CN218339748U - Device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol - Google Patents

Abstract

The utility model provides a device for preparing tetrahydrofuran by cyclization of 1, 4-butanediol, comprising: a hollow reactor; the reactor is provided with a rectifying device, a catalyst feeding mechanism, a raw material feeding mechanism and a gas feeding mechanism at the top part in a communicating way, and the reactor is provided with a heat exchanger. The rectifying device, the catalyst feeding mechanism, the raw material feeding mechanism and the gas feeding mechanism are communicated with the inner cavity of the reactor; wherein, the part of the raw material feeding mechanism in the reactor is communicated with the liquid distributor, and the part of the gas feeding mechanism in the reactor is communicated with the gas distributor. The rectification device is internally provided with a condensation section, and a gas phase discharging mechanism communicated with an external collecting device is arranged at a preset temperature section. The utility model discloses a stirring of gas and liquid is mixed, has increased the contact probability of 1, 4-butanediol and catalyst, improves the reaction airspeed effectively, and is showing the investment that reduces whole equipment.

Description

Device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol

Technical Field

The disclosure relates to the technical field of tetrahydrofuran preparation, and particularly relates to a device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol.

Background

In the prior art, the processes for industrially producing Tetrahydrofuran (THF) mainly comprise: furfural hydrogenation, maleic anhydride direct hydrogenation, 1, 4-Butanediol (BDO) dehydration. Wherein: 1. the furfural method has complex process and serious pollution which is gradually eliminated. 2. The direct maleic anhydride hydrogenation process uses maleic anhydride water solution as raw material and makes hydrogenation reaction under the condition of very high pressure. In addition, the maleic anhydride aqueous solution shows strong acidity, so the requirement on equipment materials is high. The fixed investment and the operation cost of the process are high. The dehydration method of 1, 4-butanediol is to make 1, 4-butanediol undergo the dehydration reaction under the condition of acid catalysis to obtain tetrahydrofuran, and has the characteristics of low reaction temperature, low operation pressure and high product yield.

The 1, 4-butanediol dehydration method is the main process method for preparing tetrahydrofuran by cyclizing 1, 4-butanediol at present due to the excellent characteristics of the tetrahydrofuran prepared by the 1, 4-butanediol dehydration method. The common 1, 4-butanediol dehydration method continuous preparation equipment in the prior art comprises: a fixed reaction bed type technical system and a reaction rectification device technical system. Wherein:

the fixed reaction bed type technical system adopts a fixed reaction bed as a reactor, the reactor is filled with a solid catalyst, and liquid phase reactant flows are subjected to catalytic reaction under the action of the solid catalyst, but the preparation method is limited by chemical balance, so that the reaction conversion degree is low (the conversion rate is usually 35-45%), the product yield is influenced, a large amount of unreacted 1, 4-butanediol needs to be recovered, and the whole preparation process cost is increased.

The reaction and separation process is coupled into a chemical device, unreacted raw materials are discharged from the bottom of a reaction kettle, and the raw materials are reused after impurity removal treatment, so that the reaction product can be continuously removed, and the conversion rate of the raw materials 1, 4-butanediol is increased to about 90%. But are also present; 1. the discharged unreacted raw materials must be subjected to impurity removal treatment, so that the process difficulty and the cost are increased. 2. The operation mode, the amount of the catalyst and the generated byproduct water have great influence on the conversion rate of the raw material 1, 4-butanediol. If the operation proportion is improper or the weight hourly space velocity is not matched, higher conversion rate is difficult to achieve through a single reaction rectification device, and even abnormal operation states of the device are caused, so that the risk of equipment shutdown is further caused.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a device for preparing tetrahydrofuran by cyclization of 1, 4-butanediol, which comprises: a hollow reactor; the top of the reactor is communicated with a rectifying device, the top or the side wall of the reactor is provided with a catalyst feeding mechanism, the part of the side wall close to the bottom is provided with a raw material feeding mechanism, and the bottom of the reactor is provided with a gas feeding mechanism; the reactor is provided with a heat exchanger. The rectifying device, the catalyst feeding mechanism, the raw material feeding mechanism and the gas feeding mechanism are all communicated with the inner cavity of the reactor; wherein, the part of the raw material feeding mechanism in the reactor is communicated with the liquid distributor, and the part of the gas feeding mechanism in the reactor is communicated with the gas distributor.

The liquid dispenser includes: a liquid inlet pipe; one end of the liquid inlet pipe is communicated with the raw material feeding mechanism, and the other end of the liquid inlet pipe is communicated with the liquid uniform distribution pipe; and a plurality of liquid injection pipes are arranged on the liquid uniform distribution pipe.

Furthermore, a condensation section is arranged in the rectifying device, and a gas phase discharging mechanism communicated with an external collecting device is arranged in the preset temperature section.

Further, the gas distributor includes: an air inlet pipe; one end of the gas inlet pipe is communicated with the gas feeding mechanism, and the other end of the gas inlet pipe is communicated with each annular pipe in the annular pipe group through a gas primary distribution pipe; and the bottom of the annular pipe is provided with an air injection pipe.

Further, the annular tube group is divided into an inner annular tube region and an outer annular tube region; the average distance between adjacent pipes of the inner annular pipe group in the inner annular pipe area is L1, and the average distance between adjacent pipes of the outer annular pipe group in the outer annular pipe area is L2; wherein L2 > L1.

Further, the average distance between the gas injection pipes arranged on the annular pipes of the inner annular pipe group is M1, and the average distance between the gas injection pipes arranged on the annular pipes of the outer annular pipe group is M2; wherein M2 > M1.

Furthermore, the liquid uniform distribution pipe is of an annular structure, and the plurality of liquid injection pipes are parallel to each other and arranged along the same direction, and form an included angle of 20-60 degrees with the radius of the liquid uniform distribution pipe.

Further, the heat exchanger includes: at least one of an inner heat exchanger and an outer heat exchanger.

Further, the internal heat exchanger includes: the first heat exchange tube array is arranged in the inner cavity of the reactor; the medium inlet of the first heat exchange tube array is communicated with a first heat medium supply device outside the reactor through a first pipeline, and the medium outlet of the first heat exchange tube array is communicated with a first medium recovery device outside the reactor through a second pipeline.

Further, the external heat exchanger includes: a first circulation pipe and a second circulation pipe communicated with the internal cavity of the reactor; the parts of the first circulating pipe and the second circulating pipe, which are positioned outside the reactor, are communicated through a third circulating pipe; an external heat exchanger and an external circulating pump are arranged on the third circulating pipe; after entering the third circulating pipe from the first circulating pipe and being heated at the external heat exchanger, the circulating medium is blown into the inner cavity of the reactor by the external circulating pump through the second circulating pipe; and a degassing baffle is arranged at the outlet of the second circulating pipe in the cavity inside the reactor.

Furthermore, temperature and pressure measuring ports are arranged on the reactor.

Further, a cooler is arranged inside the rectifying device; the cooler includes: the second heat exchange tube array is positioned in the rectifying device; and a medium inlet of the second heat exchange tube array is communicated with second medium supply equipment outside the rectifying device through a third pipeline, and a medium outlet of the second heat exchange tube array is communicated with second medium recovery equipment outside the rectifying device through a fourth pipeline.

Furthermore, a constant pressure valve is arranged at the top of the rectifying device and controls the reaction pressure of the inner cavity of the reactor communicated with the rectifying device by controlling the air pressure in the rectifying device. Meanwhile, the gas pressure of the gas-phase component output outwards by the rectifying device can be controlled.

After the technical scheme is adopted, the utility model discloses one of following beneficial effect has at least:

(1) The utility model discloses a gaseous and stirring of liquid is mixed, has increased the contact probability of BDO and catalyst, improves the reaction airspeed effectively, and is showing the investment that reduces whole equipment.

(2) The utility model discloses can provide the heat for reaction and result evaporation jointly through the gas mixture of outside THF and water and heat transfer element, the heating is effectual, reaction environment temperature intensity is controllable and temperature control is stable. Meanwhile, the pressure of the reaction process can be controlled.

(3) The utility model discloses a material, the mixture of catalyst in the flow promotion reactor of gas mixture and BDO realize the catalyst suspension on the one hand, increase the contact probability of catalyst and raw materials, on the other hand has avoided using the broken problem of catalyst and the sealed problem of (mixing) shaft that mechanical stirring brought.

(4) The utility model discloses a catalyst suspends in reactor whole liquid phase space, and the volume ratio of reaction space and reactor is far above the volume ratio of other prior art. The amount of conversion per unit reactor space is therefore also higher than in other prior art.

(5) The utility model discloses the condensation segment at reactor top can realize that the BDO that smugglies secretly in the gaseous phase and the BDO condensation of gasification and backward flow to the reaction space of reactor, increase BDO's overall conversion rate.

(6) The utility model discloses a common cauldron formula reactor need not cut apart into high temperature reaction district and low temperature reaction district with the reaction interval. And the heat insulation problem of the middle baffle plate in the high-temperature area and the low-temperature area is also avoided.

Drawings

FIG. 1 is a schematic structural view of a BDO cyclization THF preparation device of the present invention;

FIG. 2 is a schematic structural view of another apparatus for preparing THF by cyclization of BDO according to the present invention;

FIG. 3 is a schematic structural view of still another apparatus for preparing THF by BDO cyclization according to the present invention;

FIG. 4 is a schematic structural view of the gas distributor of the present invention;

FIG. 5 is a schematic structural view of the annular tube and the gas injection tube of the present invention;

fig. 6 is a schematic structural view of the liquid distributor according to the present invention.

Description of reference numerals:

1. a reactor; 101. a gas feed mechanism; 102. a catalyst feed mechanism; 103. temperature and pressure measuring ports; 2. an internal heat exchanger; 201. a first array of heat exchange tubes; 202. a first conduit; 203. a second conduit; 3. a raw material feeding mechanism; 4. a gas distributor; 401. an air inlet pipe; 402. an inner annular tube set; 403. a primary gas distribution pipe; 404. an outer annular tube set; 405. an inner annular tube region; 406. an outer annular tube region; 407. a gas ejector tube; 5. a rectification device; 501. a condensing section; 502. a gas phase discharging mechanism; 503. a mixture feeding mechanism; 6. a cooler; 601. a second array of heat exchange tubes; 602. a third pipeline; 603. a fourth pipe; 7. an external heat exchanger; 701. a first circulation pipe; 702. a second circulation pipe; 703. a third circulation pipe; 704. an external circulating pump; 705. circulating the medium; 706. an external heat exchanger; 8. liquid is uniformly distributed on the pipe; 801. a liquid inlet pipe; 802. uniformly distributing the liquid; 803. a liquid injection tube.

Detailed Description

The present disclosure will be described in further detail with reference to embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant matter and not restrictive of the disclosure.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. The present disclosure will be described in detail below with reference to embodiments.

Example 1

A device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol is shown in figure 1 and comprises: a hollow reactor 1; the top of the reactor 1 is communicated with a rectifying device 5, the top or the side wall of the reactor is provided with a catalyst feeding mechanism 102, the part of the side wall close to the bottom is provided with a raw material feeding mechanism 3, and the bottom is provided with a gas feeding mechanism 101; the reactor 1 is provided with a heat exchanger.

The rectifying device 5, the catalyst feeding mechanism 102, the raw material feeding mechanism 3 and the gas feeding mechanism 101 are all communicated with the cavity inside the reactor 1; wherein, the part of the raw material feeding mechanism 3 located inside the reactor 1 is communicated with the liquid distributor 8, and the part of the gas feeding mechanism 101 located inside the reactor 1 is communicated with the gas distributor 4.

The rectifying device 5 is internally provided with a condensing section 501, and a gas phase discharging mechanism 502 communicated with an external collecting device is arranged at a preset temperature section. The top of the rectifying device is provided with a constant pressure valve (not shown in the figure), and the constant pressure valve controls the reaction pressure of the inner cavity of the reactor communicated with the rectifying device by controlling the air pressure in the rectifying device. Meanwhile, the gas pressure of the gas-phase component output outwards by the rectifying device can be controlled.

The reactor 1 is provided with a temperature and pressure measuring port 103.

The heat exchanger includes: an internal heat exchanger 2.

The inner heat exchanger 2 includes: a first heat exchange tube array 201 disposed inside the inner cavity of the reactor 1; the medium inlet of the first heat exchange tube array 201 is communicated with a first heat medium supply device outside the reactor 1 through a first pipe 202, and the medium outlet of the first heat exchange tube array 201 is communicated with a first medium recovery device outside the reactor 1 through a second pipe 203.

Example 2

An apparatus for preparing tetrahydrofuran by cyclization of 1, 4-butanediol is shown in fig. 2, and comprises: a hollow reactor 1; the top of the reactor 1 is communicated with a rectifying device 5, the top or the side wall of the reactor is provided with a catalyst feeding mechanism 102, the part of the side wall close to the bottom is provided with a raw material feeding mechanism 3, and the bottom of the reactor is provided with a gas feeding mechanism 101; the reactor 1 is provided with a heat exchanger.

The rectifying device 5, the catalyst feeding mechanism 102, the raw material feeding mechanism 3 and the gas feeding mechanism 101 are all communicated with the cavity inside the reactor 1; wherein, the part of the raw material feeding mechanism 3 located inside the reactor 1 is communicated with the liquid distributor 8, and the part of the gas feeding mechanism 101 located inside the reactor 1 is communicated with the gas distributor 4.

The rectifying device 5 is internally provided with a condensing section 501, and a gas phase discharging mechanism 502 communicated with an external collecting device is arranged at a preset temperature section. And a constant pressure valve (not shown in the figure) is arranged at the top of the rectifying device and controls the reaction pressure of the inner cavity of the reactor communicated with the rectifying device by controlling the air pressure in the rectifying device. Meanwhile, the gas pressure of the gas-phase component output outwards by the rectifying device can be controlled.

The reactor 1 is provided with a temperature and pressure measuring port 103.

The heat exchanger includes: an external heat exchanger 7.

The external heat exchanger 7 includes: a first circulation pipe 701 and a second circulation pipe 702 communicating with the inner cavity of the reactor 1; the portions of the first circulation pipe 701 and the second circulation pipe 702 located outside the reactor 1 are communicated through a third circulation pipe 703; an external heat exchanger 706 and an external circulating pump 704 are arranged on the third circulating pipe 703; after entering the third circulation pipe 703 from the first circulation pipe 701, the circulation medium 705 is heated at the external heat exchanger 706 and then blown into the internal cavity of the reactor 1 through the second circulation pipe 702 by the external circulation pump 704; in the internal cavity of the reactor 1, a degassing baffle is arranged at the outlet of the second circulation pipe 702.

Example 3

A device for preparing tetrahydrofuran by cyclization of 1, 4-butanediol is shown in figure 3 and comprises: a hollow reactor 1; the top of the reactor 1 is communicated with a rectifying device 5, the top or the side wall of the reactor is provided with a catalyst feeding mechanism 102, the part of the side wall close to the bottom is provided with a raw material feeding mechanism 3, and the bottom of the reactor is provided with a gas feeding mechanism 101; the reactor 1 is provided with a heat exchanger.

The rectifying device 5, the catalyst feeding mechanism 102, the raw material feeding mechanism 3 and the gas feeding mechanism 101 are all communicated with the inner cavity of the reactor 1; wherein, the part of the raw material feeding mechanism 3 located inside the reactor 1 is communicated with the liquid distributor 8, and the part of the gas feeding mechanism 101 located inside the reactor 1 is communicated with the gas distributor 4.

The rectifying device 5 is internally provided with a condensing section 501, and a gas phase discharging mechanism 502 communicated with an external collecting device is arranged at a preset temperature section. The top of the rectifying device is provided with a constant pressure valve (not shown in the figure), and the constant pressure valve controls the reaction pressure of the inner cavity of the reactor communicated with the rectifying device by controlling the air pressure in the rectifying device. Meanwhile, the gas pressure of the gas-phase component output outwards by the rectifying device can be controlled.

The reactor 1 is provided with a temperature and pressure measuring port 103.

The heat exchanger includes: an inner heat exchanger 2 and an outer heat exchanger 7.

The inner heat exchanger 2 includes: a first heat exchange tube array 201 disposed inside the inner cavity of the reactor 1; the medium inlet of the first heat exchange tube array 201 is communicated with a first heat medium supply device outside the reactor 1 through a first pipeline 202, and the medium outlet of the first heat exchange tube array 201 is communicated with a first medium recovery device outside the reactor 1 through a second pipeline 203;

the external heat exchanger 7 in fig. 3 employs the external heat exchanger 7 shown in fig. 2, and a part of the structure is not shown in fig. 3. The external heat exchanger 7 includes: a first circulation pipe 701 and a second circulation pipe 702 communicating with the inner cavity of the reactor 1; the portions of the first circulation pipe 701 and the second circulation pipe 702 located outside the reactor 1 are communicated through a third circulation pipe 703; an external heat exchanger 706 and an external circulating pump 704 are arranged on the third circulating pipe 703; the circulating medium 705 enters the third circulating pipe 703 from the first circulating pipe 701, is heated by the external circulating pump 704, and is blown into the internal cavity of the reactor 1 through the second circulating pipe 702; in the internal cavity of the reactor 1, a degassing baffle is arranged at the outlet of the second circulation pipe 702.

As shown in examples 1 to 3, in the apparatus for producing tetrahydrofuran by cyclization of 1, 4-butanediol according to the present invention, the raw material BDO is first fed into the internal cavity of the reactor 1 from the raw material feeding mechanism 3 through the liquid distributor 8, and the raw material BDO is made to form a rotational flow in the internal cavity of the reactor 1 by the liquid distributor 8. The catalyst is added into the inner cavity of the reactor 1 from the catalyst feeding mechanism 102 and is mixed with the BDO raw material in a rotational flow mode. Then, the mixed gas of THF and water is fed from the gas feed mechanism 101 through the gas distributor 4 into the internal cavity of the reactor 1, and the gas flow direction is toward the catalyst accumulation-prone region, such as the bottom of the internal cavity of the reactor 1. Under the stirring action of the gas flow, the catalyst and the raw material BDO can be further promoted to be fully mixed, on one hand, the raw material BDO can be quickly cyclized to be THF, and thus the speed of the Tiangong reaction is promoted. On the other hand, continuous mechanical stirring is not needed, so that dynamic sealing treatment is not needed at the stirring shaft, the equipment investment is reduced, and the maintenance frequency of the equipment is reduced. On the other hand, the catalytic activity of the catalyst is fully utilized, and the yield is improved.

The THF and water formed in the reaction then leave the liquid-phase space of the reactor 1 in the gas phase under the reaction conditions and are passed together with unreacted BDO into the rectification apparatus 5 in the upper part of the reactor. The gas-liquid two phases transfer heat and mass on the surface of the condensation section 501, re-condense BDO evaporated and entrained in the reactor 106, and flow back to the liquid phase space of the reactor 106 for further reaction. The gas phase product of THF and water exits the reactor from gas phase take-off 502 to a downstream separation device. After a part of the THF and water separated by the downstream separation apparatus is split, they are fed from the gas feed mechanism 101 through the gas distributor 4 into the internal cavity of the reactor 1.

The utility model discloses as required condensation segment 501 can be condensation piece, filler etc. as required. The utility model discloses the condensation segment at reactor top can realize that the BDO that smugglies secretly in the gaseous phase and the BDO condensation of gasification and backward flow to the reaction space of reactor, increase BDO's overall conversion rate.

The utility model discloses can select inside heat exchanger 2 or outside heat exchanger 7 or the combination of the two as required. The heating mode of the internal heat exchanger 2 is as follows: the first heat medium supplying device is a circulation pump device having a heating function. The first heat medium supplying device heats a medium, which is a medium for general heating, such as steam, heat transfer oil, and the like. Then, the heat medium heated to the target temperature is blown into the first heat exchange tube array 201 through the first pipe 202, and the first heat exchange tube array 201 completes the heat exchange with the liquid phase portion inside the reactor 1, thereby heating the liquid phase portion inside the reactor 1. The medium which completes heat exchange in the first heat exchange tube array 201 flows from the second tube 203 to the first medium recovery device, which may be a liquid storage tank or other device with certain medium storage capacity. Meanwhile, the first medium recovery device is communicated with the inlet end of the first heat medium supply device to supply the first heat medium supply device with the circulating medium.

The utility model discloses outside heat exchanger 7's heating methods does: the external circulation pump 704 draws out a liquid phase portion inside the reactor 1 from the first circulation pipe 701, and after the third circulation pipe 703 is heated to a target temperature by the external heat exchanger 706, it is sent to the inside of the reactor 1 through the second circulation pipe 702. Wherein, the setting of degasification baffle can prevent the liquid containing bubbles from entering the circulating medium pump.

The heat exchanger can provide necessary heat energy for reaction and evaporation for the liquid phase part in the reactor 1, and has good heat supply effect, controllable temperature intensity of the reaction environment and stable temperature control, thereby effectively improving the utilization rate of equipment and stabilizing the yield.

Furthermore, the utility model discloses a common cauldron formula reactor need not cut apart into high temperature reaction district and low temperature reaction district with the reaction interval. And the heat insulation problem of the middle baffle plate in the high-temperature area and the low-temperature area is also avoided.

Example 4

As shown in fig. 4 and 5, the gas distributor 4 comprises: an intake pipe 401; one end of the air inlet pipe 401 is communicated with the air feeding mechanism 101, and the other end of the air inlet pipe is respectively communicated with each annular pipe in the annular pipe group through an air primary distribution pipe 403; and the bottom of the annular pipe is provided with an air injection pipe 407.

At this time, the mixture gas of THF and water from the gas feed mechanism 101 is introduced into each of the annular tubes in the annular tube group through the gas inlet pipe 401 by the gas primary distribution pipe 403, and is ejected from the gas ejection pipe 407 of the annular tube. The ejected gas flow can disturb the liquid phase part in the reactor 1 from different directions and different positions, so that the material and the catalyst are pushed by the gas flow to be disturbed and mixed continuously, and meanwhile, the continuous gas flow can ensure that the catalyst is not accumulated at a fixed position and is continuously and fully mixed with the liquid phase part in the reactor 1. On one hand, the catalyst suspension is realized, the contact probability of the catalyst and the liquid phase reaction raw material BDO is increased, and on the other hand, the problems of catalyst crushing and stirring shaft sealing caused by mechanical stirring are avoided. And simultaneously, the utility model discloses a catalyst suspends in the whole liquid phase space of reactor, has not only realized the utilization to traditional reaction space, still mixes through the reactant and the catalyst intensive mixing with the reactor bottom, has realized that the head space that will show its bottom also changes for reaction space, consequently this application reaction space is far higher than the volume ratio of other prior art with the volume ratio of reactor. The amount of conversion per unit reactor space is therefore also higher than in other prior art. The significance of this advantage increases significantly, in particular, with increasing reactor diameter.

The annular tube group is divided into an inner annular tube region 405 and an outer annular tube region 406; the average spacing between adjacent tubes of the inner annular tube set 402 in the inner annular tube region 405 is L1, and the average spacing between adjacent tubes of the outer annular tube set 404 in the outer annular tube region 406 is L2; wherein L2 > L1.

The average distance between the gas injection pipes 407 arranged on the annular pipes of the inner annular pipe group 402 is M1, and the average distance between the gas injection pipes 407 arranged on the annular pipes of the outer annular pipe group 404 is M2; wherein M2 > M1.

Because the liquid can easily form a vortex in the middle part during the rotational flow, solid-phase materials such as the catalyst are accumulated in the middle part, and the annular pipe group and the air injection pipe 407 are arranged at intervals, on one hand, more jet flow disturbance can be carried out on the mixed gas of THF and water in the middle part, so that the problem that the catalyst gathers to the center of the rotational flow liquid phase is effectively avoided, and the catalyst can be more uniformly distributed in the liquid phase component. On the other hand, the catalyst is fully suspended and uniformly dispersed in the reactants, so that the stability of the operation of the reactor can be enhanced, the mechanical wear rate of catalyst particles is reduced, and the service life of the catalyst is prolonged.

Example 5

In an apparatus for producing tetrahydrofuran by cyclization of 1, 4-butanediol according to any one of embodiments 1 to 3, as shown in fig. 6, the liquid distributor 8 includes: a liquid inlet pipe 801; one end of the liquid inlet pipe 801 is communicated with the raw material feeding mechanism 3, and the other end of the liquid inlet pipe is communicated with the liquid uniform distribution pipe 802; the liquid distribution pipe 802 is provided with a plurality of liquid injection pipes 803.

The liquid distribution pipe 802 is an annular structure, and the liquid injection pipes 803 are parallel to each other and arranged along the same direction, and form an included angle of 20-60 degrees with the radius of the liquid distribution pipe 802.

At this time, the material BDO enters the liquid distribution pipe 802 through the liquid inlet pipe 801 and enters the internal cavity of the reactor 1 from the liquid injection pipe 803. Because liquid is the loop configuration, and several liquid injection pipe 803 is parallel to each other and is set up along the same direction, and is 20 ° -60 contained angle with the radius of liquid uniform distribution pipe 802, thereby make the raw materials BDO that gets into reactor 1 inside cavity can be with certain speed and direction, flow in from many positions, thereby make the inside liquid phase part of reactor 1 form the liquid whirl, cooperation gas distributor 4, can disturb liquid phase component, make abundant and even dispersion of catalyst in raw materials BDO, gaseous THF and the vapor that generates simultaneously can evaporate fast and leave the liquid phase part, thereby make raw materials BDO continue to react, thereby make the utility model discloses raw materials BDO's conversion can promote more than 90%.

Example 6

Based on the device for preparing tetrahydrofuran by cyclizing 1, 4-butanediol as described in any one of examples 1-3, as shown in FIG. 2, a cooler 6 is arranged in the rectifying device 5; the cooler 6 includes: a second heat exchange tube array 601 located inside the rectifying device 5; a medium inlet of the second heat exchange tube array 601 is communicated with a second medium supply device outside the rectifying device 5 through a third pipe 602, and a medium outlet of the second heat exchange tube array 601 is communicated with a second medium recovery device outside the rectifying device 5 through a fourth pipe 603.

At this time, the low-temperature medium is blown into the second heat exchange tube array 601 from the second medium supply device through the third pipe 602, and sufficiently exchanges heat with the THF, water, BDO mixed gas flowing through, and the temperature of the THF, water, BDO mixed gas is reduced, so that BDO is condensed again and flows back to the inner cavity of the reactor 1. The low-temperature medium after heat exchange flows into second medium recovery equipment from the fourth pipeline 603, for example, a liquid storage tank and other equipment with storage function and standing cooling function such as a standing sedimentation tank. The second medium recovery device communicates with the second medium supply device and supplies the circulating low-temperature medium to the second medium supply device. The low temperature medium may be room temperature water as desired. The second medium supplying device may be a circulation pump.

The arrangement can further promote the condensation and reflux of BDO entrained in the mixed gas of THF, water and BDO and gasified BDO to the reaction space of the reactor, and increase the overall conversion rate of BDO.

Example 7

Based on the device for preparing tetrahydrofuran by cyclizing 1, 4-butanediol described in any one of examples 1 to 3, as shown in FIG. 1, a mixture feeding mechanism 503 is installed at the top of the rectifying device 5. At this time, a mixture of THF and water at 40-90 deg.C may be introduced into the internal cavity of the reactor 1 from the top of the rectifying unit 5, so that the condensation of BDO is more sufficient.

In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment/mode or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.

It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of illustration of the disclosure and are not intended to limit the scope of the disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and are still within the scope of the present disclosure.

Claims (8)

1. A device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol is characterized by comprising: a hollow reactor (1) and a heat exchanger; the top of the reactor (1) is communicated with a rectifying device (5), the top or the side wall is provided with a catalyst feeding mechanism (102), the part of the side wall close to the bottom is provided with a raw material feeding mechanism (3), and the bottom is provided with a gas feeding mechanism (101);

the reactor (1) is provided with a heat exchanger comprising: at least one of an internal heat exchanger (2) and an external heat exchanger (7);

the rectifying device (5), the catalyst feeding mechanism (102), the raw material feeding mechanism (3) and the gas feeding mechanism (101) are communicated with the inner cavity of the reactor (1);

the part of the raw material feeding mechanism (3) positioned in the reactor (1) is communicated with the liquid distributor (8), and the part of the gas feeding mechanism (101) positioned in the reactor (1) is communicated with the gas distributor (4);

the liquid distributor (8) comprises: a liquid inlet pipe (801); one end of the liquid inlet pipe (801) is communicated with the raw material feeding mechanism (3), and the other end of the liquid inlet pipe is communicated with the liquid uniform distribution pipe (802); the liquid uniform distribution pipe (802) is provided with a plurality of liquid injection pipes (803).

2. The device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol according to claim 1, wherein a condensation section (501) is arranged in the rectification device (5), and a gas phase discharging mechanism (502) communicated with an external collecting device is arranged at a preset temperature section.

3. The apparatus for cyclizing 1, 4-butanediol to produce tetrahydrofuran according to claim 1, wherein the gas distributor (4) comprises: an intake pipe (401); one end of the air inlet pipe (401) is communicated with the air feeding mechanism (101), and the other end of the air inlet pipe is communicated with each annular pipe in the annular pipe group through an air primary distribution pipe (403); and the bottom of the annular pipe is provided with an air injection pipe (407).

4. The device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol according to claim 1, wherein the liquid distribution pipe (802) is of an annular structure, and the plurality of liquid injection pipes (803) are arranged in parallel and in the same direction and form an included angle of 20-60 degrees with the radius of the liquid distribution pipe (802).

5. An apparatus for the cyclization of 1, 4-butanediol to tetrahydrofuran according to claim 1, wherein said internal heat exchanger (2) comprises: a first heat exchange tube array (201) arranged inside the inner cavity of the reactor (1); the medium inlet of the first heat exchange tube array (201) is communicated with a first heat medium supply device outside the reactor (1) through a first pipeline (202), and the medium outlet of the first heat exchange tube array (201) is communicated with a first medium recovery device outside the reactor (1) through a second pipeline (203).

6. Device for the cyclisation of 1, 4-butanediol to tetrahydrofuran according to claim 1, characterized in that said external heat exchanger (7) comprises: a first circulation pipe (701) and a second circulation pipe (702) which are communicated with the inner cavity of the reactor (1); the parts of the first circulating pipe (701) and the second circulating pipe (702) which are positioned outside the reactor (1) are communicated through a third circulating pipe (703); an external heat exchanger (706) and an external circulating pump (704) are arranged on the third circulating pipe (703); after entering the third circulating pipe (703) from the first circulating pipe (701), the circulating medium (705) is heated at the external heat exchanger (706) and then is blown into the inner cavity of the reactor (1) by the external circulating pump (704) through the second circulating pipe (702); a degassing baffle is arranged in the inner cavity of the reactor (1) at the outlet of the second circulating pipe (702).

7. The device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol according to claim 1, wherein the reactor (1) is provided with a temperature and pressure measuring port (103).

8. The device for preparing tetrahydrofuran through cyclization of 1, 4-butanediol according to claim 1, characterized in that a cooler (6) is arranged in the rectifying device (5); the cooler (6) comprises: a second heat exchange tube array (601) positioned inside the rectifying device (5); and a medium inlet of the second heat exchange tube array (601) is communicated with a second medium supply device outside the rectifying device (5) through a third pipeline (602), and a medium outlet of the second heat exchange tube array (601) is communicated with a second medium recovery device outside the rectifying device (5) through a fourth pipeline (603).

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