WO2003012009A1

WO2003012009A1 - Downflow type catalytic cracking reaction apparatus and method for producing gasoline and light oil using waste synthetic resins using the same

Info

Publication number: WO2003012009A1
Application number: PCT/KR2001/001488
Authority: WO
Inventors: Ho-Kyun Kim; Dong-Chun Kim
Original assignee: Ho-Kyun Kim; Dong-Chun Kim
Priority date: 2001-07-31
Filing date: 2001-09-03
Publication date: 2003-02-13
Also published as: KR20030012189A; KR100517898B1

Abstract

The present invention discloses a downflow type catalytic cracking reaction apparatus and a method for producing gasoline and light oil from waste synthetic resins using the same. According to the present invention, it is capable of producing gasoline and light oil of high quality at a high yield. Also, the catalyst poisoned after the catalytic cracking reaction can be regenerated and recycled, thereby allowing oil to be mass-produced in a continuous process.

Description

DOWNFLOW TYPE CATALYTIC CRACKING REACTION APPARATUS AND METHOD FOR PRODUCING GASOLINE AND LIGHT OIL USING WASTE SYNTHETIC RESINS USING THE SAME

Technical Field The present invention relates to a do nflo type catalytic cracking reaction apparatus and a method for producing gasoline and light oil from waste synthetic resins using the same. More particularly, the present invention relates to a downflow type catalytic cracking reaction apparatus using acidic catalyst and waste synthetic resins and waste oil as raw materials and a method for producing gasoline and light oil using the same.

Background Art The present invention is a novel technology for producing gasoline and light oil of good quality from waste synthetic resins and waste oil . The present technology has been developed after conducting researches and studies based on the thermal cracking reaction technology disclosed in Korean Patent No. 191075, which was issued to the present applicant and titled "Apparatus and method for producing gasoline and light oil using waste vinyl materials" and the cracking technology using catalysts of nickel, copper and aluminum oxide, and enzymes disclosed in Korean Patent No. 288731, which was also issued to the present applicant and titled "Apparatus and method for producing gasoline and light oil using waste vinyls and waste plastics" . Generally, dehydrogenation of waste synthetic resins means eliminating of hydrogen atoms in the polymeric molecules of raw waste synthetic resins so as to reduce the hydrogen content therein. When producing oil by dehydrogenation of waste resins, there is generated a great quantity of aromatic material, particularly benzene, and also a great quantity of olefin. Such materials can be readily carbonized. Therefore, the conversion ratio of raw material to oil is decreased and the quality of the produced oil is deteriorated.

Reference to Korean petroleum standards will be made. According to the gasoline quality standards which became effective from January 1, 2001, it is regulated that contents of aromatic compounds should be maximally 35 volume%, contents of benzene should be maximally 2 volume% and contents of olefin should be maximally 23 volume% .

If gasoline contains high levels of the aromatic compounds, benzene, olefin, etc, the amount of carcinogenic substances released in the exhaust gas from automobiles is increased. In the case of light oil, which contains more of the above listed materials, its cetane value becomes lower, incomplete combustion of fuel takes place, and the content of carcinogenic substances in the exhaust gas is increased, as with gasoline. Therefore, all countries of the world continuously tighten their standards regarding the quality of the gasoline or light oil in consideration of the generation of air pollution.

Presently, many companies produce gasoline, kerosene and light oil from waste resins and waste oils. Analysis of oil produced from the waste resins and the waste oils shows that kerosene and light oil cannot be produced at the same time. Kerosene is a fraction discharged next to gasoline during the distillation of oil and has a boiling point of 160 to 325^°C. Light oil is a fraction discharged next to kerosene and has a boiling point of 200 to 370°C. Comparing the boiling points of kerosene and light oil, it can be seen that a certain amount of light oil can be contained in the kerosene fraction and a certain amount of kerosene can be contained in the light oil fraction. However, in case of light oil, the component having a boiling point of less than 300°C has a critical effect on the fuel efficiency.

When an oil fraction having a boiling point of less than 300 °C is high, the amount of fuel consumed by the engine is decreased. Therefore, it is desirable for the fraction having a boiling point of less than 300°C to be maximized, in consideration of reducing toxic emissions in exhaust gases .

The waste plastics are high molecular weight hydrocarbons. In terms of reactivity during pyrolysis, as the molecular weight of a hydrocarbon increases, bonds between carbon atoms are more easily broken under a condition of a constant temperature to form low molecular weight molecules. That is, specifically, high molecular hydrocarbons of waste synthetic resins can undergo carbon-carbon bond breakage even at a temperature of 200°C, and the breaking rate is increased with increasing temperature.

From the above theory and practical observations, it can be seen that when heated to a temperature between 350 to 370^°C, the high molecular hydrocarbons go through vigorous thermal cracking reaction, from which mixed gases including methane, ethane, ethylene, etc, and fractions of gasoline, light oil and the like are formed. However, the oils from the above thermal cracking reaction are of poor quality and thus can hardly be used as engine fuel. Accordingly, it is noted that by heating the waste synthetic resins to a temperature of 350 to 370°C, it is impossible to obtain an oil of high quality.

By means of a catalytic cracking reactor of a fluidized bed type, oil can be produced from waste synthetic resins. However, in order to produce oil safely, some requirements should be satisfied. In particular, there is a requirement associated with pressure equilibration. It is preferred that the pressure within the reactor is in equilibrium with the atmospheric pressure in order for the catalytic cracking reactor of the fluidized bed type to be operated safely. To maintain the atmospheric pressure, there should be no pressure difference generated between a rectifying column tower and the catalytic cracking reactor. The rectifying column tower which is used in most facilities of the oil production companies uses a tower plate of ASPEN type. The rectifying column tower of this type has some pressure difference generated in the lower part of the tower. Therefore, it is not suitable for use in a fluidized bed type catalytic cracking reactor with the rectifying column of the ASPEN type.

The gasoline produced from waste synthetic resins by thermal cracking method has a low octane value. Also, it has high temperatures of 10% outflow and 50% outflow. Therefore, problems associated with starting and acceleration of automobiles cannot be easily solved. More over, in case of light oil, since it does not essentially comprise an isomerized material, its low fluidity can cause troubles in winter time.

The conventional thermal cracking reactor has low conversion efficiency and a poor yield in processing the raw materials of the waste synthetic resins. Also, a large amount of Carbon is produced and secondary pollution associated with disposing of sludge produced during the process can be caused. In order to overcome the problems involved in the conventional thermal cracking reactor, the present inventors use a downflow type catalytic cracking reaction apparatus for producing oil from waste synthetic resins.

Disclosure of Invention

Therefore, the object of the present invention is to provide a method for producing oil at a high yield using a downflow type catalytic cracking reactor.

Another object of the present invention is to provide a method for producing oil from waste synthetic resins in which the catalyst can be recycled, thereby allowing oil to be mass-produced in a continuous process .

A still further object of the present invention is to provide a method for producing oil from waste synthetic resins in which the heat required for the cracking reaction is provided by combustion heat of Carbon produced as a cracking reaction by-product and acting as a catalytic poison, thereby preventing waste of fuel.

According to the present invention, there is provided downflow type catalytic cracking reaction apparatus comprising: a catalytic cracking reactor producing an oil-gas mixture through a direct contact catalytic cracking reaction by bringing the raw material in liquid phase into contact with the catalyst, the catalytic cracking reactor having a steam injector which is installed therein and connected to a steam boiler, and provided at its lower end with a waste catalyst discharging valve and a regulating valve; a catalyst regenerating and transporting pipe connected at its lower end with the catalytic cracking reactor via a pipe line and serving to transport and regenerate poisoned catalysts discharged from the catalytic cracking reactor, the catalyst regenerating and transporting pipe extending vertically and connected at its lower end with a heat exchanger which is connected in series to a ring blower; a cyclone connected at its upper end with the catalyst regenerating and transporting pipe and serving to separate air from the catalyst circulated and treated through the transport pipe, the cyclone being provided at its top with a gas exhaust line for discharging gas of Carbon combustion; a catalyst-storing tank connected at its upper end with the cyclone and serving to temporarily store a given amount of the regenerated catalyst, the catalyst- storing tank having a catalyst cooler installed therein and provided at its lower end with a flow regulating valve; a first mixing pipe connected with the catalyst- storing tank and serving to carry out primary mixing of the catalyst and raw material of the waste synthetic resins in liquid phase from melt furnaces, the first mixing pipe being provided with an inlet to receive the raw material through a transport line from the melt furnaces; and a second mixing pipe connected at its upper end with the first mixing pipe and at its lower end with the catalytic cracking reactor and serving to carry out secondary mixing of the catalyst and the raw material , the second mixing pipe provided with an outlet to discharge the oil-gas mixture produced in the catalytic cracking reactor toward a rectifying column tower for the production of oil.

Brief Description of Drawings The above object and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a schematic diagram illustrating an oil producing system using the downflow type catalytic cracking reaction apparatus according to the present invention;

Fig. 2 is a view illustrating the melt furnace for liquefying the raw material of the waste synthetic resins; and

Fig. 3 is a view illustrating the downflow type catalytic cracking reaction apparatus according to the present invention.

Best Modes for Carrying out the Invention The catalytic cracking reaction apparatus which is used according to the present invention is a equipment of high efficiency using waste resins and waste oil as raw materials. This reactor uses a solid catalyst of high acidity (for example, alumina silicate) . It can produce oil from the raw materials of the waste synthetic resins within several seconds. Therefore, a relatively small amount of Carbon is formed and consequently, the oil yield is increased. Also, by using acidic catalyst, the produced oil is excellent in its quality, whereby it can be used as gasoline and light oil for engines.

According to the present invention, the heat which is required to perform the cracking reaction is supplied by the combustion heat of the Carbon forming the barrier of the catalyst. The catalyst can be reused after regeneration. Therefore, the method for producing oil according to the present invention is characterized by being capable of mass-producing oil in a continuous process .

Now, the theoretical grounds supporting the fact that light oil of good quality can be produced by using a solid acidic catalyst is presented.

The important properties of gasoline include an octane value and volatility. An ideal substance capable of enhancing the octane value is hard isoparaffin having a number of branches in the molecular structure of the hydrocarbon. As the number of branches increases, the octane value becomes higher and the boiling point is lowered. For a substance of fuel having significant effect on the starting property of the gasoline engine comprises various mixtures consisting of hydrocarbons flowed out at a temperature of 10% flow out of below 70°C. Such mixtures should meet a certain standard in order to improve the starting property and octane value. Typically, it is preferable that the substances mainly comprise a mixture of hydrocarbons containing 4 to 5 carbon atoms in the molecule . The products from the catalytic cracking reaction and thermal cracking reaction of, for example, cetane are analyzed for their ingredients and the results are shown in Table 1 below. Table 1

As seen from the above table, by the catalytic cracking reaction, more C₄, C₅ and C₆ hydrocarbons are produced. Thus, it is noted that by the catalytic cracking reaction light gasoline is mainly produced and heavy gasoline is produced in a minor amount, as desired.

As to the above result, the reference will be made to Korean Patent Publication No. 288731, which was issued to the present applicant.

The light oil produced by thermal cracking reaction cannot be used in winter season due to lack of fluidity. The fluidity of the light oil is associated with the solidifying point. When the solidifying point is low, the fluidity is improved and when the solidifying point is high the fluidity is deteriorated. Under a condition of not using a fluidity enhancer, the fluidity point is determined by structure and size of the hydrocarbon molecules making up the light oil fraction. When there are many hydrocarbons making up the light oil having T-shaped molecular structure c-c-c-c-c c-c-c-c

( C ) or π -shape molecular structure ( c c ) , the fluidity is improved. Also, when the sizes of molecules are small within the range of allowable flash points, the fluidity point is lowered. The materials having T-shape or π -shape molecular structure cannot be formed by the thermal cracking reaction. Only the catalytic cracking reaction can produce such materials of T-shape or π -shape.

The acidic catalyst can cause the isomerization of hydrocarbon.

The acidity of the solid acid is 100 or more times of that of normal sulfuric acid. When a solution of melted waste synthetic resins is brought into contact with a catalyst of solid acid at a temperature of 520°C or more, the resins are converted into carbocation instantaneously.

+ The resulting carbocation ( CH3-CH-CH2^~CIi3 ) ±_{s no} stable and is thus rapidly converted to a tertiary

carbocation ( CH3 ) . Then, the tertiary carbocation will gain a hydrogen ion H^" from another molecular to form an isomer. Meanwhile the molecule which lost the hydrogen ion H- becomes a carbocation. This procedure is repeated over and over. Thermal equilibrium analysis

The heat needed in the catalytic cracking reaction is obtained from the combustion heat of the Carbon which is formed during the catalytic cracking reaction. This may be explained theoretically as follows.

Normally, the catalytic cracking reaction is carried out at a temperature of 480 to 540°C. The Carbon by-product is not made up purely of only carbon atoms but contains hydrogen in a small amount. That is, it is generally said that the Carbon is made up of large content of carbon and small content of hydrogen, typically the ratio of hydrogen to carbon being 1:9. The empirical formula of the Carbon is CH_N, in which N is 0.5 to 1. For illustrative purposes, it is assumed that an equipment disposes 1 ton/hour of waste synthetic resins at 300°C. The catalytic cracking reaction proceeds for 1 to 4 seconds. 9% of the raw material is outputted as the Carbon. That is, from the above equipment 90 kg of Carbon is produced hourly. The atomic weight of carbon (C) is 12, molecular weight of H₂ is 2, molecular weight of 0₂ is 31.99, and molecular weight of N₂ is 28.

Combustion of Carbon

As described above, the Carbon consists of carbon and hydrogen in the ratio of 9:1. Thus, 90 kg of Carbon which is resulted from the catalytic cracking reaction of 1 ton of waste synthetic resins consists of 81 kg of carbon and 9 kg of hydrogen. The above values can be converted into 6.75 kmole (81 ÷ 12) and 4.5 kmole (9 ÷ 2) of each element, respectively. When Carbon is burned, two types of gases, that is, carbon dioxide and carbon monoxide are produced in a ratio of 1.5:1. The amount of carbon converted to C0₂ from the Carbon is 4.05 kmole (6.75 x 1.5 /(1.5 + 1)). The amount of carbon converted to CO from the Carbon is 2.7 kmole (6.75 - 4.05).

Theoretical amount of air needed for combustion of Carbon

To produce C0₂ from 4.05 kmole of carbon, 4.05 kmole of 0 is needed. To produce CO 1.35 kmole (2.7 ÷ 2) of 0₂ is needed. To produce H₂0 2.25 kmole (4.5 ÷ 2) of 0₂ is needed.

Thus, the amount of oxygen (0₂) needed to burn 90 kg of the Carbon is the sum of 4.05, 1.35 and 2.25, e.i. 7.65 kmole. The amount of Nitrogen (N₂) theoretically needed is 28.78 kmole (7.65 x (79/21)). Therefore, the theoretical amount of air without moisture needed for the combustion of the Carbon is 36.43 kmole (7.65 + 28.78) . Practical amount of air needed for combustion of Carbon

In practice, upon burning of the Carbon, 100 % of air cannot be consumed. In the smoke, 0.5 % volume (or mole) of oxygen remains. The remaining oxygen (0_2re) and nitrogen (N_2re) in the smoke can be obtained by calculating the following equations:

O

0.5% = 2 re o Ire

CO, ₊ CO ₊ N_{2 +} N_2re + 0_{2re 28 8 Q χ} 79

11

The remaining oxygen (0_2re) is 0.18198 kmole (5.82 kg) and the remaining nitrogen (N_2re) is 0.684 kmole

(19.16 kg) .

Therefore, the amount of air practically needed for the combustion of 90 kg of Carbon is the sum of 36.43, 0.18198 and 0.684, e,i, 37.2986 kmole (1075.5 kg) .

Meanwhile, for air with moisture, the vapor in the air is considered in the calculation. In the case of air having a relative humidity of 50% at 25^°C, the ratio of vapor to air without moisture is 0.01:1. Therefore, for the combustion of 90 kg of the Carbon, a further 10.755 kg (1075.5 x 0.01) of air is needed.

Thermal equilibrium

The quantity of heat generated when burning the Carbon by-product of the cracking reaction is calculated according to ESSO method. More particularly, by the ESSO method the respective heats of carbon (C) and hydrogen (H₂) are calculated separately considering the Carbon as being a mixture consisting of carbon (C) and hydrogen (H₂) . The heat generated when 1 kg of carbon is oxidized into carbon dioxide is 33,873 kJ/kg. The heat generated when 1 kg of carbon is oxidized into carbon monoxide is 10258 kJ/kg. The heat generated when 1 kg of hydrogen is oxidized into water (H₂0) is 11,980 kJ/kg. Accordingly, the total heat generated by burning 90 kg of Carbon is calculated as follows:

The heat generated when forming C0₂ : 48.6 x 33,873 = 1,646,227.8 (kJ) .

The heat generated when forming CO : 32.4 x 10,258 = 332,359.2 (kJ) .

The heat generated when forming H₂0: 9 x 11,890 = 107,910 (kJ) .

The total amount of heat : 1,646,227.8 + 332,359.2 + 107,910 = 2,086,497 kJ/hour. The above heat is used to regenerate the catalyst.

However, a part of the heat is used for the following states :

(1) 11.5% of the generated heat is used to release carbon atom. That is, 23,994.715 kJ (2,086,497 x 11.5 ÷ 100) is used to release carbon atom (the heat for releasing carbon atom is 11.5% of the total heat);

(2) For the combustion of the Carbon, the temperature of the air should be heated from 140^°C to 650 °C . The heat needed for this is calculated as follows:

1,050.52 X 1.09 X (650 - 140) = 583,695 (kJ) in which the specific heat of air is 1.09 kJ/kg^°C ;

(3) The vapor contained in the air should be heated from 140^°C to 650^°C. The heat needed for this is calculated as follows:

10.755 X 2.07 X (650 - 140) = 11354 (kJ) in which the specific heat of air is 2.07 kJ/kg^°C;

(4) The catalyst is regarded as having a specific heat the same as the carbon, 1.097 kJ/kg°C .

The heat amount needed to raise the temperature of carbon from 140^°C to 650^°C is calculated as follows: 81 X 1.097 X (650 - 140) = 45317.07 (kJ) ;

(5) The catalyst being regenerated contains vapor, which is originated from the vinyl solution of the waste synthetic resins. The vinyl solution of the waste synthetic resins has a concentration of 2%(w/w). The heat needed to raise the temperature of the vapor from 470 ^°C to 650 °C is calculated as follows: 20 x 2.16 x (650-470) = 776 (kJ) in which the specific heat of vapor is 2.16 kJ/kg^°C; and (6) Upon combustion of the carbon atom there occurs a loss of heat. The lost heat is calculated as follows: 582 x 81 = 47,142 (kJ) in which 582 (kJ/kg) is an empirical value.

Therefore, the heat which is absorbed by the catalyst is determined by subtracting the sum of the heat amounts calculated in (1) to (6) from the heat generated by the combustion of the Carbon, e.i. 2,086,497 kJ.

2,086,497 - (239,947.15 + 583,695 + 11,354 + 45,317.07 + 7,776 + 47,142) = 1,151,265.75 (kJ)

Accordingly, 1,151,265.75 (kJ) can be incorporated into the catalytic cracking reactor. Meanwhile, the amount of the circulating catalyst

(G) can be calculated by the following equation: 1,151,265.75 = G X 1.097 (650 - 470) G = 5,830.37 (kg)

Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Now, the method for producing oil from the waste synthetic resins using the downflow type catalytic cracking reaction apparatus according to the present invention will be described in detail .

Firstly, the processes for pretreating the waste synthetic resins will be described, as to individual steps, referring to Fig. 1 to Fig 2.

The waste synthetic resins are ground using a mechanical grinder. The well ground raw material of waste synthetic resins is supplied into a sorter to remove impurities such as metal, soil, dust, stones, etc.

The sorted powder from the above step is then fed into a first extruder 20 and then a second extruder 25, through which the solid material is converted into the liquid phase at a temperature of 280^°C.

The extruded material is supplied into a furnace 30, where the material is heated to a temperature between 280°C to 300°C. When the temperature of the raw material reaches to 300^°C, the thermal cracking reaction begins to progress slowly. At this time, chlorine atoms within the molecular structure of the waste synthetic resins are released in a rapid reaction and bound with water or hydrogen to form hydrochloride .

The hydrochloride which is generated during the thermal cracking reaction is dissolved into water to form a strong acid. Since this strong acid can erode the equipment, it should be neutralized. According to the present invention, about 98% or more of chlorine is dechlorinated via a HCl neutralizing means, shown in Fig. 2. At this time, sludge produced in the first melt furnace 30 is discharged out of the furnace by a sludge- discharging means 40.

The raw material at 300°C discharged from the first melt furnace 30 is then supplied to a second melt furnace 60 by the action of high pressure pump PI for transport of a high viscosity fluid, as shown in Fig. 2. In the second melt furnace 60, the raw material is again subjected to the thermal cracking reaction at a slow rate, while kept at a temperature of 300°C. As a result, the raw material in liquid phase comes to have an improved fluidity so that it can be readily mixed with catalyst in the later step. The sludge produced in the second melt furnace 60 is discharged out of the furnace by a sludge discharging means 70. <step for transporting the raw material in liquid phase> The raw material in liquid phase after having passed through the second melt furnace 60 is then supplied to the downflow type catalytic cracking reaction apparatus according to the present invention through a pipe 13 by the action of high pressure pump P2 for transport of a high viscosity fluid.

The configuration and operation principle of the downflow type catalytic cracking reaction apparatus will be described.

Firstly, the configuration of the downflow type catalytic cracking reaction apparatus will be described, referring to Fig. 3.

The downflow type catalytic cracking reaction apparatus according to the present invention comprises a catalytic cracking reactor 1, a catalyst regenerating and transporting pipe 9, a catalyst storing tank 10, a catalyst cooler 11, a heat exchanger, a ring blower 7, a catalyst make-up feeder 8, a cyclone 14 and pipes for connecting the members to one another.

The catalytic cracking reactor 1 produces an oil- gas mixture through a direct contact catalytic cracking reaction by bringing the raw material in liquid phase into contact with the catalyst. in the catalytic cracking reactor, there is installed a steam injector 2 which is connected to a steam boiler 3. The catalytic cracking reactor 1 is connected with the catalyst- storing tank 10 through two mixing pipes 16,18. In the mixing pipes, the catalyst from the catalyst-storing tank 10 is mixed with the liquid phase raw material supplied from a transport line 1*3 , which is connected to the second melt furnace 60 via the pump P2. Tthe first mixing pipe 16 is provided with an inlet (not shown) to receive the raw material in liquid phase through the transport line 13. The second mixing pipe 18 is provided with an outlet (not shown) to discharge a resulting oil- gas mixture toward a rectifying column tower for the production of oil. The catalytic cracking reactor 1 is provided at its lower end with a waste catalyst discharging valve 5 and a regulating valve 4 and connected with the catalyst regenerating and transport line 9 through a pipe line 19. The pipe line 19 has a catalyst make-up feeder for feeding supplementing catalyst .

The catalyst regenerating and transporting pipe 9 extends vertically and serves to regenerate and transport the poisoned catalyst discharged from the catalytic cracking reactor 1. The pipe 9 is connected at its lower end with the heat exchanger 6 which is provided with a ring blower 7. The blower serves to supply air at a high temperature into the interior of the pipe 9. The upper end of the pipe 9 is connected with the cyclone 14.

The cyclone 14 serves to separate air from the catalyst circulated and treated through the transport pipe 9. It is provided at its top with a gas exhaust line 15 for discharging the gas of the Carbon combustion. It is downwardly connected to the catalyst- storing tank 10.

The catalyst-storing tank 10 serves as a temporary reservoir storing a given amount of the catalyst and has a catalyst cooler 11 installed therein. It is provided at its lower end with a flow regulating valve 12. Secondly, the operational principle of the downflow type catalytic cracking reaction apparatus according to the present invention will be described.

The catalytic cracking reactor 1 and the catalyst- storing tank 10 contain the catalyst up to desired levels, respectively. The catalyst from the catalyst- storing tank 10 flows by gravity in a downward direction along the pipe 19 and reaches the catalyst regenerating and transporting pipe 9. In the catalyst regenerating and transporting pipe 9, the catalyst is heated by the action of the heat exchanger 6 and the ring blower 7, regenerated, and then is transported to the cyclone 14. In the cyclone 14, the air contained in the catalyst is removed. The air-removed catalyst is then fed to and stored in the catalyst-storing tank 10. Meanwhile, the air separated from the catalyst is exhausted through the combustion gas discharge line 15 connected to the top of the cyclone 14. The catalyst contained in the catalyst-storing tank 10 is introduced into the first mixing pipe 18 at a constant rate regulated by the valve 12. The catalyst then passes through the second mixing pipe 19 and flows down to the catalytic cracking reactor 1. After the cracking reaction, the poisoned catalyst is discharged from the catalytic cracking reactor 1 through the discharging valve 5 in a constant amount regulated by the valve 4 and flows down to the catalyst regenerating and transporting pipe 9. After the catalyst circulates the above mentioned system several times, its temperature is raised to 520°C or more.

The molted raw material (the melted waste synthetic plastic) is directed to the first mixing pipe line 18 via the transport line 13 by the action of the high pressure pump P2. In the first mixing pipe line 18 the melt is primarily mixed with the catalyst. The primarily mixed melt and catalyst are thoroughly mixed again while passing through the second mixing pipe line 19 and then are downwardly fed to the catalytic cracking reactor 1. In the catalytic cracking reactor 1, the mixture is subjected to the catalytic cracking reaction. Meanwhile, the Carbon which is produced from the catalytic cracking reaction is deposited on the catalyst to form a physical barrier preventing the catalyst from contacting the melt of the waste synthetic resins. That is, the catalyst is now poisoned. The poisoned catalyst must be regenerated to restore its catalytic activity. In the catalyst regenerating and transporting pipe line 9 the poisoned catalyst is regenerated. The Carbon existing on the catalyst in the form of a barrier comes into contact with oxygen in the hot air supplied by the ring blower 7 and is burned off. At this time, the catalyst absorbs the heat energy from the heat generated upon the combustion of the Carbon, so that it is heated to a temperature of 600 "C or more (the regeneration of the catalyst) . Gases resulted from the combustion of the Carbon and gases separated in the cyclone 14 are outwardly' discharged via the pipe line 15.

As the melt of the waste synthetic resins comes into contact with the catalyst in the catalytic cracking reactor 1, an oil-gas mixture is produced. As shown in Fig. 1, this mixture is then fed to the first and second rectifying column towers, in this order, via the transport pipe line 17. The oil-gas mixture is distilled into the gasoline fraction and the light oil fraction in the rectifying column towers (the rectification of the mixture of oils and gases) .

As a result, basic gasoline and basic light oil are extracted from the distilled gasoline and light oil fractions by chemical extractants A and B in an extraction tower. To the above basic oils, respective additives may be added in given amounts to form gasoline and light oil of a high quality satisfying the standards for petroleum products. Respective final products are stored in respective reserve tanks .

Industrial Applicability

As described above, the present invention has advantageous effects as follows. Since the present invention uses a solid catalyst of high acidity, the produced oil is excellent in quality and yield. Also, according to the present invention, it is possible to have generally increased economic benefits through the process. More particularly, according to the present invention, the poisoned catalyst from the cracking reaction can be regenerated. Therefore, the amount of the supplemented catalyst can be reduced and the process can be carried out continuously, thereby enabling mass- production of oil. Also, the heat generated during the regeneration of the poisoned catalyst can be introduced into the cracking reactor by the catalyst which absorbs the generated heat. Accordingly, the heat required for the cracking reaction is partially supplied by the heat generated upon the regeneration of the catalyst.

Further, it is possible to use the light oil produced by disposing of the waste synthetic resins to supply the heat required for pretreating the waste synthetic resins into a liquid phase in the melt furnaces. In practice, it is shown that electricity consumption of the reactor can be reduced by 70%. While there have been illustrated and described what are considered to be preferred specific embodiments of the present invention, it will be understood by those skilled in the art that the present invention is not limited to the specific embodiments thereof, and various changes and modifications and equivalents may be substituted for elements thereof without departing from the true scope of the present invention.

Claims

1. A downflow type catalytic cracking reaction apparatus comprising: a catalytic cracking reactor producing an oil-gas mixture through a direct contact catalytic cracking reaction by bringing the raw material in liquid phase into contact with the catalyst, the catalytic cracking reactor having a steam injector which is installed therein and connected to a steam boiler, and provided at its lower end with a waste catalyst discharging valve and a regulating valve; a catalyst regenerating and transporting pipe connected at its lower end with the catalytic cracking reactor via a pipe line and serving to transport and regenerate poisoned catalysts discharged from the catalytic cracking reactor, the catalyst regenerating and transporting pipe extending vertically and connected at its lower end with a heat exchanger which is connected in series to a ring blower; a cyclone connected at its upper end with the catalyst regenerating and transporting pipe and serving to separate air from the catalyst circulated and treated through the transport pipe, the cyclone being provided at its top with a gas exhaust line for discharging gas of Carbon combustion; a catalyst-storing tank connected at its upper end with the cyclone and serving to temporarily store a given amount of the regenerated catalyst, the catalyst- storing tank having a catalyst cooler installed therein and provided at its lower end with a flow regulating valve ; a first mixing pipe connected with the catalyst- storing tank and serving to carry out primary mixing of the catalyst and raw material of the waste synthetic resins in liquid phase from melt furnaces, the first mixing pipe being provided with an inlet to receive the raw material through a transport line from the melt furnaces ; and a second mixing pipe connected at its upper end with the first mixing pipe and at its lower end with the catalytic cracking reactor and serving to carry out secondary mixing of the catalyst and the raw material, the second mixing pipe provided with an outlet to discharge the oil-gas mixture produced in the catalytic cracking reactor toward a rectifying column tower for the production of oil.

2. The apparatus according to claim 1, wherein the pipe line connecting the catalytic cracking reactor with the catalyst regenerating and transporting pipe has a catalyst make-up feeder for feeding supplementing catalyst.

3. A method for producing gasoline and light oil using the apparatus according to claim 1, wherein the catalyst and a raw material of the waste synthetic resins in liquid phase from melt furnaces are mixed primarily in the first mixing pipe, a pre-mix of the catalyst and the raw material of the waste synthetic resins are mixed secondarily in the second mixing pipe, a resulting mixture of the catalyst and the raw material of the waste synthetic resins are subjected to a direct contact catalytic cracking reaction to produce an oil- gas mixture, the oil-gas mixture is then fed to first and second rectifying column towers, in this order, via a transport pipe line, and in the rectifying column towers the oil-gas mixture is distilled into a gasoline fraction and a light oil fraction to produce gasoline and light oil .

4. The method according to claim 3 , wherein the catalyst which has been poisoned (or lost catalytic activity) by Carbon produced from the catalytic cracking reaction is transferred to the catalyst regenerating and transporting pipe, in which the poisoned catalyst comes into contact with oxygen in the hot air supplied by the ring blower and is regenerated by combustion of the Carbon, and the regenerated catalyst is then circulated at a temperature of 600°C or more toward the cyclone and brought into contact with the liquid phase raw material of the waste synthetic resins in the catalytic cracking reactor to produce the oil-gas mixture.

5. The method according to claim 4, wherein the poisoned catalyst from the cracking reaction is regenerated and recycled, thereby enabling continuous mass-production of oil.

6. The method according to claim 3 or 4 , wherein the catalyst in the catalytic cracking reactor is kept at a temperature of 520 °C or more.

7. The method according to claim 3 or 4 , wherein the catalyst in the catalyst regenerating and transporting pipe is kept at a temperature of 600^°C or more.

8. The method according to claim 3 or 4 , wherein the liquid phase raw material of the waste synthetic resins is introduced to the catalytic cracking reactor at a temperature of 300°C or more.