A cracking still for castor oil acid cracking reaction

Abstract

The utility model provides a kind of for castor oil acid cracking reaction's cracking kettle, including cracking kettle body, agitator, cracking kettle body includes the upper kettle and lower kettle of intercommunication arrangement, upper kettle top is equipped with inlet and waste gas discharge port, lower kettle bottom is equipped with discharge port, cracking kettle body outer surface is equipped with fused salt jacket, cracking kettle body center is provided with agitator, agitator includes stirring shaft and the upper stirring unit, lower stirring unit of being arranged on stirring shaft, upper stirring unit includes left stirring rod and right stirring rod being connected in the two sides of stirring shaft by cross bar, left and right stirring rod width is different, height is same, lower stirring unit includes two frame-shaped stirring rods being symmetrically arranged with the axis of stirring shaft as symmetry axis symmetry.This utility model cracking kettle in reactant mixing efficiency is high, gaseous product produced is discharged in time, product yield is high.

Description

Technical Field

[0001] This invention belongs to the field of sebacic acid preparation technology, and in particular relates to a cracking reactor for the acid cracking reaction of castor oil. Background Technology

[0002] The disodium salt of sebacic acid is an intermediate in the production of industrial sebacic acid. It is produced from castor oil as a starting material, hydrolyzed under pressure and heat in the presence of zinc oxide catalyst to form ricinoleic acid and glycerol. After separating the ricinoleic acid and glycerol, the ricinoleic acid is mixed with phenol as a flux in the required ratio to form a mixture of oleic acid and phenol, simply called oleophenol. Then, oleophenol and sodium hydroxide solution are injected into a cracking reactor and heated to 250–300°C to crack and produce the disodium salt of sebacic acid, 2-octanol, and hydrogen gas. The cracking reaction is an endothermic process, and uneven heat absorption is a common problem in the cracking reactor, leading to incomplete reaction and affecting the yield, product quantity, and quality.

[0003] Chinese utility model CN222401435U discloses a cracking reactor for producing sebacic acid from castor oil. The cracking reactor body is divided into an upper reactor and a lower reactor, which are separated by a partition plate. The partition plate has multiple gas dispersion channels. The gas dispersion channels are made of non-stick, high-temperature resistant material and are angled channels. The inlet and outlet ends are symmetrically arranged, and a feed channel is provided above. An internal channel is provided at the top of the cracking reactor body. The partition plate has through holes, and the internal channel passes through the through holes of the partition plate and communicates with the lower reactor. The feed channel enters the cracking reactor body and communicates with the internal channel. The internal channel is a double-layer pipe, with the inner space being a stirring rod channel and the outer space being a feed liquid channel. The stirring rod extends through the stirring rod channel into the lower reactor, and the stirring paddle is spirally located at the lower end of the stirring rod. The stirrer in the above device uses concentric stirring blades. During stirring, the reactants "swirl" in the center of the vessel, which causes uneven heating of the reactants in the vessel center and on the vessel wall. The heating time is different, resulting in a small part of the cracked material being over-cracking and a small part being under-cracking. Summary of the Invention

[0004] The technical problem solved by this invention is that the materials in the existing cracking reactor for producing sebacic acid are not heated evenly, resulting in incomplete reaction and affecting the yield and quality of the product.

[0005] This utility model provides a cracking reactor for the acid cracking reaction of castor oil, characterized in that it includes a cracking reactor body and a stirrer.

[0006] The cracking reactor body includes an upper reactor and a lower reactor connected together. The upper reactor has a feed inlet and an exhaust outlet at the top, with the exhaust outlet connected to a condenser via a pipe. The lower reactor has a discharge outlet at the bottom, which is connected to a molten salt tank via a pipe. The outer surface of the cracking reactor body is equipped with a molten salt jacket.

[0007] The agitator is located at the center of the cracking reactor body. The agitator includes a stirring shaft and an upper stirring unit and a lower stirring unit mounted on the stirring shaft. The upper stirring unit includes a left stirring rod and a right stirring rod connected to both sides of the stirring shaft by a crossbar. Both the left and right stirring rods are L-shaped, with different widths but the same height, so that the upper stirring unit has an eccentric structure. The lower stirring unit includes two frame-shaped stirring rods, which are symmetrically arranged about the axis of the stirring shaft. The frame-shaped stirring rods have diagonally opposite connecting rods inside, which are inclined downwards towards the axis.

[0008] Furthermore, the feed inlet is equipped with an oil-phenol input pipe and a liquid alkali input pipe, and an oil-alkali baffle is provided below the oil-phenol input pipe and the liquid alkali input pipe.

[0009] Furthermore, the upper end of the stirring shaft passes through the vessel body and is coaxially connected to the motor shaft via a reducer, while the lower end of the stirring shaft passes through the vessel body and is connected to a shaft support.

[0010] Furthermore, the molten salt jacket includes an upper molten salt jacket and a lower molten salt jacket that are connected together. The upper molten salt jacket has a lower floating molten salt outlet at the top and an upper molten salt inlet at the bottom. The lower molten salt jacket has an upper molten salt outlet at the top and a lower molten salt inlet at the bottom. The upper and lower molten salt inlets are connected to the outlet of the molten salt trough. The upper and lower molten salt outlets are connected to the inlet of the molten salt trough via a return pipe.

[0011] Furthermore, both the upper and lower vessels are equipped with thermometers.

[0012] Furthermore, the upper part of the upper vessel is provided with an inspection port and a cracking vessel sight glass.

[0013] Furthermore, the condenser is used to recover 2-octanol from the waste gas. The condenser is provided with a condensate outlet and a hydrogen emission outlet. The condensate outlet is connected to the 2-octanol separation tank for recovering 2-octanol, and the hydrogen emission outlet is used to discharge the hydrogen generated during the cracking reaction.

[0014] The present invention has the following beneficial effects: The present invention is used in the cracking reactor for the acid cracking reaction of castor oil. (1) By setting the upper stirring unit to eccentric stirring and the lower stirring unit to concentric stirring, the reactants in the cracking reactor are mixed evenly, dead zones are reduced, mixing efficiency is improved, and the reactants can reach the temperature required for cracking. (2) By setting the condenser, the gaseous products generated during the reaction of the cracking reactor are discharged in time while realizing the recovery of octanol, so that the pressure in the reactor does not increase, the occurrence of reverse reaction is weakened, and the reaction is promoted to proceed in the direction of forward reaction. At the same time, the occurrence of side reaction is reduced and the product recovery rate is improved. (3) By setting the phenol input pipe and the liquid alkali input pipe and the oil-alkali baffle below them in the feed port, the phenol and 48% NaOH solution are preheated and flow into the oil-alkali baffle in the reactor in a 1:1 ratio through the phenol input pipe and the liquid alkali input pipe, and then slide down into the reactor, avoiding the phenomenon of clumping due to saponification. Attached Figure Description

[0015] Figure 1 A schematic diagram of the cracking reactor used in the acid cracking reaction of castor oil according to this utility model. Detailed Implementation

[0016] To clearly illustrate the technical features of this solution, specific embodiments are described below in conjunction with the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort should fall within the protection scope of this utility model.

[0017] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] like Figure 1 As shown, a cracking reactor for the acid cracking reaction of castor oil includes a cracking reactor body and a stirrer.

[0019] The cracking reactor body includes an upper reactor and a lower reactor connected together. The top of the upper reactor is provided with a feed inlet and an exhaust outlet. The feed inlet is equipped with an oil-phenol input pipe and a liquid alkali input pipe. An oil-alkali baffle is provided below the oil-phenol input pipe and the liquid alkali input pipe. The two reactants, oil-phenol and 48% NaOH solution, are first preheated by an oil-alkali distributor. Then, they flow into the oil-alkali baffle in the reactor through the oil-phenol input pipe and the liquid alkali input pipe in a 1:1 ratio, and then slide down into the reactor to avoid the two reactants from clumping due to saponification. The exhaust outlet is connected to condenser 2 via a pipeline. Condenser 2 is equipped with a condensate outlet 202 and a hydrogen outlet 201. The condensate outlet 202 is connected to a 2-octanol separation tank to recover 2-octanol from the exhaust gas. The hydrogen outlet connects a small amount of hydrogen to a long straight pipe for high-altitude discharge. Condenser 2 promptly discharges the gaseous products generated during the reaction, preventing the pressure inside the reactor from increasing, thus reducing the occurrence of the reverse reaction and promoting the reaction towards the forward reaction direction. At the same time, it reduces the occurrence of side reactions and improves the product recovery rate.

[0020] Both the upper and lower reactors are equipped with thermometers 11 to measure the internal temperature of the reactors for timely temperature control. The upper reactor has an inspection port 12 and a sight glass 13 for observing the reaction inside the reactor. The lower reactor has a discharge port 3 at the bottom, which is connected to a material storage tank 4 via a pipeline.

[0021] A stirrer is installed at the center of the cracking reactor body. The stirrer includes a stirring shaft 5, a reducer 6, and a motor 7. The upper end of the stirring shaft 5 passes through the reactor body and is coaxially connected to the motor 7 shaft via the reducer 6. The lower end of the stirring shaft 5 passes through the reactor body and is connected to a shaft support 8. An upper stirring unit 9 and a lower stirring unit 10 are fixed to the upper and lower reactors respectively. The upper stirring unit 9 is an eccentric stirring unit, and the lower stirring unit 10 is a concentric stirring unit. The arrangement of the upper and lower stirring units ensures uniform mixing of the reactants, reduces dead zones, improves mixing efficiency, and ensures that all reactants reach the temperature required for cracking. In this embodiment, the upper stirring unit 9 includes a left stirring rod and a right stirring rod connected to both sides of the stirring shaft by a crossbar. The left and right stirring rods are made of rhomboid steel and are both L-shaped. The left and right stirring rods have different widths but the same height, making the upper stirring unit 9 an eccentric structure. In this embodiment, the left stirring rod is about 2 cm from the inner wall of the reactor, and the right stirring rod is about 8 cm from the inner wall of the reactor. The lower stirring unit 10 includes two frame-shaped stirring rods, which are symmetrically arranged about the axis of the stirring shaft 5. In this embodiment, the frame-shaped stirring rods are made of rhomboid steel. The frame-shaped stirring rods are 2cm away from the vessel wall. The frame-shaped stirring rods are provided with connecting rods diagonally inside the frame-shaped stirring rods, and the connecting rods are inclined downwards towards the axis.

[0022] The outer surface of the cracking reactor body is provided with a molten salt jacket 14. The molten salt jacket 14 includes an upper molten salt jacket and a lower molten salt jacket that are connected to each other. The upper molten salt jacket has a lower molten salt outlet 1401 at the top and an upper molten salt inlet 1402 at the bottom. The lower molten salt jacket has an upper molten salt outlet 1403 at the top and a lower molten salt inlet 1404 at the bottom. The upper and lower molten salt inlets are connected to the outlet of the molten salt tank 15, so that high-temperature molten salt is transported into the molten salt jacket 14 of the reactor body to provide heat energy for the reactants and ensure the required temperature of the cracking reactor. The upper and lower molten salt outlets are connected to the inlet of the molten salt tank 15 through a reflux pipe for reheating and recycling of the molten salt.

[0023] All other parts of this utility model that are not described in detail belong to the prior art, and therefore will not be described in detail here.

[0024] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A cracking reactor for acid cracking of castor oil, characterized in that, Including the cracking reactor body and the agitator, The cracking reactor body includes an upper reactor and a lower reactor connected together. The upper reactor has a feed inlet and an exhaust outlet at the top, with the exhaust outlet connected to a condenser via a pipe. The lower reactor has a discharge outlet at the bottom, which is connected to a molten salt tank via a pipe. The outer surface of the cracking reactor body is equipped with a molten salt jacket. The agitator is located at the center of the cracking reactor body. The agitator includes a stirring shaft and an upper stirring unit and a lower stirring unit mounted on the stirring shaft. The upper stirring unit includes a left stirring rod and a right stirring rod connected to both sides of the stirring shaft by a crossbar. Both the left and right stirring rods are L-shaped, with different widths but the same height, so that the upper stirring unit has an eccentric structure. The lower stirring unit includes two frame-shaped stirring rods, which are symmetrically arranged about the axis of the stirring shaft. The frame-shaped stirring rods have diagonally opposite connecting rods inside, which are inclined downwards towards the axis.

2. The cracking reactor for acid cracking of castor oil according to claim 1, characterized in that, The feed inlet is equipped with an oil-phenol input pipe and a liquid alkali input pipe, and an oil-alkali baffle is provided below the oil-phenol input pipe and the liquid alkali input pipe.

3. The cracking reactor for acid cracking of castor oil according to claim 1, characterized in that, The upper end of the stirring shaft passes through the vessel body and is coaxially connected to the motor shaft via a reducer, while the lower end of the stirring shaft passes through the vessel body and is connected to a shaft support.

4. The cracking reactor for acid cracking of castor oil according to claim 1, characterized in that, The molten salt jacket includes an upper molten salt jacket and a lower molten salt jacket that are connected to each other. The upper molten salt jacket has a lower molten salt outlet at the top and an upper molten salt inlet at the bottom. The lower molten salt jacket has an upper molten salt outlet at the top and a lower molten salt inlet at the bottom. The upper and lower molten salt inlets are connected to the outlet of the molten salt trough. The upper and lower molten salt outlets are connected to the inlet of the molten salt trough via a return pipe.

5. The cracking reactor for acid cracking of castor oil according to claim 1, characterized in that, Both the upper and lower vessels are equipped with thermometers.

6. The cracking reactor for acid cracking of castor oil according to claim 1, characterized in that, The upper part of the upper reactor is equipped with an inspection port and a cracking reactor sight glass.

7. The cracking reactor for the acid cracking reaction of castor oil according to claim 1, characterized in that, The condenser is used to recover 2-octanol from the waste gas. The condenser is equipped with a condensate outlet and a hydrogen emission outlet. The condensate outlet is connected to the 2-octanol separation tank for recovering 2-octanol, and the hydrogen emission outlet is used to discharge the hydrogen generated during the cracking reaction.

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