CN213943065U

CN213943065U - Production process system of o-chlorotoluene and p-chlorotoluene

Info

Publication number: CN213943065U
Application number: CN202022539404.1U
Authority: CN
Inventors: 胡帅
Original assignee: Hubei Shanshui Chemical Co ltd
Current assignee: Hubei Shanshui Chemical Co ltd
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2021-08-13
Anticipated expiration: 2030-11-05

Abstract

The utility model relates to a production process system of o-chlorotoluene and p-chlorotoluene, which comprises a tail gas absorption device, an o-chlorotoluene tower, a dryer, a chlorination tower, a distillation tower, a toluene removing tower, a primary separation tower, a crystallization tower and a p-chlorotoluene refining tower which are connected in sequence; the chlorination tower and the distillation tower are connected with a tail gas absorption device; the top outlet of the primary separation tower is connected with the middle inlet of the o-chlorotoluene tower, and the lower inlet of the primary separation tower is connected with the bottom outlet of the o-chlorotoluene tower; the bottom outlet of the primary separation tower is connected with the inlet of the crystallization tower, and the upper inlet of the primary separation tower is connected with the mother liquor outlet of the crystallization tower. The utility model relates to a rationally, equipment utilization is high, and the energy consumption is lower relatively, and reaction environment seals, can regulate and control, and green is pollution-free, can effectively improve adjacent chlorotoluene and parachlorotoluene's synthetic rate, productivity and purity, reduction in production cost, and then improve economic benefits and be convenient for application and development of low reaches fine chemicals.

Description

Production process system of o-chlorotoluene and p-chlorotoluene

Technical Field

The utility model belongs to the technical field of the chemical industry, concretely relates to production process systems of o chloro toluene and p chloro toluene.

Background

Chlorotoluene is an important fine chemical raw material and an organic chemical intermediate with wide application. In recent years, chlorotoluene is used as a starting material for producing various novel intermediates of medicines, pesticides, dyes and the like, the intermediates show very bright development prospects, the markets at home and abroad are consistently good, and many of the intermediates become hotspot development products.

At present, the liquid phase chlorination reaction of toluene is mainly adopted in the industry at home and abroad to produce p-chlorotoluene and o-chlorotoluene. The liquid phase chlorination of toluene produces 3 kinds of isomers of monochlorotoluene, i.e. p-chlorotoluene, o-chlorotoluene and m-chlorotoluene, wherein the ratio of m-chlorotoluene is small, and a small amount of dichlorotoluene is produced as a byproduct in the reaction. Therefore, after the reaction is finished, the mixed product needs to be separated, and the p-chlorotoluene and the o-chlorotoluene with higher purity can be obtained. Thus, the production of p-chlorotoluene and o-chlorotoluene is divided into two stages, the first stage being the liquid phase chlorination of toluene and the second stage being the separation of isomers.

The traditional production process system of o-chlorotoluene and p-chlorotoluene is laggard, and production equipment is not improved, so that the production cost of o-chlorotoluene and p-chlorotoluene is high, the synthesis rate is low, the productivity and the purity are not high, the economic benefit is influenced, and the application and development of downstream fine chemicals are limited.

For example, the float valve type chlorination tower in the production process system is a chlorination tower for chlorination by adopting a float valve type tower plate, and is characterized in that a valve plate capable of moving up and down is installed at each sieve pore. When the air speed in the sieve pore is high, the valve plate is jacked up and rises, and when the air speed is low, the valve plate falls due to self weight, and the lifting position of the valve plate is automatically adjusted along with the air flow, so that the air speed entering the liquid layer is basically stable.

The existing floating air valve structure mainly comprises a valve cap and supporting legs, and the valve cap drives the supporting legs to move up and down in sieve holes during work. When the air current that flows through the sieve mesh is unstable or inhomogeneous, the float valve can take place to rotate the phenomenon, causes the wearing and tearing between stabilizer blade and the sieve mesh serious, in case three stabilizer blade all are worn out, the valve cap will drop, leads to the function failure of float valve to seriously influence the chlorination of toluene. Furthermore, the instability of the air flow can cause the floating valve to shift, and even cause the floating valve to be stuck in the sieve hole. In addition, the downcomer above the tray is usually a simple downcomer design, resulting in a large impact force on the tray caused by the liquid phase toluene, which seriously affects the service life of the tray.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the technical problem who exists among the prior art, the production process system who provides adjacent chlorotoluene and parachlorotoluene, effectively solve traditional adjacent chlorotoluene and parachlorotoluene's production process system comparatively lags behind, production facility also does not improve, for example, chlorination tower's air valve structural stability is poor, the operational reliability is low and the life of column plate is low, the manufacturing cost who leads to adjacent chlorotoluene and parachlorotoluene is higher, the synthetic rate is lower, productivity and purity are not high, and then influence economic benefits and restrict at least one in the application of low reaches fine chemicals and the development scheduling problem.

The utility model provides an above-mentioned technical problem's technical scheme as follows:

the production process system of the o-chlorotoluene and the p-chlorotoluene comprises a tail gas absorption device, an o-chlorotoluene tower, a dryer, a chlorination tower, a distillation tower, a toluene removing tower, a primary separation tower, a crystallization tower and a p-chlorotoluene refining tower which are sequentially connected; the chlorination tower and the distillation tower are connected with a tail gas absorption device; the top outlet of the primary separation tower is connected with the middle inlet of the adjacent chlorotoluene tower, and the lower inlet of the primary separation tower is connected with the bottom outlet of the adjacent chlorotoluene tower; the bottom outlet of the primary separation tower is connected with the inlet of the crystallization tower, and the upper inlet of the primary separation tower is connected with the mother liquor outlet of the crystallization tower.

The utility model has the advantages that: production technology system reasonable in design, equipment utilization is high, and the energy consumption is lower relatively, and reaction environment seals, can regulate and control, and green is pollution-free, can effectively improve adjacent chlorine toluene and parachlorotoluene's synthetic rate, productivity and purity, reduction in production cost, and then improve economic benefits and be convenient for application and development of low reaches fine chemicals.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Further, the tail gas absorption device comprises a first-stage condenser, a second-stage condenser, a third-stage condenser and a falling film absorber which are sequentially connected.

Further, the chlorination tower comprises a tower body; a plurality of uniformly distributed tower plates are fixedly arranged in the tower body; the column plate is provided with an overflow plate, a liquid discharging assembly and a plurality of uniformly distributed air valves.

Further, the air floating valve comprises a through hole formed in the tower plate; a valve seat is fixedly connected around the through hole; the top of the valve seat is fixedly connected with a valve cap; a valve cover is connected inside the valve cap in a sliding manner; the bonnet including a base plate and a plurality of legs; the valve cover comprises a cover plate and a plurality of connecting rods in sliding fit with the support legs; the floating air valve also comprises a limiting component for preventing the valve cover from deviating and a buffering component for reducing impact force when the valve cover is opened and closed.

Furthermore, a sliding groove in sliding fit with the support leg is arranged on the connecting rod.

Furthermore, the limiting assembly comprises a plurality of limiting rods and limiting holes matched with the limiting rods; the limiting rod is fixedly connected with the cover plate; the limiting hole is formed in the bottom plate.

Further, the buffering assembly comprises a first elastic element used for reducing impact force when the valve cover is opened and a second elastic element used for reducing impact force when the valve cover is closed.

Further, the lower liquid assembly comprises a lower liquid pipeline arranged between the tower plates and the tower body, a mounting rack and a buffer plate arranged below the lower liquid pipeline; the lower liquid pipeline and the buffer plate are fixedly connected with the tower body through the mounting frame.

Furthermore, a plurality of liquid discharging holes which are uniformly distributed are formed in the buffer plate.

Furthermore, the one end that the tower body was kept away from to the buffer board is provided with the fender stream board that slopes upwards.

The beneficial effect of adopting the further scheme is that:

(1) the utility model discloses a tail gas absorbing device makes HCl gas into byproduct hydrochloric acid to recycle and innocent treatment HCl gas, when improving resource utilization and economic benefits, avoid causing the harm to the environment.

(2) The floating air valve designed by the utility model has simple structure, good stability and high working reliability; the precision of the valve cover during movement and the working stability of the floating air valve are obviously improved through the limiting assembly, and the valve cover is effectively prevented from being deviated or clamped in the valve cover during movement; the impact force generated when the valve cover is opened and closed is reduced through the buffer assembly, and the working stability and the service life of the air floating valve are further improved.

(3) The utility model discloses a lower liquid subassembly is rational in infrastructure, effectively reduces the impact force that liquid phase toluene caused to the column plate to improve the life of column plate.

Drawings

FIG. 1 is a schematic structural diagram of a production process system according to the present invention;

FIG. 2 is a schematic diagram of the internal structure of the chlorination tower of the present invention;

FIG. 3 is a sectional view of an air float valve in a chlorination tower according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of an aeration valve in a chlorination column according to another embodiment of the present invention;

fig. 5 is a schematic structural diagram of a lower liquid component in the chlorination tower.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the device comprises a dryer, 2, a chlorination tower, 21, a tower body, 22, a tower plate, 23, a floating valve, 231, a through hole, 232, a valve seat, 233, a valve cap, 2331, a bottom plate, 2332, a support leg, 234, a valve cover, 2341, a cover plate, 2342, a connecting rod, 2343, a sliding chute, 235, a limiting component, 2351, a limiting rod, 2352, a limiting hole, 236, a buffer component, 2361, a first elastic element, 2362, a second elastic element, 24, an overflow plate, 25, a liquid discharging component, 251, a liquid discharging pipeline, 252, a mounting frame, 253, a buffer plate, 254, a liquid discharging hole, 255, a flow baffle plate, 3, a distillation tower, 4, a tail gas absorption device, 5, a toluene removal tower, 6, a toluene removal tower, 7, a primary separation tower, 8, an adjacent chlorine toluene tower, 9, a crystallization tower, 10 and a toluene purification tower.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

It should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" are intended to be construed broadly, as if they were connected either fixedly or removably, or as integrally formed structures. To those of ordinary skill in the art, the specific meaning of such terms in this patent may be understood as appropriate.

As shown in fig. 1-4, the production process system of o-chlorotoluene and p-chlorotoluene designed by the utility model comprises a tail gas absorption device 4, an o-chlorotoluene tower 8, and a dryer 1, a chlorination tower 2, a distillation tower 3, a toluene removing tower 5, a toluene removing tower 6, a primary separation tower 7, a crystallization tower 9 and a p-chlorotoluene refining tower 10 which are connected in sequence; the chlorination tower 2 and the distillation tower 3 are connected with a tail gas absorption device 4; the top outlet of the primary separation tower 7 is connected with the middle inlet of the adjacent chlorotoluene tower 8, and the lower inlet of the primary separation tower 7 is connected with the bottom outlet of the adjacent chlorotoluene tower 8; the bottom outlet of the primary separation tower 7 is connected with the inlet of the crystallization tower 9, and the upper inlet of the primary separation tower 7 is connected with the mother liquor outlet of the crystallization tower 9.

Further, the tail gas absorption device 4 comprises a first-stage condenser, a second-stage condenser, a third-stage condenser and a falling film absorber which are sequentially connected. HCl gas is made into byproduct hydrochloric acid through the tail gas absorption device 4, so that the HCl gas is recycled and subjected to harmless treatment, the resource utilization rate and the economic benefit are improved, and the environment is prevented from being damaged.

As the chlorination reaction is carried out under the condition of high-temperature boiling, a large amount of toluene steam is carried in HCl gas discharged from the top of the chlorination tower 2, and in order to recover the material, a section of condenser (square meter 60) is adopted in a gas phase system, and industrial water is cooled; a two-section condenser (40 square meters) is cooled by freezing water; three-section condenser (square meter 10), cooling with frozen brine, separating gas from liquid in phase separator, falling film and ripple tower spraying, and the HCl gas after spraying absorption treatment is delivered to the by-product absorption tower through tail gas delivery pipe, and the HCl gas enters from the bottom of absorption tower, and water is added to the tower top to produce hydrochloric acid as by-product.

As shown in fig. 2, the chlorination column 2 includes a column body 21; a plurality of uniformly distributed tower plates 22 are fixedly arranged in the tower body 21; the column plate 22 is provided with an overflow plate 24, a liquid discharging assembly 25 and a plurality of air valves 23 which are uniformly distributed. Namely, the gas-phase chlorine gas moves upwards through a plurality of air floatation valves 23 on the tower plate 22; the liquid phase toluene passes through the tray 22 and the overflow plate 24 to form a liquid flow layer having a certain height to sufficiently react with chlorine and moves downward through the lower liquid assembly 25.

As shown in fig. 3 and 4, the aeration valve 23 includes a through hole 231 opened on the tray 22; a valve seat 232 is fixedly connected around the through hole 231; the top of the valve seat 232 is fixedly connected with a valve cap 233; a valve cover 234 is slidably connected inside the valve cap 233; the bonnet 233 includes a base plate 2331 and a plurality of legs 2332; the valve cover 234 includes a cover plate 2341 and a plurality of connecting rods 2342 slidably engaged with the legs 2332; the float valve 23 further includes a stopper 235 for preventing the valve cover 234 from being deviated, and a buffer 236 for reducing an impact force when the valve cover 234 is opened and closed.

As shown in fig. 3 and 4, the connecting rod 2342 is provided with a sliding slot 2343 slidably engaged with the supporting leg 2332, so that the connecting rod 2342 is slidably engaged with the supporting leg 2332.

The working process of the air floatation valve 23 is as follows: when the gas velocity is high (the pressure inside the valve seat 232 is higher than the pressure outside), the valve cover 234 is pushed open and lifted, and the chlorine gas moves upwards through the through hole 231, so that the chlorine gas fully reacts with the toluene in the liquid flow layer; when the air speed is low (the pressure inside the valve seat 232 is lower than the pressure outside), the valve cover 234 descends into the valve seat 232 by its own weight to close the through hole 231; the lifting position of the valve cover 234 is automatically adjusted along with the flow rate of chlorine gas, so that the gas velocity entering the liquid flow layer is basically stable, the generation of polychlorinated substitution side reactions is effectively avoided, and the yield of monochlorotoluene, namely the reaction conversion rate and the content of parachlorotoluene in the product are improved.

As shown in fig. 3 and 4, the spacing assembly 235 includes a plurality of spacing rods 2351 and spacing holes 2352 that cooperate with the spacing rods 2351; the limiting rod 2351 is fixedly connected with the cover plate 2341; the limiting hole 2352 is opened on the bottom plate 2331, and is used for remarkably improving the precision of the valve cover 234 during movement and the stability of the float valve 23 during operation, and effectively preventing the valve cover 234 from shifting or being clamped in the valve cap 233 during movement.

As shown in fig. 3 and 4, the cushioning assembly 236 includes a first elastic element 2361 for reducing the impact force when the valve cover 234 is opened, and a second elastic element 2362 for reducing the impact force when the valve cover 234 is closed.

The first elastic element 2361 may be installed on the bottom of the bottom plate 2331 (fig. 3) or on the top of the cover plate 2341 (fig. 4). The second elastic element 2362 may be installed at the bottom of the connecting rod 2342 (fig. 4) and may also be installed at the through hole 231 (fig. 3). The first elastic element 2361 is preferably a rubber ring (fig. 3 and 4), and the second elastic element 2362 is preferably a rubber ring (fig. 3) or a rubber block (fig. 4), and is provided to buffer an impact force, thereby reducing the impact force when the valve cover 234 is opened and closed, and improving the working stability and the service life of the air float valve 23.

As shown in fig. 5, the lower liquid assembly 25 comprises a lower liquid pipe 251 disposed between the tray 22 and the tower body 21, a mounting frame 252, and a buffer plate 253 disposed below the lower liquid pipe 251; the lower liquid pipe 251 and the buffer plate 253 are both fixedly connected with the tower body 21 through a mounting frame 252; the buffer plate 253 is provided with a plurality of lower liquid holes 254 which are uniformly distributed, so that the impact force of liquid-phase methylbenzene on the tower plate 22 is effectively reduced, and the service life of the tower plate 22 is prolonged.

As shown in fig. 5, an end of the buffer plate 253, which is away from the tower body 21, is provided with a flow baffle 255 inclined upward, and the flow baffle 255 and the buffer plate 253 cooperate to further reduce the impact force of the liquid-phase toluene, thereby prolonging the service life of the tower plate 22.

The working process of the liquid discharging assembly 25 is as follows: the liquid-phase toluene moves downward through the lower liquid pipe 251, the mounting frame 252 and the buffer plate 253 play a role in buffering the impact force of the liquid-phase toluene, and the lower liquid holes 254 guide the liquid-phase toluene on the buffer plate 253 downward.

The mechanisms, assemblies and components of the present invention not described with respect to the specific structure are all prior art structures that exist in the prior art, such as dryers. Can be purchased directly from the market.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. The production process system of the o-chlorotoluene and the p-chlorotoluene is characterized by comprising a tail gas absorption device (4), an o-chlorotoluene tower (8), a dryer (1), a chlorination tower (2), a distillation tower (3), a toluene removing tower (5), a toluene removing tower (6), a primary separation tower (7), a crystallization tower (9) and a p-chlorotoluene refining tower (10) which are sequentially connected; the chlorination tower (2) and the distillation tower (3) are connected with a tail gas absorption device (4); an outlet at the top of the primary separation tower (7) is connected with an inlet at the middle part of the o-chlorotoluene tower (8), and an inlet at the lower part of the primary separation tower (7) is connected with an outlet at the bottom of the o-chlorotoluene tower (8); the bottom outlet of the primary separation tower (7) is connected with the inlet of the crystallization tower (9), and the upper inlet of the primary separation tower (7) is connected with the mother liquor outlet of the crystallization tower (9).

2. The production process system according to claim 1, wherein the tail gas absorption device (4) comprises a first-stage condenser, a second-stage condenser, a third-stage condenser and a falling film absorber which are connected in sequence.

3. The production process system according to claim 1, wherein the chlorination column (2) comprises a column body (21); a plurality of uniformly distributed tower plates (22) are fixedly arranged in the tower body (21); an overflow plate (24), a liquid discharging assembly (25) and a plurality of air valves (23) which are uniformly distributed are arranged on the tower plate (22).

4. A production process system according to claim 3, wherein the aeration valve (23) comprises a through hole (231) opened on the tray (22); a valve seat (232) is fixedly connected to the periphery of the through hole (231); the top of the valve seat (232) is fixedly connected with a valve cap (233); a valve cover (234) is connected inside the valve cap (233) in a sliding way; the bonnet (233) includes a base plate (2331) and a plurality of legs (2332); the valve cover (234) comprises a cover plate (2341) and a plurality of connecting rods (2342) in sliding fit with the supporting legs (2332); the air floatation valve (23) further comprises a limiting component (235) used for preventing the valve cover (234) from deviating and a buffering component (236) used for reducing impact force when the valve cover (234) is opened and closed.

5. The production process system as claimed in claim 4, wherein the connecting rod (2342) is provided with a sliding slot (2343) slidably engaged with the supporting leg (2332).

6. The production processing system of claim 4, wherein the spacing assembly (235) comprises a plurality of spacing rods (2351) and spacing holes (2352) that mate with the spacing rods (2351); the limiting rod (2351) is fixedly connected with the cover plate (2341); the limiting hole (2352) is arranged on the bottom plate (2331).

7. The production process system according to claim 4, wherein the buffer assembly (236) comprises a first elastic element (2361) for reducing impact force when the valve cover (234) is opened, and a second elastic element (2362) for reducing impact force when the valve cover (234) is closed.

8. The production process system according to claim 3, wherein the lower liquid assembly (25) comprises a lower liquid pipe (251) arranged between the tray (22) and the tower (21), a mounting frame (252), and a buffer plate (253) arranged below the lower liquid pipe (251); the lower liquid pipeline (251) and the buffer plate (253) are fixedly connected with the tower body (21) through a mounting frame (252).

9. The production process system according to claim 8, wherein a plurality of uniformly distributed lower liquid holes (254) are provided on the buffer plate (253).

10. The production process system according to claim 8, wherein the end of the buffer plate (253) away from the tower body (21) is provided with an upward inclined flow baffle plate (255).