KR930011919B1 - Thermal cracking process for production of liquid hydrocarbon mixtures from waste tires - Google Patents

Abstract

This relates to pyrolysis of waste tires with waste oil as heat medium in order to recover oil from wast oil/tires. The method comprises: putting pulverized waste tires (T) in the moving reactor (3) and supplying waste oil in the ratio of 1:1-2 by weight; heating at 400-600 deg.C; separating and recovering the generated oil (O) and gas (G) by quenching bath (5) and condensing reactor (6); circulating the residue for furnace (8); decomposing the waste oil and tires, which is not decomposed at the reactor (3), at the screw reactor (9); separating and recovering the oil and gas; and separating iron content (S) and carbon black (C) from the residue.

Description

Pyrolysis Process for Oil Recovery from Waste Tires Using Waste Oil as Fruit

1 is a pyrolysis device of waste tires using waste oil as a fruit.

2 is a change in the production yield according to the charging ratio (waste oil / waste tire).

3 is the distillation curve of the oil produced.

4 is the relationship between the average particle diameter of residue and the degree of asphalt penetration.

5 is the relationship between the average particle diameter of residue and the viscosity of asphalt.

TABLE 1 Distribution of pyrolysis products.

Table 2 Analysis of kinematic viscosity, flash point and sulfur content of pyrolysis-produced oils.

Table 3 BTX Analysis of Produced Oils.

Table 4 Sulfur and heavy metal content in the product.

* Explanation of symbols for main parts of the drawings

1: Hopper 2: Metering supply device

3: reactor 4: waste oil

5: quench tank 6: condenser

7: generated gas 8: heating furnace

9 reactor 10 generated oil

The present invention relates to a method and apparatus for thermally decomposing waste tires into a heat medium for the purpose of recovering oil from the waste oil / waste tire of the present invention.

Recently, the generation of waste tires and waste oil has been rapidly increasing due to the rapid increase in the acceptance of automobiles. However, since there is no development of a process that can efficiently deal with this problem, environmental pollution caused by waste tires and waste oils is greatly generated, and energy efficiency has not been achieved. have.

There may be a number of processes for recycling waste tires and waste oil, but processes for treating these two types of wastes at the same time have not yet been developed. However, this process can increase the treatment efficiency of the waste tire and increase the amount of oil recovery by pyrolyzing the waste tire and the waste oil at the same time in the same reactor.

Tire components include natural rubber, synthetic rubber, carbon black, steel, process oil and other additives. Among these components, natural rubber, synthetic rubber and process oil can be converted into gas and oil by pyrolysis. Natural rubber is a cispoly-soprene component, and synthetic rubber is made of polystyrene-butadiene, polybutadiene, poly 2-chloro-butadiene, polychloroprene, polynitrile-butadiene component and the like. The polymer chains of these rubbers are broken when heat is strong from outside, and most of them are converted into unit hydrocarbon compounds and can be separated into oil and gas by condensation.

In the Kobe steel mill process (Japanese Patent 49-111986, 52-110788) of Japan, waste tires were shredded into a size of 10-20 mm, put into a rotary rotary kiln and pyrolyzed. At this time, the pyrolysis temperature is in the range of 500-800 ° C. and the yield of pyrolysis oil is the highest at 600 ° C. at 50%.

On the other hand, the yield of product gas increased from 5.8% to 30.2% in the same temperature range. Most of the remaining components after conversion to oil and gas are carbon black, which was recovered by removing volatiles and reused for industrial purposes.

The pyrolysis process developed at the University of Hamburg, Germany, is a process of pyrolyzing barrel tires by fluidizing sand. The treatment temperature is 800 ℃ and the treatment time is about 2-3 minutes. At this time, the yield of oil and gas was 27% and 22%, respectively, and the yield of oil was lower and the yield of gas was higher than that of Kobe Steel Works.

The characteristic of the process of pyrolyzing only waste tires is that the pyrolysis temperature is higher than the rubber decomposition temperature of 350-550 ℃ and the oil production yield is maintained within 50%. This is because when the pyrolysis temperature is higher than the decomposition temperature of rubber, the yield of gas increases, which reduces the production of relatively valuable oil. This tendency is inevitable when only pyrolysis of waste tires occurs. This is because local heating generates a large amount of hydrocarbon compounds of C ₃ or less, which are main components of the non-condensable gas.

Therefore, in the present invention, waste oil is used as a fruit to pyroly decompose waste tires near the decomposition temperature of rubber, thereby suppressing the generation of non-condensable gases, thereby increasing the yield of oil, and converting the waste oil itself into oil, thus producing a total oil. Can be increased even more.

Due to the role of swelling agent of the waste oil, which increases the heat transfer rate to the waste tire, it is possible to process the waste tire at a temperature of about 100-150 ° C lower than the process of directly pyrolyzing the waste tire, thereby reducing the energy consumption for oil production. It has the characteristics.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a pyrolysis process that can be used for two cases of softening the barrel tires and the cut waste tires to separate iron and then adding them in a slurry state or injecting crushed waste tires (T). In case of crushed tire, it is cut into 3-4cm size and intermittently introduced from the hopper (1) by the metering feeder (2). While introducing into the waste tire, the waste oil 4 in a ratio of 1: 1 to 2 is introduced into the waste tire as an oil circulation pump.

In the moving bed reactor (3), a heated non-condensable gas is injected into a nozzle having a constant pore size to increase the heat transfer and mass transfer of slurry rubber and waste oil. At this time, the temperature of the moving bed reactor (3) is 400-. Maintained at 600 ° C.

The gas produced by pyrolysis in the moving bed reactor 3 is discharged into the quench tank 5 and primary condensed gas that can be recovered to the high boiling oil by the oil sprayed from the top. The gas that has passed through the quench system is finally condensed by the condenser (6) and recovered from the reservoir (7) to the product oil (0), and the non-condensing product gas (G) is circulated to provide energy for the reactor heating furnace (8). Or as a carrier gas for a mobile bed reactor.

Waste oil and waste tires which are not pyrolyzed in the moving bed reactor (3) are transferred to an inclined spiral reactor (9) and pyrolyzed to 550-600 ° C. where the gases produced are treated in the same way as the product gas treatment of the moving bed reactor. do.

The parts of the waste tires and waste oil which are not converted to gas or oil are discharged as residues. Double dampers are used to prevent the inflow of air. In case of pyrolysis using crushed waste tires, steel (S) and carbon black (C) are separated by a magnetic separator (10). When the waste tires are pyrolyzed after passing through a softening device, carbon black is removed. It can be directly recycled to recycle the asphalt mixture or reinforcement contained in 8-10% of the asphalt. In the figure, reference numeral 11 denotes cooling water 12 combustion air.

Table 1 shows the distribution of pyrolysis products obtained through pyrolysis experiments for representative cases. Figure 2 is a table of Table 1, it can be seen that the production amount or yield of oil, gas, residues change according to the change of the ratio of waste oil to waste tires. As the loading rate increases, the yield of oil increases and the yield of gases and residues decreases. The oil yield is high at 73% and the gas and residue yields are low at 15.5% and 11.8%, respectively.

In addition, the waste tire reference oil yield is calculated based on the yield of 78.3% of the oil produced when only the waste oil is pyrolyzed, and it can be seen that it increases as the loading rate of the waste oil increases. This indicates that the yield of condensable gas increases due to the increase in heat transfer rate and swelling mentioned above due to the fruiting role of the waste oil on the waste tire.

3 compares the boiling point characteristics of the oil produced from the pyrolysis unit by distillation by petroleum distillation unit (Korean Industrial Standard KSM 2031). It can be seen that in the case of the product oil obtained by pyrolysis of only waste tires, the boiling point distribution is the lowest, and about 75% of the waste tires fall within 160 ° C of industrial gasoline. On the other hand, the waste oil generated oil contains a high boiling point oil in the case of waste tire, which corresponds to about 35% of the oil produced up to the outflow range of kerosene, and light heavy oil as a whole. It can be said that. However, in the case of the superflow point, all the generated oils have almost the same value as about 50 ° C.

In the case of the product oil obtained by pyrolyzing the waste oil and the waste tire at the same time, it can be seen that it contains more high-boiling oil than when only the waste oil is obtained by pyrolysis. In particular, it shows that the oil has a high boiling point when the loading ratio of the waste oil to the waste tire is increased from 1.3 to 2.0. It is assumed that when pyrolysis of waste tires using fruits as waste oil, polymer chains of polymers are converted into hydrocarbon compounds having multiple chains rather than monomolecules by thermal decomposition, resulting in high boiling point. . This can be seen from the fact that the production yield of gas decreases and the production yield of oil increases with increasing charging ratio, as shown in FIG. In addition, when the flash point of the oil produced by simultaneously pyrolyzing the waste oil and the waste tire in Table 2 is higher than that of the oil obtained by pyrolyzing only the waste oil, it also indirectly demonstrates the high boiling point phenomenon.

Table 2 shows kinematic viscosity (Korean Industrial Standard KSM 2014), Flash Point (Korean Industrial Standard KSM 2010), and Sulfur (Korean Industrial Standard) for the same waste oil, waste tire, waste oil and pyrolysis generated oil as the samples used in the petroleum distillation experiment. The analysis results of KSM 2027) are compared with Korean industrial standards such as bunker A, kerosene and diesel.

As can be seen from this table, the kinematic viscosity is the lowest as 1.8, resulting from pyrolysis of only waste tires, and it is equivalent to 5.0 or more for pyrolysis of waste oils, waste oils and waste tires. However, since this figure is much lower than bunker oil, the three types of oil characteristics are close to diesel in terms of kinematic viscosity.

In the case of the flash point, all three types of oil have lower values than the flash point of kerosene 40 ° C, which can be seen from the low initial point of 50 ° C as shown in FIG.

The sulfur content is the same as that of the product oil obtained by pyrolysis of only waste tires (0.8%) and 0.6% for the rest. On the basis of sulfur content, the three types of generated oils are close to the specifications of bunker A oil 1, and in the case of diesel, they are halfway between high and low sulfur.

Table 3 shows the results of analyzing the contents of benzene, fluene, and xylene by gas chromatograph. It can be seen that the oil produced when only pyrolysis of waste tires had a high BTX content and significantly lower when pyrolysis of only waste oil. This suggests that the oil produced from the waste tires has many components pyrolyzed from aromatic polymer compounds, whereas the oils produced from the waste oil are mainly high boiling point paraffin components.

Table 4 shows the analysis of sulfur and heavy metals of waste oil, waste tires, oils produced from waste oil / waste tires, pyrolysis residues, etc., compared with the regulation items and contents of the fuel notices announced by the Ministry of Environment. Lead is the highest among heavy metals, and the amount of chromium in waste lubricants is about 4 ppm due to engine wear. The sulfur content is 1.9% for waste tires, which is believed to be used as a sulphur for tire production.

As shown in Fig. 4, when the waste tires were thermally decomposed using the waste oil as a fruit, most of these heavy metals remained in residues and only a small amount was contained in the produced oil. The heavy metal content of the produced oil is lower than the environmental standard value when using the fuel, so it can be seen that there is no problem in using the fuel. Although the content of lead is the highest among the heavy metals remaining in the pyrolysis residue, it is not a big problem because the content of lead in asphalt concrete is lowered below 40 ppm when the residue is used as reinforcement for asphalt.

4 and 5 are examples to determine whether the residue (carbon black) after pyrolysis of waste tires using the waste oil as a fruit can be used as an asphalt reinforcement material. At this time, the residue content of asphalt was adjusted to about 10%. .

In the case of FIG. 4, the penetration test was measured according to the Korean Industrial Standard (KSM 2252). The fineness of the residue was ground to 1-5 μm and mixed with asphalt, which was 10-12% higher than that of pure asphalt. It can be seen that the lower the degree of increase the firmness of the asphalt. However, when the crushed particles of the residue reaches about 8 μm, it can be seen that the reinforcing effect does not appear even when mixed with asphalt.

5 shows that the viscosity of the asphalt increases with the addition of residues. The viscosity increases when the residues with the smallest particle size are mixed and increase by 30% more than pure asphalt. This suggests that the residue can be mixed to increase the firmness of the asphalt.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

Claims (1)

Generated oil (0) generated by supplying the waste oil (4) at a weight ratio of 1: 1 to 2 with respect to the waste tire while putting the crushed waste tire (T) into the moving bed reactor (0). ) And the generated gas (G) are separated and recovered by the quench tank (5) and the condenser (6), and some of them are circulated for the furnace (8). Waste oil and waste tire not pyrolyzed in the moving bed reactor (3) are pyrolyzed in the spiral reactor (9) to recover and circulate the product oil (0) and the product gas (G), and the residue is a magnetic separator (10). Oil from waste tires, comprising waste oil as a fruit, comprising the step of separating into steel (S) and carbon black (C) and using it as an asphalt mixture or reinforcement added to the asphalt. Pyrolysis process for recovery.