Efficient treatment method for waste plastic pyrolysis

Abstract

The invention discloses an efficient treatment method for waste plastic pyrolysis, which is characterized in that waste plastic is pretreated into 200-300 [mu] m powder, the reaction surface area is increased, and the pyrolysis efficiency is promoted; the powder and the Fe-Zr / ZSM-5 catalyst are mixed in a three-strand impinging stream feeding device, so that the mixing uniformity and the reaction acceleration are ensured. In the descending reactor, the mixture is pyrolyzed under the controlled carbon dioxide atmosphere and heating rate, and local overheating is avoided; a gas phase, a liquid phase and a solid phase generated by pyrolysis are effectively separated and preliminarily cooled through a cyclone separator and a cooling system; large-particle dust is removed from pyrolysis gas in an inner cylinder cyclone dust collector of the integrated radial bed, and dust removal and dechlorination are performed through an interlayer filled with modified activated carbon, so that the purity of pyrolysis oil is improved; pyrolysis gas is cooled to the room temperature, and pyrolysis oil, gas and solid residues are conveniently collected; through comparative analysis of the embodiment, the particle size range of 200-300 microns is determined as the optimal operation condition, at the moment, the pyrolysis efficiency is highest, and the quality of the generated pyrolysis oil is optimal.

Description

Technical Field

[0001] The invention relates to the technical field of pyrolysis treatment of waste plastics, and in particular to an efficient treatment method for pyrolysis of waste plastics. Background Art

[0002] In today's society, the disposal of waste plastics has become a global environmental issue. Since waste plastics are difficult to degrade, long-term accumulation will cause serious damage to the ecosystem, and also waste its potential energy and material value. Traditional methods of waste plastic disposal, such as landfill and incineration, have problems of environmental pollution and waste of resources. Therefore, it is of great significance to seek an efficient and environmentally friendly treatment method.

[0003] As a feasible solution, waste plastic pyrolysis technology achieves resource utilization of waste plastics by heating waste plastics in an oxygen-deficient or controlled atmosphere to decompose them into pyrolysis oil, combustible gas and solid residue. However, problems such as the release of volatile substances, local overheating and thermal stress during pyrolysis may affect the pyrolysis efficiency and product quality. In addition, the particle size of waste plastics also has a significant impact on the pyrolysis process. Smaller particles tend to aggregate, reducing the pyrolysis efficiency, while larger particles may lead to uneven pyrolysis1.

[0004] In order to overcome the shortcomings of the prior art, the present invention provides an efficient treatment method for pyrolysis of waste plastics, including the steps of pretreatment, mixing, pyrolysis heating, product separation, dust removal, etc. The method effectively improves the pyrolysis efficiency and product quality, and reduces environmental pollution by precisely controlling the particle size of the waste plastic powder, the mixing ratio of the mixture and the catalyst, the pyrolysis temperature and the heating rate, and adopting technical means such as an integrated radial bed inner cylinder cyclone dust collector and modified activated carbon.

[0005] Therefore, it is necessary to provide an efficient treatment method for pyrolysis of waste plastics to solve the above technical problems. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and provides an efficient treatment method for pyrolysis of waste plastics.

[0007] To achieve the above object, the technical solution adopted by the present invention is: an efficient treatment method for pyrolysis of waste plastics, comprising the following steps:

[0008] S1: pre-treating the waste plastics and crushing the waste plastics into waste plastic powder with a particle size ranging from 200 to 300 μm;

[0009] S2: A three-stream impingement flow feeding device is arranged at the inlet of the reactor to mix the waste plastic powder and the catalyst in the reactor to form a mixture;

[0010] S3: The mixed material is pyrolyzed and heated in the descending reactor, the mixed material is pyrolyzed in a controlled atmosphere at a temperature of 500-600° C., and slowly heated to a set temperature at a heating rate of 1-5° C. / s;

[0011] S4: separating the pyrolysis gas, pyrolysis liquid and solid residue generated by pyrolysis, and preliminarily cooling them through a cooling system to prepare for the next step of dust removal;

[0012] S5: introducing the dust carried by the pyrolysis gas after preliminary cooling into the inner cylinder cyclone dust collector of the integrated radial bed to separate the particle dust, and separating and collecting the dust from the gas by the principle of centrifugal force;

[0013] S6: The pyrolysis gas after the cyclone dust collector enters the interlayer, which is filled with high-temperature dechlorination adsorbent particles with a particle size of 2-5mm, and further removes fine dust particles of 30-300μm and ≤30μm at the operating temperature to achieve dechlorination and deep dust removal, and then the pyrolysis gas is further cooled to room temperature to collect pyrolysis oil, gas and solid residue respectively.

[0014] In a preferred embodiment of the present invention, in S2, the mixed material is impact mixed in a three-stream impact flow feeding device at an angle of 60° and a speed of 5-10 m / s, and the mass ratio of the waste plastic powder to the catalyst is 1:1.

[0015] In a preferred embodiment of the present invention, in S2, the mixing time of the waste plastic powder and the catalyst in the three-stream impinging flow feeding device is 5-10 minutes.

[0016] In a preferred embodiment of the present invention, in said S2, the catalyst is Fe-Zr / ZSM-5.

[0017] In a preferred embodiment of the present invention, in S3, the inner lining of the descending reactor is made of a material with high heat conduction efficiency, and an agitator is provided in the descending reactor to keep the mixture heated evenly.

[0018] In a preferred embodiment of the present invention, in said S3, the temperature is set in the range of 500-600°C.

[0019] In a preferred embodiment of the present invention, in said S4, the cooling range of the cooling system is 200-300° C., and the cooling time is 2-5 min.

[0020] In a preferred embodiment of the present invention, in S5, the inner drum cyclone dust collector is used to separate the particle dust of ≥300 μm.

[0021] In a preferred embodiment of the present invention, in S6, the warm dechlorination adsorbent particles are modified activated carbon.

[0022] In a preferred embodiment of the present invention, in said S6, the operating temperature ranges from 550°C to 650°C.

[0023] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0024] (1) The present invention ensures efficient energy transfer and sufficient release of volatile substances during the pyrolysis process by pre-treating waste plastics to waste plastic powders not exceeding 300 μm. In particular, a three-stream impinging stream feeding device is used to achieve mixing of waste plastic powders and catalysts in step S2. This unique mixing method improves mixing efficiency and uniformity, creating ideal conditions for subsequent pyrolysis reactions. At the same time, in step S3, by precisely controlling the heating rate and temperature, the method effectively avoids local overheating and incomplete reactions that may be caused by rapid pyrolysis, thereby improving the yield and quality of pyrolysis oil.

[0025] (2) In the present invention, in steps S5 and S6, an integrated radial bed inner cylinder cyclone dust collector and high-temperature dechlorination adsorbent particles in the interlayer are used for deep dust removal and dechlorination treatment, which not only effectively removes dust in the pyrolysis gas, but also further improves the purity of the pyrolysis oil and reduces secondary pollution. In particular, the use of modified activated carbon shows excellent adsorption performance, ensures the cleanliness of the pyrolysis gas, and provides high-quality raw materials for the subsequent application of the pyrolysis product.

[0026] (3) In the present invention, by controlling the particle size of the waste plastic powder to 200-300 μm, efficient energy conversion and pyrolysis oil output are achieved, while ensuring a more uniform heat distribution and a more complete reaction during the pyrolysis process, significantly improving the pyrolysis efficiency and output rate, and reducing energy loss. Under optimized pyrolysis conditions, by heating to 500-600°C at a precise heating rate of 1-5°C / s in a controlled atmosphere (carbon dioxide), local overheating can be effectively prevented, ensuring the uniformity and completeness of the reaction, thereby optimizing the composition and quality of the pyrolysis product. In addition, the use of Fe-Zr / ZSM-5 catalyst further improves the selectivity of the product. The present invention not only improves the resource utilization rate of waste plastics, but also significantly improves the purity of pyrolysis oil through deep dust removal and dechlorination treatment, providing high-quality raw materials for the high-value application of pyrolysis oil. The application of modified activated carbon not only improves the quality of oil products, but also reduces environmental pollution, embodies the design concept of green chemistry and circular economy, and achieves a dual improvement in environmental and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 It is a flow chart of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] like Figure 1 As shown, the present invention provides an efficient treatment method for pyrolysis of waste plastics, comprising the following steps:

[0032] S1: pre-treating the waste plastics and crushing the waste plastics into waste plastic powder with a particle size ranging from 200 to 300 μm;

[0033] S2: A three-stream impingement feed device is set at the inlet of the reactor. The mixed material is impinged and mixed in the three-stream impingement feed device at an angle of 60° and a speed of 5-10 m / s. The mass ratio of the waste plastic powder and the catalyst is 1:1. The waste plastic powder and the catalyst are mixed in the reactor for 5-10 minutes to form a mixed material. The catalyst is Fe-Zr / ZSM-5;

[0034] S3: The mixed material is pyrolyzed and heated in the descending reactor. The inner lining of the descending reactor is made of a material with high heat conduction efficiency. A stirrer is provided in the descending reactor to keep the mixed material heated evenly. The mixed material is pyrolyzed in a controlled atmosphere at a temperature of 500-600° C. and slowly heated to 500-600° C. at a heating rate of 1-5° C. / s.

[0035] S4: The pyrolysis gas, pyrolysis liquid and solid residue generated by pyrolysis are separated and preliminarily cooled through a cooling system in preparation for the next step of dust removal, so that the cooling range of the cooling system is 200-300°C.

[0036] Cooling time is 2-5min;

[0037] S5: introducing the dust carried by the pyrolysis gas after preliminary cooling into the inner cylinder cyclone dust collector of the integrated radial bed, the inner cylinder cyclone dust collector is used to separate the particle dust ≥300μm, and separate and collect the dust from the gas by the principle of centrifugal force;

[0038] S6: The pyrolysis gas after the cyclone dust collector enters the interlayer, which is filled with high-temperature dechlorination adsorbent particles with a particle size of 2-5 mm. The high-temperature dechlorination adsorbent particles are modified activated carbon, which further removes fine dust particles of 30-300μm and ≤30μm at an operating temperature range of 550-650℃ to achieve dechlorination and deep dust removal, and then the pyrolysis gas is further cooled to room temperature to collect pyrolysis oil, gas and solid residue respectively.

[0039] It should be noted that:

[0040] S1: The pretreatment step ensures that the waste plastic is effectively broken into fine powder with a particle size of no more than 300μm, which increases the surface area of ​​the pyrolysis reaction, thereby improving the pyrolysis efficiency and the yield of pyrolysis oil. The uniformity of the fine powder helps to achieve more uniform pyrolysis in the subsequent steps.

[0041] S2: The design of the three-stream impingement flow feed device promotes the mixing of waste plastic powder and catalyst at a specific angle and speed, ensuring the uniformity and sufficiency of the mixing. The addition of Fe-Zr / ZSM-5 catalyst at a mass ratio of 1:1 helps to accelerate the pyrolysis reaction and improve the selectivity of the product, while shortening the mixing time to 5-10 minutes and improving the processing efficiency.

[0042] S3: The high heat conduction efficiency materials and agitator design inside the descending reactor ensure that the mixture is evenly heated throughout the pyrolysis process, avoiding local overheating and ensuring the uniformity and completeness of the pyrolysis reaction. The controlled atmosphere and precise heating rate (1-5℃ / s) to 500-600℃ help to adjust the composition of the pyrolysis products and optimize the quality and yield of the pyrolysis oil, where the controlled atmosphere is carbon dioxide.

[0043] S4: The gas, liquid and solid phases produced after pyrolysis are separated and initially cooled in the range of 200-300°C through a cooling system. This step helps stabilize the pyrolysis products and provides suitable temperature conditions for subsequent dust removal. At the same time, the cooling time is controlled within 2-5 minutes to ensure the continuity and efficiency of the treatment.

[0044] S5: The inner cyclone dust collector of the integrated radial bed effectively separates the dust particles ≥300μm, and improves the dust removal efficiency by using the centrifugal force principle, reduces the content of large dust particles in the pyrolysis gas, and provides a guarantee for obtaining purer pyrolysis gas.

[0045] S6: The modified activated carbon filled in the interlayer acts as a high-temperature dechlorination adsorbent. At an operating temperature of 550-650°C, it further removes fine dust particles in the pyrolysis gas to achieve deep dust removal and dechlorination. This step significantly improves the purity of the pyrolysis oil. At the same time, the operation of cooling to room temperature ensures the effective separation and collection of the pyrolysis oil, gas and solid residue, laying a good foundation for subsequent resource utilization.

[0046] Embodiment 1:

[0047] S1: First, the collected waste plastics are washed and dried to remove impurities and moisture, and then the waste plastics are crushed into waste plastic powder with a particle size of 200-300 μm using a pulverizer.

[0048] S2: The obtained waste plastic powder is mixed with the Fe-Zr / ZSM-5 catalyst in a mass ratio of 1:1 to form a mixture. At the inlet of the reactor, a three-stream impingement flow feed device is set to ensure that the mixture is impinged and mixed at an angle of 60° and a speed of 5-10m / s. The mixing time is controlled within 7 minutes to ensure that the waste plastic powder and the catalyst are fully mixed.

[0049] S3: The mixed material is fed into the descending reactor, which is lined with carbon steel. The descending reactor is equipped with a stirrer to keep the mixed material heated evenly. Under controlled carbon dioxide, the mixed material is slowly heated to 550°C at a heating rate of 5°C / s for pyrolysis.

[0050] S4: After pyrolysis, the pyrolysis gas, pyrolysis liquid and solid residue are separated by a cyclone separator. Subsequently, the product is preliminarily cooled by a cooling system within the range of 250°C, and the cooling time is controlled within 3.5 minutes to stabilize the product and prepare for the next step of processing.

[0051] S5: The dust carried by the pyrolysis gas after preliminary cooling is introduced into the inner cylinder cyclone dust collector of the integrated radial bed. Using the principle of centrifugal force, the cyclone dust collector effectively separates the particle dust ≥300μm, thereby purifying the pyrolysis gas.

[0052] S6: The pyrolysis gas treated by the cyclone dust collector enters the interlayer, which is filled with modified activated carbon with a particle size of 3mm. At an operating temperature of 600℃, the modified activated carbon further removes fine dust particles of 30-300μm and ≤30μm in the pyrolysis gas, achieving deep dust removal and dechlorination. Finally, the pyrolysis gas is cooled to room temperature to facilitate the collection of pyrolysis oil, gas and solid residue.

[0053] Embodiment 2:

[0054] This embodiment is basically the same as the embodiment 1, except that in step S1, a pulverizer is used to crush the waste plastic into waste plastic powder with a particle size ranging from 100 to 200 μm.

[0055] Embodiment three:

[0056] This embodiment is basically the same as the embodiment 1, except that in step S1, a pulverizer is used to crush the waste plastic into waste plastic powder with a particle size ranging from 1 to 100 μm.

[0057] Embodiment 4:

[0058] This embodiment is basically the same as the embodiment 1, except that in step S1, a pulverizer is used to crush the waste plastic into waste plastic powder with a particle size ranging from 300 to 400 μm.

[0059] Embodiment five:

[0060] This embodiment is basically the same as the embodiment 1, except that in step S1, a pulverizer is used to crush the waste plastic into waste plastic powder with a particle size ranging from 500 to 600 μm.

[0061] Table 1:

[0062] in:

[0063] Expected aggregation level:

[0064] High: refers to powders with smaller particle sizes, which are more likely to aggregate into larger particles due to electrostatic force or van der Waals force, reducing the effective contact area with the heat source; Medium: refers to moderate particle size and moderate powder aggregation; Very high: refers to very small particle size, which is very easy to form dust and has a very high aggregation degree; Low: refers to large particle size, which is not easy to aggregate; Very low: refers to very large particle size and almost no aggregation occurs.

[0065] Expected pyrolysis efficiency: High: It is expected that within a given particle size range, the efficiency of the pyrolysis reaction will be very high, that is, it can produce more pyrolysis oil or other useful products; Medium: The expected pyrolysis efficiency is average; Low: The expected pyrolysis efficiency is low, which may be due to the particle size being too small or too large, affecting the heat transfer or reaction surface area; Low: The expected pyrolysis efficiency is low.

[0066] Volatile matter release: Medium: A moderate amount of volatile matter is expected to be released during pyrolysis; Low: A small amount of volatile matter is expected to be released; Very low: Almost no or very little volatile matter is expected to be released.

[0067] Solid residue amount: Less: Not much solid residue is expected to remain after pyrolysis; Moderate: The solid residue is expected to be at a medium level; More: A lot of solid residue is expected; Much: A lot of solid residue is expected, which may mean incomplete pyrolysis.

[0068] Pyrolysis efficiency determination: The pyrolysis efficiency is evaluated by measuring the amount of pyrolysis oil and other products obtained during the pyrolysis process. The pyrolysis efficiency can be expressed as the yield of pyrolysis oil or the energy recovery rate.

[0069] Volatile substance release: The volatile substances released during the pyrolysis process are condensed and collected, and their release amount is quantitatively analyzed.

[0070] Solid residue amount: The amount of solid residue remaining after pyrolysis was measured to evaluate the yield of solid products.

[0071] Uniform pyrolysis conditions: Ensure that all examples are carried out under the same pyrolysis conditions, including temperature, time, atmosphere, and heating rate, to ensure comparability of the results.

[0072] Experimental repeatability: Each example was repeated multiple times to ensure the accuracy and reliability of the data.

[0073]

[0074]

[0075] From Table 1 we can see that:

[0076] Particle size and aggregation degree: Smaller particle sizes (such as Examples 2 and 3) are more likely to aggregate due to electrostatic forces or van der Waals forces to form larger particle clusters, which reduces the effective contact area between the powder and the heat source, thereby possibly reducing the pyrolysis efficiency. Larger particle sizes (such as Examples 4 and 5) are less likely to aggregate.

[0077] Particle size and pyrolysis efficiency: Example 1 showed the highest pyrolysis efficiency (75%), which indicates that the particle size range of 200-300 μm provides the best reaction surface area and heat transfer efficiency for pyrolysis.

[0078] Particle size and release of volatile substances: The waste plastic powder with a particle size range of 200-300 μm (Example 1) released a moderate amount of volatile substances during pyrolysis, which shows that this particle size range is conducive to the effective release of volatile substances while avoiding dust formation caused by too small particle size.

[0079] Particle size and solid residue amount: Example 1 produced less solid residue, which may mean a more complete pyrolysis reaction and a higher pyrolysis oil yield.

[0080] Particle size and thermal distribution: Larger particle sizes (such as Examples 4 and 5) may lead to local hot spots during pyrolysis because heat is transferred to the interior of the particles more slowly, which may lead to uneven release of volatile substances.

[0081] Optimal particle size range: According to the data in Table 1, the particle size range of 200-300 μm in Example 1 shows the best overall performance. This is because this particle size range balances the reaction surface area and heat transfer efficiency while avoiding the aggregation and dust problems of small particles, as well as the uneven heat distribution and low pyrolysis efficiency of large particles.

[0082] In summary:

[0083] The high-value utilization of waste plastics is achieved through steps S1-S6. First, the waste plastics are pretreated and crushed into powders of 200-300μm. This particle size range is conducive to improving pyrolysis efficiency and output. Then, the powder is mixed with the Fe-Zr / ZSM-5 catalyst in a mass ratio of 1:1 and fully mixed through a three-stream impact flow feeding device to ensure the uniformity of the mixing and the acceleration of the reaction. In the descending reactor, the mixture is slowly heated to 550°C at a heating rate of 5°C / s under a controlled carbon dioxide atmosphere, achieving uniformity and completeness of the pyrolysis reaction.

[0084] The gas, liquid and solid phases produced after pyrolysis are effectively separated and preliminarily cooled by the cyclone separator and cooling system, providing stable conditions for subsequent processing. Subsequently, the pyrolysis gas passes through the inner cylinder cyclone dust collector of the integrated radial bed to effectively separate large particles of dust, and then passes through the interlayer filled with modified activated carbon to achieve deep dust removal and dechlorination, which significantly improves the purity of the pyrolysis oil. Finally, the pyrolysis gas is cooled to room temperature, which is convenient for collecting pyrolysis oil, gas and solid residue.

[0085] Through comparative analysis of the examples, it is clear that the particle size range of 200-300 μm is the best operating condition, at which not only the pyrolysis efficiency is the highest, but also a better quality pyrolysis oil can be obtained. The whole method not only improves the pyrolysis efficiency of waste plastics, but also ensures the quality of the pyrolysis products and the feasibility of resource utilization through fine process design and operating condition control.

[0086] 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. An efficient treatment method for pyrolysis of waste plastics, characterized in that: The following steps are involved: S1: pre-treating the waste plastics and crushing the waste plastics into waste plastic powder with a particle size ranging from 200 to 300 μm; S2: A three-stream impingement flow feeding device is arranged at the inlet of the reactor to mix the waste plastic powder and the catalyst in the reactor to form a mixture; S3: The mixed material is pyrolyzed and heated in the descending reactor, the mixed material is pyrolyzed in a controlled atmosphere at a temperature of 500-600° C., and slowly heated to a set temperature at a heating rate of 1-5° C. / s; S4: separating the pyrolysis gas, pyrolysis liquid and solid residue generated by pyrolysis, and preliminarily cooling them through a cooling system to prepare for the next step of dust removal; S5: introducing the dust carried by the pyrolysis gas after preliminary cooling into the inner cylinder cyclone dust collector of the integrated radial bed to separate the particle dust, and separating and collecting the dust from the gas by the principle of centrifugal force; S6: The pyrolysis gas after the cyclone dust collector enters the interlayer, which is filled with high-temperature dechlorination adsorbent particles with a particle size of 2-5mm, and further removes fine dust particles of 30-300μm and ≤30μm at the operating temperature to achieve dechlorination and deep dust removal, and then the pyrolysis gas is further cooled to room temperature to collect pyrolysis oil, gas and solid residue respectively.

2. The highly efficient treatment method for pyrolysis of waste plastics according to claim 1, characterized in that: In S2, the mixed material is impact mixed in a three-stream impact flow feeding device at an angle of 60° and a speed of 5-10 m / s, and the mass ratio of the waste plastic powder to the catalyst is 1:

1.

3. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In S2, the mixing time of the waste plastic powder and the catalyst in the three-impinging stream feeding device is 5-10 minutes.

4. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In the S2, the catalyst is Fe-Zr / ZSM-5.

5. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In the above S3, the inner lining of the descending reactor is made of a material with high heat conduction efficiency, and a stirrer is provided in the descending reactor to keep the mixed material heated evenly.

6. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In S3, the temperature is set in the range of 500-600°C.

7. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In the step S4, the cooling range of the cooling system is 200-300°C, and the cooling time is 2-5 minutes.

8. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In S5, the inner drum cyclone dust collector is used to separate the particle dust with a size of ≥300 μm.

9. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In the S6, the warm dechlorination adsorbent particles are modified activated carbon.

10. The efficient treatment method of waste plastics by pyrolysis according to claim 1, characterized in that: In S6, the operating temperature ranges from 550°C to 650°C.

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