is added into the fluidized catalytic depolymerization reactor, and the plastic is depolymerized under the action of the catalyst, with the mass ratio of the plastic and the catalyst being 10:1;

[0054] 5) The depolymerization product is separated by the first cyclone separator 2, and part of the separated solid product (i.e. the catalyst and the working medium) is transported to the fluidized catalytic depolymerization reactor 1 for recycling; part of the separated solid product is transported to the working medium regenerating heater 6 for heating treatment; and the separated high-temperature gas product is transported to the waste heat recovery device 3 for waste heat recovery;

[0055] The waste heat recovery device 3 is a generator; the gas after waste heat recovery enters the steam generator 4, and the generated steam is used as the fluidizing gas of the fluidized catalytic depolymerization reactor 1;

[0056] The gas output from the steam generator 4 enters the three-phase separator 5; the gas component separated by the three-phase separator 5 is sent to the working medium regenerating heater 6 and used as fuel gas for heating part of the catalyst and the working medium recovered from the first cyclone separator 2, and after being heated to 350°C, the heated working medium is transported to the working medium hopper 9 and then to the fluidized catalytic depolymerization reactor 1 for recycling.

[0057] Further, the liquid oil component separated from the three-phase separator 5 is stored in the storage tank 11, and the by-products are separated by water immersion, acidification and other processes.

[0058] Further, the water component separated from the three-phase separator 5 is transported to the water treatment device 10, and after water treatment, the treated water is transported to the steam generator 4 for recycling.

[0059] The present application adopts the catalytic depolymerization strategy to effectively convert the organic solid waste into synthesis gas, low-carbon olefins and liquid oil and other high-value-added products, and the conversion rate of the organic components is more than 90%; and through a special process route, the closed-loop utilization of the depolymerization product and energy is realized.

[0060] Example 3

[0061] The polyethylene terephthalate and biomass recovery is operated according to the following steps:

[0062] 1) The collected plastics are mixed according to a certain mass ratio, and in this embodiment, the polyethylene terephthalate and the biomass are crushed (mass ratio 1:6), and then added into the screw conveying mechanism 7 with heating function through the hopper, and heated to a molten state;

[0063] 2) The organic solid waste in molten state is transported into the separator 8, the liquid is sprayed from the bottom of the second cyclone separator 8 into the fluidized catalytic depolymerization reactor 1, and the gas is transported from the top of the second cyclone separator 8 to the top of the fluidized catalytic depolymerization reactor 1;

[0064] 3) The iron / graphite carbon catalyst is mixed with the heating medium of sandstone, and then the mixture is added into the fluidized catalytic depolymerization reactor 1 through the medium hopper 9;

[0065] The iron / graphite carbon catalyst is prepared as follows: first, 5 parts of graphite carbon, 60 parts of deionized water, 10 parts of ferric nitrate, and 1 part of sodium hydroxide are stirred and mixed uniformly at room temperature for 2 hours. Then, it is transferred into a reaction kettle and reacted at 180°C for 24 hours. After the reaction, it is filtered, rinsed, and dried to obtain the catalyst.

[0066] 4) The mass ratio of the mixture of the plastic and the catalyst is 2:1, and 60 parts of the mixture is added into the fluidized catalytic depolymerization reactor. Under the action of the catalyst, the plastic undergoes depolymerization reaction;

[0067] 5) The depolymerization products are separated by the first cyclone separator 2, and part of the solid products (i.e. the catalyst and the medium) obtained by separation is transported to the fluidized catalytic depolymerization reactor 1 for recycling, and part of it is transported to the medium regenerating heater 6 for heating treatment. The high-temperature gas product obtained by separation is transported to the waste heat recovery device 3 for waste heat recovery;

[0068] The waste heat recovery device 3 is a generator. The gas after waste heat recovery enters the steam generator 4, and the generated steam is used as the fluidizing gas of the fluidized catalytic depolymerization reactor 1;

[0069] The gas from the steam generator 4 enters the three-phase separator 5;

[0070] The gas components separated by the three-phase separator 5 are sent to the medium regenerating heater 6 and used as fuel gas for heating part of the catalyst and the medium recovered from the first cyclone separator 2. After being heated to 450°C, they are transported to the medium hopper 9 and then to the fluidized catalytic depolymerization reactor 1 for recycling.

[0071] The liquid oil components separated by the three-phase separator 5 are stored in the storage tank 11 and separated into by-products through water immersion and acidification processes.

[0072] The water components separated by the three-phase separator 5 are transported to the water treatment device 10 and then to the steam generator 4 for recycling after water treatment.

[0073] The application adopts catalytic depolymerization strategy to effectively convert organic solid waste into high value-added products such as synthesis gas, low-carbon olefin and liquid oil, and the conversion rate of organic components is more than 90%; and through a special process route, the depolymerization products and energy are closed-loop utilized.

[0074] Example 4

[0075] The polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyurethane are recycled by the following operation steps:

[0076] 1) The collected plastics are mixed according to a certain mass ratio, in this embodiment, the polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyurethane are pre-mixed after being crushed, and are added into the screw conveying mechanism 7 with heating function through the hopper and heated to a molten state;

[0077] 2) The molten organic solid waste is conveyed into the separator 8, the liquid is sprayed into the fluidized catalytic depolymerization reactor 1 from the bottom of the second cyclone separator 8, and the gas is conveyed to the top of the fluidized catalytic depolymerization reactor 1 from the top of the second cyclone separator 8;

[0078] 3) The zinc / graphite carbon catalyst is used, the sandstone is used as the heating working medium, the catalyst and the working medium are fully mixed, and then are added into the fluidized catalytic depolymerization reactor 1 through the working medium hopper 9;

[0079] The preparation method of the zinc / graphite carbon catalyst used is as follows: first, 5 parts of graphite carbon, 60 parts of deionized water, 0.3 parts of zinc nitrate, and 0.5 parts of sodium hydroxide are stirred and mixed uniformly at room temperature for 2 hours. Then, it is transferred into a reaction kettle and reacted at 220°C for 16h, after which it is filtered, rinsed, and dried to finally obtain the catalyst.

[0080] 4) The mixture is mixed with the zinc / graphite carbon catalyst and 0.5 mol / L sodium hydroxide according to a mass ratio of 10:1:10, 70 parts of the mixture are added into the fluidized catalytic depolymerization reactor, and the plastic occurs depolymerization reaction under the action of the catalyst;

[0081] 5) The first cyclone separator 2 is used to separate and treat the depolymerization products, part of the solid products (i.e. the catalyst and the working medium) separated and obtained is conveyed to the fluidized catalytic depolymerization reactor 1 for recycling; part of the solid products is conveyed to the working medium regenerating heater 6 for heating treatment; the high-temperature gas product separated and obtained is conveyed to the waste heat recovery device 3 for waste heat recovery; the waste heat recovery device 3 is a generator; the gas after waste heat recovery enters the steam generator 4, and the steam generated is used as the fluidizing gas of the fluidized catalytic depolymerization reactor 1;

[0082] The gas output from the steam generator 4 enters the three-phase separator 5;

[0083] The gas component separated by the three-phase separator 5 is sent to the working medium regenerative heater 6 and used as fuel gas to heat part of the catalyst and working medium recovered from the first cyclone separator 2, and after being heated to 180°C, is delivered to the working medium hopper 9 and then to the fluidized catalytic depolymerization reactor 1 for recycling. Under the fluidization of water vapor, the organic solid waste liquid is fully mixed and heat exchanged, providing the energy required for the depolymerization reaction of the organic solid waste and accelerating the depolymerization reaction rate.

[0084] The liquid oil component separated by the three-phase separator 5 is stored in the storage tank 11 and separated by water immersion, acidification and other processes to obtain by-products.

[0085] The water component separated by the three-phase separator 5 is delivered to the water treatment device 10, treated and then delivered to the steam generator 4 for recycling.

[0086] The present application adopts the catalytic depolymerization strategy to effectively convert the organic solid waste into syngas, low-carbon olefins and liquid oil and other high-value-added products, and the conversion rate of the organic components reaches 95%; and through a special process route, the closed-loop utilization of the depolymerization products and energy is realized.

[0087] The above has made a detailed introduction to the present application, and the description has applied specific examples to describe the principles and implementation modes of the present application, but the examples are only used to help understand the present application and should not be understood as limiting the present application.

Claims

1. An organic solid waste high-value processing system, characterized by, The system comprises a fluidized catalytic depolymerization reactor (1), a first cyclone separator (2), a waste heat recovery device (3), a steam generator (4), a three-phase separator (5), and a working medium regenerative heater (6) arranged in sequence. The organic solid waste is fed into the fluidized catalytic depolymerization reactor (1) after being treated by melting, and a depolymerization reaction occurs under the action of a catalyst and a working medium. The depolymerization products are separated by the first cyclone separator (2); part of the separated solid products is fed into the fluidized catalytic depolymerization reactor (1) for recycling, and part of the separated solid products is fed into the working medium regenerative heater (6) for heat treatment; the high-temperature gas separated by the first cyclone separator (2) is fed into the waste heat recovery device (3) to recover waste heat; the gas after waste heat recovery is fed into the steam generator (4) to generate steam used as fluidizing gas for the fluidized catalytic depolymerization reactor (1). The gas output from the steam generator (4) is fed into the three-phase separator (5); the gas components separated by the three-phase separator (5) are fed into the working medium regenerative heater (6) as fuel gas for heating the solid products recovered from the first cyclone separator (2); the heated solid products are fed into the fluidized catalytic depolymerization reactor (1) for recycling; the water separated by the three-phase separator (5) is fed into the steam generator (4) for recycling after being treated by water treatment.

2. The system of claim 1, wherein, The system further comprises a conveying mechanism (7) which is a screw conveying mechanism and has a heating function for heating the organic solid waste to a molten state, and the heating function is realized by microwave, photo-thermal or electromagnetic methods.

3. The system of claim 2, wherein, The system comprises a second cyclone separator (8), the organic solid waste in a molten state is fed into the second cyclone separator (8), liquid is sprayed into the fluidized catalytic depolymerization reactor (1) from the bottom of the second cyclone separator (8), and gas is fed into the fluidized catalytic depolymerization reactor (1) from the top of the second cyclone separator (8).

4. The system of claim 3, wherein, The system further comprises a working medium hopper (9) for feeding the mixture of the catalyst and the working medium into the fluidized catalytic depolymerization reactor (1).

5. The system of claim 4, wherein, The solid products separated from the first cyclone separator (2) are heated in the working medium regenerative heater (6) and then fed into the working medium hopper (9).

6. The system of claim 5, wherein, The system further comprises a water treatment system (10) for feeding the water separated by the three-phase separator (5) into the water treatment device (10) for recycling after being treated by water treatment.

7. The system of claim 6, wherein, The liquid oil components separated by the three-phase separator (5) are used to obtain by-products by water immersion, acidification and other processes.

8. The system of claim 1, wherein, The organic solid waste includes one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyurethane, nylon, rubber, waste tires, waste clothes, electronic waste, waste lubricating oil or waste biomass.

9. The system of claim 1, wherein, The working medium includes one or more of molten salt, sandstone, biochar, graphite carbon, amorphous carbon, zinc oxide, cerium oxide, indium oxide or iron oxide.

10. The system of claim 1, wherein, The catalyst is composed of one or more of nickel, iron, cobalt, tungsten, magnesium, zinc, indium oxide, indium tin oxide, zirconium oxide, tungsten oxide, zinc oxide, aluminum oxide, molecular sieve or graphite carbon.

11. The system of claim 10, wherein, When the two-component catalyst is used, the mass ratio between the components of the catalyst satisfies (0.01-100):(0.01-100); when the three-component catalyst is used, the mass ratio between the components satisfies (0.01-100):(0.01-100):(0.01-100).

12. A method for treating organic solid waste by using the organic solid waste high-value treatment system according to any one of claims 1-11.

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