JP-7855316-B2 - Hydrolysis continuous processing apparatus

Inventors

• 馬場 剛志
• 滑 尚子
• 尾崎 智史
• 平脇 聡志

Assignees

• 本田技研工業株式会社

Dates

Publication Date

20260508

Application Date

20210318

Claims (5)

1. A heating cylinder having an introduction section for a fiber-containing hydrolyzable resin composition and an introduction section for water, A hydrolysis reaction vessel having a screw inserted into the heating cylinder and transporting the hydrolyzable resin composition and the water downstream within the heating cylinder while mixing them, A pressure regulating valve is provided downstream of the hydrolysis reaction vessel, which sets the pressure in the hydrolysis reaction vessel to a predetermined pressure for the hydrolysis reaction to proceed, while allowing the hydrolysis product and fibers to flow downstream. A sealing portion formed from the molten hydrolyzable resin composition, positioned upstream of the water inlet in the longitudinal direction of the heating cylinder, and sealing the gap between the heating cylinder and the screw, Equipped with, The pressure regulating valve is a diaphragm that adjusts the flow path cross-sectional area according to the indicated pressure. A continuous hydrolysis apparatus characterized in that when the pressure between the hydrolysis reaction vessel and the pressure regulating valve reaches a preset second pressure that is higher than a first pressure that allows the hydrolysis reaction in the hydrolysis reaction vessel to proceed, the pressure regulating valve increases its opening.
2. A heating cylinder having an introduction section for a fiber-containing hydrolyzable resin composition and an introduction section for water, A hydrolysis reaction vessel having a screw inserted into the heating cylinder and transporting the hydrolyzable resin composition and the water downstream within the heating cylinder while mixing them, A pressure regulating valve is provided downstream of the hydrolysis reaction vessel, which sets the pressure in the hydrolysis reaction vessel to a predetermined pressure for the hydrolysis reaction to proceed, while allowing the hydrolysis product and fibers to flow downstream. A sealing portion formed from the molten hydrolyzable resin composition, positioned upstream of the water inlet in the longitudinal direction of the heating cylinder, and sealing the gap between the heating cylinder and the screw, Equipped with, When the pressure between the hydrolysis reaction vessel and the pressure regulating valve reaches a preset second pressure that is higher than the first pressure that allows the hydrolysis reaction in the hydrolysis reaction vessel to proceed, the pressure regulating valve increases its opening . The continuous hydrolysis apparatus according to claim 1, wherein the fiber-containing hydrolyzable resin composition is a nylon 6 fiber-reinforced material as a raw material, and the temperature of the blocks from the block that supplies the nylon 6 fiber-reinforced material to the water supply position is set to 220°C or lower, which is the melting temperature of nylon 6.
3. The continuous hydrolysis apparatus according to claim 1, characterized in that the pressure regulating valve maintains an open state at a predetermined pressure or higher.
4. A continuous hydrolysis apparatus according to any one of claims 1 to 3, characterized in that it comprises a switching valve between the hydrolysis reaction vessel and the pressure regulating valve, and a discharge channel leading from the switching valve to the outside of the apparatus.
5. The continuous hydrolysis apparatus according to claim 1, further comprising a flash tank for reducing the pressure of the high-temperature, high-pressure hydrolysis product flowing from the pressure regulating valve and for vaporizing and recovering the hydrolysis product.

Description

This invention relates to a continuous hydrolysis apparatus . Conventionally, batch-type depolymerization apparatuses are known that produce ε-caprolactam by depolymerizing nylon 6 in the presence of catalysts such as phosphoric acid and ionic liquids. For example, in the depolymerization apparatus disclosed in Patent Document 1, when recycling polycaprolactam-containing waste, both melting and compression of the waste are carried out simultaneously in a conventional extruder as a melting device, and then the molten material compressed in the melting device is brought into contact with superheated steam in a hydrolysis reactor. The mixture discharged from the hydrolysis reactor is fed to a vacuum device and then to a separation device. In the separation device, insoluble additives such as glass fibers, pigments, and other polymers are removed. This separation device consists of conventional filtration devices such as belt filters, backwashable cylindrical filters, and other filtration devices that can discharge continuously or periodically. Special Publication No. 10-510280 This is a diagram illustrating the configuration of a continuous hydrolysis apparatus according to an embodiment of the present invention.Figure 1 is an exploded perspective view illustrating the configuration of the back pressure valve in the continuous hydrolysis processing apparatus.Figure 2 is a schematic cross-sectional view illustrating the operation of the back pressure valve.Figure 1 is a schematic diagram illustrating the operation of the hydrolysis reaction vessel in the continuous hydrolysis processing apparatus. Next, a continuous hydrolysis apparatus and a continuous hydrolysis method according to an embodiment of the present invention will be described in detail. In this embodiment, the present invention will be specifically described using a continuous hydrolysis apparatus and a continuous hydrolysis method for hydrolyzing a fiber-reinforced resin (hydrolyzable resin composition) containing nylon 6 and glass fibers as an example. However, the continuous hydrolysis apparatus and continuous hydrolysis method of the present invention are not limited to this and can also be applied to other hydrolyzable resin compositions described later. <Continuous Hydrolysis Treatment System> As shown in Figure 1, the hydrolysis continuous processing apparatus 1 of this embodiment mainly comprises a hydrolysis reaction vessel 2, a back pressure valve 3, a flash tank 4, a condenser 5, a first dryer 6, and a second dryer 7. Furthermore, the back pressure valve 3 corresponds to the "pressure regulating valve" as referred to in the claims. In this embodiment, the hydrolysis reaction vessel 2 is assumed to consist of a twin-screw extruder equipped with a heating cylinder 8 and a pair of screws 9. However, the hydrolysis reaction vessel 2 of the present invention is not limited to this and can also be configured to include a single-screw 3. Furthermore, the heating cylinder 8 corresponds to the "heating container" as referred to in the claims. The screw 3 corresponds to the "kneading means" and "conveying means" as referred to in the claims. The heating cylinder 8 comprises a cylinder 12 formed by connecting a plurality of cylinder blocks (not shown) in one direction, and a band heater (not shown) arranged on the outer circumference of the cylinder 12. At the rear end of the heating cylinder 8, which is the upstream side, fiber-reinforced resin R (waste plastic crushed material), which is waste material containing nylon 6 (PA6) and glass fiber (GF), is fed in via the hopper 13. Furthermore, a water inlet 14 is provided on the downstream side of the hopper 13 in the heating cylinder 8. Water is supplied to this water inlet 14 from the water supply pump 14a via the heater 14b. The water supplied to the heating cylinder 8 from the water inlet 14 is high temperature and high pressure, as will be described later. A heat-insulating block 15 with a heater (not shown) is positioned at the front end of the heating cylinder 8, which is on the downstream side. A flow path 16 communicating with the inside of the heating cylinder 8 is formed in this heat-insulating block 15, and a reaction liquid valve 16a and a molten resin valve 16b are positioned in the flow paths that branch off downstream of this flow path 16. A pipe 20a is connected to the reaction solution valve 16a. The downstream end of this pipe 20a is connected to the back pressure valve 3, which will be described later. A pipe 20b is connected to the molten resin valve 16b. The downstream end of this pipe 20b is connected to a molten resin recovery tank (not shown). Furthermore, the reaction liquid valve 16a and the molten resin valve 16b correspond to the "switching valves" as defined in the claims, and the piping 20b corresponds to the "discharge channel" as defined in the claims. The screw 9 is inserted into the heating cylinder 8 so as to follow the longitudinal direction of the heating cylind