Epoxy propane purification control device

Abstract

The invention provides an epoxypropane purification control device, relates to the technical field of chemical equipment, and solves the problems that in the existing production process, the alkalinity control means is not in place, so that the alkalinity of epoxypropane is too high, and the product quality is influenced. The device comprises an acid liquor tank, a mixer, an alcohol washing tower and a flash tower, a PH analyzer is connected between the water inlet end of an acid liquor delivery pump and the water outlet end of the mixer in parallel, an upper discharge port of the flash tower is communicated with the water inlet end of a condenser through a pipeline, and the water outlet end of the condenser is connected with the water inlet end of a return tank through a pipeline. The water outlet end of the reflux tank is connected with the water inlet end of a reflux pump through a pipeline, the water outlet end of the reflux pump is connected with a first post-treatment connecting pipe and a reflux inlet of the flash tower in a shunting manner through pipelines, and the lower end of the flash tower is connected with a reboiler in parallel. The method has the beneficial effects that the alkali removal effect and efficiency are better, the acidity of the product is effectively controlled, the product quality is ensured, and the downstream market requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, and in particular to a propylene oxide purification control device. Background Art

[0002] Propylene oxide is a very important organic compound raw material and the third largest propylene derivative after polypropylene and acrylonitrile. At present, the main methods for producing propylene oxide in the world are the chlorohydrin method, ethylbenzene co-oxidation method and hydrogen peroxide direct oxidation method. The hydrogen peroxide direct oxidation method uses titanium silicon molecular sieve as a catalyst and methanol as a solvent. Under appropriate reaction conditions, propylene and hydrogen peroxide enter the catalyst bed in the liquid phase system to undergo an oxidation reaction to produce propylene oxide and water; the process flow is relatively simple, and the entire production process is basically pollution-free. It is a new mainstream production route for propylene oxide products in the future. However, in the current production process, the alkalinity control means are not in place, resulting in high alkalinity of propylene oxide, which affects product quality. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that in the existing production process, the basicity control means is not in place, resulting in high basicity of propylene oxide and affecting product quality.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A propylene oxide purification control device, characterized in that it comprises an acid liquid tank, a mixer, an alcohol washing tower and a flash tower, the water outlet end of the acid liquid tank is connected to the water inlet end of the mixer through an acid liquid discharge pipe, the alcohol washing tower is connected to the water inlet end of the mixer through a chemical reaction product discharge pipe, an upper feed port is arranged on the upper side wall of the flash tower, the water outlet end of the mixer is connected to the upper feed port of the flash tower through a pipeline, an acid liquid delivery pump and a first regulating valve are sequentially connected to the acid liquid discharge pipe, an alcohol washing tower kettle pump and a third regulating valve are sequentially connected to the chemical reaction product discharge pipe, and a pH analyzer is connected in parallel between the water inlet end of the acid liquid delivery pump and the water outlet end of the mixer;

[0006] An upper discharge port is provided at the upper end of the flash tower, a reflux port is provided on the upper side wall of the flash tower on the other side of the upper feed port, a lower discharge port is provided at the lower end of the flash tower, the upper discharge port of the flash tower is connected to the water inlet end of the condenser through a pipeline, the water outlet end of the condenser is connected to the water inlet end of the reflux tank through a pipeline, the water outlet end of the reflux tank is connected to the water inlet end of the reflux pump through a pipeline, the water outlet end of the reflux pump is connected to the first post-processing connecting pipe and the reflux port of the flash tower through a pipeline diversion, a reboiler is connected in parallel at the lower end of the flash tower, the lower discharge port at the lower end of the flash tower is connected to the water inlet end of the flash tower kettle pump through a pipeline, and the water outlet end of the flash tower kettle pump is connected to the second post-processing connecting pipe.

[0007] A further improvement is that a reboiler return port is also provided at the lower end of the flash tower, a reboiler return port is provided at the bottom side wall of the flash tower, the reboiler return port of the flash tower is connected to the feed port of the reboiler through a pipeline, and the discharge port of the reboiler is connected to the reboiler return port of the side wall of the flash tower.

[0008] A further improvement is that a second regulating valve is connected between the water outlet end of the reflux pump and the reflux end of the flash tower.

[0009] A further improvement is that the water outlet ends of the first post-processing connecting pipe and the second post-processing connecting pipe are both connected to the water inlet ends of the processing device of the subsequent process.

[0010] A further improvement is that the flash tower includes a first distributor and a second distributor, and the first distributor is located above the second distributor.

[0011] A further improvement is that a first filler is arranged between the first distributor and the second distributor; a first filler support is arranged on the inner wall of the flash tower below the first filler, and a first filler pressure ring is arranged on the inner wall of the flash tower above the first filler.

[0012] A further improvement is that a second filler is arranged below the second distributor; a second filler support is arranged on the inner wall of the flash tower below the second filler; and a second filler pressure ring is arranged on the inner wall of the flash tower above the second filler.

[0013] A further improvement is that the mixer is a spiral mixing device.

[0014] A further improvement is that a tower tray is arranged in the flash tower.

[0015] Compared with the existing technology, the above technical solution has the following beneficial effects:

[0016] The acid solution is provided by the acid tank and mixed with the epoxidation reaction product, and then the secondary mixing is carried out in the flash tower, and the purification is carried out through heating distillation in the reboiler. The alkali removal effect is more efficient, which effectively controls the acidity of propylene glycol and propylene glycol methyl ether acidity products, ensures product quality and meets the downstream market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the flash tower in the present invention.

[0020] Explanation of the reference numerals: acid liquid tank 1, mixer 2, flash tower 3, pH analyzer 4, reboiler 5, condenser 6, reflux tank 7, reflux pump 8, second regulating valve 9, flash tower kettle pump 10, acid liquid delivery pump 11, first regulating valve 12, first post-treatment connecting pipe 13, second post-treatment connecting pipe 14, epoxidation reaction product discharge pipe 15, alcohol washing tower kettle pump 16, alcohol washing tower 17, third regulating valve 18, first distributor 31, first packing pressure ring 32, first packing 33, first packing support 34, second distributor 35, second packing pressure ring 36, second packing 37, second packing support 38, upper feed port 39, upper discharge port 310, reflux port 311, lower discharge port 312, reboiler discharge port 313, reboiler return port 314. DETAILED DESCRIPTION

[0021] See also Figure 1-Figure 2 As shown, the technical solution adopted in this specific embodiment is: a propylene oxide purification control device, characterized in that it includes an acid liquid tank 1, a mixer 2, an alcohol washing tower 17 and a flash tower 3, the water outlet end of the acid liquid tank 1 is connected to the water inlet end of the mixer 2 through an acid liquid discharge pipe 19, the alcohol washing tower 17 is connected to the water inlet end of the mixer 2 through a chemical reaction product discharge pipe 15, an upper feed port 39 is provided on the upper side wall of the flash tower 3, the water outlet end of the mixer 2 is connected to the upper feed port 39 of the flash tower 3 through a pipeline, the acid liquid discharge pipe 19 is sequentially connected to an acid liquid delivery pump 11 and a first regulating valve 12, the chemical reaction product discharge pipe 15 is sequentially connected to an alcohol washing tower kettle pump 16 and a third regulating valve 18, and a pH analyzer 4 is connected in parallel between the water inlet end of the acid liquid delivery pump 21 and the water outlet end of the mixer 2;

[0022] An upper discharge port 310 is provided at the upper end of the flash tower 3, a reflux port 311 is provided on the upper side wall of the flash tower 3 on the other side of the upper feed port 39, a lower discharge port 312 is provided at the lower end of the flash tower 3, the upper discharge port 310 of the flash tower 3 is connected to the water inlet end of the condenser 6 through a pipeline, the water outlet end of the condenser 6 is connected to the water inlet end of the reflux tank 7 through a pipeline, the water outlet end of the reflux tank 7 is connected to the water inlet end of the reflux pump 8 through a pipeline, the water outlet end of the reflux pump 8 is connected to the first post-processing connecting pipe 13 and the reflux port 311 of the flash tower 3 through a pipeline diversion, the lower end of the flash tower 3 is connected in parallel with a reboiler 5, the lower discharge port 312 at the lower end of the flash tower 3 is connected to the water inlet end of the flash tower kettle pump 10 through a pipeline, and the water outlet end of the flash tower kettle pump 10 is connected to the second post-processing connecting pipe 14.

[0023] Among them, the lower end of the flash tower 3 is also provided with a reboiler discharge port 313, and the bottom side wall of the flash tower 3 is provided with a reboiler return port 314. The reboiler discharge port 313 of the flash tower 3 is connected to the feed port of the reboiler 5 through a pipeline, and the discharge port of the reboiler 5 is connected to the reboiler return port 314 on the side wall of the flash tower 3.

[0024] Wherein, a second regulating valve 9 is connected between the water outlet end of the reflux pump 8 and the reflux end of the flash tower 3 .

[0025] The water outlets of the first post-processing connecting pipe 13 and the second post-processing connecting pipe 14 are both connected to the water inlet of a treatment device in a subsequent process.

[0026] The flash tower 3 includes a first distributor 31 and a second distributor 35 , and the first distributor 31 is located above the second distributor 35 .

[0027] A first filler 33 is provided between the first distributor 31 and the second distributor 35 ; a first filler support 34 is provided on the inner wall of the flash tower 3 at the lower end of the first filler 33 , and a first filler pressure ring 32 is provided on the inner wall of the flash tower 3 at the upper end of the first filler 33 .

[0028] A second filler 37 is disposed below the second distributor 35 ; a second filler support 38 is disposed on the inner wall of the flash tower 3 at the lower end of the second filler 37 ; and a second filler pressure ring 36 is disposed on the inner wall of the flash tower 3 at the upper end of the second filler 37 .

[0029] Wherein, the mixer 2 is a spiral mixing device.

[0030] Wherein, a tower tray is arranged in the flash tower.

[0031] The working principle of the present invention is as follows: the acid used for de-alkalinity in the acid tank can be an organic acid or an inorganic acid; the prepared acid solution is stored in the acid tank, and during operation, the de-alkalinity acid is pumped into the mixer through the acid delivery pump, and the epoxidation reaction product in the alcohol washing tower is pumped into the mixer through the alcohol washing tower kettle pump, and mixed by a spiral mixing device inside the mixer, and the amount of acid solution introduced is controlled by a first regulating valve, and a pH analyzer is connected in parallel to maintain the pH value of the online pH analyzer at 6 to 6.5; the de-alkalinity acid and the epoxidation reaction product are preliminarily mixed in the mixer to form a premixed liquid; the premixed liquid enters the flash tower, and is secondary distributed in the distributor and filler in the flash tower A mixed liquid is formed; the mixed liquid descends through the tray in the flash tower; the mixed liquid in the flash tower is circulated and heated by a reboiler, and the discharge material above the flash tower returned from the reflux port inside the flash tower sprays the mixed liquid downward; the mixed liquid is separated in the flash tower, and the propylene oxide mixture with alkalinity removed to below 5 formed after evaporation flows out to the flash tower condenser through the discharge pipe above the flash tower, enters the flash tower reflux tank after condensation, and is sent to the subsequent treatment process through the flash tower reflux tank, and the product generated by the reaction of the alkalinity-removing acid solution with the alkaline impurities and the residues such as the solvent methanol are sent to the subsequent treatment process through the discharge pipe below the flash tower and the flash tower kettle pump.

[0032] The above shows and describes the basic principles and main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents. Anything not described in detail in the present invention is a well-known technology of those skilled in the art.

Claims

1. A propylene oxide purification control device, characterized in that: It includes an acid liquid tank, a mixer, an alcohol washing tower and a flash tower, wherein the water outlet of the acid liquid tank is connected to the water inlet of the mixer through an acid liquid discharge pipe, the alcohol washing tower is connected to the water inlet of the mixer through a chemical reaction product discharge pipe, an upper feed port is arranged on the upper side wall of the flash tower, the water outlet of the mixer is connected to the upper feed port of the flash tower through a pipeline, the acid liquid discharge pipe is sequentially connected to an acid liquid delivery pump and a first regulating valve, the chemical reaction product discharge pipe is sequentially connected to an alcohol washing tower kettle pump and a third regulating valve, and a pH analyzer is connected in parallel between the water inlet of the acid liquid delivery pump and the water outlet of the mixer; An upper discharge port is provided at the upper end of the flash tower, a reflux port is provided on the upper side wall of the flash tower on the other side of the upper feed port, a lower discharge port is provided at the lower end of the flash tower, the upper discharge port of the flash tower is connected to the water inlet end of the condenser through a pipeline, the water outlet end of the condenser is connected to the water inlet end of the reflux tank through a pipeline, the water outlet end of the reflux tank is connected to the water inlet end of the reflux pump through a pipeline, the water outlet end of the reflux pump is connected to the first post-processing connecting pipe and the reflux port of the flash tower through a pipeline diversion, a reboiler is connected in parallel at the lower end of the flash tower, the lower discharge port at the lower end of the flash tower is connected to the water inlet end of the flash tower kettle pump through a pipeline, and the water outlet end of the flash tower kettle pump is connected to the second post-processing connecting pipe.

2. A propylene oxide purification control device according to claim 1, characterized in that: The lower end of the flash tower is also provided with a reboiler return port, and the bottom side wall of the flash tower is provided with a reboiler return port. The reboiler return port of the flash tower is connected to the feed port of the reboiler through a pipeline, and the discharge port of the reboiler is connected to the reboiler return port of the side wall of the flash tower.

3. A propylene oxide purification control device according to claim 1, characterized in that: A second regulating valve is connected between the water outlet end of the reflux pump and the reflux end of the flash tower.

4. A propylene oxide purification control device according to claim 1, characterized in that: The water outlet ends of the first post-processing connecting pipe and the second post-processing connecting pipe are both connected to the water inlet ends of the processing devices of the subsequent process.

5. A propylene oxide purification control device according to claim 1, characterized in that: The flash tower includes a first distributor and a second distributor, wherein the first distributor is located above the second distributor.

6. A propylene oxide purification control device according to claim 5, characterized in that: A first filler is arranged between the first distributor and the second distributor; a first filler support is arranged on the inner wall of the flash tower at the lower end of the first filler, and a first filler pressure ring is arranged on the inner wall of the flash tower at the upper end of the first filler.

7. A propylene oxide purification control device according to claim 6, characterized in that: A second filler is arranged below the second distributor; a second filler support is arranged on the inner wall of the flash tower at the lower end of the second filler; and a second filler pressure ring is arranged on the inner wall of the flash tower at the upper end of the second filler.

8. The propylene oxide purification control device according to claim 1, characterized in that: The mixer is a spiral mixing device.

9. A propylene oxide purification control device according to claim 1, characterized in that: A tower tray is arranged in the flash tower.

Images