Method for improving the yield of bio-oil from waste shoes and clothes

Abstract

The application discloses a method for improving the yield of bio-oil from waste shoes and clothes, and belongs to the technical field of resource recovery. The method comprises the following steps: drying, crushing and screening the waste shoes and clothes; drying, grinding and screening the red mud; pickling the red mud with a dilute hydrochloric acid solution, drying, screening and calcining the red mud to obtain a modified red mud catalyst; putting the screened waste shoes and clothes and the modified red mud particles into a tubular furnace for pyrolysis treatment; collecting liquid oil and waxy oil generated in the pyrolysis process, and condensing the condensable gas to obtain bio-oil. The method can improve the yield of bio-oil from waste shoes and clothes by using the acidified red mud as a catalyst, and realizes effective resource utilization of the waste shoes and clothes.

Description

Technical Field

[0001] This invention relates to a method for increasing the bio-oil yield from waste footwear and clothing, belonging to the field of resource recycling technology. Background Technology

[0002] Waste footwear and apparel refers to materials and products discarded during production and use. It is often composed of cotton, linen, polyamide, and polyester materials, characterized by high carbon content and low impurity content. Resource scarcity and environmental pollution are common global problems. With the improvement of people's living standards, the lifespan of footwear and apparel products has shortened significantly, leading to a sharp increase in the amount of waste footwear and apparel. This waste is rarely recycled; instead, it is directly discarded, incinerated, or landfilled. Due to the special nature of footwear and apparel materials, they are difficult to degrade in air or biodegrade, resulting not only in huge resource waste but also serious environmental pollution problems, posing a serious threat to the natural environment and human health. Therefore, it is urgent to improve the resource utilization rate of waste footwear and apparel in my country to alleviate resource and environmental pressures.

[0003] Currently, the main processing technologies for waste footwear and clothing include: (1) incineration for power generation; (2) landfill; and (3) recycling or degradation to prepare chemicals. These three types of processing technologies either pollute the environment or produce products with low added value and weak market self-driving force. There is an urgent need to promote new processes and technologies to transform waste footwear and clothing into high-value-added products. Recycling waste footwear and clothing and obtaining high-performance raw materials or products through classification, recycling and reprocessing is an effective way, but the existing process technologies are not suitable for waste footwear and clothing.

[0004] Red mud is a major type of solid waste in the aluminum industry. Generally, producing 1-2 tons of red mud will generate 1 ton of alumina. Currently, with the government's continued policy support, the resource utilization of red mud is receiving more and more attention. Red mud contains a variety of minerals, such as hematite, quartz, calcite, ilmenite, goethite, nepheline calcium, etc., and its chemical composition includes oxides such as Fe2O3, Al2O3, SiO2, CaO, Na2O, and TiO2.

[0005] To improve resource utilization efficiency, certain technologies can be used to recover energy and valuable resources from waste footwear and clothing. This can not only reduce the consumption of fossil fuels but also promote the recycling of waste footwear and clothing. Since waste footwear and clothing are mostly made of mixed materials and contain dyes and pigments that are difficult to separate, recycling them using conventional physical or chemical methods requires pretreatment such as component separation and purification, which is difficult and costly. Among various technologies, catalytic pyrolysis is considered one of the emerging technologies for recovering energy and chemical components from organic waste. It can transform organic solid waste into high-value-added products and has broad prospects. However, the catalysts currently used face problems such as easy deactivation and high cost. Summary of the Invention

[0006] This invention provides a method to improve the bio-oil yield of waste footwear and clothing, in order to solve the problems of incomplete treatment, pollution generation, high treatment costs, and low resource utilization rate in the current waste footwear and clothing treatment. It also makes up for the shortcomings of high catalyst cost and low product quality in catalytic pyrolysis technology, and at the same time broadens the ways to utilize industrial solid waste red mud resources.

[0007] The method of this invention uses acidified red mud as a catalyst and pyrolyzes it together with waste shoes and clothing to obtain bio-oil. The specific steps are as follows: (1) Old shoes and clothing are washed, dried, crushed and screened to obtain old shoes and clothing granules.

[0008] (2) Dry the red mud, grind it, and sieve it to obtain red mud particles.

[0009] (3) The red mud particles obtained in step (2) were acid-washed with hydrochloric acid solution, then washed with deionized water until neutral, dried in an oven, sieved and calcined to obtain modified red mud catalyst for use.

[0010] (4) The old shoe and clothing particles obtained in step (1) and the modified red mud catalyst obtained in step (3) are mixed and then subjected to pyrolysis treatment to obtain liquid oil and waxy oil.

[0011] (5) Collect the liquid oil and waxy oil produced in step (4), collect the condensable gas and condense it to obtain bio-oil.

[0012] Preferably, in step (1), the drying of old shoes and clothing utilizes an electric heating constant temperature blower drying oven, with drying conditions of 60-80℃ for 12-24 hours, and the sieve used for sieving is 60-80 mesh.

[0013] Preferably, the drying equipment used in step (2) is an electric constant temperature blower drying oven, and the drying conditions are drying at 100-120℃ for 24-48 hours. The sieve used for sieving is 60-100 mesh.

[0014] Preferably, the hydrochloric acid solution in step (3) is a dilute hydrochloric acid solution with a concentration of 2 mol / L to 4 mol / L. The drying equipment is an electric thermostatic drying oven, and the drying conditions are drying at 100°C for 24 hours. The sieve used for sieving is 60 to 100 mesh, and the calcination equipment is a muffle furnace, and the calcination conditions are calcination at 400 to 600°C for 4 hours.

[0015] Preferably, the mass ratio of the amount of old shoe and clothing particles to the modified red mud catalyst in step (4) is 2:1 to 1:2.

[0016] Preferably, the reaction temperature of the pyrolysis treatment in step (4) is controlled at 500-700°C, the pyrolysis environment is anaerobic or hypoxic, and the pyrolysis treatment time is 10-60 minutes.

[0017] Preferably, step (4) requires introducing N2 into the tubular furnace.

[0018] Beneficial effects of the present invention (1) The present invention modifies red mud by simple acid treatment, thereby increasing the content of active metal oxides and enhancing catalytic activity. It is used as a catalyst to degrade waste shoes and clothing with high carbon content into liquid pyrolysis products. Due to the presence of many weak and strong acid sites and Fe2O3, Al2O3 and SiO2 in the modified red mud structure, the C-C single bond breaking and liquid aromatization of waste shoes and clothing are promoted, which increases the yield of bio-oil and reduces the generation of pyrolysis gas and carbon. At the same time, the presence of modified red mud reduces the reaction activation energy and further increases the yield of bio-oil.

[0019] (2) Using red mud, a bulk solid waste, as a catalyst, the modification method is simple and low-cost, while reducing pollution and greatly improving the yield of bio-oil.

[0020] (3) The bio-oil produced by this invention can be used in the energy and chemical industries. By using it to generate electricity and then using the electricity in the pyrolysis process, the energy consumption of waste footwear and clothing pyrolysis treatment can be further reduced.

[0021] (4) This invention enables red mud and waste shoes and clothing to be disposed of to varying degrees, providing a new approach to the resource utilization of solid waste and the reduction of environmental pollution caused by the accumulation of pollutants. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0023] Figure 2 XRD pattern of red mud particles. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following embodiments are merely simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims. Example 1

[0025] A method to increase the bio-oil yield from waste footwear and apparel, such as Figure 1 As shown, it includes the following steps: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were cleaned, dried at 60°C for 12 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through a 60-mesh sieve to obtain old shoe and clothing particles.

[0026] (2) Bayer process red mud produced by an aluminum company in Wenshan Prefecture, Yunnan Province was dried at 100°C for 24 hours in an electric constant temperature drying oven, and then ground through a 60-mesh sieve in an agate mortar to obtain red mud particles.

[0027] (3) The red mud particles obtained in step (2) were acid washed with 2 mol / L dilute hydrochloric acid solution and washed with deionized water until neutral. They were dried at 100℃ for 24 hours in an electric thermostatic drying oven, ground through a 60-mesh sieve in an agate mortar, and calcined in a muffle furnace at 400℃ for 4 hours to obtain the modified red mud catalyst for later use.

[0028] (4) The old shoe and clothing particles obtained in step (1) and the modified red mud catalyst obtained in step (3) are fed into a tube furnace at a mass ratio of 1:1 for pyrolysis. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 500℃, the pyrolysis time is 10 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0029] (5) Collect the liquid oil and waxy oil produced in step (4), collect the condensable gas and condense it to obtain bio-oil. Example 2

[0030] A method to increase the bio-oil yield from waste footwear and apparel, such as Figure 1 As shown, it includes the following steps: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were dried at 70°C for 18 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through a 70-mesh sieve to obtain old shoe and clothing particles.

[0031] (2) Bayer process red mud produced by an aluminum company in Wenshan Prefecture, Yunnan Province was dried at 110°C for 36 hours in an electric constant temperature drying oven, and then ground through an 80-mesh sieve in an agate mortar to obtain red mud particles.

[0032] (3) The red mud particles obtained in step (2) were acid washed with 3 mol / L dilute hydrochloric acid solution and washed with deionized water until neutral. They were dried at 100℃ for 24 hours in an electric thermostatic drying oven, ground through an 80-mesh sieve in an agate mortar, and calcined in a muffle furnace at 500℃ for 4 hours to obtain the modified red mud catalyst for later use.

[0033] (4) The old shoe and clothing particles obtained in step (1) and the modified red mud catalyst obtained in step (2) are fed into a tube furnace for pyrolysis treatment at a mass ratio of 2:1. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 600℃, the pyrolysis time is 30 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0034] (5) Collect the liquid oil and waxy oil produced in step (4), collect the condensable gas and condense it to obtain bio-oil. Example 3

[0035] A method to increase the bio-oil yield from waste footwear and apparel, such as Figure 1 As shown, it includes the following steps: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were dried at 80°C for 24 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through an 80-mesh sieve to obtain old shoe and clothing particles.

[0036] (2) Bayer process red mud produced by an aluminum company in Wenshan Prefecture, Yunnan Province was dried at 120°C for 48 hours in an electric constant temperature drying oven, and then ground through a 100-mesh sieve in an agate mortar to obtain red mud particles for later use.

[0037] (3) The red mud particles obtained in step (2) were acid washed with 4 mol / L dilute hydrochloric acid solution and washed with deionized water until neutral. They were dried at 100℃ for 24 hours in an electric thermostatic drying oven, ground through a 100-mesh sieve in an agate mortar, and calcined in a muffle furnace at 600℃ for 4 hours to obtain the modified red mud catalyst for later use.

[0038] (4) The old shoe and clothing particles obtained in step (1) and the modified red mud catalyst obtained in step (3) are fed into a tube furnace for pyrolysis treatment at a mass ratio of 1:2. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 700℃, the pyrolysis time is 60 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0039] (5) Collect the liquid oil and waxy oil produced in step (4), collect the condensable gas and condense it to obtain bio-oil.

[0040] Comparative Example 1 The raw materials and conditions in this embodiment are the same as in Example 1, except that red mud is not added. Specifically: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were dried at 60°C for 12 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through a 60-mesh sieve to obtain old shoe and clothing particles.

[0041] (2) The old shoe and clothing particles obtained in step (1) are sent into a tube furnace for pyrolysis. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 500℃, the pyrolysis time is 10 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0042] (3) Collect the liquid oil and waxy oil produced in step (2), collect the condensable gas and condense it to obtain bio-oil.

[0043] Comparative Example 2 The raw materials and conditions in this embodiment are the same as in Example 1, except that untreated red mud that has not undergone acidification is added. Specifically: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were dried at 60°C for 12 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through a 60-mesh sieve to obtain old shoe and clothing particles.

[0044] (2) Bayer process red mud produced by an aluminum company in Wenshan Prefecture, Yunnan Province was dried at 100°C for 24 hours in an electric constant temperature drying oven, and then ground through a 60-mesh sieve in an agate mortar to obtain red mud particles.

[0045] (3) The old shoe and clothing particles obtained in step (1) and the red mud particles obtained in step (2) are fed into a tube furnace for pyrolysis treatment at a mass ratio of 1:1. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 500℃, the pyrolysis time is 10 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0046] (4) Collect the liquid oil and waxy oil produced in step (3), collect the condensable gas and condense it to obtain bio-oil.

[0047] Comparative Example 3 The raw materials and conditions in this embodiment are the same as in Example 1, except that red mud is replaced with calcium oxide, specifically: (1) The shoes and clothing produced by a shoe and clothing factory in Yunnan Province were dried at 60°C for 12 hours in an electric constant temperature drying oven, and then crushed in a crusher and passed through a 60-mesh sieve to obtain old shoe and clothing particles.

[0048] (2) Calcium oxide produced by a certain mineral products company in Yunnan Province was ground through an agate mortar and passed through a 60-mesh sieve to obtain calcium oxide particles for later use.

[0049] (3) The old shoe and clothing particles obtained in step (1) and the calcium oxide particles obtained in step (2) are fed into a tube furnace for pyrolysis in a mass ratio of 1:1. N2 is introduced during the pyrolysis process, the pyrolysis temperature is 500℃, the pyrolysis time is 10 minutes, and the pyrolysis process is kept in an oxygen-free environment.

[0050] (4) Collect the liquid oil and waxy oil produced in step (3), collect the condensable gas and condense it to obtain bio-oil.

[0051] Figure 2 The image shows the XRD pattern of the red mud used in the example. As can be seen from the image, the red mud contains Fe2O3, Al2O3, Ca2CO3, and Na2CO3.

[0052] The yields of bio-oil from the pyrolysis of waste footwear and clothing in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0053] Table 1. Bio-oil yield from pyrolysis of waste footwear and clothing in Examples 1-3 and Comparative Examples 1-3

[0054] As can be seen from Table 1, comparing Example 1 with Comparative Example 1, it can be seen that adding red mud to the catalytic pyrolysis reaction can significantly improve the yield of bio-oil. This is because Fe2O3, Al2O3 and SiO2 are the main components of red mud, and there are weak acid and strong acid sites in its structure. Modified red mud can be considered as a solid acid catalyst.

[0055] A comparison of Example 1 and Comparative Example 2 shows that, compared to untreated and unroasted red mud, the addition of modified red mud increased the yield of bio-oil. This is because acid washing and roasting effectively reduced the amount of Na+ in the red mud that inhibited catalysis. + The content, and makes the red mud contain Fe 3+ And Al 3+ The minerals are transformed into more stable Fe2O3 and Al2O3, increasing the content of active metal oxides and enhancing catalytic activity.

[0056] A comparison of Example 1 and Comparative Example 3 shows that, compared with calcium oxide catalysis, the use of red mud catalysis improves the yield of bio-oil. This is because the presence of Fe2O3 and TiO2 in the red mud components allows for other reaction pathways, such as hydrogenation or hydrocracking, thereby increasing the yield of bio-oil.

Claims

1. A method for increasing the yield of bio-oil from waste footwear and clothing, characterized in that: Bio-oil is produced by pyrolyzing acidified red mud as a catalyst together with waste footwear and clothing. The specific steps are as follows: (1) Old shoes and clothing are washed, dried, crushed and sieved to obtain old shoe and clothing granules; (2) Dry, grind and sieve the red mud to obtain red mud particles; (3) The red mud particles obtained in step (2) were acid washed with hydrochloric acid solution, then washed with deionized water until neutral, dried in an oven, sieved and calcined to obtain the modified red mud catalyst for use. (4) The old shoe and clothing particles obtained in step (1) and the modified red mud catalyst obtained in step (3) are mixed and then subjected to pyrolysis to obtain liquid oil and waxy oil; (5) Collect the liquid oil and waxy oil produced in step (4), collect the condensable gas and condense it to obtain bio-oil; The hydrochloric acid solution mentioned in step (3) is a dilute hydrochloric acid solution with a concentration of 2mol / L to 4mol / L. The drying equipment is an electric constant temperature drying oven, and the drying conditions are drying at 100℃ for 24 hours. The sieve used for sieving is 60 to 100 mesh. The calcination equipment is a muffle furnace, and the calcination conditions are calcination at 400 to 600℃ for 4 hours. Red mud contains Fe2O3, Al2O3, CaCO3 and Na2CO3.

2. The method for increasing the bio-oil yield from waste footwear and clothing according to claim 1, characterized in that: In step (1), the old shoes and clothing are dried using an electric constant temperature blower drying oven. The drying conditions are 60-80℃ for 12-24 hours, and the sieve used for sieving is 60-80 mesh.

3. The method for increasing the bio-oil yield from waste footwear and clothing according to claim 1, characterized in that: In step (2), the drying equipment used is an electric constant temperature drying oven, and the drying conditions are 100-120℃ for 24-48 hours. The sieve used for sieving is 60-100 mesh.

4. The method for increasing the yield of bio-oil from waste footwear and clothing according to claim 1, characterized in that: In step (4), the mass ratio of the amount of old shoe and clothing particles to the modified red mud catalyst is 2:1 to 1:

2.

5. The method for increasing the yield of bio-oil from waste footwear and clothing according to claim 1, characterized in that: The reaction temperature of the pyrolysis treatment in step (4) is controlled at 500-700℃, the pyrolysis environment is oxygen-free, and the pyrolysis treatment time is 10-60 minutes.

6. The method for increasing the yield of bio-oil from waste footwear and clothing according to claim 1, characterized in that: Step (4) requires introducing N2 into the tubular furnace.

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