CN113083205B

CN113083205B - NMP synthesizer

Info

Publication number: CN113083205B
Application number: CN202110516328.9A
Authority: CN
Inventors: 丁龙奇; 赵建军
Original assignee: Chongqing Zhongrun New Materials Co ltd
Current assignee: Chongqing Zhongrun New Materials Co ltd
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2023-07-07
Anticipated expiration: 2041-05-12
Also published as: CN113083205A

Abstract

The invention belongs to the technical field of NMP production, and in particular relates to an NMP synthesis device, which comprises: GBL elevated tank, monomethylamine elevated tank, reactor, GBL measuring pump, monomethylamine measuring pump and static mixer, the reactor includes coil pipe and casing, the coil pipe is fixed to be set up in the casing, there is the clearance between coil pipe and the casing, introduce GBL elevated tank with GBL raw materials, again through GBL metering pump to static mixer in, static mixer enters into the coil pipe with GBL and monomethylamine after intensive mixing, add the conduction oil of settlement temperature from the casing oil inlet, make the conduction oil fill up the clearance of coil pipe and casing, heat the coil pipe, GBL and monomethylamine take place the reaction in the coil pipe and produce NMP. According to the scheme, the NMP is prepared by adopting high-purity monomethylamine, so that the separation of finished products and water after reaction is reduced, and the running cost is reduced; the water entering the coil pipe is reduced, the heat loss is reduced, and meanwhile, the contact area between the monomethylamine and the GBL is enlarged, so that the reaction speed is increased.

Description

NMP synthesizer

Technical Field

The invention belongs to the technical field of NMP production, and particularly relates to an NMP synthesis device.

Background

NMP is N-methyl pyrrolidone (NMP), which is a high boiling point environment friendly solvent with low viscosity, high chemical stability, good heat stability, high polarity, low volatility, and infinite miscibility with water and many organic solvents. The market application field of N-methyl pyrrolidone is mainly concentrated in industries such as lithium batteries, circuit boards, insulating materials, petrifaction, medicines, pesticides, cleaning, macromolecules and the like. NMP is produced mainly by ammonification of GBL with monomethylamine.

The prior art CN201921049113.5 discloses an ammonification reaction device for NMP production, which comprises a shell, wherein a preheating chamber and a reaction chamber are arranged in the shell, a GBL feed pipe and a monomethylamine feed pipe which are in a horizontal serpentine trend and in a horizontal corrugated shape are respectively arranged in the preheating chamber, the discharge ports of the GBL feed pipe and the monomethylamine feed pipe are respectively connected with a reaction pipe in the reaction chamber, and the reaction pipe sequentially comprises a stabilizing section, a mixing section and a reaction section according to the trend of reaction materials; the mixing section is a spiral flat tube, and the stabilizing section and the reaction section are linear round tubes. The device has the advantages of simple structure, easy disassembly and maintenance, reduced heat load required by heating materials to reaction temperature, and energy conservation and production cost.

According to the scheme, the monomethylamine solution is adopted, a large amount of water in the system needs to be separated, the running cost is increased, and the energy consumption of unit products is high; meanwhile, as the sleeve is longer, the heat loss is larger, and the energy consumption is correspondingly increased; large-scale production is realized, equipment investment is large, and operation difficulty is large.

Disclosure of Invention

The scheme provides an energy-saving NMP synthesis device.

In order to achieve the above object, the present invention provides an NMP synthesizing apparatus comprising: GBL overhead tank, monomethylamine overhead tank and reactor; further comprises: a GBL metering pump, a monomethylamine metering pump and a static mixer; the GBL overhead tank is communicated with the GBL metering pump; the monomethylamine elevated tank a methylamine metering pump is communicated; the GBL metering pump and the monomethylamine metering pump are communicated with the static mixer; the reactor comprises a coil pipe and a shell; the coil pipe is fixedly arranged in the shell; a gap exists between the coil pipe and the shell; the coil pipe is communicated with the static mixer; and the two ends of the shell are respectively provided with an oil inlet and an oil outlet.

The principle of the scheme is as follows: the GBL raw material is introduced into a GBL overhead tank and then is pumped into a static mixer through GBL metering pump, meanwhile, the monomethylamine raw material is introduced into a monomethylamine overhead tank, the monomethylamine raw material is high-purity monomethylamine, and then is pumped into the static mixer through monomethylamine metering pump. The static mixer fully mixes GBL and monomethylamine before entering the reactor, the fully mixed GBL and monomethylamine enter the coil pipe, the heat conduction oil with the set temperature is filled in the gap between the coil pipe and the shell from the oil inlet of the shell, the coil pipe is soaked in the heat conduction oil, the GBL and monomethylamine react in the coil pipe to generate NMP, and after the GBL and monomethylamine react for the set time, the materials in the coil pipe are discharged for the next procedure.

The beneficial effect of this scheme: the GBL metering pump and the monomethylamine metering pump control the proportion of raw materials, so that stable raw materials enter a static mixer, high-purity monomethylamine is adopted to prepare NMP, separation of finished products and water after reaction is reduced, and running cost is reduced; the water entering the coil pipe is reduced, so that the heat for heating the water is reduced, namely the heat loss is reduced; meanwhile, the contact area between monomethylamine and GBL is enlarged by reducing water, so that the reaction speed is increased.

Further, the coil pipe is communicated with a high-pressure buffer tank; a monomethylamine detector and a PLC controller are arranged on the high-pressure buffer tank; the high-pressure buffer tank is provided with an exhaust hole, an electric valve is arranged at the exhaust hole, the exhaust hole is communicated with a disqualified tank, and the disqualified tank is communicated with the static mixer; the monomethylamine detector is arranged at the feed inlet of the high-pressure buffer tank, and is positioned in the high-pressure buffer tank; and the PLC is electrically connected with the monomethylamine detector and the electric valve switch.

When the product in the coil pipe is discharged into the high-pressure buffer tank, and when the reaction is unqualified, a certain amount of monomethylamine remains in the high-pressure buffer tank, and when the monomethylamine detector detects that the monomethylamine concentration exceeds a set value, the PLC controller controls to open an electric valve, so that the reacted high-temperature gas is discharged into the unqualified tank and enters the static mixer again for reaction. When the concentration of monomethylamine is lower than the set value, the PLC controls the electric valve to be closed. The prior art judges that the product is qualified according to experience or inspection when the product is finished, and the cost of the product is relatively high. And whether the finished product is qualified or not is detected by a monomethylamine detector, and the reaction is performed again after the finished product is unqualified, so that the cost is saved, and the product yield is improved.

Further, a nitrogen inlet is arranged on the high-pressure buffer tank, and the nitrogen inlet is communicated with a high-pressure nitrogen tank; the nitrogen gas inlet is communicated with a first branch pipe, and the outlet of the first branch pipe corresponds to the detection port of the monomethylamine detector; the first branch pipe is internally provided with a first electric valve, and the first electric valve switch is electrically connected with the PLC.

When the monomethylamine detector detects that the monomethylamine concentration exceeds a set value, a PLC controller is enabled to open a first electric valve, a first branch pipe is enabled to be opened, high-pressure nitrogen enters a high-pressure buffer tank from the first branch pipe, and high-pressure gas enables reaction products to completely enter an unqualified tank, so that product residues are prevented; the high-pressure gas can accelerate the reaction speed of the reaction product (for chemical reactions involving gas, other conditions are unchanged (volume is divided), the pressure is increased, namely the volume is reduced, the concentration of the reactant is increased, the number of activated molecules in unit volume is increased, the effective collision times in unit time is increased, and the reaction speed is accelerated), so that the raw materials are fully reacted; and meanwhile, the nitrogen washes the monomethylamine detector, so that monomethylamine is prevented from remaining on the monomethylamine detector, and the sensitivity of the monomethylamine detector is ensured.

Further, the nitrogen gas inlet is communicated with a second branch pipe, and the outlet of the second branch pipe corresponds to the detection port of the monomethylamine detector; a second electric valve is arranged in the second branch pipe, and a second electric valve switch is electrically connected with the PLC; the first branch pipe and the second branch pipe are respectively positioned at two ends of the monomethylamine detector. When the monomethylamine detector detects that the monomethylamine concentration exceeds a set value, the PLC controller is enabled to intermittently switch and open the first electric valve or the second electric valve in set time, so that nitrogen washes the monomethylamine detector, the monomethylamine detector is cleaned more comprehensively, and the sensitivity of the monomethylamine detector is guaranteed.

Further, a monomethylamine mixer is arranged between the monomethylamine metering pump and the static mixer; a GBL mixer is arranged between the GBL metering pump and the static mixer; the monomethylamine mixer is used for providing stable materials for a monomethylamine metering pump and can buffer the supply of system materials. The GBL mixer is used for providing stable materials for the GBL metering pump and simultaneously can buffer the supply of the system materials.

Further, the base used for supporting the buffer tank is arranged at the bottom of the high-pressure buffer tank, so that the buffer tank is more stable.

Further, the high-pressure buffer tank is provided with a discharge port; the discharge port is provided with a flow regulating valve, so that the flow of the discharged product can be conveniently regulated.

Furthermore, the two ends of the shell are respectively provided with four oil inlets and four oil outlets, so that the heat conduction oil can be rapidly filled up and flows uniformly distributed in the tank body.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a high-pressure buffer tank according to an embodiment of the present invention.

Detailed Description

The following is a further detailed description of the embodiments:

reference numerals in the drawings of the specification include: the device comprises an electric valve 1, a nitrogen inlet pipe 2, a feed pipe 3, a discharge pipe 4, a monomethylamine detector 5, a manhole 6, a hole cover 7, a GBL overhead tank 8, a monomethylamine overhead tank 9, a GBL metering pump 10, a monomethylamine metering pump 11, a static mixer 12, a reactor 13, an oil outlet 14, an oil inlet 15, a reject tank 16, a high-pressure nitrogen tank 17, a high-pressure buffer tank 18, a first branch pipe 19 and a second branch pipe 20.

Examples:

as shown in figure 1, the NMP synthesis device comprises a GBL high-level tank 8, a monomethylamine high-level tank 9, a GBL metering pump 10, a monomethylamine metering pump 11 and a static mixer 12, wherein the GBL high-level tank 8 is communicated with the GBL metering pump 10, the monomethylamine high-level tank 9 is communicated with the monomethylamine metering pump 11, and the GBL metering pump 10 and the monomethylamine metering pump 11 are communicated with the static mixer 12. A methylamine mixer is arranged between the methylamine metering pump 11 and the static mixer 12; a GBL mixer is arranged between the GBL metering pump 10 and the static mixer 12; the monomethylamine mixer is used to provide stable feed to monomethylamine metering pump 11 while also providing a buffer for the feed of system material. The GBL mixer is used for providing stable materials for the GBL metering pump 10 and can buffer the supply of the system materials.

GBL high tank 8: the GBL raw materials outside the boundary area are introduced into the GBL overhead tank 8 and then sent to the GBL mixer through the GBL metering pump 10, and the purpose of the equipment is to provide stable materials for the metering pump, and meanwhile, the equipment can play a role in buffering the supply of system materials. A methylamine overhead tank 9: the monomethylamine raw material outside the boundary region is introduced into a monomethylamine overhead tank 9 and fed to a monomethylamine mixer via a monomethylamine metering pump 11, the purpose of this apparatus being to provide stable material for the metering pump and at the same time to buffer the supply of system material.

GBL metering pump 10: the GBL in the overhead tank is pumped by metering to the static mixer 12, the purpose of this equipment being to provide a steady flow of GBL into the reaction system and to provide sufficient pressure of the feed.

Methylamine metering pump 11: the monomethylamine in the overhead tank was pumped by metering to the static mixer 12, the purpose of this equipment being to provide a steady flow of monomethylamine into the reaction system and to provide sufficient pressure for the feed.

Static mixer 12: the purpose of the static mixer 12 is to thoroughly mix the GBL and monomethylamine prior to entering the reactor 13, increasing the efficiency of the reaction.

The reactor 13 comprises a coil pipe and a shell, wherein the coil pipe is fixedly arranged in the shell, a gap exists between the coil pipe and the shell, the coil pipe is communicated with the static mixer 12, the shell is provided with an oil inlet 15 and an oil outlet 14, the oil inlet 15 and the oil outlet 14 are both communicated with the coil pipe and the shell in a gap, the left end of the shell is also connected with four oil inlets 15, the four oil inlets 15 are uniformly distributed along the circumferential direction of the shell, the right end of the shell is connected with four oil outlets 14, and the four oil outlets 14 are uniformly distributed along the circumferential direction of the shell. The arrangement enables the heat conduction oil to be filled up rapidly and flow evenly distributed in the tank body. The coil is in communication with a high pressure buffer tank 18.

The GBL raw material is introduced into the GBL overhead tank 8 and then conveyed into the static mixer 12 through the GBL metering pump 10, meanwhile, the monomethylamine raw material is introduced into the monomethylamine overhead tank 9, and the monomethylamine raw material is high-purity monomethylamine and then conveyed into the static mixer 12 through the monomethylamine metering pump 11. The static mixer 12 fully mixes GBL and monomethylamine before entering the reactor 13, the fully mixed GBL and monomethylamine enter a coil pipe, heat conduction oil with a set temperature is filled in a gap between the coil pipe and the shell from an oil inlet 15 of the shell, the coil pipe is soaked in the heat conduction oil, GBL and monomethylamine react in the coil pipe to generate NMP, and after GBL and monomethylamine react for a set time, materials in the coil pipe are discharged.

As shown in fig. 2, the high-pressure buffer tank 18 is provided with a monomethylamine detector 5 and a PLC controller, the model of the amine detector 5 is RBT-6000-ZLG, and the measuring range is 0-100ppm. The side of the bottom of the high-pressure buffer tank 18 is provided with a feed inlet, and the feed inlet is communicated with a feed pipe 3. The bottom of the high-pressure buffer tank 18 is provided with a discharge hole, and the discharge hole is communicated with a discharge pipe 4. The discharge port is provided with a flow regulating valve, so that the flow of the discharged product can be conveniently regulated. The bottom of the high-pressure buffer tank 18 is provided with a base for supporting the buffer tank, so that the buffer tank is more stable. The base is provided with an inspection hole, and the base is filled with heat preservation cotton, so that the high-pressure buffer tank 18 can be inspected conveniently, and the heat loss of reaction products is reduced.

The high-pressure buffer tank 18 is provided with an exhaust hole, the exhaust hole is provided with an electric valve 1, the exhaust hole is communicated with a disqualified tank 16, the disqualified tank 16 is communicated with the static mixer 12, the monomethylamine detector 5 is arranged at the feed inlet of the high-pressure buffer tank 18, and the monomethylamine detector 5 is positioned in the high-pressure buffer tank 18. The PLC controller is electrically connected with the monomethylamine detector 5 and the electric valve 1. When the product in the coil pipe is discharged into the high-pressure buffer tank 18, and when the reaction is unqualified, a certain amount of monomethylamine remains in the high-pressure buffer tank 18, and when the monomethylamine detector 5 detects that the monomethylamine concentration exceeds a set value, the PLC controller controls the electric valve 1 to be opened, so that the high-temperature gas after the reaction is discharged into the unqualified tank and enters the static mixer 12 again for reaction. When the monomethylamine detector 5 cannot detect monomethylamine, the PLC controller controls the electric valve 1 to be closed. The prior art judges that the product is qualified according to experience or inspection when the product is finished, and the cost of the product is relatively high. Whether the finished product is qualified or not is detected by a monomethylamine detector 5, and the reaction is carried out again after the finished product is unqualified, so that the finished product is saved, and the product yield is improved.

Be equipped with the nitrogen gas air inlet on the high-pressure buffer tank 18, nitrogen gas air inlet intercommunication has high-pressure nitrogen gas jar 17, nitrogen gas air inlet intercommunication has nitrogen gas intake pipe 2, nitrogen gas intake pipe 2 is located the high-pressure buffer tank 18 inside, nitrogen gas intake pipe 2 intercommunication has first branch pipe 19 and second branch pipe 20, first branch pipe 19 and second branch pipe 20 are located the upper and lower extreme of monomethylamine detector 5 respectively, first branch pipe 19 export and second branch pipe 20 export all correspond with monomethylamine detector 5 detection mouth, be equipped with first electric valve in the first branch pipe 19, first electric valve switch is connected with the PLC controller electricity. A second electric valve is arranged in the second branch pipe 20, and a second electric valve switch is electrically connected with the PLC.

When the monomethylamine detector 5 detects that the monomethylamine concentration exceeds a set value, the PLC controller is enabled to intermittently switch and open the first electric valve or the second electric valve in a set time, so that high-pressure nitrogen enters the high-pressure buffer tank 18 from the first branch pipe 19 or the second branch pipe 20, the monomethylamine detector 5 is flushed by the nitrogen, the first branch pipe 19 or the second branch pipe 20 is intermittently started and opened to clean the monomethylamine detector 5 more comprehensively, and the sensitivity of the monomethylamine detector 5 is ensured; the high-pressure nitrogen completely enters the non-mixing tank to prevent the residual of the reaction product; the high-pressure nitrogen can accelerate the reaction speed of the reaction product (for chemical reactions involving gases, other conditions are unchanged (except for volume), the pressure is increased, namely the volume is reduced, the concentration of the reactant is increased, the number of activated molecules in unit volume is increased, the number of effective collisions in unit time is increased, and the reaction speed is accelerated), so that the raw materials are fully reacted.

The manhole 6 is arranged on the side wall of the lower end of the high-pressure buffer tank 18, the manhole 6 is provided with the hole cover 7, the manhole 6 is fixedly connected with the hole cover 7 through bolts, and when the manhole 6 is used for forming sharp overpressure or vacuum in the tank, the accident caused by damaging the storage tank is prevented, and the safety fire-retarding effect can be achieved.

The operation method of the scheme comprises the following steps: the GBL raw material is introduced into the GBL overhead tank 8 and then conveyed into the static mixer 12 through the GBL metering pump 10, meanwhile, the monomethylamine raw material is introduced into the monomethylamine overhead tank 9, and the monomethylamine raw material is high-purity monomethylamine and then conveyed into the static mixer 12 through the monomethylamine metering pump 11. The static mixer 12 fully mixes GBL and monomethylamine before entering the reactor 13, the fully mixed GBL and monomethylamine enter a coil pipe, heat conduction oil with a set temperature is filled in a gap between the coil pipe and the shell from an oil inlet 15 of the shell, the coil pipe is soaked in the heat conduction oil, GBL and monomethylamine react in the coil pipe to generate NMP, after GBL and monomethylamine react for 4-6 hours, materials in the coil pipe are discharged, when products in the coil pipe are discharged into the high-pressure buffer tank 18, and when the reaction is disqualified, a certain amount of monomethylamine remains in the high-pressure buffer tank 18, when the monomethylamine concentration detected by the monomethylamine detector 5 exceeds a set value of 1ppm, the PLC controller is controlled to open the electric valve 1, high-temperature gas after the reaction is discharged into an unqualified tank, and the high-temperature gas enters the static mixer 12 again for reaction. The PLC is set to intermittently switch and open the first electric valve or the second electric valve in 3S, high-pressure nitrogen enters the high-pressure buffer tank 18 through the first branch pipe 19 or the second branch pipe 20, the high-pressure nitrogen washes the monomethylamine detector 5, the monomethylamine detector 5 is cleaned more comprehensively, and the sensitivity of the monomethylamine detector 5 is ensured; the high pressure nitrogen allowed the reaction product to go completely into the knock-out pot. When the monomethylamine detector 5 detects that the monomethylamine concentration is lower than the set value of 1ppm, the PLC controller controls the electric valve 1 and the high-pressure nitrogen tank 17 to be closed and then controls the flow rate regulating valve to discharge the reaction product to the next process. According to the scheme, the NMP is prepared from the high-purity monomethylamine, so that the separation of finished products and water after the reaction is reduced, the running cost is reduced, the water entering into the coil pipe is reduced, the heat for heating the water is reduced, namely the heat loss is reduced, and meanwhile, the contact area between monomethylamine and GBL is enlarged, so that the reaction speed is accelerated. The high-pressure nitrogen is flushed into the high-pressure buffer tank 18, the high-pressure gas enables reaction products to completely enter the non-mixing tank, product residues are prevented, an ammonia gas detector can be cleaned, meanwhile, the pressurizing effect is achieved, the synthesis reaction is promoted, and the reaction is promoted to be complete.

The foregoing is merely exemplary embodiments of the present invention, and specific structures and features that are well known in the art are not described in detail herein. It should be noted that modifications and improvements can be made by those skilled in the art without departing from the structure of the present invention, and these should also be considered as the scope of the present invention, which does not affect the effect of the implementation of the present invention and the utility of the patent. The protection scope of the present application shall be subject to the content of the claims, and the description of the specific embodiments and the like in the specification can be used for explaining the content of the claims.

Claims

1. An NMP synthesis unit comprising: GBL overhead tank (8), monomethylamine overhead tank (9) and reactor (13); characterized by further comprising: a GBL metering pump (10), a monomethylamine metering pump (11) and a static mixer (12); the GBL overhead tank (8) is communicated with the GBL metering pump (10);

the monomethylamine overhead tank (9) is communicated with a monomethylamine metering pump (11); the GBL metering pump (10) and the monomethylamine metering pump (11) are both communicated with the static mixer (12), the reactor (13) comprises a coil pipe and a shell, the coil pipe is fixedly arranged in the shell, a gap exists between the coil pipe and the shell, the coil pipe is communicated with the static mixer (12), and an oil inlet (15) and an oil outlet (14) are respectively arranged at two ends of the shell;

the coil pipe is communicated with a high-pressure buffer tank (18), a monomethylamine detector (5) and a PLC (programmable logic controller) are arranged on the high-pressure buffer tank (18), an exhaust hole is formed in the high-pressure buffer tank (18), an electric valve (1) is arranged at the exhaust hole, an unqualified tank (16) is communicated with the exhaust hole, the unqualified tank (16) is communicated with a static mixer (12), the monomethylamine detector (5) is arranged at a feed inlet of the high-pressure buffer tank (18), the monomethylamine detector (5) is positioned in the high-pressure buffer tank (18), and the PLC is electrically connected with the monomethylamine detector (5) and an electric valve (1) switch;

be equipped with nitrogen gas air inlet on high-pressure buffer tank (18), nitrogen gas air inlet intercommunication has high-pressure nitrogen gas jar (17), nitrogen gas air inlet intercommunication has first branch pipe (19), and first branch pipe (19) export is corresponding with monomethylamine detector (5) detection mouth, be equipped with first electric valve in first branch pipe (19), first electric valve switch is connected with the PLC controller electricity.

2. An NMP synthesis unit according to claim 1, characterized in that: the nitrogen gas air inlet is communicated with a second branch pipe (20), an outlet of the second branch pipe (20) corresponds to a detection port of the monomethylamine detector (5), a second electric valve is arranged in the second branch pipe (20), a second electric valve switch is electrically connected with the PLC, and the first branch pipe (19) and the second branch pipe (20) are respectively positioned at two ends of the monomethylamine detector (5).

3. An NMP synthesis unit according to claim 1, characterized in that: a monomethylamine mixer is arranged between the monomethylamine metering pump (11) and the static mixer (12), and a GBL mixer is arranged between the GBL metering pump (10) and the static mixer (12).

4. An NMP synthesis unit according to claim 1, characterized in that: the bottom of the high-pressure buffer tank (18) is provided with a base for supporting the buffer tank.

5. An NMP synthesis unit according to claim 1, characterized in that: the high-pressure buffer tank (18) is provided with a discharge port, and a flow regulating valve is arranged at the discharge port.

6. An NMP synthesis unit according to claim 1, characterized in that: four oil inlets (15) and four oil outlets (14) are respectively arranged at two ends of the shell.