Resource utilization method of waste corrugated board

Abstract

The invention discloses a resource utilization method of waste corrugated boards, which comprises the following steps: crushing the waste corrugated boards used in the packaging and transportation industry, and pyrolyzing the crushed waste corrugated boards in a fluidized bed reactor to respectively prepare bio-oil and biochar. According to the method, the bio-oil and the biochar are simultaneously prepared from the waste corrugated boards, the preparation process is simple and easy to operate, and the yield and the quality of the obtained bio-oil are higher than those of bio-oil obtained by pyrolyzing common biomass; and the obtained biochar also has a relatively high specific surface area and can be used for adsorbing and removing heavy metals in industrial wastewater. Therefore, according to the method disclosed by the invention, the energy of the waste corrugated boards is utilized to the maximum extent, the problem of environmental pollution of the waste corrugated boards is solved, and clean and efficient resource utilization of the waste corrugated boards is realized.

Description

Technical Field

[0001] The invention relates to a method for waste treatment and resource utilization, and in particular to a method for preparing bio-oil and bio-char by pyrolysis of waste corrugated paperboard. Background Art

[0002] As the most common transportation packaging product, corrugated cardboard accounts for about 75% of paper packaging products. While corrugated cardboard provides convenience for our lives, it also consumes huge resources. At present, the main methods for treating waste corrugated cardboard are incineration and recycling. Although incineration of waste corrugated cardboard is simple to operate, it will cause air pollution; after recycling and reprocessing, waste corrugated cardboard can be prepared into new corrugated cardboard and other paper products, but the strength of recycled corrugated cardboard will be reduced. Therefore, the actual recycling rate of waste corrugated cardboard is less than 10%. The large-scale use of waste corrugated cardboard, the resource utilization of corrugated cardboard and pollution prevention and control have become issues that need to be urgently addressed.

[0003] Waste corrugated cardboard has a similar composition to biomass (cellulose, hemicellulose, lignin). If value-added products such as bio-oil and biochar can be obtained through pyrolysis of waste corrugated cardboard, waste corrugated cardboard will be recycled to the maximum extent possible. Summary of the invention

[0004] The purpose of the present invention is to provide a method for resource utilization of waste corrugated cardboard, which fully utilizes the composition characteristics of waste corrugated cardboard and transforms it into bio-oil and biochar with high added value to achieve resource utilization of waste corrugated cardboard, reduce its harm to the environment, and reduce the disposal cost of waste corrugated cardboard.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A method for resource utilization of waste corrugated cardboard comprises crushing the waste corrugated cardboard and then placing the waste corrugated cardboard in a fluidized bed reactor for pyrolysis to obtain bio-oil and bio-char respectively.

[0006] Furthermore, the waste corrugated cardboard is waste generated in the packaging and transportation industry.

[0007] Furthermore, the waste corrugated cardboard is crushed to be able to pass through a 90-mesh sieve.

[0008] Furthermore, the pyrolysis is specifically carried out by first heating the temperature from room temperature to 450-650°C at a rate of 20°C / min under a N2 gasification atmosphere, and reacting at a constant temperature for 10 minutes. The condensable gases generated in the heating and constant temperature stages are collected by cooling, condensing, and obtaining bio-oil. Then, N2 is switched to water vapor, and the constant temperature reaction is continued for 30 minutes. After the reaction is completed, the temperature is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0009] Furthermore, during the pyrolysis process, the N2 flow rate was 350 mL / min.

[0010] Furthermore, during the pyrolysis process, the water vapor flow rate was 250 mL / min.

[0011] The method for recycling waste corrugated cardboard of the present invention has the following beneficial effects: 1. The method of the present invention uses a fluidized bed to pyrolyze waste corrugated cardboard, and the material is heated evenly, so that the volatile matter in the corrugated cardboard can be fully released, thereby obtaining a higher yield of bio-oil. At the same time, because the material is in a fluidized state, it is not easy to coke during the pyrolysis process, and the obtained granular activated carbon has a uniform particle size and better adsorption performance.

[0012] 2. The present invention converts waste corrugated paper into bio-oil and activated carbon with higher added value through pyrolysis, so as to maximize the utilization of the energy of waste corrugated paperboard, realize the clean and efficient resource utilization of waste corrugated paperboard, achieve the purpose of environmental protection, waste resource utilization and sustainable development, and has important significance for my country's economic construction. DETAILED DESCRIPTION

[0013] A method for resource utilization of waste corrugated cardboard comprises the following steps: crushing the waste corrugated cardboard until it passes through a 90-mesh screen, and then placing the cardboard in a fluidized bed reactor; firstly, heating the temperature from room temperature to 450-650°C at a rate of 20°C / min under a N2 gasification atmosphere with a flow rate of 350 mL / min, and conducting a constant temperature reaction for 10 minutes; and collecting the condensable gas generated in the heating and constant temperature stages through cooling, condensation, and obtaining bio-oil; and then switching N2 to water vapor with a flow rate of 250 mL / min, and continuing the constant temperature reaction for 30 minutes. After the reaction is completed, the cardboard is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0014] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0015] The waste corrugated cardboards used in the examples are all wastes generated during packaging and transportation.

[0016] Embodiment 1: Waste corrugated cardboard is crushed until it passes through a 90-mesh sieve, and then 60 g of powder is taken and placed in a fluidized bed reactor (Φ 50mm×900mm). First, under a fluidized atmosphere with a N2 flow rate of 350 mL / min, the reactor is heated from room temperature to 450°C at a heating rate of 20°C / min, and the temperature is maintained at 450°C for 10 minutes. The condensable gas generated during the heating and constant temperature stages is condensed and cooled and collected to obtain bio-oil; then the fluidizing gas N2 is switched to water vapor with a flow rate of 250 mL / min. After continuing the constant temperature reaction for 30 minutes, the reactor is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0017] The yield of bio-oil obtained in this example (water-free basis) is 27.2%, the calorific value is 21.7 MJ / kg, and the pH is 5.1; the yield of activated carbon obtained is 48.1%, and the specific surface area is 221 m 2 / g, iodine adsorption value is 168mg / g, and methylene blue adsorption value is 75.7%.

[0018] Embodiment 2: Waste corrugated cardboard was crushed until it passed through a 90-mesh sieve, and then 60 g of powder was taken and placed in a fluidized bed reactor (Φ 50mm×900mm). First, under a fluidized atmosphere with a N2 flow rate of 350 mL / min, the reactor was heated from room temperature to 500°C at a heating rate of 20°C / min, and the temperature was kept constant at 500°C for 10 minutes. The condensable gas generated during the heating and constant temperature stages was condensed and cooled and collected to obtain bio-oil; then the fluidizing gas N2 was switched to water vapor with a flow rate of 250 mL / min. After continuing the constant temperature reaction for 30 minutes, the reactor was cooled to room temperature, and the pyrolysis residue was taken out to obtain activated carbon.

[0019] The yield of bio-oil obtained in this example (anhydrous basis) is 32.7%, the heat value is 24.5 MJ / kg, and the pH is 6.2; the yield of activated carbon obtained is 44.1%, and the specific surface area is 283m 2 / g, iodine adsorption value is 196mg / g, and methylene blue adsorption value is 79.5%.

[0020] Embodiment 3: Waste corrugated cardboard is crushed until it passes through a 90-mesh sieve, and then 60 g of powder is taken and placed in a fluidized bed reactor (Φ 50mm×900mm). First, under a fluidized atmosphere with a N2 flow rate of 350 mL / min, the reactor is heated from room temperature to 550°C at a heating rate of 20°C / min, and the temperature is maintained at 550°C for 10 minutes. The condensable gas generated during the heating and constant temperature stages is condensed and cooled and collected to obtain bio-oil; then the fluidizing gas N2 is switched to water vapor with a flow rate of 250 mL / min. After continuing the constant temperature reaction for 30 minutes, the reactor is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0021] The yield of bio-oil obtained in this example (anhydrous basis) is 40.5%, the heat value is 28.7 MJ / kg, and the pH is 6.8; the yield of activated carbon obtained is 37.3%, and the specific surface area is 345m 2 / g, iodine adsorption value is 265mg / g, and methylene blue adsorption value is 85.8%.

[0022] Embodiment 4: Waste corrugated cardboard is crushed until it passes through a 90-mesh sieve, and then 60 g of powder is taken and placed in a fluidized bed reactor (Φ 50mm×900mm). First, under a fluidized atmosphere with a N2 flow rate of 350 mL / min, the reactor is heated from room temperature to 600°C at a heating rate of 20°C / min, and the temperature is maintained at 600°C for 10 minutes. The condensable gas generated during the heating and constant temperature stages is condensed and cooled and collected to obtain bio-oil; then the fluidizing gas N2 is switched to water vapor with a flow rate of 250 mL / min. After continuing the constant temperature reaction for 30 minutes, the reactor is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0023] The yield of bio-oil obtained in this example (anhydrous basis) is 48.3%, the heat value is 30.2 MJ / kg, and the pH is 7.2; the yield of activated carbon obtained is 33.4%, and the specific surface area is 396 m 2 / g, iodine adsorption value is 295mg / g, and methylene blue adsorption value is 92.6%.

[0024] Embodiment 5: Waste corrugated cardboard is crushed until it passes through a 90-mesh sieve, and then 60 g of powder is taken and placed in a fluidized bed reactor (Φ 50mm×900mm). First, under a fluidized atmosphere with a N2 flow rate of 350 mL / min, the reactor is heated from room temperature to 650°C at a heating rate of 20°C / min, and the temperature is maintained at 650°C for 10 minutes. The condensable gas generated during the heating and constant temperature stages is condensed and cooled and collected to obtain bio-oil; then the fluidizing gas N2 is switched to water vapor with a flow rate of 250 mL / min. After continuing the constant temperature reaction for 30 minutes, the reactor is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

[0025] The yield of bio-oil obtained in this example (anhydrous basis) is 45.6%, the heat value is 29.8MJ / kg, and the pH is 7.1; the yield of activated carbon obtained is 34.3%, and the specific surface area is 352m 2 / g, iodine adsorption value is 286mg / g, and methylene blue adsorption value is 90.3%.

[0026] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for recycling waste corrugated cardboard, characterized in that: Waste corrugated cardboard was shredded and then placed in a fluidized bed reactor for pyrolysis to obtain bio-oil and biochar, respectively.

2. The method for recycling waste corrugated cardboard according to claim 1, characterized in that: Crush the waste corrugated cardboard until it can pass through a 90-mesh sieve.

3. The method for recycling waste corrugated cardboard according to claim 1, characterized in that: Specifically, the pyrolysis is first carried out under a N2 fluidized atmosphere, with the temperature raised from room temperature to 450-650°C at a rate of 20°C / min, with a constant temperature reaction for 10 minutes, and the generated condensable gas is collected, which is cooled and condensed to obtain bio-oil; then the N2 is switched to water vapor, and the constant temperature reaction is continued for 30 minutes. After the reaction is completed, it is cooled to room temperature, and the pyrolysis residue is taken out to obtain activated carbon.

4. The method for recycling waste corrugated cardboard according to claim 3, characterized in that: During the pyrolysis process, the N2 flow rate was 350 mL / min.

5. The method for recycling waste corrugated cardboard according to claim 3, characterized in that: During the pyrolysis process, the water vapor flow rate was 250 mL / min.