JP6241436B2 - Waste plastic oil conversion method and oil conversion system - Google Patents

Description

  The present invention relates to a waste plastic oil conversion method and an oil conversion system in which solid waste plastic is heated and gasified together with a catalyst and the gas is cooled to generate cracked oil.

The present inventor has provided a structure described in Patent Document 1 as a waste plastic oil converting apparatus intended for continuous oil conversion operation of pulverized waste plastic and efficient discharge of residues.
In this waste plastic oil converting device, the cracked oil produced by gas cooling is precipitated with an oil separator to discharge untreated waste plastic powder, which is recirculated with a pump and reprocessed (reoiled). I am doing so.

  On the other hand, Patent Document 2 intends to recover oil that can be transferred even at a low temperature of 0 ° C. corresponding to heavy oil A or third petroleum from the cracked oil of waste plastic, and the waste plastic is reacted at a reaction temperature of 650 ° C. After pyrolysis treatment in a pyrolysis furnace adjusted to ± 20 ° C to generate pyrolysis gas, the generated pyrolysis gas is introduced into the pyrolysis oil generator to cool the pyrolysis gas, and in the pyrolysis gas Discloses a method for condensing and recovering an oily component having a flash point of 60 ° C. or higher or a flash point of 70 ° C. or higher.

  Patent Document 3 switches between a thermal decomposition apparatus that thermally decomposes waste plastic in the absence of oxygen and a waste plastic thermal decomposition and recovery apparatus that includes a distillation apparatus that distills the cracked gas produced by the thermal decomposition apparatus. A method of recovering useful components by thermally decomposing styrene waste plastic and olefin waste plastic separately, comprising a first distillation device and a second distillation device as distillation devices, and styrene waste plastic In this case, it is thermally decomposed under reduced pressure by a thermal decomposition apparatus, and the generated cracked gas is separated from styrene under reduced pressure by a first distillation apparatus, and then separated from styrene under reduced pressure by a second distillation apparatus. The styrene is recovered by separating the high-boiling components. At that time, the pressure of the first distillation apparatus is made higher than the pressure of the second distillation apparatus. There is disclosed a method for recovering gasoline components by pyrolyzing them under normal pressure with a pyrolyzer and separating the generated cracked gas from gasoline components and higher boiling components under normal pressure with a first distillation device. .

  Patent Document 4 intends to produce low-boiling point oil from waste plastic, and a fine powder neutralizer for neutralizing chlorine (dechlorination) and 5-35 wt. % Of FCC waste catalyst and sand heated to a high temperature of 600 ° C. to 950 ° C. are added as a heat medium, and the waste plastic is added to the FCC waste catalyst together with the FCC waste catalyst by a fluidized bed in which the high temperature sand is circulated. A method of thermal decomposition by heating at a temperature of ° C. is disclosed.

JP2013-234216A JP 2008-266252 A Japanese Patent No. 3348378 JP 2001-107058 A

  Waste plastics contain various plastics such as polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), and uniform properties from cracked oil produced by gas cooling. If the oil is not collected separately, it has no utility value as a recycled product, but the structure described in Patent Document 1 does not give such consideration.

  On the other hand, the technique described in Patent Document 2 maintains the reaction temperature in the pyrolysis furnace within a high temperature range of 650 ° C. ± 20 ° C., so that A heavy oil or a third petroleum (liquid at a temperature of 20 ° C. at 1 atm. (A flash point of 70 ° C. or higher and lower than 200 ° C.) is generated, and this is a decomposition method specialized for this.

  In the technique described in Patent Document 3, a thermal decomposition apparatus that thermally decomposes waste plastic, a first distillation apparatus and a second distillation apparatus that distill the decomposition gas therefrom, and in the case of styrene waste plastic, decomposition gas is used. In the case of olefin waste plastics, the first distillation unit separates low-boiling components from styrene under reduced pressure, and the second distillation unit separates high-boiling components from styrene under reduced pressure to recover high-purity styrene. The gasoline component is recovered from the cracked gas by separating the gasoline component and the higher boiling point component under normal pressure in the first distillation apparatus.

By the way, for example, JIS (Japanese Industrial Standards) regulations on petroleum specify properties such as flash points when classified as petroleum products such as gasoline, kerosene, light oil, and heavy oil. Difficult to commercialize.
However, in the technique described in Patent Document 2, when the reaction temperature in the pyrolysis furnace is within a high temperature range of 650 ° C. ± 20 ° C., the aromatization reaction of long chain aliphatic hydrocarbons proceeds rapidly and the long chain Paying attention to the change of aliphatic hydrocarbons to aromatic hydrocarbons corresponding to A heavy oil with aliphatic side chains, A heavy oil with the highest carbon number and the highest boiling point among petroleum products (or third It is produced only for petroleum). That is, in this technique, the carbon number is large by maintaining the reaction temperature in the pyrolysis furnace within a high temperature range of 650 ° C. ± 20 ° C. so that re-polymerization that once polymerizes by distillation does not occur again. Only those, that is, only heavy oil A (or third petroleum) is produced by distillation, and the regeneration range of waste plastic oil conversion is limited to this.

In addition, the technology described in Patent Document 3 is an oxygen-depleting method in which waste plastic is replaced with an inert gas such as nitrogen gas at a high temperature of 600 ° C. to 800 ° C. and a reduced pressure of 20 Torr or more without using a catalyst in a thermal decomposition apparatus. Thermal decomposition is performed in the presence state, and the cracked gas is distilled in the first distillation apparatus and the second distillation apparatus under different conditions depending on whether the waste plastic is styrene or olefin. Also during the distillation, the first distillation apparatus and the second distillation apparatus are similarly put into an oxygen-free state in which the inert gas is substituted.
For this reason, it must be separated into styrene waste plastic and olefin waste plastic in advance, and the thermal decomposition apparatus must be at a high temperature of 600 ° C. to 800 ° C. and a reduced pressure state of 20 Torr or more. In addition, heat resistance and pressure resistance satisfying such conditions are required. Furthermore, equipment for substituting with an inert gas and reducing the pressure is also necessary.

  The technology described in Patent Document 4 includes a fluidized bed combustion furnace for forming a fluidized bed by heating and circulating sand at a high temperature of 600 ° C. to 950 ° C., and dechlorination by adding a neutralizing agent to waste plastic. Using a rotary kiln for chlorine and a pyrolysis furnace that mixes FCC waste catalyst with waste plastic to which this is added and pyrolyzes it, heat high-temperature sand from a fluidized bed combustion furnace to a rotary kiln for dechlorination and a pyrolysis furnace. Since it is a fluidized bed heating system that circulates again from the pyrolysis furnace to the fluidized bed combustion furnace, there are problems in that it is difficult to control and control the temperature, and the piping equipment and the scale of the apparatus become large.

  Therefore, the object of the present invention is to separate waste plastic mixed with polypropylene (PP), polyethylene (PE), polystyrene (PS), etc., for example, without prior separation such as separation between styrene and olefin, Waste plastic that can be efficiently recycled at a relatively small reaction temperature economically in a small-scale facility as a highly marketable petroleum product such as gasoline, kerosene, and light oil with stable properties that meet petroleum standards such as JIS An object of the present invention is to provide an oil conversion method and an oil conversion system.

In order to achieve this object, a first aspect of the waste plastic oil converting method according to the present invention is a fluid heat medium in which solid waste plastic and a catalyst are placed in a dissolution evaporation tank and enclosed in a peripheral wall cavity of the dissolution evaporation tank. The waste plastic is stirred and dissolved together with the catalyst within the predetermined temperature range (T1 to T2) while being indirectly heated, and evaporated, and the evaporated gas component is cooled to cool the primary cracked oil. And the primary cracked oil is heated and evaporated in the distillation tank within a predetermined temperature range (T3 to T4) (T3 <T2) lower than that of the primary cracked oil generating process. The secondary cracked oil production step for producing the secondary cracked oil having a carbon number of a predetermined number or less by cooling the gas component, and the secondary cracked oil production step in the constant temperature heating tank Heating temperature (T3-T4 Substantially heated and maintained at a constant temperature (T5) lower than, and a flash point adjustment step for evaporation at that temperature (T5).
In this first aspect, what has not evaporated in the secondary cracked oil production step can be returned to the dissolution evaporation tank and reprocessed.

  The heating temperature range (T1 to T2) in the primary cracking oil production process is 350 ° C to 450 ° C, the heating temperature range (T3 to T4) in the secondary cracking oil production process is 190 ° C to 300 ° C, and the tertiary cracking oil production process. The heating temperature (T5) is preferably 120 to 130 ° C.

In a second aspect of the method for converting waste plastic oil according to the present invention, solid waste plastic and a catalyst are placed in a dissolution evaporation tank, and a fluid heat medium sealed in a peripheral wall cavity of the dissolution evaporation tank is heated to dispose of waste. Production of primary cracked oil that stirs and dissolves plastic together with catalyst in the specified temperature range (T1-T2) while indirectly heating, evaporates, and cools the evaporated gas to produce primary cracked oil The process and the primary cracked oil are returned to the dissolution and evaporation tank and evaporated by heating within a predetermined temperature range (T3 to T4) (T3 <T2) lower than the primary cracked oil generating process without using a catalyst. A secondary cracked oil producing step for producing a secondary cracked oil having a carbon number of not more than a predetermined number Cx by cooling the gas that has evaporated, and the secondary cracked oil in the constant temperature heating tank. Heating temperature (T To T4) substantially heated to maintain a constant temperature (T5) lower than, and a flash point adjustment step for evaporation at that temperature (T5).
In this second aspect, the material remaining in the dissolution evaporating tank in the secondary cracked oil production step may be treated in the same manner as the primary cracked oil generating step in the dissolution evaporating tank together with new solid waste plastic. it can.

  Also in the second aspect, the heating temperature range (T1 to T2) in the primary cracked oil production step is 350 ° C to 450 ° C, and the heating temperature range (T3 to T4) in the secondary cracked oil production step is 190 ° C to 300 ° C. The heating temperature (T5) in the tertiary cracked oil production step is preferably 120 ° C to 130 ° C.

In both cases of the first aspect and the second aspect, the catalyst used in the primary cracked oil production step is preferably an FCC (fluid catalytic cracking) waste catalyst mainly composed of silica (Si) and alumina (Al). .
When discharging the catalyst remaining in the dissolution evaporation tank to the outside of the tank, the heating temperature of the dissolution evaporation tank by the heat medium is higher than the heating temperature (T1 to T2) of the primary cracked oil generation step (T6) ( However, the temperature is raised to T6> T2), and the catalyst remaining in the dissolution evaporation tank is heated at this temperature (T6) and then discharged out of the dissolution evaporation tank.

  In each of the secondary cracked oil production process and the flash point adjustment process, cracked oil is produced, but part of the secondary cracks produced in the secondary cracked oil production process are used in order to effectively use a part of them in the system. Either the cracked oil or a part of the cracked oil that has not evaporated in the flash point adjustment step is injected into a waste plastic charging path for charging solid waste plastic into the dissolution evaporation tank.

  A first aspect of the waste plastic oil conversion system according to the present invention includes a dissolution evaporation tank in which a cavity is formed in a peripheral wall and a fluid heat medium is enclosed therein, a heating unit for heating the heat medium, and a stirrer. Decomposing waste plastics that react with a solid waste plastic in a dissolution evaporating tank and dissolve it by stirring it with a stirrer while indirectly heating within a predetermined temperature range (T1-T2) with a heat medium An apparatus, a primary cooling device for generating a primary cracked oil by cooling a gas component evaporated from the dissolution evaporating tank, and a predetermined temperature lower than a heating temperature (T1 to T2) in the melting evaporating tank. A distillation tank that heats and distills within a temperature range (T3 to T4) (where T3 <T2), and a secondary cooling device that cools a gas component evaporated from the distillation tank and generates secondary cracked oil. The secondary cracked oil A flash point adjusting device which is introduced into a constant temperature heating tank, heated at a substantially constant temperature (T5) lower than the heating temperature (T3 to T4) in the distillation tank, and evaporated at that temperature (T5) Including.

  A second aspect of the waste plastic oil conversion system according to the present invention includes a dissolution evaporation tank in which a cavity is formed in a peripheral wall and a fluid heat medium is enclosed therein, a heating unit for heating the heat medium, and a stirrer. Decomposing waste plastics that react with a solid waste plastic in a dissolution evaporating tank and dissolve it by stirring it with a stirrer while indirectly heating within a predetermined temperature range (T1-T2) with a heat medium An apparatus; a cooling device that cools the gas evaporated from the dissolution evaporation tank to generate primary cracked oil; and a precipitation separator that precipitates and separates the primary cracked oil and returns it to the dissolution evaporation tank. Yes. And the said waste plastic oil-ized apparatus is within the predetermined temperature range (T3-T4) lower than the said heating temperature (T1-T2) by adjusting the temperature of the primary cracked oil from the said precipitation separation apparatus in the said heating part. (However, it is also used for a catalyst-free distillation process in which T3 <T2) and evaporate by heating without using a catalyst. The cooling device is also used for generating secondary cracked oil that cools the gas that has evaporated by the catalyst-free distillation process, thereby generating secondary cracked oil having a carbon number of not more than a predetermined number Cx. Furthermore, this waste plastic oil conversion system introduces the secondary cracked oil from the cooling device into a constant temperature heating tank and maintains it at a substantially constant temperature (T5) lower than the heating temperature (T3 to T4). It has a flash point adjustment device that heats and evaporates at that temperature (T5).

The present invention is intended to liquefy waste plastic mixed with PP, PE, PS, etc., but is mainly intended to regenerate gasoline, kerosene, and light oil, which are highly marketable, among the petroleum products. Perform stage processing.
That is, in the first stage, a dissolution evaporating tank in which a cavity is formed in a peripheral wall and a fluid heat medium is enclosed therein is used, and waste plastic is put together with a catalyst in a predetermined temperature range (T1 to T1) in the dissolving evaporating tank. In T2), the mixture is stirred and dissolved while indirectly heated, and evaporated, and the evaporated gas is cooled to produce primary cracked oil.
When the waste plastic is heated indirectly while reacting with the catalyst in such a dissolution evaporation tank, the heat medium enclosed in the peripheral wall cavity of the dissolution evaporation tank flows along the peripheral wall to transfer heat, It is possible to heat the entire area from the peripheral surface uniformly and efficiently, and to make the average temperature in the dissolution and evaporation tank equal to the temperature of the heat medium. Therefore, measuring the temperature of the heat medium is equivalent to measuring the heating temperature in the dissolution evaporating tank. Therefore, the adjustment and management of the heating temperature is easy, and the melting (pyrolysis) makes the carbon number excessive. In addition to preventing melting unevenness, thermal decomposition that concentrates only on a certain number of carbon atoms can be suppressed, and thermal decomposition under intended stable conditions can be performed. In addition, there is an advantage that the gas generated as a by-product in the treatment of the present invention can be used as a fuel for heating the heat medium of the dissolution evaporation tank.

In the second stage, the primary cracked oil produced in the first stage is distilled within a predetermined temperature range (T3 to T4) lower than the heating temperature range (T1 to T2) in the first stage, Is cooled to produce a secondary cracked oil having a carbon number of not more than a predetermined number Cx.
By distillation here, a fraction having a carbon number equal to or higher than the expected value (with a carbon number exceeding the upper limit) can be easily removed by a relatively low temperature distillation treatment.

In the third stage, the secondary cracked oil produced in the second stage is heated and maintained at a substantially constant temperature (T5) lower than the heating temperature range (T3 to T4) in the second stage, and the temperature ( Evaporation at T5) is performed.
By such a constant temperature heat treatment, a fraction having a flash point below the expected value can be separated, and a product oil that satisfies the JIS petroleum standards as gasoline, kerosene, and light oil can be taken out.
In summary, the first-stage treatment is intended to avoid thermal decomposition that has a small number of carbon atoms and is specified in a narrow range, but rather includes those that contain a large number of carbon atoms. In this case, the distillation is intended to limit the number of carbon atoms excluding those having a large number of carbon atoms, and the third stage treatment is intended to adjust the flash point for extraction as a petroleum product having a stable property. And by organic combination of these three-stage treatments with different purposes, waste plastic mixed with PP, PE, PS, etc. satisfies the properties of oil standards such as JIS, that is, both carbon number and flash point. A highly marketable petroleum product such as gasoline, kerosene, and light oil that satisfies the above property standards can be efficiently regenerated in a small-scale facility at a relatively low reaction temperature.

  In the second stage, when primary cracked oil is heated and distilled in a distillation tank, some carbon repolymerization occurs and the number of carbons increases. Since it remains, if it is returned to the dissolution evaporation tank and the first stage pyrolysis treatment is repeated, a secondary cracked oil having a desired carbon number range can be produced with a high yield.

Since the 1st aspect of this invention can be set as the continuous processing system which performs said three steps of processing continuously, production efficiency is good.
On the other hand, the second aspect of the present invention is a so-called batch type, and the first stage pyrolysis process using a catalyst and the second stage distillation process without a catalyst are performed using a common dissolution evaporation tank. Since it is easy to adjust and control the heating temperature of the dissolution evaporation tank as described above, there is no problem even if the heating temperature range is different between the first stage and the second stage as described above. Can save equipment costs.

In both cases of the first aspect and the second aspect of the present invention, as a preferable temperature, the heating temperature range (T1 to T2) of the primary cracked oil producing step is 350 ° C. to 450 ° C., and the secondary cracked oil producing step. The heating temperature range (T3 to T4) is 190 ° C to 300 ° C, and the heating temperature (T5) in the tertiary cracked oil production step is 120 ° C to 130 ° C for the following reason.
First, regarding the first stage pyrolysis treatment,
(1) To avoid fractions with carbon numbers exceeding C40.
(2) When the waste plastic is PP or PS, the decomposition starts from about 320 ° C and ends at about 380 ° C. In the case of PE, the decomposition starts from about 380 ° C and ends at about 420 ° C.
(3) When the oil component is gasified and removed from the catalyst before discharging the catalyst remaining in the dissolution evaporation tank, the residual catalyst is heated at a temperature higher than the heating temperature in the primary cracked oil production step. The heating temperature should be about 500 ° C or higher.
(4) Since the cracked oil becomes more colored as it is thermally decomposed at a high temperature, the heating temperature is desired to be kept as low as possible, so the range of 350 ° C. to 450 ° C. is appropriate.

  For the second stage distillation treatment, the standard for JIS distillation properties for kerosene is 270 ° C. or less and 95% or more is distilled, so that the range is about 270 ° C., 190 ° C. If it is carried out below, the residue will increase without distillation, and if it is carried out at 300 ° C. or higher, it will be distilled until the carbon number exceeds C20, and the carbon number of the secondary cracked oil will be kept to C20 or lower. A range of 300 ° C. is suitable.

  Regarding the third-stage constant temperature heat treatment, according to the JIS standard, the boiling point of carbon number C8 is 126 ° C., and the kerosene belonging to the second petroleum has a carbon number of about C9 to C15. The flash point is set to 40 ° C. or higher, and in order to satisfy the first priority, the maintenance temperature of constant temperature heating is suitably 120 ° C. to 130 ° C.

In both cases of the first aspect and the second aspect of the present invention, the catalyst used in the first stage pyrolysis is preferably an FCC waste catalyst mainly composed of silica and alumina. The reason is as follows. It is as follows.
(1) The FCC waste catalyst is a used FCC catalyst that is discharged from a refinery or the like, and is much cheaper than a virgin FCC catalyst because it is discharged in large quantities.
(2) Although it has deteriorated because it is once used as a catalyst, the catalytic reaction at the time of thermal decomposition is reduced, but the virgin FCC catalyst has good reaction, so when used on waste plastic, When the FCC waste catalyst is used, the product oil that is finally regenerated is limited to petroleum products having a carbon number of C9 or less because the pyrolysis tends to be concentrated mainly at a low value of C9 or less. Since the reaction is low, it has the advantage that it can be regenerated not only for petroleum products with C9 or less carbon but also for petroleum products with higher carbon number such as kerosene, and suitable for thermal decomposition at lower temperature than in high temperature range. That.
(3) Since the present invention is intended to economically and efficiently regenerate highly marketable petroleum products such as gasoline, kerosene and diesel oil having a carbon number of C20 or less, silica and alumina are particularly preferred. The FCC waste catalyst as the main component is evaporated in the first stage by pyrolysis performed by indirect heating in the dissolution evaporation tank, or the remaining FCC waste catalyst is heated at a high temperature to evaporate the attached oil. There are advantages that the heating temperature as described above can be easily controlled and the disposal can be easily performed.

When discharging the catalyst remaining in the dissolution evaporation tank to the outside of the tank, heating the catalyst with a heating temperature higher than the heating temperature in the first stage treatment will remove the oil trapped in the catalyst. Since it can be evaporated from the catalyst and the catalyst can be discharged in a smooth state without oil, it is useful for disposal of the catalyst.
Solid waste plastic is usually crushed and then transported to the dissolution evaporation tank. Static electricity is generated during the transportation process in the pulverized state, causing adsorption and aggregation due to static electricity, which also adds heat from the dissolution evaporation tank. However, if part of the cracked oil produced in the second stage or part of the cracked oil produced in the third stage is injected into the waste plastic charging path to the dissolution evaporator, it will be adsorbed by static elimination. Aggregation can be prevented, and smooth feeding can be performed by a lubricating action.

It is a system configuration figure of Example 1 of the present invention. It is a system configuration | structure figure of Example 2 of this invention. It is a block diagram of the waste plastic decomposition apparatus which can be used in common in both Examples. 3 is a timing chart showing a procedure of a first processing step in Example 1. It is a timing chart which similarly shows the procedure of a 2nd process process. 6 is a timing chart showing a procedure of a third processing step in Example 1 and Example 2. 3 is a timing chart illustrating a procedure of a residue treatment process in Example 1. 6 is a timing chart showing a procedure of a first processing step in Example 2. It is a timing chart which similarly shows the procedure of a 2nd process process.

  Since the present invention can be implemented in two forms, a continuous processing type capable of continuously performing a series of processing and a batch processing type capable of simplifying equipment which cannot be continuously processed, examples of each case will be described below. To do.

  FIG. 1 is an overall system configuration diagram showing a first embodiment in the case of a continuous processing type. Waste plastic which is a raw material mixed with PP, PE, PS, etc. is crushed by a crusher 1 and washed by a washing dehydrator 2 And after dehydration, volume reduction by the thermal volume reducer 3 and cooling by the water washing and cooling device 4, it is carried into the feeding hopper 6 by the conveyor 5 and is pulverized and temporarily stored there. . The process up to here is the pretreatment process, and the process from this point on is the process according to the invention.

The pulverized waste plastic (hereinafter referred to as pulverized raw material) first stored in the charging hopper 6 drives the horizontal conveyor 7 and the vertical conveyor 8 connected to the horizontal conveyor 7 and inputs the leading end of the vertical conveyor 8. By opening the valve 9, the waste plastic decomposition apparatus 10 is charged into the melting / evaporating tank 11 from the inlet 11 b of the ceiling portion 11 a.
In FIG. 1, the waste plastic decomposition apparatus 10 is shown in a schematic view, but FIG. 3 shows a specific example of its structure. Therefore, after clarifying the structure of the waste plastic decomposing apparatus 10 with reference to FIG. 3, the process (first process step) will be described later.

  The melting and evaporating tank 11 of the waste plastic decomposition apparatus 10 is accommodated in a heat insulating casing 11B, and a burner 14 is installed in the lower part of the empty chamber 13 between them. The lower part of the dissolution evaporating tank 11 has a tapered funnel shape, and the peripheral wall of the dissolution evaporating tank 11 including the lower part has a double wall structure composed of an inner wall 11c and an outer wall 11d, and a peripheral wall cavity 12 between the inner and outer walls. Is formed, and the heat medium 15 is enclosed therein. The heat medium 15 is preferably made of a phase change material that is hardened like wax at room temperature, but melts and flows in the peripheral wall cavity 12 when heated to a certain temperature or higher, for example, 190 ° C. or higher.

  A partition wall 16 is spirally provided between the outer wall 11b of the dissolution evaporation tank 11 and the heat insulation casing 11B, and an exhaust port 17 is formed in the heat insulation casing 11B in the upper part of the empty chamber 13. The empty chamber 13 from the burner 14 to the exhaust port 17 becomes a spiral flue. Therefore, the heat from the burner 14 becomes a rising vortex and heats the heat medium 15 in the peripheral wall cavity 12.

  A stirrer 18 is incorporated in the dissolution evaporating tank 11. The stirrer 18 uses a reversible rotary motor 19 installed outside the ceiling portion 11a of the dissolution evaporating tank 11 as a drive source, and a rotating shaft 20 rotated by the motor 19 with a support frame of the helical stirring blade 21. A rotating frame 22 is mounted, and a feed screw 23 having the rotating shaft 20 as a coaxial is provided. While the stirring blade 21 has a spiral shape that gradually increases upward, the feed screw 23 is smaller than the spiral of the stirring blade 21 and reaches the residue discharge port 24 at the bottom lower end of the dissolution evaporating tank 11 at the center thereof. It extends and rotates integrally with the stirring blade 21.

  The ceiling portion 11a of the dissolution evaporating tank 11 is also provided with a catalyst inlet 25 for introducing a catalyst, and a cracked oil return pipe 26 for feeding the cracked oil to be returned is provided with a cracked oil injection valve 27. Further, a gas pipe 29 is connected to the condenser 28 which is an external gas cooling device, and a temperature sensor 30 for measuring the temperature of the heat medium 15 in the peripheral wall cavity 12 is installed. On the other hand, a residue hopper 32 is disposed via a residue discharge valve 31 on the outside lower side of the heat insulation casing 11B.

The first treatment process is performed as follows by the waste plastic decomposition apparatus 10 having such a structure. FIG. 4 shows a timing chart of the procedure in the first embodiment.
First, a required amount of catalyst is charged into the dissolution evaporation tank 11 from the catalyst charging port 25 (see FIG. 4 (1)). As the catalyst, an FCC waste catalyst mainly composed of silica and alumina is used.

  After the catalyst is charged, the charging valve 9 is closed (see FIG. 4 (2)), and then heating by the burner 14 is performed (see FIG. 4 (3)). Since the heat medium 15 enclosed in the peripheral wall cavity 12 of the dissolution evaporating tank 11 melts at about 190 ° C., flows in the peripheral wall cavity 12, and heats the inside of the peripheral wall of the dissolution evaporating tank 11, so that the temperature sensor The measurement temperature of the heat medium 15 by 30 can be identified with the heating temperature in the tank.

When the measurement temperature (heating temperature) reaches 300 ° C. or higher, the charging valve 9 is opened (see FIG. 4 (4)), and the pulverized raw material in the charging popper 6 is dissolved and evaporated in the horizontal axis conveyor 7 and the vertical axis conveyor 8. (See FIG. 4 (5)). Then, the stirrer 18 is driven to rotate forward (see FIG. 4 (6)), and the pulverized raw material and the FCC waste catalyst are heated while being stirred.
This stirring action is because the feed screw 23 moves the ground raw material and the FCC waste catalyst upward from the converged bottom portion at the center in the dissolution evaporating tank 11, and at the same time, stirs the stirring blade 21 to wind up around it. The pulverized raw material and the FCC waste catalyst are evenly stirred while repeating the up-and-down circulation and the vortex as shown by the arrow S.
As for the heating, the heat medium 15 in the peripheral wall cavity 12 is heated as a vortex flow in which the heat from the burner 14 rises as described above, and since the heated heat medium 15 flows in the peripheral wall cavity 12, dissolution and evaporation occur. The inside of the tank 11 is evenly heated from the entire peripheral wall.

The pulverized raw material and the FCC waste catalyst are indirectly heated by the heat from the burner 14 while being stirred in this manner in the dissolution evaporating tank 11. The heating temperature is monitored by the temperature sensor 30 and is 350 ° C. to 450 ° C. Within the range of ° C. Within this temperature range, the FCC waste catalyst reacts with the pulverized raw material, which is waste plastic, and causes thermal decomposition. FCC waste catalyst is inferior in reaction to plastics such as PP, PE, PS, etc. compared to virgin catalyst, so pyrolysis occurs in a wide range of C1-C40, and the gas generated by pyrolysis is such carbon. In several ranges, it is discharged from the dissolution evaporating tank 11 through the gas pipe 29 and cooled by the condenser 28 to generate cracked oil (see FIG. 4 (7)). This cracked oil is fed into the distillation tank 34 of the secondary distillation apparatus 33 shown in FIG. 1, and the next process (second processing step) is performed in the secondary distillation apparatus 33.
The FCC waste catalyst is advantageous from the viewpoint of economy as described above because the raw material to be treated is waste plastic such as PP, PE, and PS. However, the present invention uses a virgin FCC catalyst. There is no limit.

  The secondary distillation apparatus 33 is intended to lower the high range of the carbon number range by heating and distilling the cracked oil produced in the waste plastic decomposition apparatus 10 in the distillation tank 34, A heater 35 is built in the distillation tank 34, and a temperature sensor 36 for measuring the heating temperature is attached to the distillation tank 34. Moreover, the condenser 37 which cools and gasifies the gas which evaporated from the distillation tank 34, and the precipitation separation apparatus 38 which carries out precipitation separation of the oil content and is used as secondary cracked oil are provided. The bottom of the distillation tank 34 has a funnel shape, and a distillation residual oil discharge valve 39 is disposed outside the lower end of the distillation tank 34. Instead of incorporating the heater 35 in the distillation tank 34, a burner may be installed outside the distillation tank 34.

In FIG. 5, the procedure of the secondary treatment process performed in the secondary distillation apparatus 33 is shown.
When the distillation residual oil discharge valve 39 is opened, the distillation residual oil in the distillation tank 34 is returned to the dissolution and decomposition tank 11 through the residual oil return path 40 (see FIG. 5 (1)). The returned distillation residual oil is injected from the cracked oil injection port 41 into the vertical conveyor 8 shown in FIG. 3 (see FIG. 4 (8)), and is fed from the vertical conveyor 8 to the dissolution cracking tank 11. It is used for antistatic of the crushed raw material and for lubrication of the flow.

  The cracked oil that has entered the distillation tank 34 is distilled by heating with the heater 35 (see FIG. 5 (2)), and the heating temperature is monitored by the temperature sensor 36 and is in the range of 190 ° C. to 300 ° C. And As a result of distillation at this temperature, the number of evaporated coal layers becomes approximately C20 or less, and those exceeding C20 remain in the distillation tank 39 as distillation residual oil. The distilled residual oil can be injected into the vertical conveyor 8 and used as described above, and is reprocessed in the dissolution / decomposition tank 11, but if necessary, the cracked oil return shown in FIG. Reprocessing can also be performed by returning from the flow pipe 26 into the dissolution / decomposition tank 11 as needed (see FIG. 5 (3)).

  The gas component evaporated in the distillation tank 34 is cooled by a condenser 37 to be oiled, and the oil component is precipitated and separated by a precipitation separator 38 (see FIG. 5 (4)). It is produced as a secondary cracked oil (see FIG. 5 (5)). This secondary cracked oil is fed into the constant temperature heating tank 44 of the flash point adjusting device 43 by opening the valve 42 in FIG.

  The flash point adjusting device 43 heats the secondary cracked oil from the viewpoint of adjusting the flash point. The heater 45 is built in the constant temperature heating tank 44, and a temperature sensor 46 for measuring the heating temperature by the heater 45 is provided in the constant temperature heating tank 44. It is attached to. Moreover, since the gas derived from petroleum evaporates from the constant temperature heating tank 44, the gas holder 47 which collects it by activated carbon adsorption is provided.

Processing (third processing step) by the flash point adjusting device 43 is performed as follows. FIG. 6 shows the procedure.
The secondary cracked oil that has entered the constant temperature heating tank 44 is heated while the temperature is maintained at a constant temperature within the range of 120 ° C. to 130 ° C. by monitoring the heating temperature of the heater 45 with the temperature sensor 46 ( (See FIG. 6 (1)). By constant temperature heating while maintaining such a temperature, those having a low flash point with a carbon number of less than C9 evaporate, and those having a carbon number in the range of C9 to C20 remain in the constant temperature heating tank 44.

The gas collected by the gas holder 47 is used for the combustion of the burner 14 of the waste plastic decomposition apparatus 10 (see FIG. 6 (2)), and the gas that has not been collected is released into the atmosphere. On the other hand, part of the produced oil in the constant temperature heating tank 44 is provided as fuel for the burner 14 (see FIG. 6 (3)). The produced oil in the constant temperature heating tank 44 is sent to the product tank 49 at an appropriate time by opening the valve 48 and stored therein (see FIG. 6 (4)). The stored produced oil becomes a highly marketable petroleum product having a carbon number in the range of C9 to C20.
A part of the generated oil can be used as fuel for the burner 14 of the waste plastic decomposition apparatus 10.

  The first processing step, the second processing step, and the third processing step described above are continuously performed in series. However, in the case of performing a periodic operation such as a daily operation, the waste plastic decomposition is performed. Residue processing is performed in the apparatus 10 as follows. FIG. 7 shows a residue treatment procedure.

With the closing valve 7 closed (see FIG. 7 (1)), the heating temperature in the dissolution and evaporation tank 11 by the burner 14 is about 500 ° C., which is higher than the heating temperature (350 ° C. to 450 ° C.) in the first treatment step. The temperature is raised for the required time (see FIG. 7 (2)). By such high temperature heating, the waste plastic residue in the dissolution evaporating tank 11 is rapidly pyrolyzed, and the oil component captured by the FCC waste catalyst is forcibly evaporated. Thereafter, heating by the burner 14 is stopped (see FIG. 7 (3)).
After the temperature in the dissolution evaporating tank 11 has dropped to a safe temperature, the agitator 18 is reversed (see FIG. 7 (4)), and the residue discharge valve 30 is opened to remove the residue containing the FCC waste catalyst. 11 (see FIG. 7 (5)) and collected in the residue hopper 31.

  When the agitator 18 is reversed, the residue is collected by the stirring blade 21 so that the residue converges to the lower end of the central portion in the dissolution evaporating tank 11. Is forcibly dropped and discharged. The residue containing the FCC waste catalyst recovered in the residue hopper 31 is easily disposed of because the oil content is removed by evaporation from the FCC waste catalyst.

  Next, FIG. 2 is an overall system configuration diagram showing Example 2 in the case of a batch processing type, and the secondary distillation apparatus 33 in Example 1 is omitted, and in Example 1, the secondary distillation apparatus 33 performs this operation. In the second embodiment, the secondary processing step that has been performed is replaced by reusing the waste plastic decomposition apparatus 10 and the capacitor 28. Therefore, in Example 2, the primary cracked oil obtained in the first treatment step is returned to the waste plastic cracking apparatus 10, and at this time, a cracked oil precipitation storage tank 50 for separating and storing the primary cracked oil is provided. Yes.

FIG. 8 shows the procedure of the first processing step in the case of the second embodiment.
An FCC waste catalyst mainly composed of silica and alumina is introduced into the dissolution evaporation tank 11 (see FIG. 8 (1)), the introduction valve 9 is closed (see FIG. 8 (2)), and heating by the burner 14 is performed. (See FIG. 4 (3)). When the measurement temperature (heating temperature) reaches 300 ° C. or higher, the charging valve 9 is opened (see FIG. 8 (4)), and the pulverized raw material in the charging popper 6 is dissolved and evaporated in the horizontal axis conveyor 7 and the vertical axis conveyor 8. (See FIG. 8 (5)). Then, the stirrer 18 is driven to rotate forward (see FIG. 8 (6)), and the pulverized raw material and the FCC waste catalyst are heated while being stirred.
The heating temperature is monitored by the temperature sensor 30 and is in the range of 350 ° C to 450 ° C. Within this temperature range, the FCC waste catalyst reacts with the pulverized raw material, which is waste plastic, and causes thermal decomposition. Thermal decomposition occurs in a wide range of carbon numbers C1 to C40, and the gas generated by the thermal decomposition is discharged from the dissolution evaporation tank 11 through the gas pipe 29 in such a carbon number range, cooled by the condenser 28, and primary cracked oil. Is generated (see FIG. 8 (7)).

  The processing up to this point and the operation as described above are the same as in the case of the first embodiment, but after this, unlike the first embodiment, the primary cracked oil from the condenser 28 is stored in the cracked oil precipitation storage tank 50. Is done. The cracked oil having a large number of carbons stored here is injected into the charging path of the pulverized raw material into the dissolution evaporation tank 11, that is, the vertical conveyor 8 which is a charging conveyor (see FIG. 8 (8)). As in the case of, the ground raw material is used for preventing static electricity and lubrication, and is reprocessed in the dissolution evaporation tank 11.

When the processing target amount of the pulverized raw material is charged into the melting and evaporating tank 11 and thermally decomposed, the charging valve 7 is closed (see FIG. 8 (9)), and the heating temperature in the melting and evaporating tank 11 by the burner 14 is required to reach about 500 ° C. Only the temperature is increased (see FIG. 8 (10)). By such high temperature heating, the waste plastic residue in the dissolution evaporating tank 11 is rapidly pyrolyzed, and the oil component captured by the FCC waste catalyst is forcibly evaporated. Thereafter, heating by the burner 14 is stopped (see FIG. 8 (11)).
Thereafter, the agitator 18 is reversed (see FIG. 8 (12)), the residue discharge valve 30 is opened, and the residue containing the FCC waste catalyst is discharged from the dissolution evaporation tank 11 (see FIG. 8 (13)). It collects in the hopper 31 and waits until the temperature of the dissolution / evaporation tank 11 is lowered, and proceeds to the next second processing step (see FIG. 8 (14)).

FIG. 9 shows the procedure of the second processing step in the case of the second embodiment.
When it is confirmed by monitoring the temperature of the temperature sensor 30 that the temperature of the dissolution / evaporation tank 11 has dropped to about 250 ° C. (see FIG. 9 (1)), the primary cracked oil stored in the cracked oil precipitation storage tank 50. Is returned to the dissolution / evaporation tank 11 through the vertical conveyor 8 or the cracked oil return pipe 26 (see FIG. 9 (2)). Then, the burner 14 is ignited again to heat the primary cracked oil in the dissolution evaporating tank 11 without using a catalyst (see FIG. 9 (3)). The heating temperature at this time shall be the range of 190 to 300 degreeC lower than the heating temperature in a 1st process process. By this heating, the primary cracked oil is distilled, and the evaporated component is cooled again by the condenser 28 to produce the secondary cracked oil (see FIG. 9 (4)). Since the heating temperature of distillation is in the range of 190 ° C to 300 ° C, the number of coal layers of the secondary cracked oil produced is approximately C20 or less, and those that did not evaporate are dissolved and evaporated as distillation residual oil having a carbon number exceeding C20. It remains in the tank 11.

  In the dissolution and evaporation tank 11, the first treatment step described above can be restarted while leaving the distillation residual oil as it is. However, the secondary cracked oil produced by the condenser 28 is adjusted for the flash point as in the first embodiment. It transfers to the constant temperature heating tank 44 of the apparatus 43, and transfers to the 3rd process process similar to Example 1 by the flash point adjustment apparatus 43. FIG. The procedure is the same as that of the first embodiment shown in FIG.

  The present invention is not limited to the case where waste plastics such as PP, PE, and PS are used as raw materials, but can also be applied to cases where waste oil is used as raw materials.

Claims (11)

Solid waste plastic and catalyst are placed in a dissolution evaporation tank, and the fluid heat medium sealed in the peripheral wall cavity of the dissolution evaporation tank is heated, so that the waste plastic is brought together with the catalyst within a predetermined temperature range (T1 to T2). A primary cracked oil producing step of stirring and dissolving while indirectly heating, evaporating, and cooling the evaporated gas to produce a primary cracked oil;
Heating and evaporating the primary cracked oil in a distillation tank within a predetermined temperature range (T3 to T4) (T3 <T2) lower than the primary cracked oil producing step, and cooling the evaporated gas component A secondary cracked oil producing step for producing a secondary cracked oil having a carbon number of a predetermined number or less,
The secondary cracked oil is heated in a constant temperature heating tank while being maintained at a substantially constant temperature (T5) lower than the heating temperature (T3 to T4) of the secondary cracked oil production step, and at that temperature (T5) A flash point adjustment process for evaporation;
A method for converting waste plastics into oil.   The waste plastic oil conversion method according to claim 1, wherein what is not evaporated in the secondary cracked oil production step is returned to the dissolution evaporation tank.   The heating temperature range (T1 to T2) in the primary cracking oil production step is 350 ° C to 450 ° C, the heating temperature range (T3 to T4) in the secondary cracking oil production step is 190 ° C to 300 ° C, and the tertiary cracking. The waste plastic oil conversion method according to claim 1 or 2, wherein the heating temperature (T5) in the oil production step is 120 ° C to 130 ° C. Solid waste plastic and catalyst are placed in a dissolution evaporation tank, and the fluid heat medium sealed in the peripheral wall cavity of the dissolution evaporation tank is heated, so that the waste plastic is brought together with the catalyst within a predetermined temperature range (T1 to T2). A primary cracked oil producing step of stirring and dissolving while indirectly heating, evaporating, and cooling the evaporated gas to produce a primary cracked oil;
The primary cracked oil is returned to the dissolution evaporating tank and evaporated by heating within a predetermined temperature range (T3 to T4) (where T3 <T2) lower than the primary cracked oil production step without using a catalyst, A secondary cracked oil producing step for producing a secondary cracked oil having a carbon number of not more than a predetermined number Cx by cooling the evaporated gas component;
The secondary cracked oil is heated in a constant temperature heating tank while maintaining a substantially constant temperature (T5) lower than the heating temperature (T3 to T4) of the secondary cracked oil production step, and at that temperature (T5) A flash point adjustment process for evaporation;
A method for converting waste plastics into oil.   What is left in the distillation tank in the secondary cracked oil production step is returned to the dissolution and evaporation tank, and the same treatment as the primary cracked oil production step is performed together with new solid waste plastic. Item 6. A method for converting waste plastics into oil according to Item 4.   The heating temperature range (T1 to T2) in the primary cracking oil production step is 350 ° C to 450 ° C, the heating temperature range (T3 to T4) in the secondary cracking oil production step is 190 ° C to 300 ° C, and the tertiary cracking. The waste plastic oil-forming method according to claim 4 or 5, wherein the heating temperature (T5) in the oil production step is 120 ° C to 130 ° C.   The waste plastic oil conversion method according to any one of claims 1 to 6, wherein the catalyst used in the primary cracked oil production step is an FCC waste catalyst mainly composed of silica and alumina.   The heating temperature of the dissolution evaporating tank by the heat medium is increased to a heating temperature (T6) (where T6> T2) higher than the heating temperature (T1 to T2) of the primary cracked oil generation step, and the inside of the melting evaporating tank The waste plastic oil conversion method according to any one of claims 1 to 7, wherein the catalyst remaining in the catalyst is heated at this temperature (T6) and then discharged out of the dissolution evaporation tank.   Either a part of the secondary cracked oil produced in the secondary cracked oil production process or a part of the cracked oil that did not evaporate in the flash point adjusting process, the solid waste plastic into the dissolution evaporation tank The waste plastic oil conversion method according to any one of claims 1 to 8, wherein the waste plastic oil is injected into a waste plastic input path. It is equipped with a dissolution evaporating tank in which a cavity is formed and a fluid heat medium is sealed inside, a heating unit for heating the heat medium, and a stirrer, and the catalyst reacts with solid waste plastic in the melting evaporating tank. A waste plastic decomposition apparatus that stirs and dissolves with the stirrer while indirectly heating within a predetermined temperature range (T1 to T2) with the heat medium, and evaporates;
A primary cooling device for cooling the gas evaporated from the dissolution evaporation tank to produce primary cracked oil;
A distillation tank for heating and distilling the primary cracked oil within a predetermined temperature range (T3 to T4) (where T3 <T2) lower than the heating temperature (T1 to T2) in the dissolution evaporation tank;
A secondary cooling device that cools the gas evaporated from the distillation tank and generates secondary cracked oil;
The secondary cracked oil is introduced into a constant temperature heating tank, heated at a substantially constant temperature (T5) lower than the heating temperature (T3 to T4) in the distillation tank, and evaporated at that temperature (T5). A flash point adjusting device for performing
Waste plastic oil conversion system characterized by including. It is equipped with a dissolution evaporating tank in which a cavity is formed and a fluid heat medium is sealed inside, a heating unit for heating the heat medium, and a stirrer, and the catalyst reacts with solid waste plastic in the melting evaporating tank. A waste plastic decomposition apparatus that stirs and dissolves with the stirrer while indirectly heating within a predetermined temperature range (T1 to T2) with the heat medium, and evaporates;
A cooling device for generating a primary cracked oil by cooling a gas component evaporated from the dissolution evaporation tank;
A precipitation separation device for separating the primary cracked oil and returning it to the dissolution evaporation tank;
With
The waste plastic oil converting apparatus adjusts the temperature of the primary cracked oil from the precipitation separating apparatus in the heating unit to a predetermined temperature range (T3 to T4) lower than the heating temperature (T1 to T2) ( However, T3 <T2) is also used for distillation without catalyst, which is heated and evaporated without using catalyst,
The cooling device is also used for secondary cracked oil generation for generating a secondary cracked oil having a carbon number of not more than a predetermined number Cx by cooling a gas component evaporated by a catalyst-free distillation process,
Furthermore, the secondary cracked oil from the cooling device is introduced into a constant temperature heating tank and heated at a substantially constant temperature (T5) lower than the heating temperature (T3 to T4), and at that temperature (T5) A waste plastic oil conversion system comprising a flash point adjusting device for evaporating water.

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