Pretreatment device for mixed C3 in ethane cracking production

Abstract

The invention discloses a pretreatment device for mixed C3 in ethane cracking production, which belongs to the field of chemical engineering technology production, and comprises a first dryer and a second dryer, the second dryer is provided with a liquid level meter b, and the first dryer and the second dryer are respectively connected with a pipeline e and a pipeline f. An online water content analyzer is connected between the pipeline e and the pipeline f, a pipeline g is connected between the pipeline e and the pipeline f, a regeneration device is arranged on the pipeline g, a light component removal tower light component is arranged in the regeneration device, a mixing device is connected between the pipeline e and the pipeline f, and a reaction device is connected on the mixing device. According to the invention, the drying agent in the dryer is dried and regenerated, and meanwhile, the continuous water removal of the mixed C3 liquid material is ensured, and light components left in the dryer do not influence the mixed C3 liquid material entering the dryer next time while the drying agent is dried; and the mixed C3 liquid material discharged during the regeneration of the drying agent in the dryer is recycled, and the re-dewatering operation is immediately carried out.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, in particular to a pretreatment device for mixed carbon three in ethane cracking production. Background Art

[0002] In the production system, the mixed C3 raw material comes from the deethanizer kettle in the ethane cracking unit. This part of the material contains a certain proportion of water, propyne, and propadiene components. These impurities are extremely harmful to the C3 hydrogenation catalyst and can easily cause the reactor to overheat, reducing the activity and service life of the catalyst. In order to completely remove the impact of these impurities on the C3 hydrogenation reactor, the mixed C3 raw material needs to be pretreated to remove the impurity components such as water, propyne, and propadiene in the raw material. A dryer is needed in the dehydration process. An interlayer is provided in the dryer, and a desiccant is placed in the interlayer. When the mixed C3 liquid passes through the desiccant, the moisture in the liquid is absorbed by the desiccant to achieve the purpose of dehydration. However, after the desiccant is fully adsorbed, it needs to be regenerated in order to enable it to continue to be used. The existing technology dries it by heating the air, but the mixed C3 in the dryer needs to be discharged during the regeneration process. Liquid material, resulting in waste of mixed C3 liquid material in the dryer, and the need to stop the machine for processing, delaying work time. At the same time, the air remaining in the dryer will produce an oxidation reaction with the components in the mixed C3 liquid material, causing the liquid material to deteriorate. Patent CN219462976U discloses a crude propylene drying and separation device, in which a first mesh screen, a molecular sieve, and a second mesh screen are arranged in sequence from bottom to top in the drying device, and the crude propylene raw material is dried in a bottom-in-top-out manner, but the water content and drying effect thereof are not introduced, and the judgment of the dryer operation effect and the disposal process after penetration are not mentioned.

[0003] Patent CN105732284B discloses a selective hydrogenation method for a C3 fraction, wherein the propyne-allene content in the C3 fraction is approximately 1 to 3% (mol), and the liquid phase material enters an adiabatic hydrogenation reactor equipped with a Pd-Cu catalyst. Under certain conditions, the purpose of removing propyne-allene can be achieved, and the yield of the target product propylene can be significantly increased. However, the water in the C3 fraction is not treated and directly enters the reactor for hydrogenation treatment. Summary of the invention

[0004] In order to solve the technical problems mentioned in the above background technology, the present invention provides a pretreatment device for mixed carbon three in ethane cracking production, and the technical scheme adopted is as follows:

[0005] The invention comprises a first dryer and a second dryer, wherein the first dryer and the second dryer are connected by a pipeline a and a pipeline b is arranged on the left of the pipeline a, a pump a, a valve a, a valve b and a pump b are arranged on the pipeline a from top to bottom, a pipeline c is connected to the pipeline a, the pipeline c is connected to the pipeline b, a valve c and a pump c are arranged on the pipeline c, a liquid level gauge a is arranged on the first dryer, a pipeline q is arranged on the first dryer, and a valve k is arranged on the pipeline q;

[0006] The pipeline a is connected to the pipeline d, the pipeline d is connected to the pipeline c and the pipeline d is provided with a valve d and a pump d, the second dryer is provided with a liquid level gauge b, the second dryer is provided with a pipeline r, and the pipeline r is provided with a valve l;

[0007] The first dryer and the second dryer are connected to pipeline e and pipeline f respectively, an online water content analyzer is connected between pipeline e and pipeline f, and pumps f and pumps g are respectively provided on pipeline e and pipeline f;

[0008] A pipeline g is connected between pipeline e and pipeline f, and a pump e, a valve e, a valve f and a pump f are arranged on pipeline g in order from top to bottom;

[0009] A regeneration device is provided on the pipeline g, and a light component removal tower is provided in the regeneration device;

[0010] A mixing device is connected between pipeline e and pipeline f, and a reaction device is connected to the mixing device.

[0011] Preferably, the regeneration device includes a heater a, a pipeline h is connected to the upper part of the heater a, steam is arranged in the pipeline h, a valve g is arranged on the pipeline h, a pipeline i is arranged on the left part of the heater a, light components of a light removal tower are arranged in the pipeline i, and a pipeline j is connected between the heater a and the pipeline g.

[0012] Preferably, the mixing device comprises a mixer, a pipeline k is connected to the left of the mixer, a pipeline s is connected to the pipeline k, hydrogen is arranged in the pipeline s, a valve h is arranged on the pipeline s, the pipeline k is connected to the pipeline e and the pipeline f, and the mixer is connected to the reaction device.

[0013] Preferably, the reaction device comprises a heater b and a reactor, a pipeline l is connected to the upper part of the heater b, steam is arranged in the pipeline l, a pipeline m is arranged between the heater b and the mixer, and a pipeline n is connected between the heater b and the reactor.

[0014] Preferably, the pipeline m is connected to the pipeline o and the pipeline o is provided with a valve i, the pipeline o is connected to the pipeline n, the pipeline l is provided with a valve j, and the pipeline n is provided with a temperature controller a and a temperature controller b.

[0015] Preferably, the pipeline b is connected to a coalescer, and the coalescer is connected to a pipeline p.

[0016] The present invention has the following advantages: through the control and coordination of multiple valves and multiple pipelines, after the desiccant in one of the first dryer and the second dryer is saturated, one of them is closed and the other is opened, the closed dryer first discharges the mixed C3 liquid, and then passes the light component dry gas of the downstream de-light tower through the regeneration device as the regeneration gas source, while drying the desiccant, the light component remaining in the closed dryer does not affect the mixed C3 liquid that enters next time, through the control of the liquid level meter and the valve, the wet steam generated by drying the desiccant in the closed dryer is discharged from this dryer, at the same time, the mixed C3 liquid discharged from the closed dryer enters the pipeline b and then enters the opened dryer to perform the dehydration operation of the mixed C3 liquid, the present invention ensures the continuous dehydration of the mixed C3 liquid while drying and regenerating the desiccant in the dryer, and the light component remaining in the dryer while drying the desiccant does not affect the mixed C3 liquid that enters the dryer next time, and the mixed C3 liquid discharged from the dryer during the regeneration of the desiccant is recovered and immediately dehydrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the present invention.

[0018] Figure: 1 first dryer, 2 second dryer, 3 pipeline a, 4 pipeline b, 5 pump a, 6 valve a, 7 valve b, 8 pump b, 9 pipeline c, 10 valve c, 11 pump c, 12 liquid level gauge a, 13 pipeline d, 14 valve d, 15 pump d, 16 liquid level gauge b, 17 pipeline e, 18 pipeline f, 19 online moisture content analyzer, 20 pipeline g, 21 pump e, 22 valve e, 23 valve f, 24 pump f, 25 heater a, 26 pipeline h , 27 valve g, 28 pipeline i, 29 pipeline j, 30 mixer, 31 pipeline k, 32 valve h, 33 heater b, 34 reactor, 35 pipeline l, 36 pipeline m, 37 pipeline n, 38 pipeline o, 39 valve i, 40 valve j, 41 temperature controller a, 42 temperature controller b, 43 coalescer, 44 pipeline p, 45 pipeline q, 46 valve k, 47 pipeline r, 48 valve l, 49 pump f, 50 pump g, 51 pipeline s. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example

[0021] Please refer to Figure 1 :

[0022] The present invention provides a pretreatment device for mixed C3 in ethane cracking production, comprising a first dryer 1 and a second dryer 2, wherein a desiccant is arranged at the center of the first dryer 1 and the second dryer 2, the first dryer 1 and the second dryer 2 are connected by a pipeline a3, and a pipeline b4 is arranged on the left of the pipeline a3, the mixed C3 liquid enters the pipeline a3 through the pipeline b4, and the mixed C3 liquid enters the first dryer 1 and the second dryer 2 through the pipeline a3, and a pump a5, a valve a6, a valve b7 and a pump b8 are arranged on the pipeline a3 from top to bottom, and the mixed C3 liquid in the pipeline a3 is controlled to enter the first dryer 1 or the second dryer 2 respectively by the pump a5, the valve a6 and the valve b7, the pump b8, and the pipeline a3 is connected with a pipeline c 9, pipeline c9 is connected to pipeline b4, and valve c10 and pump c11 are provided on pipeline c9. When the mixed C3 liquid in the first dryer 1 needs to be discharged, valve c10 is opened, and the mixed C3 liquid in the first dryer 1 enters pipeline b4 through pipeline c9 through pump c11. The first dryer 1 is provided with a liquid level meter a12 to measure the liquid level of the mixed C3 liquid in the first dryer 1. The first dryer 1 is provided with pipeline q45, and valve k46 is provided on pipeline q45. When valve k46 is opened, the steam dried by the desiccant is discharged through pipeline q45. Pipeline d13 is connected to pipeline a3, and pipeline d13 is connected to pipeline c9 and valve d14 and pump d15 are provided on pipeline d13. When valve d14 is opened, the steam in the second dryer 2 The steam after the desiccant is dried is discharged through pipeline d13. The second dryer 2 is provided with a level meter b16 to measure the liquid level of the mixed C3 liquid in the second dryer 2. The second dryer 2 is provided with a pipeline r47. The pipeline r47 is provided with a valve l48. The first dryer 1 and the second dryer 2 are respectively connected with pipeline e17 and pipeline f18. An online water content analyzer 19 is connected between pipeline e17 and pipeline f18 to measure the water content of the mixed C3 liquid in pipeline e17 and pipeline f18 respectively. Pumps f49 and pump g50 are respectively provided on pipeline e17 and pipeline f18. The mixed C3 liquid in e17 and f18 can be extracted respectively by pumps f49 and pump g50. Pipeline e17 and pipeline f18 are connected with a pipe Line g20, pump e21, valve e22, valve f23 and pump f24 are arranged on pipeline g20 from top to bottom in sequence, pipeline g20 is provided with a regeneration device, and a light component of a light removal tower is arranged in the regeneration device, and the light component of the light removal tower in the regeneration device enters pipeline g20, and the light component of the light removal tower is the product of the downstream light removal tower, which is a dry material gas, and its composition does not affect the mixed C3, and a mixing device is connected between pipeline e17 and pipeline f18, and the mixed C3 liquid material passes through a desiccant in the first dryer 1 or the second dryer 2, so that the water in the mixed C3 liquid material is absorbed, and then the mixed C3 liquid material enters the mixing device and is mixed with hydrogen, and the hydrogen reacts with propyne and propadiene in the mixed C3 liquid material, so that the propyne and propadiene in the mixed C3 liquid material are removed,The mixing device is connected to a reaction device, and water, propyne and propadiene removed from the mixing device enter the reaction device for reaction.

[0023] The regeneration device includes a heater a25, and a pipeline h26 is connected to the upper part of the heater a25. Steam is arranged in the pipeline h26. A valve g27 is arranged on the pipeline h26. When the valve g27 is opened, the steam enters the heater a25 through the pipeline h26. A pipeline i28 is arranged on the left part of the heater a25. The light components of the light removal tower are arranged in the pipeline i28. A pipeline j29 is connected between the heater a25 and the pipeline g20. The light components of the light removal tower of the pipeline i28 enter the heater a25 to be heated, and then enter the pipeline g20.

[0024] The mixing device includes a mixer 30, a pipeline k31 is connected to the left side of the mixer 30, a pipeline s51 is connected to the pipeline k31, hydrogen is arranged in the pipeline s51, a valve h32 is arranged on the pipeline s51, the valve h32 is opened, the hydrogen enters the pipeline k31 through the pipeline s51 and then enters the mixer 30 together with the mixed C3 liquid material from which the water is removed to mix and react, the pipeline k31 is connected to the pipeline e17 and the pipeline f18, the mixed C3 liquid material in the pipeline e17 or the pipeline f18 enters the pipeline k31, and the mixer 30 is connected to a reaction device.

[0025] The reaction device includes a heater b33 and a reactor 34. A pipeline l35 is connected to the upper part of the heater b33. Steam is arranged in the pipeline l35. The steam enters the heater b33 through the pipeline l35 to heat the heater b33. A pipeline m36 is arranged between the heater b33 and the mixer 30. A pipeline n37 is connected between the heater b33 and the reactor 34. After the mixed C3 liquid material from which water, propyne and propadiene are removed is heated by the heater b33, it enters the reactor 34 through the pipeline n37 to meet certain reaction conditions. Line m36 is connected to pipeline o38 and valve i39 is provided on pipeline o38. Pipeline o38 is connected to pipeline n37. Valve j40 is provided on pipeline l35. Temperature controller a41 and temperature controller b42 are provided on pipeline n37. When temperature controller b42 detects that the temperature of the mixed C3 liquid in pipeline n37 is lower than the set reaction temperature, temperature controller b42 controls valve i39 to close, temperature controller a41 controls valve j40 to open, and steam enters heater b33 to heat heater b33.

[0026] The pipeline b4 is connected to the coalescer 43, and the pipeline p44 is connected to the coalescer 43. The mixed C3 liquid enters the coalescer 43 through the pipeline p44, and a part of the water in the mixed C3 liquid can be removed first, thereby reducing the water removal in the dryer 1 or the dryer 2.

[0027] Working principle of the present invention:

[0028] The mixed C3 liquid enters the agglomerator 43 through the pipeline P44, and a part of the water in the mixed C3 liquid is removed through the agglomerator 43, and then enters the pipeline A3 through the pipeline B4, the valve A6 and the pump A5 are opened, the valve B7 and the pump B8 are closed, and the mixed C3 liquid enters the first dryer 1 through the pipeline A3, and the water in the mixed C3 liquid is absorbed by the desiccant in the first dryer 1, and the water in the mixed C3 liquid is first removed, and then it is sent to the pipeline K31 through the pump F49, the valve H32 is opened, and hydrogen enters the pipeline K31 through the pipeline S51 and enters the mixer 30 together with the mixed C3 liquid, the hydrogen reacts with the propyne and propadiene in the mixed C3 liquid, and the propyne and propadiene in the mixed C3 liquid are removed, and then it enters the heater B36 through the pipeline M36 for heating, and then enters the reactor 34 through the pipeline N37 for reaction.

[0029] When the desiccant in the first dryer 1 absorbs water fully, the water in the mixed C3 liquid is detected to be excessive by the online water content analyzer 19, and the valve a6 and pump a5 are closed, and the valve b7 and pump b8 are opened, and the mixed C3 liquid no longer enters the first dryer 1, and the pump f49 is also closed, and the valve c10 and pump c11 are opened, and the mixed C3 liquid in the first dryer 1 is discharged into the pipeline b4 through the pipeline c9, and then enters the second dryer 2 through the pipeline a3. When the liquid level of the mixed C3 liquid in the first dryer 1 is detected to be low by the level meter a12, At pipeline q45, close valve c10 and pump c11, open valve k46, at this time the light components of the light removal tower enter heater a25 through pipeline i28 for heating, then enter pipeline g20 through pipeline j29, and then enter pipeline e17, until entering the first dryer 1, passing through saturated desiccant from top to bottom to dry the desiccant, and the dried light component steam of the light removal tower is discharged through pipeline q45. At the same time, the mixed C3 liquid discharged from the first dryer 1 enters the second dryer 2, opens pump g50, and enters pipeline k31.

[0030] When the desiccant in the second dryer 2 is saturated with absorption, open pump f49, pump a5 and valve a6, close valve b7, pump b8 and pump g50, open valve d14 and pump d15, so that the mixed C3 liquid in the second dryer 2 enters pipeline d13, then enters pipeline c9, and then enters pipeline b4 and pipeline a3, until it enters the first dryer 1. When the mixed C3 liquid level in the second dryer 2 is detected by level meter b to be lower than pipeline r47, close valve d14 and pump d15, and the light components of the light removal tower pass through pipeline f18, and then enter the second dryer 2, passing through the desiccant in the second dryer 2 from top to bottom to dry the desiccant. Open valve l48, and the dried light component steam of the light removal tower is discharged through pipeline 47r.

[0031] The present invention is simple to operate, convenient to use, and suitable for comprehensive promotion and application. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pretreatment device for mixed C3 in ethane cracking production, characterized in that: The invention comprises a first dryer (1) and a second dryer (2), wherein the first dryer (1) and the second dryer (2) are connected via a pipeline a (3) and a pipeline b (4) is arranged on the left of the pipeline a (3), a pump a (5), a valve a (6), a valve b (7) and a pump b (8) are arranged on the pipeline a (3) from top to bottom, a pipeline c (9) is connected to the pipeline a (3), the pipeline c (9) is connected to the pipeline b (4), a valve c (10) and a pump c (11) are arranged on the pipeline c (9), a liquid level gauge a (12) is arranged on the first dryer (1), a pipeline q (45) is arranged on the first dryer (1), and a valve k (46) is arranged on the pipeline q (45); The pipeline a (3) is connected to the pipeline d (13), the pipeline d (13) is connected to the pipeline c (9) and the pipeline d (13) is provided with a valve d (14) and a pump d (15), the second dryer (2) is provided with a liquid level gauge b (16), the second dryer (2) is provided with a pipeline r (47), and the pipeline r (47) is provided with a valve l (48); The first dryer (1) and the second dryer (2) are respectively connected to a pipeline e (17) and a pipeline f (18), an online water content analyzer (19) is connected between the pipeline e (17) and the pipeline f (18), and a pump f (49) and a pump g (50) are respectively provided on the pipeline e (17) and the pipeline f (18); A pipeline g (20) is connected between the pipeline e (17) and the pipeline f (18), and a pump e (21), a valve e (22), a valve f (23) and a pump f (24) are sequentially arranged on the pipeline g (20) from top to bottom; A regeneration device is provided on the pipeline g (20), and a light component removal tower is provided in the regeneration device; A mixing device is connected between pipeline e (17) and pipeline f (18), and a reaction device is connected to the mixing device.

2. The pretreatment device for mixed C3 in ethane cracking production according to claim 1, characterized in that: The regeneration device comprises a heater a (25), a pipeline h (26) is connected to the upper part of the heater a (25), steam is arranged in the pipeline h (26), a valve g (27) is arranged on the pipeline h (26), a pipeline i (28) is arranged on the left part of the heater a (25), light components of a light removal tower are arranged in the pipeline i (28), and a pipeline j (29) is connected between the heater a (25) and the pipeline g (20).

3. The pretreatment device for mixed C3 in ethane cracking production according to claim 1, characterized in that: The mixing device comprises a mixer (30), a pipeline k (31) is connected to the left of the mixer (30), a pipeline s (51) is connected to the pipeline k (31), hydrogen is arranged in the pipeline s (51), a valve h (32) is arranged on the pipeline s (51), the pipeline k (31) is connected to the pipeline e (17) and the pipeline f (18), and the mixer (30) is connected to the reaction device.

4. The pretreatment device for mixed C3 in ethane cracking production according to claim 1, characterized in that: The reaction device comprises a heater b (33) and a reactor (34), wherein a pipeline l (35) is connected to the upper part of the heater b (33), steam is arranged in the pipeline l (35), a pipeline m (36) is arranged between the heater b (33) and the mixer (30), and a pipeline n (37) is connected between the heater b (33) and the reactor (34).

5. A pretreatment device for mixed C3 in ethane cracking production according to claim 4, characterized in that: The pipeline m (36) is connected to the pipeline o (38) and the pipeline o (38) is provided with a valve i (39), the pipeline o (38) is connected to the pipeline n (37), the pipeline l (35) is provided with a valve j (40), and the pipeline n (37) is provided with a temperature controller a (41) and a temperature controller b (42).

6. The pretreatment device for mixed C3 in ethane cracking production according to claim 1, characterized in that: The pipeline b (4) is connected to a coalescer (43), and the coalescer (43) is connected to a pipeline p (44).

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