A method for preparing fuel based on industrial waste

Abstract

The present invention discloses a method for preparing fuel based on industrial waste, comprising the following steps: S1 mixing and pressurizing: industrial waste and crop waste are mixed in proportion and put into a reaction tank, and the reaction tank is continuously pressurized at the same time; S2 intermittent pressure reduction: firstly, a single tank body is instantaneously depressurized, and then the adjacent tank body is mechanically depressurized instantly, and the connecting plate between the adjacent tank bodies is opened at the same time; the above steps are repeated until all tank bodies are depressurized; S3 initial pressurization: adjusting the water content of the mixture, closing all valves and sending steam to heat and pressurize the tank body; S4, continuous pressurization: adding an organic heat carrier to an organic heat carrier boiler, realizing an organic heat carrier circulation with a temperature greater than 200°C in the heating sleeve, and continuing heating and pressurization; S5, extrusion molding: collecting the product in the tank body and extruding it into a fuel block. In the present invention, by designing a continuous explosion and crushing reaction, the reactant is fibrotic and easy to react, and the calorific value and recovery value of the fuel are improved at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive resource utilization, and in particular to a method for preparing fuel based on industrial waste. Background Art

[0002] Industrial waste refers to solid, semi-solid, liquid and gaseous substances in containers that have lost their original value or have not lost their value but have been abandoned or discarded during industrial production activities, mainly including metallurgical waste slag, mining waste slag, fuel waste slag and chemical waste slag. With the acceleration of urbanization and the gradual improvement of people's living standards, more and more industrial solid waste has appeared in my country. A large amount of industrial waste will pollute the environment and endanger people's physical and mental health. Enterprises need to meet the requirements of reduction, harmlessness and resource utilization in the treatment of industrial waste.

[0003] The treatment of industrial waste in the prior art has the following problems: 1. When the waste is crushed uniformly, it is easy to cause accumulation, which reduces the crushing effect, and the particle size of the waste after crushing is uneven, which takes a long time in the subsequent pyrolysis and the pyrolysis effect is inconsistent; 2. The temperature required for incineration pyrolysis is too high and the energy demand is large, while the landfill method will cause secondary pollution to the environment and soil. Summary of the invention

[0004] The present invention overcomes the shortcomings of the prior art and provides a method for preparing fuel based on industrial waste, aiming to solve the problem of how to achieve harmless and resourceful treatment of industrial waste in the prior art, while reducing energy demand and waste during treatment.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing fuel based on industrial waste, comprising the following steps:

[0006] S1. Mixing industrial waste and crop waste with cell wall structure in a ratio of 2-4:1 and putting them into several reaction tanks, and continuously pressurizing the several reaction tanks until the pressure is 4.69MPa-8.43MPa and the temperature is greater than 200°C;

[0007] S2, including the following steps: ① Instantaneously depressurize a single tank within 0.3-0.5s, reduce the internal pressure to atmospheric pressure and keep the pressure unchanged; ② After depressurizing a single tank, repeat step ① for the adjacent tank, and open the connecting plate between the adjacent tanks within 0.5-1s; ③ Repeat steps ① and ② until all tanks are depressurized;

[0008] S3, adding water to the fibrous mixture obtained in S2 and mixing, adjusting the water content of the mixture to 15%-20%, closing all valves and introducing steam to heat and pressurize it to a temperature of 135°C-250°C and a pressure of 1.36-3.68MPa;

[0009] S4. Adding organic heat carrier into the organic heat carrier boiler, realizing the circulation of organic heat carrier with a temperature greater than 200° C. in the heating sleeve, and continuing to heat and pressurize so that the temperature in the reaction tank is 250° C.-350° C. and the pressure is 3.68 MPa-7.91 MPa;

[0010] S5, discharging the remaining water vapor and heat in the tank body obtained in S4, collecting the products in the tank body and squeezing them into block fuel with a hollow structure, and coating the inner wall of the hollow structure with a combustion-aiding agent solution.

[0011] It should be noted that the continuous increase in temperature and pressure inside the reaction tank will cause most of the water in the crop waste to turn into water vapor. Due to the high temperature, the pressure of the water vapor increases, causing the softened crop waste to expand. At this time, the pressure inside and outside the crop waste is balanced. At this time, the pressure is suddenly reduced, causing the crop waste to come into contact with an environment with lower air pressure, breaking away from the restraining force of the air pressure in the tank. The water in the crop waste expands rapidly, causing the cell walls of the crop waste to break and explode, tearing plant tissue and dispersing it into fibers. In this process, the crop waste will form a diffuse explosion, while driving the industrial waste to diffuse in the tank in the form of an explosion.

[0012] In a preferred embodiment of the present invention, the direction of reducing the pressure on the tank bodies in S2 is to reduce the pressure on the central tank body first and then on the tank bodies on both sides in sequence. Due to energy attenuation after a single blast, the oscillation frequency and oscillation speed of the crop waste and industrial waste in the sealed reaction tank will be reduced. The order of reducing the pressure on the central tank body first and then on the tank bodies on both sides can allow the oscillation to be transmitted between adjacent tank bodies, thereby increasing the final value of the previous oscillation attenuation, thereby further improving the blasting and crushing effect.

[0013] In a preferred embodiment of the present invention, the direction of reducing the pressure on the tank body in S2 is from one end to the other end in sequence, forming a segmented energy supply form, thereby improving the effect of blasting in the next stage, and at the same time, part of the blasting oscillation energy is transmitted back to the previous tank body, thereby improving the blasting and crushing effect of a single tank body to a certain extent.

[0014] In a preferred embodiment of the present invention, the extrusion molding pressure in S5 is 50-120 MPa to ensure that the mixture can form a fuel block with a hollow structure after cooling, and the structure is tight and not loose.

[0015] In a preferred embodiment of the present invention, the combustion improver solution is one or more of ethylene glycol waste, waste methanol, waste ethane, waste ethanol, waste paint, waste acetone, waste butanol, waste mercaptan or oil waste. The combustion improver solution penetrates into the fuel block. When used, the combustion improver is conducive to the rapid occurrence of combustion, and cooperates with the hollow structure to ensure the continuity and high efficiency of combustion.

[0016] In a preferred embodiment of the present invention, the industrial waste is combustible waste, including metal slag, fly ash, coal slag, metal dust, waste plastics, rubber waste, papermaking waste, etc.

[0017] The present invention also provides a device for preparing fuel based on industrial waste, comprising a storage bin, a plurality of reaction tanks, a heating sleeve, a steam once-through boiler, an organic heat carrier boiler, a cyclone dust collector and a deodorizing device, characterized in that:

[0018] The storage bin is arranged on one side of the plurality of reaction tanks, the cyclone dust collector is connected to the outlet at the bottom of the reaction tank and the deodorizing device, a heating sleeve is installed at the lower part of the reaction tank, and a drain pipe is arranged on the heating sleeve, and the steam direct-flow boiler and the organic heat carrier boiler are respectively connected to the reaction tank and the heating sleeve;

[0019] An organic heat carrier is added inside the organic heat carrier boiler.

[0020] In a preferred embodiment of the present invention, a pressure regulating valve is provided on the connecting pipe between the reaction tank and the cyclone dust collector, and a pressure regulating valve is also provided on the connecting pipe between the reaction tank and the steam direct current boiler.

[0021] In a preferred embodiment of the present invention, a plurality of the reaction tanks are provided with a pressure reduction control valve, a temperature display and an air pressure display. The pressure reduction control valve is used to control the release of air pressure in a short period of time, so that the tank body forms an instantaneous pressure reduction.

[0022] It should be noted that a protective cover is provided around the pressure reducing control valve in the tank body to reduce the risk of damage to the pressure reducing control valve caused by the explosion vibration of waste during the explosion.

[0023] In a preferred embodiment of the present invention, the reaction tank is also connected to the booster module and the water tank, and the water temperature in the water tank is 125-150° C. and the pressure is 0.195-1.385 MPa. The water is pretreated to become subcritical water, thereby reducing the time required for subsequent waste treatment.

[0024] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0025] (1) In the present invention, industrial waste is pre-treated, i.e., blasting and crushing treatment is performed. The characteristic that an object will form an explosion-like state after continuous pressurization and then instantaneous depressurization is utilized. The industrial waste and crop waste are mixed and then pressurized and depressurized. The crop waste is made to explode first and drive the industrial waste to oscillate back and forth in a diffusion manner in the sealed tank, thereby destroying the external morphological structure of the industrial waste. Then, the industrial waste itself is made to explode, changing its internal morphology into a crushed fibrous mixture, so as to facilitate the subsequent subcritical water treatment of the waste.

[0026] (2) The present invention designs a number of interconnected reaction tanks, which respectively control the duration of the explosion of the material in a single tank and the duration of the communication between adjacent tanks through a pressure reducing valve and a connecting plate, thereby forming a segmented explosion, which enables the explosion energy to be communicated between adjacent tanks, reduces the attenuation of energy, and produces a superposition effect on the explosion oscillation result, thereby improving the blasting effect to a certain extent; at the same time, since the water content, air pressure, temperature, material form and material content in the tank are not exactly the same, the explosion oscillation energy generated by adjacent tanks is also different, resulting in different energy oscillation attenuation and different energy replenishment.

[0027] (3) The present invention uses crop waste with a cell wall structure as a reactant, so that under the treatment of pressure increase and pressure reduction as well as high temperature and high pressure, lignin, hemicellulose and other substances are released, and the molten state is maintained and distributed in the waste mixture, and further dispersed in the block fuel during extrusion molding. After cooling, an adhesion effect is generated, and the block fuel is formed into a fixed shape, ensuring that its structure is tight and not loose, which is convenient for transportation, and at the same time does not affect the combustion and use of the fuel.

[0028] (4) By designing the fuel block to have a hollow structure, the contact area with oxygen during the combustion process is larger, and the combustion is more complete; at the same time, an injection hole is provided on the extrusion device, and the inner wall surface of the hollow structure is coated with a combustion aid solution. During the extrusion molding process, the combustion aid is covered on the inner wall of the hollow structure and in the fuel block, making it easier to ignite during use, thereby improving the combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a schematic diagram of a preferred embodiment of the present invention; DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0033] like Figure 1 As shown, a schematic flow diagram of a method for preparing fuel based on industrial waste includes the following steps:

[0034] S1. Mixing combustible industrial waste and crop waste with cell wall structure in a ratio of 2-4:1 into several reaction tanks, and continuously pressurizing the several reaction tanks until the pressure is 4.69MPa-8.43MPa and the temperature is greater than 200°C;

[0035] S2, including the following steps: ① Instantaneously depressurize a single tank within 0.3-0.5s, reduce the internal pressure to atmospheric pressure and keep the pressure unchanged; ② After depressurizing a single tank, repeat step ① for the adjacent tank, and open the connecting plate between the adjacent tanks within 0.5-1s; ③ Repeat steps ① and ② until all tanks are depressurized;

[0036] S3, adding water to the fibrous mixture obtained in S2 and mixing, adjusting the water content of the mixture to 15%-20%, closing all valves and introducing steam to heat and pressurize it to a temperature of 135°C-250°C and a pressure of 1.36-3.68MPa;

[0037] S4. Adding organic heat carrier into the organic heat carrier boiler, realizing the circulation of organic heat carrier with a temperature greater than 200° C. in the heating sleeve, and continuing to heat and pressurize so that the temperature in the reaction tank is 250° C.-350° C. and the pressure is 3.68 MPa-7.91 MPa;

[0038] S5. Expel the remaining water vapor and heat in the tank body obtained in S4, collect the products in the tank body and extrude them into block fuel with a hollow structure under a pressure of 50MPa-120MPa, and at the same time coat the inner wall of the hollow structure with a combustion-aiding agent solution, and the combustion-aiding agent solution is one or more of ethylene glycol waste, waste methanol, waste ethane, waste ethanol, waste paint, waste acetone, waste butanol, waste mercaptan or oil waste.

[0039] The direction of reducing the pressure on the tank bodies in S2 is to reduce the pressure on the central tank body first and then on the tank bodies on both sides in sequence. Due to the energy attenuation after a single blast, the oscillation frequency and oscillation speed of crop waste and industrial waste in the sealed reaction tank will be reduced. This sequence can make the oscillation be transmitted between adjacent tank bodies, increase the final value of the previous oscillation attenuation, and thus further improve the blasting and crushing effect.

[0040] The direction of reducing the pressure on the tank body in S2 is from one end to the other end in sequence, forming a segmented energy supply form, which improves the effect of blasting in the next stage. At the same time, part of the blasting oscillation energy is transmitted back to the previous tank body, which improves the blasting and crushing effect of a single tank body to a certain extent. Specific embodiment one:

[0042] S1. Mix metal slag, fly ash and waste plastic in a ratio of 1:5:4, and mix them with corn stalks in a ratio of 2:1 and put them into several reaction tanks, and continuously pressurize the several reaction tanks until the pressure reaches 4.9 MPa and the temperature reaches 206°C;

[0043] S2, including the following steps: ① Instantaneously depressurize the first tank on the left within 0.4s, reduce the internal pressure to atmospheric pressure and keep the pressure unchanged; ② After the first tank is depressurized, repeat step ① for its adjacent tank, and open the connecting plate between adjacent tanks within 0.7s; ③ Starting from the first tank on the left, depressurize the tanks on the right until all tanks are depressurized;

[0044] S3, adding water to the fibrous mixture obtained in S2 and mixing, adjusting the water content of the mixture to 16%, closing all valves and introducing steam to heat and pressurize it to a temperature of 155° C. and a pressure of 1.99 MPa;

[0045] S4, adding organic heat carrier to the organic heat carrier boiler, and continuing to heat and pressurize so that the temperature in the reaction tank is 283°C and the pressure is 3.85MPa;

[0046] S5. Expel the remaining water vapor and heat in the tank body obtained in S4, collect the products in the tank body and extrude them into block fuel with a hollow structure under a pressure of 80MPa, and at the same time coat the inner wall of the hollow structure with a mixture of ethylene glycol waste, waste methanol and waste ethane. Specific embodiment 2:

[0048] S1. Mix metal dust, waste plastics and waste rubber residue in a ratio of 2:4:4, and then mix them with soybean straw in a ratio of 3:1 and put them into several reaction tanks, and continuously pressurize the several reaction tanks until the pressure reaches 6.35 MPa and the temperature reaches 239°C;

[0049] S2, including the following steps: ① Instantaneously depressurize the middle tank within 0.5s, reduce the internal pressure to atmospheric pressure and keep the pressure unchanged; ② After the depressurization of the middle tank is completed, repeat step ① for the tanks on its left and right sides, and at the same time, open the connecting plate between the left tanks within 0.5s, and open the connecting plate between the right tanks within 1s; ③ Starting from the middle tank, depressurize the tanks on both sides in the order of left first and right, until all tanks are depressurized;

[0050] S3, adding water to the fibrous mixture obtained in S2 and mixing, adjusting the water content of the mixture to 20%, closing all valves and sending steam to heat and pressurize it to a temperature of 157° C. and a pressure of 2.06 MPa;

[0051] S4, adding organic heat carrier to the organic heat carrier boiler, and continuing to heat and pressurize so that the temperature in the reaction tank is 300°C and the pressure is 4.26MPa;

[0052] S5. Expel the remaining water vapor and heat in the tank body obtained in S4, collect the products in the tank body and extrude them into block fuel with a hollow structure under a pressure of 80MPa, and at the same time coat the inner wall of the hollow structure with a mixture of waste acetone, waste ethanol, waste butanol and waste ethane.

[0053] Comparative Example 1

[0054] S1. Mix metal dust, fly ash and rubber waste in a ratio of 1:5:4, mix with soybean straw in a ratio of 2:1, crush and put into a reaction tank;

[0055] S2. Add water to the tank and mix it, adjust the water content of the mixture to 19%, close all valves and send steam to heat and pressurize it to 150°C and 1.92MPa;

[0056] S3, adding organic heat carrier to the organic heat carrier boiler, and continuing to heat and pressurize so that the temperature in the reaction tank is 299°C and the pressure is 4.20MPa;

[0057] S4. Expel the remaining water vapor and heat in the tank body obtained in S3, collect the products in the tank body and extrude them into block fuel with a hollow structure under a pressure of 80 MPa.

[0058] For large solids (volume greater than 0.8 cm 3 , length greater than 1cm) proportion was measured, and the results showed that the contents in Example 1, Example 2 and the comparative example were 10.56%, 9.6% and 15% respectively. It can be seen that the waste treated by explosion crushing has a smaller volume, a high degree of fibrosis, and is more conducive to the reaction.

[0059] A combustion test was carried out on the fuel blocks of equal volume after extrusion molding. The results showed that the combustion times of Example 1, Example 2 and the comparative example were 14 min, 23 min and 10 min, respectively, and the high calorific value Qgr.d on a dry basis were 29.45 MJ / kg, 31.96 MJ / kg and 25.67 MJ / kg, respectively. That is, the processing method of the present invention enables the fuel to have a higher calorific value and heat energy recovery value.

[0060] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing fuel based on industrial waste, characterized in that: The following steps are involved: S1. Mix industrial waste and crop waste in a ratio of 2-4:1 and put them into several reaction tanks, and continuously pressurize the several reaction tanks until the pressure is 4.69MPa-8.43MPa and the temperature is greater than 200°C; S2. Several reaction tanks are connected to each other, and the duration of the explosion of the material in a single tank and the duration of the communication between adjacent tanks are controlled by the pressure reducing valve and the connecting plate, so as to form a segmented explosion so that the explosion energy is communicated between adjacent tanks, including the following steps: ① Instantaneously reduce the pressure of a single tank within 0.3-0.5s, reduce the internal air pressure to atmospheric pressure and keep the air pressure unchanged; ② After the pressure reduction of a single tank is completed, repeat step ① for the adjacent tank, and open the connecting plate between the adjacent tanks within 0.5-1s; ③ Repeat steps ① and ② until all tanks are depressurized; S3, adding water to the fibrous mixture obtained in S2 and mixing, adjusting the water content of the mixture to 15%-20%, closing all valves and introducing steam to heat and pressurize it to a temperature of 135°C-250°C and a pressure of 1.36-3.68MPa; S4. A heating sleeve is installed at the lower part of the reaction tank, and the organic heat carrier boiler is connected to the heating sleeve. An organic heat carrier is added to the organic heat carrier boiler, and an organic heat carrier with a temperature greater than 200° C. is circulated in the heating sleeve. At the same time, heating and pressurizing are continued to make the temperature in the reaction tank 250° C.-350° C. and the pressure 3.68 MPa-7.91 MPa; S5, discharging the remaining water vapor and heat in the tank body obtained in S4, collecting the product in the tank body and extruding it into a block fuel with a hollow structure, and coating the inner wall of the hollow structure with a combustion-supporting agent solution; The direction of reducing the pressure on the tank bodies in S2 is to reduce the pressure on the central tank body first and then on the tank bodies on both sides in sequence, or the direction of reducing the pressure on the tank bodies in S2 is to reduce the pressure from one end to the other end in sequence.

2. A method for preparing fuel based on industrial waste according to claim 1, characterized in that: The combustion-supporting agent solution is one or more of ethylene glycol waste, waste methanol, waste ethane, waste ethanol, waste paint, waste acetone, waste butanol, waste mercaptan or oil waste.

3. A method for preparing fuel based on industrial waste according to claim 1, characterized in that: The pressure of the extrusion molding in S5 is 50-120 MPa.

4. A method for preparing fuel based on industrial waste according to claim 1, characterized in that: The industrial waste is combustible waste.

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