Method and production line for the production of solid fuel from soot deriving from the pyrolysis of tire, as well as solid fuel of high calorific value

Abstract

Method for the production of solid fuel, in which o base material of carbon residue is mixed with water (11) and a cellulose ether derivative (12), wherein the base material of carbon residue is a pyrolysis soot (13) deriving from the pyrolysis of rubber, especially car tires, and that the process is carried out according to the following steps: a binder (14) is prepared by mixing the water (11) and the cellulose ether derivative (12), the resulting binder (14) is homogenized and then left to rest, further 15-25 kg of pyrolysis soot (13) is added to each liter of the binder (14) and the resulting soot-mass (15) is mixed, and then formed into briquettes (16) and then the briquettes (16) are dried. The present invention also relates to a production line for the above method as well as a fuel obtained by the above method.

Description

[0001] METHOD AND PRODUCTION LINE FOR THE PRODUCTION OF SOLID FUEL FROM SOOT DERIVING FROM THE PYROLYSIS OF TIRE, AS WELL AS SOLID FUEL OF HIGH CALORIFIC VALUE

[0002] Technical field

[0003] The present application relates to a method and production line for the production of solid fuel, preferably briquettes, deriving from the pyrolysis of rubber products, mainly car tires; it also relates to a fuel of high heating value. By this method the entire amount of the vast quantity pyro-soot generated by the pyrolysis of waste rubber products (tires or tyres) can be processed into a fuel of high calorific value and of low ash content, thus the invention contributes significantly to a large reduction of wood logging for power plant purposes, and thereby to environmental protection.

[0004] State of the art

[0005] One way to recycle waste rubber products, especially car tires, is to subject the rubber products to pyrolysis, a process that produces oil, gas and soot. The extracted oil and gas are fully used by the industry, but only a fraction of the pyrolysis soot is used again. At the end of the tire pyrolysis process, the average ratio of the product yield is as follows: 35-40% pyrolysis oil, 7-12% pyrolysis gas, and 15-20% metal and 35-40% pyrolysis soot (http: / / www. dldh.hu / wp-content / uploads / 2012 / 02 / Charmol_pirolizis.pdf also: https: / / newenergy.hu / hu / reusability). As can be seen, most of the material extracted and to be recycled are pyrolysis soot. Pyrolysis soot can be used by rubber and plastic industry as a painting material, but the industry can only use a very small amount of the soot obtained at the end of the pyrolysis process os on additive, so most of the pyrolysis soot is accumulated on the sites of pyrolysis plants. Hence, the recycling of rubber products is actually not - or only partially - solved.

[0006] Patent document RU2608733C1 describes a solid fuel made from pyrolysis soot resulting from tire pyrolysis, which is prepared by adding 200g of pyrolysis soot from tire pyrolysis to 850ml of water, and then mixing 34ml of engine oil used as a hydrocarbon reagent to the mixture. Carbamide is added as a binder, then the material is heated to between 100-133 °C then briquettes are pressed from it, the ash content of which is 5.5-6.5% by weight. If we take into account that in pyrolysis processes, the yield of solids (i.e. pyrolysis soot) can be around 30-35%, then with this process, in addition to the use of 1 liter of water, about 82g of pyrolysis soot is utilized for the production of briquettes.

[0007] The document RU2664330C1 describes the same water-pyrolysis soot-oil mixing ratios as the previous one, however, a secondary polymer (polyethylene) added in a ratio of 7-10% by weight is used as a binder, for the melting of which, the mixture must be kept at a temperature of 170-180 °C for approx. 30 minutes. The added oil in the case of this invention is M-l 00 oil, a pressure of 100 kgf I cm2(i.e. approx. 98 bar) is applied to press the briquettes.

[0008] Patent document US4647443A discloses a tire recycling process in which pyrolysis soot is pelletized. No binder is used for this operation, only 60-80 °C water to wet the entire surface of the pyrolysis soot. 25-30 kg of pyrolysis soot are moistened with 15-20 liters of water - this means that they can produce pellets from 1.25-2 kg of pyrolysis soot using 1 liter of water. The water used for wetting is then carefully evaporated in a pellet dryer. However, due to the lack of binder, the drying process is slow and there is a risk that the pellets will fall apart due to excessive steam generation. EP3354712A1 describes a process for the production of coal powder briquettes, during which pulverized coal is mixed with a pulverized binder, and then water is added to the resulting dry mixture. However, it is important to see the differences in processability arising from the completely different physical properties of coal powder and pyrolysis soot, as the raw material of the method that is the subject-matter of the present application. Coal is a naturally occurring brown or black coal that is mined from deep under the surface of the earth. From this, coal powder is obtained accidentally during extraction and conveying, or intentionally during cutting. Coal powder is not water repellent and even contains water in itself.

[0009] Soot, on the other hand, is a substance produced artificially from petroleum; a combustion product that is used by industry as an additive, e.g. for the production of vehicle tires. To this, different materials are added to adjust the hardness and wear resistance of the rubber. Soot is dry, water-repellent, and floats on the surface of the water.

[0010] The method taught in this application uses the pyrolysis soot produced during the processing, i.e. shredding and subsequent pyrolysis of used tires, which contains the previously mentioned additives as well as impurities additionally attached to the rubber during the use thereof (e.g. winter salting found on the roads, other substances). The main characteristic of pyrolysis soot, namely its hydrophobicity, remains, therefore a properly prepared binder is necessary to achieve the goal of the invention.

[0011] Document RU2043392C1 , which can be regarded as the closest piece of prior art, teaches about a solid fuel that is made from charcoal powder with a particle size of less than 200 pm formed into briquettes with the addition of a methyl cellulose derivative binder. For 1 liter of water, 860-970 g of carbon powder is added with the addition of 20-60 g of sodium carboxymethyl cellulose and 10-80 g of potassium nitrate. The obtained mass is left to rest at 70 °C for 120 minutes, then it is shaped into cylindrical briquettes with a diameter of 90 mm and a height of 150 mm under a pressure of 10 kgf I cm2(approx. 10 bar).

[0012] Due to its tiny particle size, low viscosity, and extreme hardness, which destroys even tool steel briquetting pressing machines, no solution has been found to use the significant amount of pyrolysis soot deriving from tire pyrolysis.

[0013] The problem to be solved

[0014] We have set the goal of presenting a fuel production method, a production line and fuel that can utilize the pyrolysis soot that is formed in large quantities during the recycling of waste tires much (in an order of magnitude) greater than the previous solutions.

[0015] Solution of the problem

[0016] Our goal has been achieved by a method, production line and fuel, in which the base material of carbon residue is a pyrolysis soot deriving from the pyrolysis of rubber, especially car tires, and that the method is carried out according to the following steps: a) a binder is prepared by mixing the water and the cellulose ether derivative, b) the resulting binder is homogenized and then left to rest, c) 15-25 kg of pyrolysis soot is added to each liter of the binder and the resulting soot-mass is mixed, e) and then formed into briquettes f) and then the briquettes are dried.

[0017] In step a) optionally 0.03-0.3 kg, preferably 0.06 kg of cellulose ether derivative is mixed with the water per each liter of the water. The cellulose ether derivative is preferably selected from the following materials or a combination thereof: carboxymethylcellulose, methylcellulose, sodium carboxymethylcellulose, methylethylcellulose, hydroxypropylcellulose, sodium salt of carboxymethylcellulose. This list can also be supplemented with the following substances: hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose.

[0018] In step b) the binder is preferably mixed for 5-20 minutes and then left to rest for particularly 0.3-24 hours, preferably for 0.5-2 hours.

[0019] In step c), preferably 18 kg of pyrolysis soot is added to the binder per each liter of the binder.

[0020] In step c), the soot-mass is mixed for preferably 10-30 minutes, more preferably for 20 minutes.

[0021] As a step d) between steps c) and e), the soot-mass is optionally filled into a buffer container and preferably left to rest for 30-60 minutes.

[0022] In step e), optionally a pressing machine is used for briquetting, which is operated with a pressure of 100-400 bars, preferably 150 bars.

[0023] The pushing stage of the pressing machine is preferably 4-8 seconds and the holding under pressure takes 1 -3 seconds.

[0024] In step e), optionally, in the pressing machine used for briquetting, with at least one press tool thereof, briquettes of size 0 5cm x 5cm are produced.

[0025] The briquettes obtained from the pressing machine in step e) are preferably dried in step f) for 24-48 hours.

[0026] In step c) the pyrolysis soot is added by optionally passing it through a magnetic station.

[0027] The production line for the above-referred method optionally contains a mixing machine and at least one pressing machine equipped with at least one press tool, wherein the pressing machine has a press piston with a piston rod and a piston base connected thereto, wherein the diameter of the piston base is larger than that of the piston rod. The production line preferably contains one or more conveying units for discharging material from the mixing machine, the buffer container and the pressing machine as well as for moving material; and / or contains a drying machine for drying in step f).

[0028] The fuel is preferably obtained by the method defined by the above steps.

[0029] List of Figures

[0030] In the following, the invention will be described in detail with reference to the attached drawing. In the drawing

[0031] Figure 1 is a schematic diagram of the production line according to the present invention,

[0032] Figure 2 is a flowchart of the method according to the present invention,

[0033] Figure 3 is a cross-sectional view of at least one press piston of at least one pressing machine used on the production line according to the present invention.

[0034] Detailed description of the invention

[0035] In the method according to the invention, pyrolysis soot 13 produced during pyrolysis recycling of rubber products, typically automobile tires, is used as a raw material. Pyrolysis soot 13 (or industrial soot) is commercially available for industrial use. As an example, but without affecting the scope of protection of the invention in any way, we mention that one of the commercial names of the product is: RECARB-A 28, manufactured by APX Consulting Kft. The chemical characterization of the pyrolysis soot 13 - based on the safety data sheet of the above-mentioned product - is summarized in the table below.

[0036] 1- EINECS- and ELINCS-number

[0037] 2- Chemical Abstracts Service registration number used to identify chemical substances.

[0038] 3- Based on the production method, structure and chemical composition of the material, it can be considered identical to active soot. It contains less than 50 ppm polycyclic aromatic hydrocarbons based on the HPLC analysis of US ERA after 24 hour toluene extraction.

[0039] 4- The product is exempt from registration as a recovered material.

[0040] 5- The product contains less than 3% amorphous silicon oxide and other inorganic impurities, which do not affect its classification.

[0041] Among the basic physical and chemical properties of pyrolysis soot (also listed on the product's safety data sheet), it is important to emphasize that it does not mix with water. Its solubility in water is basically achieved by the so- called naturally-based polymer compounds of the cellulose ether derivative 12 type from among the the binders and texture modifiers that can be used for making briquettes. Hydroxyl (OH) functions connected to the primary and secondary carbon atoms of cellulose can be substituted within the polymer chain under various reaction conditions by simple alkyl (e.g. methyl, ethyl, propyl), hydroxyalkyl (e.g. hydroxymethyl, hydroxyethyl), carboxymethyl, or with acyl (e.g. acetyl) groups, as well as their combination, which results in the desired physical, physico-chemical and chemical properties. From the point of view of cost-effectiveness, for the implementation of the technology taught in this description, those cellulose ether derivatives 12 are preferred which are also widely available commercially, for example: carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), methylcellulose (MC).

[0042] The elements of the fuel production line 100 are illustrated in Figure 1 , and the production method is illustrated in Figure 2 (arrows in the Figures indicate the direction of material movement). Since pyrolysis soot does not mix with water due to its highly water-repellent (hydrophobic) properties, it is not possible to follow the state-of-the-art methods of making briquettes from coal powder. In light of this, one of the important realizations of the implementation of the present invention is the sequence of preparation of the binder. This is because coal powder- as can be seen in the coal powder briquette making process disclosed in publication document EP3354712A1 - behaves completely differently with water, it can be wetted and settles to the bottom of the water; it can practically be briquetted without a binder if slightly moistened.

[0043] On the other hand, pyrolysis soot remains on top of the water, it floats on it and cannot be wetted. It can only mix with water if a binder is used, which practically binds the grains during pressing due to heat and the water evaporates from it. In other words, the phenomenon of water repellency led to the recognition of the importance of the procedure sequence, since pyrolysis soot is water repellent, it would float on the surface of water even with a small amount of other powders, such as cellulose ether derivative- type dry binders, but with a pre-mixed, dense but liquid binder it can be mixed and turned into a mass.

[0044] Accordingly, in the first step, in a first mixing container 2 a binder 14 is prepared by mixing water 1 1 stored in a separate storage tank 1 and cellulose ether derivative 12 stored in another storage tank 1. The temperature of the water 1 1 is not decisive, the temperature of the running water 1 1 available at the facility location of the given production line 100 is always appropriate. There is therefore no need to heat the water 1 1 . As an alternative solution, running water 1 1 is let directly to the cellulose ether derivative 12 fed into the first mixing container 2. In order to produce a large- scale (mass-produced) equally high-quality (e.g. non-disintegrating) product, 30 kg-300 kg, preferably 60 kg, of cellulose ether derivative 12 is added to 1000 liters of 1 1 water; then the thus obtained binder 14 is mixed preferably for 5-20 minutes, by hand or by machine; then it is left to rest for at least 20 minutes, preferably for 30-120 minutes, however, for a maximum of 24 hours. The final consistency and density of the binder is achieved during the resting time. 24 hours can be considered as the time of final use, so that the mixed material does not set before pressing, as the water would evaporate from it during this time.

[0045] At the end of the resting time, the binder 14 is transferred to a second mixing container s, and then 15-25 kg, preferably 18 kg, of pyrolysis soot per each liter thereof is added, which is also delivered from a separate storage tank 1 , through a magnetic station 4, to the second mixing container 3. The function of the magnetic station 4 and the magnetization is to remove possible metal impurities in the pyrolysis soot 13. After that, in order to achieve the most complete homogenization, the binder 14 and the pyrolysis soot 13 are mixed with an industrial mixer 30 in the second mixing container s preferably for 10- 30 minutes.

[0046] From the point of view of the invention, it is very important that the pyrolysis soot 13 is added to the binder 14 and not to the dry cellulose ether derivative 12 (as is in the case of the invention taught in the previously referenced document EP3354712A1 ). Because if the pyrolysis soot 13 were added to the dry cellulose ether derivative 12, proportionally much more cellulose ether derivative 12 would have to be used in order for the (still powdery) mixture to dissolve in the water 1 1 added later. To maintain the mixing ratio of 12 cellulose ether derivative - water 1 1 , much more water 1 1 would be needed accordingly. Therefore briquetting a unit amount of pyrolysis soot 13 would result in much higher water consumption. After mixing, the soot-mass 15 thus obtained is transferred to at least one pressing machine 6 with a conveying unit 8, preferably a conveyor belt, for pressing it into briquettes 16. The 15 soot-mass is preferably allowed to rest for 30-60 minutes between mixing and pressing. A buffer container 5 can preferably be inserted between the second mixing container 3 and the at least one pressing machine 6 in order to ensure the continuity of production. In this case, the mixed soot-mass 15 is stored in the buffer container 5, keeping at least one pressing machine 6 in continuous operation until a next portion of soot-mass 15 is mixed or allowed to rest in the second mixing container 3. If a buffer container 5 is used, the soot-mass 15 is also delivered from the buffer container 5 to the at least one pressing machine 6 with the conveying unit 8.

[0047] Pressing is carried out with a high-pressure industrial piston pressing machine 6, which is operated at a pressure of 100-400 bar. 320-380 cm3, preferably 350 cm3of soot-mass 15 is fed into a press tool 10 having an inner diameter of preferably 30-100 mm, for example 55 mm, which is shaped into briquettes 16 of 50 mm high. The press piston 9 of the pressing machine 6 has a conical design (Figure 3), i.e. along the circumference of the pressure surface 91 , a chamfer 92 is formed for the purpose of guiding the press piston 9 when it is pressed into the press tool 10.

[0048] For the same purpose, a guiding part 102 is preferably formed along the circumference of the open end 101 of the press tool 10. In order to prevent the press piston 9 from getting stuck in the press tool 10 when the soot-mass 15 is pressed, the piston rod 93 is designed so that its diameter is smaller than the diameter of the piston base 94. The outer diameter of the piston base 94 is the same as the inner diameter of the press tool 10, with appropriate fits and tolerances customary in the industry, i.e. preferably 55 mm according to the above example. The diameter of the piston rod 93 is expediently approximately 45 mm; the length of the piston base 94 in the direction of the longitudinal axis of the press piston 9 is preferably 20-40 mm, more preferably 30 mm. Studies prove that - unlike coal powder - pyrolysis soot 13 is a particularly hard substance. When producing briquettes and pellets of other materials, a maximum of 20% of pyrolysis soot 13 can be mixed with the base material (e.g. saw powder), because in case of a higher pyrolysis soot 13 content, compression problems occur, the material "burns into" the press hole during pressing. (http: / / doktori.uni- sopron.hu / id / eprint / 656 / 2 / Tezisfuzet_Papp_V_2018.pdf).

[0049] In the method according to the invention, the cycle time of pressing is 15-30 seconds, preferably 22 seconds: starting from its starting position, the pushing stage of the press piston 9 lasts 4-8 seconds, after that the time of holding under pressure is 1 -3 seconds, after which the press piston 9 returns to its starting position. At the end of the pushing stage, the final volume of the briquettes 16 is formed; the purpose of holding under pressure is that the binder 14 fixes the soot-mass 15 in the given volume. By taking into account the above parameters, it is possible to avoid that the press piston 9 of the pressing machine 6 gets stuck in the press tool 10.

[0050] The formed briquettes 16 are removed from the output part of the pressing machines 6 and then transferred to a drying station 7 to remove the remaining moisture. The drying station 7 can either be placed in a preferably covered, sunny outdoor area, or even in a room applying warm air, infrared radiation or other drying technologies. The drying preferably lasts (especially in the first case) for 24-48 hours, and in some cases it lasts for a shorter time, even just a few minutes (see example 2 below). Its duration depends on the efficiency of the drying technology. At the end of the drying process, the moisture content of the briquettes 16 of the finished product is 1 .25%m / m.

[0051] The briquettes 16 are not rectangular in design, but - in order to avoid chipping off of the edges and corners - cylindrical. Preferably, the briquettes 16 do not contain aeration holes, because that would shorten the burning time. The materials used for the production of fuel according to the method illustrated in Figure 2, their quantities, as well as the time and pressure values used during the method, are summarized in tabular form in the following examples. Example 1

[0052] - drying: in open air, at max. 50% humidity: 48 hours,

[0053] - ash content of finished product: 1 .38%m / m, sulfur content: 1 .38%m / m, moisture content: 1 .25%m / m.

[0054] Example 2

[0055] - drying: with warm air, at max. 50% humidity: 5-15 minutes,

[0056] - ash content of finished product: 1 .38%m / m, sulfur content: 1 .38%m / m, moisture content: 1 .25%m / m.

[0057] Example 3

[0058] - drying: in a sunny place, at max. 50% humidity: 24 hours,

[0059] - ash content of finished product: 1 .38%m / m, sulfur content: 1 .38%m / m, moisture content: 1 .25%m / m.

[0060] Example 4

[0061] - drying: in a sunny place, at max. 50% humidity: 24 hours

[0062] - ash content of finished product: 1 .38%m / m, sulfur content: 1 .38%m / m, moisture content: 1 .25%m / m.

[0063] Advantageous effects of the invention

[0064] With the method according to the invention, 15-25 kg of pyrolysis soot 13 can be shaped into briquettes 16 of fuel by using 1 liter of water 1 1 - by the addition of a cellulose ether derivative 12. Compared to fuels containing pyrolysis soot 13 according to the current state of the art, we can process the pyrolysis soot 13, which have been lying in piles as waste until now, with 15-25 times more efficiency.

[0065] Briquettes 16 of the fuel produced by this method have an exceptionally high calorific value of 28-32 MJ / kg. Another beneficial feature is that its burning time is extremely long: up to 17-18 hours. This is particularly important for heating e.g. greenhouses, where nighttime defrosting can be easily solved by burning briquettes 16 according to the invention.

[0066] It can also be used in household combustion equipment, and can be used to significantly reduce the time spent on heating work. Other advantageous features include the fact that the briquettes 16 do not soot the fireplace glass when they burn, their ash content is low: 1 .38%m / m, and their sulfur content is only 1 .38%m / m.

[0067] Due to its high calorific value, it completely replaces firewood and coal - thus significantly contributing to the protection of the environment.

Claims

CLAIMS1. Method for the production of solid fuel, in which o base material of carbon residue is mixed with water (1 1 ) and a cellulose ether derivative (12), characterized in that the base material of carbon residue is a pyrolysis soot (13) deriving from the pyrolysis of rubber, especially car tires, and that the method is carried out according to the following steps: a) a binder (14) is prepared by mixing the water (1 1 ) and the cellulose ether derivative (12), b) the resulting binder (14) is homogenized and then left to rest, c) 15-25 kg of pyrolysis soot (13) is added to each liter of the binder (14) and the resulting soot-mass (15) is mixed, e) and then formed into briquettes (16) f) and then the briquettes ( 16) are dried.

2. Method according to claim 1 , characterized in that in step a) 0.03-0.3 kg, preferably 0.06 kg of cellulose ether derivative ( 12) is mixed with the water (1 1 ) per each liter of this latter.

3. Method according to claim 1 or 2, characterized in that the cellulose ether derivative (12) is selected from the following materials or a combination thereof: carboxymethylcellulose, methylcellulose, sodium carboxymethylcellulose, methylethylcellulose, hydroxypropylcellulose, sodium salt of carboxymethylcellulose.

4. Method according to any of claims 1 -3, characterized in that in step b) the binder (14) is mixed for 5-20 minutes and then left to rest for 0.3-24 hours, preferably for 0.5-2 hours.

5. Method according to any of claims 1 -4, characterized in that in step c) , 18 kg of pyrolysis soot (13) is added to the binder ( 14) per each liter of this latter.

6. Method according to any of claims 1 -5, characterized in that in step c), the soot-mass (15) is mixed for 10-30 minutes, preferably for 20 minutes.

7. Method according to any of claims 1 -6, characterized in that as a step d) between steps c) and e), the soot-mass ( 15) is filled into a buffer container (5) and preferably left to rest for 30-60 minutes.

8. Method according to any of claims 1 -7, characterized in that in step e), a pressing machine (6) is used for briquetting, which is operated with a pressure of 100-400 bars, preferably 150 bars.

9. Method according to claim 8, characterized in that the pushing stage of the pressing machine (6) is 4-8 seconds and the holding under pressure takes 1 -3 seconds.

10. Method according to claim 8 or 9, characterized in that in step e), in the pressing machine (6) used for briquetting, with at least one press tool ( 10) thereof, briquettes (16) of size 0 5cm x 5cm are produced.1 1. Method according to any of claims 8-10, characterized in that the briquettes (16) obtained from the pressing machine (6) in step e) are dried in step f) for 24-48 hours.

12. Method according to any of the preceding claims, characterized in that in step c) the pyrolysis soot (13) is added by passing it through a magnetic station (4).

13. Production line for the method according to any of claims 1 -1 1 , characterized in that it contains a mixing machine (30) and at least one pressing machine (6) equipped with at least one press tool (10), where the pressing machine (6) has a press piston (9) with a piston rod (93) and a piston base (94) connected thereto, where the diameter of the piston base (94) is larger than that of the piston rod (93).

14. Production line according to claim 13, characterized in that it contains one or more conveying units (8) for discharging material from the mixing machine (30), the buffer container (5) and the pressing machine (6) as well as moving material; and / or contains a drying machine (7) for drying in step f).

15. Fuel, which is made using pyrolysis soot (13) deriving from the pyrolysis of rubber, especially car tires, characterized in that it is obtained by a method according to any one of claims 1-12.

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