CN112920016B - Preparation device and method of 1, 3-propylene glycol crude product solution - Google Patents

Preparation device and method of 1, 3-propylene glycol crude product solution Download PDF

Info

Publication number
CN112920016B
CN112920016B CN202110114490.8A CN202110114490A CN112920016B CN 112920016 B CN112920016 B CN 112920016B CN 202110114490 A CN202110114490 A CN 202110114490A CN 112920016 B CN112920016 B CN 112920016B
Authority
CN
China
Prior art keywords
tower
guide
plate
acrolein
separation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110114490.8A
Other languages
Chinese (zh)
Other versions
CN112920016A (en
Inventor
彭华峰
贾振宇
柳铭轩
张保勇
尹婉钰
冯连芳
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Zhejiang Hengyi Petrochemical Research Institute Co Ltd
Original Assignee
Zhejiang University ZJU
Zhejiang Hengyi Petrochemical Research Institute Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU, Zhejiang Hengyi Petrochemical Research Institute Co Ltd filed Critical Zhejiang University ZJU
Priority to CN202110114490.8A priority Critical patent/CN112920016B/en
Publication of CN112920016A publication Critical patent/CN112920016A/en
Application granted granted Critical
Publication of CN112920016B publication Critical patent/CN112920016B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/132—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
    • C07C29/136—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH
    • C07C29/14—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group
    • C07C29/141—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group with hydrogen or hydrogen-containing gases
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/64—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by introduction of functional groups containing oxygen only in singly bound form
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
    • C07C45/82—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

The invention relates to the field of chemical industry, and discloses a device and a method for preparing a 1, 3-propylene glycol crude product solution, wherein the method is matched with a specifically designed preparation device, and the 1, 3-propylene glycol crude product solution with high conversion rate (99%) and selectivity (88%) can be prepared through hydration reaction, acrolein separation, primary hydrogenation and secondary hydrogenation series reaction.

Description

Preparation device and method of 1, 3-propylene glycol crude product solution
Technical Field
The invention relates to the field of chemical industry, in particular to a device and a method for preparing a 1, 3-propylene glycol crude product solution.
Background
1, 3-propylene glycol (PDO) is an important chemical raw material, and can be widely applied to the fields of fibers, films, polymer devices and the like, wherein the special fiber prepared from polytrimethylene terephthalate has excellent performance and has been widely applied. Currently, the 1, 3-propanediol technology in the international market is dominated by shell and dupont, usa.
The chemical process for preparing 1, 3-propanediol mainly comprises two methods, namely (1) ethylene oxide carbonylation method (U.S. Pat. No. 3, 5304686, U.S. Pat. No. 3, 5689016, U.S. Pat. No. 3, 5777182 and the like), wherein ethylene oxide is used as raw material, and 1, 3-propanediol is prepared by hydroformylation and hydrogenation; (2) an acrolein hydration hydrogenation method (U.S. Pat. No. 4, 5364987 and U.S. Pat. No. 3, 5334778, etc.) uses acrolein as raw material and prepares it through hydration and hydrogenation.
The main problems of the method for preparing 1, 3-propylene glycol by acrolein hydration hydrogenation are that the side reactions in the hydration and hydrogenation stages are more, various byproducts are generated by complex reactions, raw materials and intermediate products are easy to react with each other to generate acetal impurities, and the generation of the side reactions affects the yield of products and the later separation. The prepared 1, 3-propylene glycol crude product solution is simply classified based on the boiling point of water, and contains light components, water, the 1, 3-propylene glycol crude solution and heavy components, and the complex components need to be removed respectively, so that the whole later refining process is difficult. The whole reaction process is sensitive to reaction temperature, reaction pressure and airspeed, so that the reasonable reaction process is designed, and the reaction device and the refining device are matched with the reaction process.
Disclosure of Invention
In order to solve the technical problems, the invention provides a device and a method for preparing a 1, 3-propylene glycol crude product solution, the method is matched with a specially designed preparation device, and the 1, 3-propylene glycol crude product solution with high conversion rate (99%) and selectivity (88%) can be prepared by hydration reaction, acrolein separation, primary hydrogenation and secondary hydrogenation series reaction.
The specific technical scheme of the invention is as follows:
in a first aspect, the invention provides a device for preparing a 1, 3-propanediol crude product solution, which comprises a hydration reactor, an acrolein separation unit, a two-stage hydrogenation unit and a gas-liquid separation unit which are connected in sequence.
The acrolein separation unit comprises an acrolein separation column, a first condenser and a first reflux drum; the hydration reactor is communicated with the acrolein separation tower, and the tower top, the first condenser and the first reflux tank of the acrolein separation tower are communicated in sequence to form a loop.
The two-stage hydrogenation unit comprises a first mixer, a first-stage hydrogenation reactor, a preheater, a second mixer and a second-stage hydrogenation reactor which are connected in sequence; the inlet of the first mixer is respectively communicated with the tower bottom outlet of the acrolein separation tower and the primary hydrogen supply pipe; the first mixer is connected with the top of the primary hydrogenation reactor, the bottom of the primary hydrogenation reactor is connected with the inlet of the preheater, and the inlet of the second mixer is respectively communicated with the outlet of the preheater and the secondary hydrogen supply pipe; the second mixer is connected with the top of the secondary hydrogenation reactor.
The gas-liquid separation unit comprises a gas-liquid separation tank, a second condenser, a dehydrogenation separation tower, a third condenser and a second reflux tank; the bottom outlet of the second-stage hydrogenation reactor is connected with a gas-liquid separation tank, the hydrogen outlet of the gas-liquid separation tank is connected with a second condenser, the liquid outlet of the gas-liquid separation tank is connected with a dehydrogenation separation tower, and the top of the dehydrogenation separation tower, a third condenser and a second reflux tank form a loop in sequence; the second reflux tank is also connected with the light component collecting pipe; the bottom outlet of the dehydrogenation separation tower leads to a 1, 3-propylene glycol refining device.
The working process of the device of the invention is roughly as follows: after completing the hydration reaction of the blended acrolein solution through a hydration reactor, feeding the acrolein solution into an acrolein separation tower to separate out unreacted acrolein, feeding bottom reaction liquid and hydrogen into a first-stage hydrogenation reactor according to a certain proportion, performing heat exchange on the primarily hydrogenated reaction liquid, supplementing certain hydrogen again, feeding the hydrogen into a second-stage hydrogenation reactor, feeding the hydrogenated and hydrogen mixture into a gas-liquid separation tank, performing gas-liquid separation under a set pressure, recycling the hydrogen at the top, feeding a crude product containing a certain amount of hydrogen at the bottom into a dehydrogenation separation tower, separating out the hydrogen, and simultaneously removing light components (water, methanol, propanol, acetic acid and the like) in the crude product solution by gas stripping.
The device of the invention is characterized in that: according to the invention, after 3-hydroxypropionaldehyde is obtained by hydration reaction by taking acrolein as a raw material, the complete hydrogenation reaction is ensured through secondary hydrogenation, and hydrogen is discharged in a gas-liquid separation and gas stripping combined mode of reaction liquid after hydrogenation is finished, wherein two functions of gas-liquid separation and gas stripping rectification can be realized without external mass transfer in a dehydrogenation separation tower, so that the efficient cyclic utilization of the hydrogen is ensured, light components of the 1, 3-propylene glycol crude product solution are removed simultaneously, and the subsequent refining process of the 1, 3-propylene glycol crude product solution is reduced.
Preferably, the first reflux tank is also connected with a reflux pipe for blending raw materials of the reaction liquid; the bottom of the acrolein separation tower is provided with a steam heat exchanger.
Preferably, the first mixer and the second mixer are pipeline type static mixers; the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are filler type fixed bed reactors, wherein the first-stage hydrogenation reactor is provided with a water-cooling jacket communicated with a cooling water supply pipe.
The group of the invention finds that the hydrogenation reaction mainly occurs in the first-stage hydrogenation stage, and the heat effect of the second-stage hydrogenation reaction is smaller, so that the first-stage hydrogenation reactor needs to be cooled by water.
Preferably, the hydrogen outlets of the second condenser and the third condenser are respectively connected with a hydrogen compressor.
Preferably, the gas-liquid separation tank is formed by connecting a plurality of stages of gas-liquid separation tanks in series.
Preferably, the hydration reactor comprises:
the top surface and the bottom surface of the shell side cylinder are respectively provided with a tube plate; the tube plate is provided with tube holes; the central area and the edge area of the tube plate are respectively a central circular non-cloth tube area and an edge annular non-cloth tube area.
And the plurality of tubes are axially arranged in the shell pass cylinder body, catalysts are filled in the tubes, and two ends of each tube are respectively communicated with tube array holes of the tube plates on the top surface and the bottom surface of the shell pass cylinder body. Each row tube is internally provided with a plurality of high-rib inner fins which are axially arranged, and the inner fins are distributed on the cross section of the row tube at equal angles.
The circular guide plates and the annular guide plates are axially arranged in the shell pass cylinder in a staggered manner to form a zigzag media removing flow channel; the outer diameter of the circular guide plate corresponds to the inner diameter of the edge annular non-distribution pipe area, and the inner diameter of the annular guide plate corresponds to the outer diameter of the central circular non-distribution pipe area.
The media removing inlet and the media removing outlet are directly or indirectly arranged on the outer side wall of the shell pass cylinder.
And the upper end enclosure is covered on the top of the shell pass cylinder body, and a reactor feed inlet or a reactor discharge outlet is arranged on the upper end enclosure.
And the lower end enclosure is covered at the bottom of the shell pass cylinder body, and a reactor discharge port or a reactor feed port is arranged on the lower end enclosure.
And the feeding distribution plate is arranged between the top surface or the bottom surface of the shell pass cylinder and the feeding hole of the reactor.
The heat release of the hydration reaction for preparing the 3-hydroxypropionaldehyde by acrolein hydration is large, the requirement on the reaction temperature is strict, the allowable change interval of the reaction temperature is small, and the influence of the temperature on the proportion of side reaction and the selectivity of the 3-hydroxypropionaldehyde is large, so that the realization of uniform distribution and uniform heat transfer of reaction materials are key factors considered during the design of a reactor.
The working principle of the hydration reactor of the invention is as follows: filling a catalyst into the tubes, feeding a mixed solution of raw material acrolein and water from a feed inlet of the lower end enclosure or the upper end enclosure, moving the mixed solution away from the tube pass, uniformly distributing the mixed solution to inlets of the tubes through a feed distribution plate, allowing the mixed solution to flow through the catalyst in the tubes, and discharging the mixed solution from a discharge outlet of the lower end enclosure or the lower end enclosure; meanwhile, the heat removing medium enters the shell side from the medium removing inlet and is discharged from the medium removing outlet, so that heat exchange is realized.
The hydration reactor with the structure has the characteristics and the technical effects that:
firstly, a plurality of axially arranged inner fins are arranged in the tubes, and the inner fins are distributed on the cross section of the tubes at equal angles. The inner fins are in close contact with the catalyst in the tubes, so that reaction heat can be quickly transferred to the tube wall and taken away by a heat removing medium, and meanwhile, reaction materials are divided into a plurality of parts, so that the axial flow (the radial flow is limited) of the reaction materials is enhanced, the catalytic reaction is more uniform, and the temperature of each part of the catalyst is ensured to be uniform to the greatest extent; meanwhile, due to the existence of the inner fins, the heat transfer medium can be used as a heat transfer medium to multiply the comprehensive heat transfer coefficient, and is particularly suitable for chemical reactions with large reaction heat release or strict requirements on reaction temperature change intervals.
In addition, the center and the edge ring of the tube plate are respectively provided with a central circular non-tube distribution area and an edge ring-shaped non-tube distribution area; meanwhile, the outer diameter of the circular guide plate corresponds to the inner diameter of the edge circular non-fabric-area, and the inner diameter of the circular guide plate corresponds to the outer diameter of the central circular non-fabric-area. Under the flow guide of the circular guide plates and the annular guide plates which are arranged in a staggered mode at intervals in the shell pass, the heat removing medium mainly flows in the horizontal radial direction in the area corresponding to the pipe distribution area on the cross section, and quickly changes into the vertical axial flow in the area corresponding to the pipe non-distribution area, so that a vortex area and a stagnant area are easily formed in the area, and the area is a part with poor heat transfer performance. Therefore, the invention is purposefully not provided with the tubes in the non-tube distribution area, the volume utilization rate of the device is not reduced a lot, but the formation of vortex and stagnant flow can be effectively avoided, so that the reaction materials and the heat removing medium form single cross flow, the heat transfer is more uniform and efficient, the shell-side pressure drop is reduced, and the invention is beneficial to the defects.
In conclusion, the structure of the hydration reactor can realize the uniform flow and the uniform heat exchange of materials, and control the reaction temperature within a reasonable small range, thereby improving the conversion rate and the selectivity of the hydration reaction.
Preferably, the number of the inner fins is 2-16, and the fin ratio is 1.3-4.0.
Preferably, two ends of each column tube are respectively provided with a spring support, the inner end of each spring support is filled with inert ceramic balls (the height of each spring support covers the spring support), and the inert ceramic balls at the two ends are filled with catalysts.
The spring support is convenient to disassemble and assemble, plays a role of axial support and catalyst fixation together with the inert porcelain ball, and can realize uniform distribution of reaction materials on the cross section of the tube array.
Preferably, the area ratio of the edge annular non-cloth pipe area to the central circular non-cloth pipe area is 1-1.5: 1.
Preferably, one or more pairs of annular channels are arranged on the circumference of the outer side wall of the shell side cylinder; media withdrawing through holes are uniformly distributed on the circumference of the outer side wall of the shell pass cylinder body corresponding to the annular channel. Wherein:
scheme provided with a pair of annular channels: the two annular channels are respectively arranged on the outer side wall of the shell pass cylinder body close to the top surface and the bottom surface, and the media withdrawing inlet and the media withdrawing outlet are respectively arranged on one annular channel.
Scheme with many pairs of annular passageways: the plurality of pairs of annular channels are sequentially arranged along the axial direction of the shell pass cylinder, and the media withdrawing inlet and the media withdrawing outlet are respectively arranged on one annular channel in each pair; and shell-side intermediate partitions for isolation (for dividing the interior of the shell-side cylinder into a plurality of chambers) are arranged at adjacent pairs of annular channels in the shell-side cylinder.
The heat removing medium through hole is used as a channel for the heat removing medium to enter the shell pass. Because the flow resistance at the medium removing through hole is far larger than the resistance in the annular channel, the medium removing through holes with the same diameter are arranged, and the heat removing medium can uniformly enter the shell pass cylinder along the circumference of the shell pass cylinder.
In addition, the design of many pairs of annular channels, and every heat removal medium's import temperature is the same, how can show the increase heat transfer difference in temperature, effectively improve reaction temperature's controllability.
Preferably, a plurality of medium withdrawing inlets or medium withdrawing outlets are arranged on the outer side of the annular channel along the circumferential direction, and a feeding baffle is arranged between each medium withdrawing inlet and the shell side cylinder.
The design of a plurality of medium withdrawing inlets or medium withdrawing outlets and the arrangement of the feeding baffle plate at the inner side of each medium withdrawing inlet can ensure that the heat withdrawing media are uniformly distributed in the annular channel, thereby realizing the uniform feeding of the medium withdrawing at each part.
Preferably, the feeding baffle is arc-shaped or splayed.
Preferably, distribution plate through holes are uniformly distributed in the areas of the feed distribution plate, which do not correspond to the edge annular non-pipe distribution area and the central circular non-pipe distribution area.
Preferably, the upper end socket and the lower end socket are of a spherical cap end socket type.
The upper and lower seal heads of the hydration reactor are both spherical seal heads, the spherical seal heads are directly welded with the flange of the shell pass cylinder, and a pipe box straight cylinder section is not arranged, so that the retention time of reaction materials in the seal heads can be reduced, and the occurrence of self-polymerization reaction and side reaction of the materials can be reduced.
Preferably, the acrolein separation tower comprises a tower body, and the top, the side and the bottom of the tower body are respectively provided with a tower top gas phase outlet, a feed inlet and a tower bottom liquid phase outlet. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates and a plurality of efficient guide tower plates are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.
The acrolein separating tower is divided into rectifying section and stripping section with the material inlet as boundary, the upper part of the rectifying section adopts high efficiency guide column plate, the lower part of the rectifying section adopts guide stereo jet column plate, and the stripping section adopts guide composite stereo jet column plate. The operating principle of the acrolein separation tower is as follows: the separated material liquid (the hydration liquid solution containing acrolein and 3-hydroxy propionaldehyde) enters the tower from the feed inlet, the mixed liquid and the gas phase rising from the tower bottom carry out mass transfer on the tower plate of the stripping section, and part of the uncondensed gas phase enters the reflux liquid on the tower plate of the rectifying section to continuously carry out gas-liquid mass transfer. The light component acrolein is obtained at the tower top and the water solution of the heavy component 3-hydroxypropionaldehyde is obtained at the tower bottom through the gas-liquid mass transfer process on the tower plates of the rectifying section and the stripping section.
The separation tower has higher acrolein concentration at the upper part and higher polymerization possibility, so that the upper part of the rectifying section adopts a high-efficiency guide sieve tray, and the lower part of the rectifying section adopts a guide three-dimensional injection tray, so that the separation tower has higher flux and higher mass transfer efficiency, and simultaneously, the tray has stronger anti-blocking performance and is easy to clean. The concentration of acrolein in the stripping section is reduced, but the concentration of the hydration product 3-hydroxypropionaldehyde is increased, the operation temperature is higher, and the possibility of polymerization is higher, so that the guide composite three-dimensional injection column plate is selected, the mass transfer efficiency of the column plate is improved, and the column plate also has higher anti-blocking performance. In a word, the invention can solve the problem of polymerization of acrolein and 3-hydroxypropionaldehyde in the separation process by selecting different internal parts in the separation tower, thereby increasing the operation period of the separation tower.
Preferably, the efficient guide column plate is provided with guide holes, the edges of the guide holes are provided with guide plates protruding upwards, and the opening of a slot formed by the guide holes and the guide plates is consistent with the flowing direction of the liquid phase on the efficient guide column plate where the guide holes and the guide plates are located.
In the above structure, the guide hole and the guide plate are combined to form a slit, and the opening of the slit coincides with the flow direction of the liquid phase. During operation, the gas phase rising from the lower tray enters the liquid phase on the tray through the guide holes and the slits, and in the process, the direction of the gas phase ejected from the slits and the direction of the liquid flow are at an angle, and the gas phase can be divided into a horizontal direction and a vertical direction by a velocity decomposition method (see FIG. 4). The gas phase in the vertical direction vertically rises and passes through the liquid layer on the tower plate to form bubbling for mass transfer, and the horizontal direction is the same as the flowing direction of the liquid phase on the tower plate, so that the flowing of the liquid phase on the tower plate can be promoted, the reduction of the liquid phase gradient is promoted, the occurrence of back mixing is reduced, and the formation of a dead zone on the tower plate is prevented.
Preferably, the distribution density of the guide holes on the high-efficiency guide tower plate at the position close to the side wall of the tower body is greater than that of the center of the high-efficiency guide tower plate.
The reason for the above design is: the part close to the tower wall is a liquid phase flow slow zone on the tower plate, and a mass transfer dead zone is easily formed at the position. The arrangement number of the guide holes is increased, so that the liquid phase on the pushing plate can be pushed to flow, and mass transfer dead zones can be prevented.
Preferably, the guided solid spray tray comprises a tray and a cap; the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with sieve holes, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
In the structure, the tower plate is provided with large holes (such as round or rectangular), the holes are provided with caps with corresponding shapes, the side surface of the upper end of each cap is provided with sieve holes, the top and the bottom of each cap are provided with slits, and the slit is arranged between the bottom of each cap and the tower plate. A number of guide holes are arranged close to the tower side wall. In the operation process, the gas phase of the lower tower plate enters the tower plate through the guide holes and the large holes on the plate respectively. The gas phase entering the guide holes and the slits promotes the reduction of the liquid phase gradient and reduces the occurrence of back-mixing, preventing the formation of dead zones on the tray. The gas phase entering the large holes on the plate lifts the liquid phase on the column plate from the slit at the lower end of the bottom of the cap cover, the liquid phase starts to be broken in the lifting process to form small liquid drops and is fully contacted and mixed with the gas phase, one part of the rising gas-liquid mixed phase is sprayed out of the cap cover through the sieve holes on the cap cover, and the other part of the rising gas-liquid mixed phase is sprayed out of the slit at the upper end of the top of the cap cover.
Preferably, the guide composite three-dimensional jet tower plate comprises a tower plate, a cap and a filler; the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the filler is filled at the top of the cap cover, sieve holes are distributed on the side wall of the cap cover, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; and the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flow direction of the liquid phase on the tower plate where the guide hole and the guide plate are positioned.
The difference between the guiding composite stereo jet tower plate and the guiding stereo jet tower plate is that a packing layer is additionally arranged at the upper end of a cap cover, one part of liquid phase entering the cap cover from a slit at the lower end of the bottom of the cap cover is sprayed out of the cap cover from a sieve pore after being crushed into small liquid drops, and the other part of liquid phase enters the packing layer at the upper end of the cap cover to complete mass transfer of gas phase and liquid phase.
Preferably, the cross section of the guide plate is an arc shape with an inner arc surface facing the guide hole.
The arc-shaped arrangement can effectively change the ascending gas phase direction into the inclined upward direction of nearly 45 degrees.
Preferably, the filler is a metal open-cell plate corrugated filler or a metal open-cell wire mesh filler.
Preferably, the number of the high-efficiency guide tower plates accounts for 10-40% of the total tower plates, and is preferably 15-30%; the number of the guide three-dimensional jet tower plates accounts for 5-35%, preferably 15-30% of the total number of the tower plates; the number of the guide composite three-dimensional jet tower plates accounts for 15-70%, preferably 30-60% of the total number of the tower plates.
The reason for the above allocation is: the high-efficiency guide sieve plate has good anti-blocking performance, but poor mass transfer efficiency and high pressure drop, and is used in an area with higher acrolein concentration at the upper part of the rectification section; the anti-blocking performance of the guide three-dimensional injection tower is weaker than that of the guide three-dimensional injection tower, but the mass transfer efficiency is higher and the pressure drop is low, and the guide three-dimensional injection tower is used for the lower part of the rectifying section; the guide composite stereo jet tower plate has high mass transfer efficiency, great pressure drop and poor blocking resistance, and is used in the stripping section area.
Preferably, the aperture ratio of the high-efficiency guide column plate is 5-15%; the aperture ratio of the guide three-dimensional jet tower plate is 5-20%, and the aperture of the upper aperture of the cap cover is 3-15 mm; the aperture ratio of the guide composite three-dimensional jet column plate is 5-20%, the aperture of the upper aperture of the cap cover is 3-15 mm, and the thickness of the filler accounts for 20-40% of the height of the cap cover.
The aperture ratio is reasonable, the pressure drop of the tower plate can be increased if the aperture ratio is small, the temperature of the tower kettle is not favorably reduced, abnormal operations such as liquid leakage and the like are easily generated on the tower plate with large aperture ratio, the mass transfer efficiency of the tower plate is reduced, and the number of theoretical plates of the whole tower is reduced. Similarly, too small an aperture will increase the pressure drop of the column plate, and too large an aperture will be unfavorable for the contact of gas-liquid two-phase, reducing the mass transfer efficiency of the column plate.
Preferably, the upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir and a down-flow guide plate; wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.
In a second aspect, the present invention provides a process for preparing a solution of a crude 1, 3-propanediol comprising the steps of:
1) the acrolein reaction liquid enters a hydration reactor from the bottom for hydration reaction, and the hydration reaction liquid flowing out from the top enters an acrolein separation tower.
2) After the acrolein is separated by the acrolein separation tower, condensing acrolein steam at the tower top, refluxing part of the condensed acrolein steam to the acrolein separation tower, returning part of the condensed acrolein steam to the reaction liquid raw material blending system, and collecting and separating the 3-hydroxypropionaldehyde solution at the tower bottom of the acrolein separation tower to enter a first-stage hydrogenation reactor.
3) The 3-hydroxy propionaldehyde solution and hydrogen are mixed and then enter a first-stage hydrogenation reactor from the top to carry out a first-stage hydrogenation reaction, and reaction liquid obtained after the reaction is finished enters a preheater.
4) The reaction liquid is preheated and then mixed with another strand of hydrogen, enters a secondary hydrogenation reactor from the top to carry out secondary hydrogenation reaction, and a mixed solution containing 1, 3-propylene glycol and hydrogen is obtained after the reaction is finished.
5) The mixed solution enters a gas-liquid separation tank for gas-liquid separation, hydrogen separated from the top of the gas-liquid separation tank is recycled after condensation, and the separated solution obtained from the bottom enters a dehydrogenation separation tower.
6) After separation in the dehydrogenation separation tower, gas-phase components in the solution are discharged from the top of the tower, condensed and separated to obtain light components and hydrogen, the hydrogen is recycled, and the light components are collected; the 1, 3-propylene glycol crude product solution is discharged from the bottom of the tower and sent to a 1, 3-propylene glycol refining device.
The invention designs the adaptive process flow and process conditions aiming at the characteristics of different reaction units such as the first-stage hydrogenation reaction, the second-stage hydrogenation reaction and the like which are connected in series, and can prepare the 1, 3-propylene glycol crude product solution with high conversion rate (99%) and selectivity (88%).
Preferably, in the step 1), the concentration of the acrolein reaction liquid is 8-20%, the reaction temperature is 30-90 ℃, the operation pressure is 0.0-0.4MPa, and the space velocity is 0.5-2h-1。
Preferably, in step 2), the temperature at the top of the acrolein separation column is 40 to 65 ℃, the absolute operating pressure is 5 to 40kPa, and the reflux ratio at the top of the acrolein separation column is 1 to 10: 1.
Preferably, in the step 3), the molar ratio of the 3-hydroxypropionaldehyde to the hydrogen is 10-40:1, the primary hydrogenation reaction temperature is 40-110 ℃, the operation pressure is 3-14MPa, and the space velocity is 5-20h-1。
Preferably, in the step 4), the molar ratio of the supplemented hydrogen to the hydrogen in the step 3) is 1:5-1:1, the temperature of the secondary hydrogenation reaction is 80-140 ℃, the operating pressure is 3-14MPa, and the space velocity is 5-20h-1。
In the step 3), the first-stage hydrogenation reaction adopts lower reaction temperature, so that the high selectivity of the 3-hydroxypropionaldehyde hydrogenation reaction is ensured, and meanwhile, the occurrence of side reactions is reduced; in the step 4), the second-stage hydrogenation reaction adopts relatively high temperature, so that the complete conversion of the 3-hydroxypropionaldehyde in the second-stage hydrogenation reaction is ensured.
Preferably, in step 5), the gas-liquid separation pressure is from 0 to 13MPa, more preferably from 2 to 12MPa, and a stepwise multistage gas-liquid separation may be employed.
And the gas-liquid separation is carried out under the set pressure, so that excessive hydrogen can be separated, the optimal pressure is 2-12MPa, and the efficient recycling of the hydrogen can be further facilitated.
Preferably, in the step 6), the temperature at the top of the dehydrogenation separation tower is 40-100 ℃, the operation pressure is normal pressure, and the reflux ratio at the top of the tower is 1-10: 1.
Separation of hydrogen and light components in the dehydrogenation separation column can be facilitated under the above conditions.
Compared with the prior art, the invention has the beneficial effects that:
(1) the method is matched with a specially designed preparation device, and the high-conversion (99-100%) and high-selectivity (88%) 1, 3-propylene glycol crude product solution can be prepared through the series reaction of hydration reaction, acrolein separation, primary hydrogenation and secondary hydrogenation.
(2) The invention can realize the high-efficiency cyclic utilization of hydrogen and the removal of light components in the solution of the crude product by carrying out gas-liquid separation on the reaction solution after hydrogenation under the set pressure.
(3) The hydration reactor can meet the hydration reaction characteristics of preparing 3-hydroxy-propionaldehyde by acrolein hydration, and has the advantages of uniform material distribution and heat transfer, high reaction efficiency, high production stability and low energy consumption.
(4) The acrolein separating tower of the present invention selects different types of tower plates, the upper part of the rectifying section adopts the high efficiency guide tower plate, the lower part of the rectifying section adopts the guide three-dimensional injection tower plate, and the stripping section adopts the guide composite three-dimensional injection tower plate. Compared with the prior rectifying device adopting the large-pore sieve plate, the tower plate efficiency is improved by 100 percent, the operation elasticity is improved by more than 50 percent, and the processing load is improved by 100 percent. Compare with patent CN101033180A column plate compound mode, the anti stifled performance of device is better, and the guiding hole on the column plate promotes the evenly distributed of liquid layer on the board, reduces the formation in liquid phase dead zone, and the separation column top adopts high-efficient direction sieve mesh column plate to change the washing moreover.
Drawings
FIG. 1 is a schematic view showing a connection of an apparatus for preparing a crude solution of 1, 3-propanediol according to the present invention;
FIG. 2 is a front cross-sectional view of a hydration reactor of the present invention;
FIG. 3 is a cross-sectional view of a tube array in a hydration reactor in accordance with the present invention;
FIG. 4 is a longitudinal sectional view of a tube array in a hydration reactor in accordance with the present invention;
FIG. 5 is a top view of a tube sheet in a hydration reactor of the present invention;
FIG. 6 is a cross-sectional view of a shell-side cartridge and annular channel in a hydration reactor of the present invention;
FIG. 7 is a top view of a feed distribution plate in a hydration reactor of the present invention;
FIG. 8 is a schematic view of the internal structure of an acrolein separation column according to the present invention;
FIG. 9 is a schematic structural view of a guide three-dimensional spray tray in the acrolein separation column of the present invention;
FIG. 10 is a schematic structural view of a guide composite three-dimensional spray tray in the acrolein separation column of the present invention;
FIG. 11 is a schematic view of a guide hole and a guide plate in an acrolein separation column according to the present invention;
FIG. 12 is a schematic view of the open area of one of the three-dimensional jet trays and the composite three-dimensional jet tray in the acrolein separation column of the present invention;
FIG. 13 is a process flow diagram for the preparation of 1, 3-propanediol without staged hydrogenation.
The reference signs are: a hydration reactor 1000, an acrolein separation column 2001, a first condenser 2002, a first reflux tank 2003, a reflux pipe 2004, a steam heat exchanger 2005, a first mixer 3001, a primary hydrogenation reactor 3002, a preheater 3004, a second mixer 3005, a secondary hydrogenation reactor 3006, a primary hydrogen supply pipe 3007, a secondary hydrogen supply pipe 3008, a cooling water supply pipe 3009, a gas-liquid separation tank 4001, a second condenser 4002, a dehydrogenation separation column 4003, a third condenser 4004, a second reflux tank 4005, a light component collection pipe 4006, and a hydrogen compressor 4007;
the reactor comprises a tube array 1001, a circular guide plate 1002, an annular guide plate 1003, a medium removing inlet 1004, a medium removing outlet 1005, an upper end enclosure 1006, a lower end enclosure 1007, a reactor feed inlet 1008, a reactor discharge outlet 1009, a feed distribution plate 1010, an annular channel 1011, a tube plate 1012, a tube array hole 1013, a central circular non-tube distribution area 1014, an edge annular non-tube distribution area 1015, a medium removing through hole 1016, a middle partition 1017, a feed baffle 1018, a spring support 1019, inert porcelain balls 1020, inner fins 1021 and a distribution plate through hole 1022;
the tower body 100, a gas phase outlet 101 at the top of the tower, a feed inlet 102, a liquid phase outlet 103 at the bottom of the tower, a guide three-dimensional spray tray 104, a high-efficiency guide tray 105, a guide composite three-dimensional spray tray 106, a guide hole 107, a guide plate 108, a tray 109, a cap 110, a large hole 111, a sieve pore 112, an upper end slit 113, a lower end slit 114, a filler 115, an overflow weir 116 and a down-flow guide plate 117.
Detailed Description
The present invention will be further described with reference to the following examples.
General examples
As shown in fig. 1, a preparation apparatus of a 1, 3-propanediol crude product solution includes a hydration reactor 1000, an acrolein separation unit, a two-stage hydrogenation unit, and a gas-liquid separation unit, which are connected in sequence.
The acrolein separation unit includes an acrolein separation column 2001, a first condenser 2002, and a first reflux tank 2003; the hydration reactor is communicated with the acrolein separation tower, and the tower top of the acrolein separation tower, the first condenser and the first reflux tank are communicated in sequence to form a loop. The first reflux tank is also connected with a reflux pipe 2004 for blending the raw materials of the reaction solution; the bottom of the acrolein separation column is provided with a steam heat exchanger 2005.
The two-stage hydrogenation unit comprises a first mixer 3001, a first-stage hydrogenation reactor 3002, a preheater 3004, a second mixer 3005 and a second-stage hydrogenation reactor 3006 which are connected in sequence; the inlet of the first mixer is respectively communicated with the tower bottom outlet of the acrolein separation tower and the primary hydrogen supply pipe 3007; the first mixer is connected with the top of the primary hydrogenation reactor, the bottom of the primary hydrogenation reactor is connected with the inlet of the preheater, and the inlet of the second mixer is respectively communicated with the outlet of the preheater and the secondary hydrogen supply pipe 3008; the second mixer is connected with the top of the secondary hydrogenation reactor. The first mixer and the second mixer are pipeline type static mixers; the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are filler type fixed bed reactors, wherein the first-stage hydrogenation reactor is provided with a water cooling jacket communicated with a cooling water supply pipe 3009.
The gas-liquid separation unit comprises a gas-liquid separation tank 4001 (which can also be in a form of series connection of multi-stage gas-liquid separation tanks), a second condenser 4002, a dehydrogenation separation tower 4003, a third condenser 4004 and a second reflux tank 4005; the bottom outlet of the second-stage hydrogenation reactor is connected with a gas-liquid separation tank, the hydrogen outlet of the gas-liquid separation tank is connected with a second condenser, the liquid outlet of the gas-liquid separation tank is connected with a dehydrogenation separation tower, and the top of the dehydrogenation separation tower, a third condenser and a second reflux tank form a loop in sequence; the hydrogen outlets of the second condenser and the third condenser are respectively connected with a hydrogen compressor 4007. The second reflux tank is also connected with a light component collecting pipe 4006; the bottom outlet of the dehydrogenation separation tower is communicated with a 1, 3-propylene glycol refining device.
As shown in fig. 2, the hydration reactor includes:
shell-side cylinder, top and bottom are tube sheets 1012; tube arraying holes 1013 are distributed on the tube plate; the central region and the edge region of the tube sheet are a central circular non-tube distribution region 1014 and an edge annular non-tube distribution region 1015 (shown in fig. 5), respectively, and the areas of the central circular non-tube distribution region and the edge annular non-tube distribution region are equal.
And the plurality of tubes 1001 are axially arranged in the shell pass cylinder, and two ends of each tube are respectively communicated with tube array holes of tube plates on the top surface and the bottom surface of the shell pass cylinder. Spring supports 1019 (the inner end is in a conical shape) are respectively arranged at two ends of each row tube, inert ceramic balls 1020 are filled at the inner ends of the spring supports, and a catalyst is filled between the inert ceramic balls at the two ends (as shown in fig. 4). In addition, each row of tubes is provided with 6 inner fins 1021 arranged axially, and the fin ratio is 2.1. The inner fins are distributed at equal angles on the cross section of the tube array (as shown in figure 3). Three groups of multi-point armored thermocouples are arranged in the tube nest to measure the temperature of the catalyst bed layer, two groups of thermocouples are arranged on the shell pass along the axial height, and three thermocouples in each group are uniformly distributed along the circumferential direction of the outer diameter of the cylinder body and are used for measuring the temperature of a heat removing medium (not shown in the thermocouple figure). And the shell side intermediate partition 1017 is arranged in the shell side cylinder body and separates the shell side into two chambers. A pair of annular channels 1011 (two annular channels in each pair) is respectively arranged on the circumference of the outer side wall of each chamber, and 2 media withdrawing inlets 1004 and media withdrawing outlets 1005 (the media withdrawing inlets are positioned on one side far away from the feed inlet) are respectively arranged on the two annular channels in each pair; and an arc-shaped feeding baffle 1018 is arranged between each medium withdrawing inlet and the shell pass cylinder. 24 medium-withdrawing through holes 1016 (shown in fig. 6) with the same diameter are uniformly distributed on the circumference of the outer side wall of the shell-side cylinder corresponding to the annular channel.
Each cavity in the shell pass cylinder is respectively provided with 2 circular guide plates 1002 and 3 annular guide plates 1003 which are axially and alternately arranged in the shell pass cylinder to form a zigzag medium removing flow channel; the outer diameter of the circular guide plate is the same as the inner diameter of the edge annular non-pipe distribution area, and the inner diameter of the annular guide plate is the same as the outer diameter of the central circular non-pipe distribution area.
An upper seal head 1006 (of a spherical cap seal head type) covers the top of the shell pass cylinder, and a reactor discharge hole 1009 is arranged on the upper seal head.
And a lower end enclosure 1007 (of a spherical cap type) is covered at the bottom of the shell pass cylinder, and a reactor feed port 1008 is arranged on the lower end enclosure.
And the feeding distribution plate 1010 is arranged between the top surface or the bottom surface of the shell pass cylinder and the feeding hole of the reactor. Distribution plate through holes 1022 (shown in fig. 7) are uniformly distributed in the feed distribution plate in the areas not corresponding to the edge annular non-pipe distribution area and the central circular non-pipe distribution area.
As shown in FIG. 8, the acrolein separation column comprises a column body 100 having a top gas phase outlet 101, a side inlet 102 and a bottom liquid phase outlet 103 at the top, side and bottom thereof, respectively. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates 104 and a plurality of efficient guide tower plates 105 are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates 106 are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.
Wherein:
the efficient guide tower plate is provided with guide holes 107 (the opening rate is 5-15%), as shown in fig. 11, the edges of the guide holes are provided with guide plates 108 protruding upwards, and the opening of a hole seam formed by the guide holes and the guide plates is consistent with the flowing direction of a liquid phase on the efficient guide tower plate where the guide holes and the guide plates are located. The distribution density of the guide holes on the efficient guide tower plate close to the side wall of the tower body is greater than that of the center of the efficient guide tower plate.
As shown in FIG. 9, the guided solid jet tray comprises a tray 109 and a cap 110; as shown in fig. 12, the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole 111 and a guide hole, and the opening rate is 5-20%; each large-hole upper cover is provided with the cap cover, the side wall of each cap cover is provided with a sieve pore 112 (the pore diameter is 3-15 mm), and the top and the bottom of the side wall of each cap cover are circumferentially provided with an upper end slit 113 and a lower end slit 114 respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
As shown in FIG. 10, the guided composite three-dimensional spray tray comprises a tray, a cap and packing 115 (metal open-plate corrugated packing or metal open-wire mesh packing); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole, and the opening rate is 5-20%; each large hole upper cover is provided with the cap cover, the top of the cap cover is filled with the filler (the thickness accounts for 20-40% of the height of the cap cover), the side wall of the cap cover is provided with sieve pores (the pore diameter is 3-15 mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
In the above structure, the cross section of the guide plate is an arc shape in which the intrados faces the guide hole. The number of the efficient guide tower plates accounts for 10-40%, preferably 15-30% of the total number of the tower plates; the number of the guide three-dimensional jet tower plates accounts for 5-35%, preferably 15-30% of the total tower plates; the number of the guide composite three-dimensional jet tower plates accounts for 15-70% of the total tower plates, and preferably 30-60%.
The upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir 116 and a down-flow guide plate 117; wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.
A process for preparing a solution of a crude 1, 3-propanediol product comprising the steps of:
1) the acrolein reaction liquid enters a hydration reactor from the bottom for hydration reaction, and the hydration reaction liquid flowing out from the top enters an acrolein separation tower. Wherein, the concentration of acrolein reaction liquid is 8-20%, the reaction temperature is 30-90 ℃, the operation pressure is 0.0-0.4MPa, and the space velocity is 0.5-2h-1。
2) After the acrolein is separated by the acrolein separation tower, condensing acrolein steam at the tower top, refluxing part of the condensed acrolein steam to the acrolein separation tower, returning part of the condensed acrolein steam to the reaction liquid raw material blending system, and collecting and separating the 3-hydroxypropionaldehyde solution at the tower bottom of the acrolein separation tower to enter a first-stage hydrogenation reactor. Wherein the tower top temperature of the acrolein separation tower is 40-65 ℃, the absolute operation pressure is 5-40kPa, and the tower top reflux ratio is 1-10: 1.
3) The 3-hydroxy propionaldehyde solution and hydrogen are mixed and then enter a first-stage hydrogenation reactor from the top to carry out a first-stage hydrogenation reaction, and reaction liquid obtained after the reaction is finished enters a preheater. Wherein, the mol ratio of the 3-hydroxypropionaldehyde to the hydrogen is 10-40:1, the primary hydrogenation reaction temperature is 40-110 ℃, the operation pressure is 3-14MPa, and the space velocity is 5-20h-1。
4) The reaction liquid is preheated and then mixed with another strand of hydrogen, enters a secondary hydrogenation reactor from the top to carry out secondary hydrogenation reaction, and a mixed solution containing 1, 3-propylene glycol and hydrogen is obtained after the reaction is finished. Wherein the mol ratio of the supplemented hydrogen to the hydrogen in the step 3) is 1:5-1:1, the temperature of the secondary hydrogenation reaction is 80-140 ℃, the operating pressure is 3-14MPa, and the space velocity is 5-20h-1。
5) And the mixed solution enters a gas-liquid separation tank for gas-liquid separation, hydrogen separated from the top of the gas-liquid separation tank is condensed and then recycled, and the separated solution obtained from the bottom enters a dehydrogenation separation tower. Wherein the gas-liquid separation pressure is 0 to 13MPa, more preferably 2 to 12 MPa.
6) After separation in the dehydrogenation separation tower, gas-phase components in the solution are discharged from the top of the tower, condensed and separated to obtain light components and hydrogen, the hydrogen is recycled, and the light components are collected; the 1, 3-propylene glycol crude product solution is discharged from the bottom of the tower and sent to a 1, 3-propylene glycol refining device. Wherein the tower top temperature of the dehydrogenation separation tower is 40-100 ℃, the operation pressure is normal pressure, and the reflux ratio of the tower top is 1-10: 1.
Example 1
As shown in fig. 1, a preparation apparatus of a 1, 3-propanediol crude product solution includes a hydration reactor 1000, an acrolein separation unit, a two-stage hydrogenation unit, and a gas-liquid separation unit, which are connected in sequence.
The acrolein separation unit includes an acrolein separation column 2001, a first condenser 2002, and a first reflux tank 2003; the hydration reactor is communicated with the acrolein separation tower, and the tower top, the first condenser and the first reflux tank of the acrolein separation tower are communicated in sequence to form a loop. The first reflux tank is also connected with a reflux pipe 2004 for blending the raw materials of the reaction solution; the bottom of the acrolein separation column is provided with a steam heat exchanger 2005.
The two-stage hydrogenation unit comprises a first mixer 3001, a first-stage hydrogenation reactor 3002, a preheater 3004, a second mixer 3005 and a second-stage hydrogenation reactor 3006 which are connected in sequence; the inlet of the first mixer is respectively communicated with the tower bottom outlet of the acrolein separation tower and the primary hydrogen supply pipe 3007; the first mixer is connected with the top of the primary hydrogenation reactor, the bottom of the primary hydrogenation reactor is connected with the inlet of the preheater, and the inlet of the second mixer is respectively communicated with the outlet of the preheater and the secondary hydrogen supply pipe 3008; the second mixer is connected with the top of the secondary hydrogenation reactor. The first mixer and the second mixer are pipeline type static mixers; the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are filler type fixed bed reactors, wherein the first-stage hydrogenation reactor is provided with a water cooling jacket communicated with a cooling water supply pipe 3009.
The gas-liquid separation unit comprises a gas-liquid separation tank 4001, a second condenser 4002, a dehydrogenation separation tower 4003, a third condenser 4004 and a second reflux tank 4005; the bottom outlet of the second-stage hydrogenation reactor is connected with a gas-liquid separation tank, the hydrogen outlet of the gas-liquid separation tank is connected with a second condenser, the liquid outlet of the gas-liquid separation tank is connected with a dehydrogenation separation tower, and the top of the dehydrogenation separation tower, a third condenser and a second reflux tank form a loop in sequence; the hydrogen outlets of the second condenser and the third condenser are respectively connected with a hydrogen compressor 4007. The second reflux tank is also connected with a light component collecting pipe 4006; the bottom outlet of the dehydrogenation separation tower leads to a 1, 3-propylene glycol refining device.
As shown in fig. 2, the hydration reactor includes:
the top surface and the bottom surface of the shell side cylinder body 1 are respectively provided with a tube plate 101; the tube plate is provided with tube array holes 102; the central area and the edge area of the tube plate are respectively a central circular non-tube distribution area 103 and an edge annular non-tube distribution area 104 (as shown in fig. 5), and the areas of the central circular non-tube distribution area and the edge annular non-tube distribution area are equal.
And the tubes 2 are axially arranged in the shell side cylinder, and two ends of each tube are respectively communicated with tube array holes of the tube plates on the top surface and the bottom surface of the shell side cylinder. Spring supports 201 (the inner ends of which are in a conical shape) are respectively arranged at two ends of each column tube, inert porcelain balls 202 are filled at the inner ends of the spring supports, and catalysts are filled between the inert porcelain balls at the two ends (as shown in fig. 4). In addition, each row of tubes is provided with 6 axially arranged inner fins 203, and the fin ratio is 2.1. The inner fins are distributed at equal angles on the cross section of the tube array (as shown in figure 3). Three groups of multi-point armored thermocouples are arranged in the tube nest to measure the temperature of the catalyst bed layer, two groups of thermocouples are arranged on the shell pass along the axial height, and three thermocouples in each group are uniformly distributed along the circumferential direction of the outer diameter of the cylinder body and are used for measuring the temperature of a heat removing medium (not shown in the thermocouple figure).
And the shell side intermediate partition plate 106 is arranged in the shell side cylinder body and separates the shell side into two chambers. A pair of annular channels 12 (each pair of two annular channels) is respectively arranged on the circumference of the outer side wall of each chamber, and 2 media withdrawing inlets and media withdrawing outlets (the media withdrawing inlets are positioned on one side far away from the feed inlet) are respectively arranged on the two annular channels in each pair; and an arc-shaped feeding baffle 107 is arranged between each media withdrawing inlet and the shell pass cylinder. 24 medium withdrawing through holes 105 (as shown in fig. 6) with the same diameter are uniformly distributed on the circumference of the outer side wall of the shell-side cylinder body corresponding to the annular channel.
Each cavity in the shell pass cylinder is respectively provided with 2 circular guide plates 3 and 3 annular guide plates 4 which are axially and alternately arranged in the shell pass cylinder to form a zigzag medium removing flow channel; the outer diameter of the circular guide plate is the same as the inner diameter of the edge annular non-pipe distribution area, and the inner diameter of the annular guide plate is the same as the outer diameter of the central circular non-pipe distribution area.
And the upper end enclosure 7 (in a spherical cap end enclosure type) covers the top of the shell pass cylinder, and a reactor discharge port 10 is arranged on the upper end enclosure.
And the lower end enclosure 8 (a spherical cap end enclosure type) is covered at the bottom of the shell pass cylinder body, and a reactor feed port 9 is arranged on the lower end enclosure.
And the feeding distribution plate 11 is arranged between the top surface or the bottom surface of the shell pass cylinder and the feeding hole of the reactor. The feed distribution plate is uniformly distributed with distribution plate through holes 1101 (shown in fig. 7) in the areas of the feed distribution plate not corresponding to the edge annular non-pipe distribution area and the central circular non-pipe distribution area.
As shown in fig. 8, the acrolein separation column includes a column body 100 (column height 8000mm, column diameter 500mm), and the top, side and bottom of the column body are respectively provided with a top gas phase outlet 101, a feed inlet 102 and a bottom liquid phase outlet 103. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; 8 guide three-dimensional jet trays 104 and 2 high-efficiency guide trays 105 are arranged in the rectifying section from bottom to top; the stripping section is internally provided with 4 guide composite three-dimensional jet trays 106; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.
Wherein:
the efficient guide column plate is provided with guide holes 107 (the aperture size is 10 × 20mm rectangular open holes, the opening rate of the guide holes is 2%), as shown in fig. 11, guide plates 108 protruding upwards are arranged at the edges of the guide holes, the height of the protrusions is 3mm, and the aperture openings formed by the guide holes and the guide plates are consistent with the flow direction of the liquid phase on the efficient guide column plate where the guide holes and the guide plates are located. The distribution density of the guide holes on the efficient guide tower plate close to the side wall of the tower body is greater than that of the center of the efficient guide tower plate.
As shown in FIG. 9, the guided solid jet tray comprises a tray 109 and a cap 110; as shown in fig. 12, the central region of the tray and the position close to the tower side wall are respectively provided with large holes 111 (rectangular holes with a pore size of 60 × 180 mm) and guiding holes 1 (rectangular holes with a pore size of 10 × 20 mm), and the total opening rate is 15%; each large hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with sieve holes 112 (the aperture is 6mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit 113 and a lower end slit 114 respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
As shown in FIG. 10, the guided composite three-dimensional jet tray comprises a tray, a cap and packing 115 (metal apertured plate corrugated packing); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole, and the opening rate is 15%; each large hole upper cover is provided with the cap cover, the top of the cap cover is filled with the filler (the thickness accounts for 30% of the total height of the cap cover), the side wall of the cap cover is provided with sieve pores (the pore diameter is 6mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
The upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir 116 and a down-flow guide plate 117; wherein: the height of an overflow weir on the high-efficiency guide tower plate is 15mm, the height of an overflow weir on the guide three-dimensional jet tower plate is 15mm, and the height of an overflow weir on the guide composite three-dimensional jet tower plate is 15 mm; the radial cross section of the down-flow guide plate is an arc parallel to the side wall of the tower body, and the down-flow guide plate extends downwards in a stepped mode and has an increasing arc diameter.
Taking a device for preparing a 1, 3-propylene glycol crude product solution prepared by an acrolein hydration hydrogenation method, wherein the yield of 1, 3-propylene glycol is 3000 tons/year and 400kg/hr as an example, the concentration of an acrolein raw material solution is 15%, and the preparation device shown in fig. 1 is adopted to prepare 1, 3-propylene glycol:
1) the 30 ℃ acrolein reaction liquid enters a hydration reactor from the bottom for hydration reaction, the hydration reaction liquid flowing out from the top enters an acrolein separation tower, wherein the reaction temperature is 50 ℃, the operation pressure is 5MPa, and the space velocity is 0.7h-1。
2) After the separation of the acrolein separation tower, condensing the acrolein steam at the tower top and then refluxing the condensed acrolein steam to the acrolein separation tower or returning the condensed acrolein steam to the reaction liquid raw material blending system, and collecting and separating the 3-hydroxypropionaldehyde solution at the tower bottom of the acrolein separation tower to enter a first-stage hydrogenation reactor. Wherein the overhead temperature of the acrolein separation column is 55 ℃, the absolute operating pressure is 18kPa, and the reflux ratio of the column is 5: 1.
3) The 3-hydroxy propionaldehyde solution and hydrogen are mixed and then enter a first-stage hydrogenation reactor from the top to carry out a first-stage hydrogenation reaction, and reaction liquid obtained after the reaction is finished enters a preheater. Wherein the mol ratio of the 3-hydroxypropionaldehyde to the hydrogen is 15: 1, the primary hydrogenation reaction temperature is 90 ℃, the operation pressure is 10MPa, and the space velocity is 10h-1。
4) The reaction liquid is preheated and then mixed with another strand of hydrogen, enters a secondary hydrogenation reactor from the top to carry out secondary hydrogenation reaction, and a mixed solution containing 1, 3-propylene glycol and hydrogen is obtained after the reaction is finished. Wherein the mol ratio of the supplemented hydrogen to the hydrogen in the step 3) is 1: 3, the temperature of the secondary hydrogenation reaction is 120 ℃, the operating pressure is 9MPa, and the space velocity is 15h-1。
5) And the mixed solution enters a gas-liquid separation tank for gas-liquid separation, hydrogen separated from the top of the gas-liquid separation tank is condensed and then recycled, and the separated solution obtained from the bottom enters a dehydrogenation separation tower. Wherein the gas-liquid separation temperature is 90 ℃, and the gas-liquid separation pressure is 2 MPa.
6) After separation in the dehydrogenation separation tower, gas-phase components in the solution are discharged from the top of the tower, condensed and separated to obtain light components and hydrogen, the hydrogen is recycled, and the light components are collected; the 1, 3-propylene glycol crude product solution is discharged from the bottom of the tower and sent to a 1, 3-propylene glycol refining device. Wherein the tower top temperature of the dehydrogenation separation tower is 85 ℃, the operation pressure is normal pressure, and the reflux ratio at the tower top is 9: 1.
According to the design features of the present invention, the adapted operating conditions, the operating conditions of each separation stage and the composition and content of the separated products of each stage are selected as shown in table 1.
TABLE 1 operating conditions at various stages of the Process
Figure GDA0003594838560000161
From the results after treatment, it can be seen that through the process flow of fig. 1, a 1, 3-propanediol crude product solution with complete acrolein reaction can be obtained through hydration reaction, primary hydrogenation reaction and secondary hydrogenation reaction processes, hydrogen separation and efficient recycling are realized through the gas-liquid separation tank, then through the light component removal tower, on the basis of further enterprise separation, rectification removal of light components is realized, the conversion rate of acrolein reaches 100% in the whole reaction process, and the total reaction selectivity is 87%.
Example 2
The process flow shown in fig. 1 was adopted to prepare an acrolein raw material solution with a concentration of 15%, and the operating conditions were adjusted, with the specific parameters shown in table 2 (see example 1 for other processes).
TABLE 2 operating conditions at the various stages of the Process
Figure GDA0003594838560000162
Figure GDA0003594838560000171
The production process reduces the temperature and pressure of the hydration reaction, and the conversion rate of the acrolein is reduced; meanwhile, the temperature and pressure of the first-stage hydrogenation and the second-stage hydrogenation are reduced, so that the conversion rate of the 3-hydroxypropionaldehyde in the first-stage hydrogenation reaction is reduced, and a small amount of 3-hydroxypropionaldehyde is not completely converted after the second-stage hydrogenation reaction is finished. The reaction was complete, with an acrolein conversion of 99.8% and a total reaction selectivity of 88%.
Example 3
The process flow shown in fig. 1 was employed to prepare an acrolein raw material solution having a concentration of 15%, and the operating conditions were adjusted as shown in table 3 (see example 1 for other processes).
TABLE 3 operating conditions at various stages of the Process
Figure GDA0003594838560000172
According to the production process, the conversion rate of the 3-hydroxypropionaldehyde in the first-stage hydrogenation reaction is reduced due to the reduction of the temperature and the pressure of the first-stage hydrogenation, the selectivity of the acrolein is reduced due to the improvement of the reaction temperature in order to ensure that the 3-hydroxypropionaldehyde is completely converted after the second-stage hydrogenation reaction is finished, the reaction is completely finished, the conversion rate of the acrolein is 99.8%, and the selectivity of the total reaction is 86%.
Comparative example 1
The non-staged hydrogenation process scheme shown in FIG. 13 is illustrated.
Taking a device for preparing 1, 3-propylene glycol crude product solution by acrolein hydration hydrogenation, wherein the 1, 3-propylene glycol capacity is 3000 tons/year and 400kg/hr as an example, the concentration of acrolein raw material liquid is 15%, and the process flow of unsegmented hydrogenation shown in figure 2 is adopted.
The adapted operating conditions, the operating conditions of the various stages and the composition and content of the products of the various stages were selected as shown in table 4.
TABLE 4 operating conditions at various stages of the Process
Figure GDA0003594838560000173
It can be seen from the results after the treatment that, by the process flow of fig. 2, a crude 1, 3-propanediol product solution with relatively complete acrolein reaction can be obtained after hydration reaction and hydrogenation reaction, because the total reaction is a first-order hydrogenation reaction, even if the overall reaction temperature is relatively high, the 3-hydroxypropionaldehyde reaction is not complete, and the reaction selectivity is reduced; the efficient cyclic utilization of hydrogen is realized through the gas-liquid separation tank, and the removal of light components is realized through the light component removal tower on the basis of further hydrogen separation, the overall conversion rate of acrolein is 97.5%, and the selectivity is 82%.
As can be seen from the comparison of the data of the example 1 and the comparative example 1, the 1, 3-propanediol crude product solution prepared by the process method of the invention has higher selectivity on the basis of ensuring the complete conversion of the 3-hydroxypropionaldehyde by carrying out the process of sectional hydrogenation on the hydrogenation procedure;
the high-efficiency recycling of hydrogen can be realized by carrying out graded gas-liquid separation on the reaction liquid after the hydrogenation under the set pressure, the hydrogenation reaction liquid after the gas-liquid separation is directly connected with the process of the light component removal tower, and the hydrogen is further separated and recycled by the creative gas-liquid separation, gas-adding and rectification design in the light component removal tower, and the light component removal in the 1, 3-propylene glycol crude product solution is realized at the same time.
The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.

Claims (18)

1. A preparation facilities of 1, 3-propylene glycol crude product solution which characterized in that: comprises a hydration reactor (1000), an acrolein separation unit, a two-stage hydrogenation unit and a gas-liquid separation unit which are connected in sequence;
the acrolein separation unit includes an acrolein separation column (2001), a first condenser (2002), and a first reflux tank (2003); the hydration reactor is communicated with the acrolein separation tower, and the tower top, the first condenser and the first reflux tank of the acrolein separation tower are communicated in sequence to form a loop;
the two-stage hydrogenation unit comprises a first mixer (3001), a first-stage hydrogenation reactor (3002), a preheater (3004), a second mixer (3005) and a second-stage hydrogenation reactor (3006) which are connected in sequence; the inlet of the first mixer is respectively communicated with the tower bottom outlet of the acrolein separation tower and a primary hydrogen supply pipe (3007); the first mixer is connected with the top of the primary hydrogenation reactor, the bottom of the primary hydrogenation reactor is connected with the inlet of the preheater, and the inlet of the second mixer is respectively communicated with the outlet of the preheater and the secondary hydrogen supply pipe (3008); the second mixer is connected with the top of the secondary hydrogenation reactor;
the gas-liquid separation unit comprises a gas-liquid separation tank (4001), a second condenser (4002), a dehydrogenation separation tower (4003), a third condenser (4004) and a second reflux tank (4005); the bottom outlet of the second-stage hydrogenation reactor is connected with a gas-liquid separation tank, the hydrogen outlet of the gas-liquid separation tank is connected with a second condenser, the liquid outlet of the gas-liquid separation tank is connected with a dehydrogenation separation tower, and the top of the dehydrogenation separation tower, a third condenser and a second reflux tank form a loop in sequence; the second backflow tank is also connected with a light component collecting pipe (4006); the bottom outlet of the dehydrogenation separation tower is communicated to a 1, 3-propylene glycol refining device;
the hydration reactor comprises:
the top surface and the bottom surface of the shell pass cylinder are respectively provided with a tube plate (1012); the tube plates are provided with tube array holes (1013); the central area and the edge area of the tube plate are respectively a central circular non-cloth area (1014) and an edge annular non-cloth area (1015);
the shell side tube body is provided with a plurality of tube arrays (1001) axially arranged in the shell side tube body, catalysts are filled in the tube arrays, and two ends of the tube arrays are respectively communicated with tube array holes of tube plates on the top surface and the bottom surface of the shell side tube body; a plurality of axially arranged inner fins (1021) are arranged in each row tube, and the inner fins are distributed on the cross section of the row tube at equal angles;
the circular guide plates (1002) and the annular guide plates (1003) are axially and alternately arranged in the shell pass cylinder to form a zigzag medium removing flow channel; the outer diameter of the circular guide plate corresponds to the inner diameter of the edge annular non-distribution pipe area, and the inner diameter of the annular guide plate corresponds to the outer diameter of the central circular non-distribution pipe area;
the media removing inlet (1004) and the media removing outlet (1005) are directly or indirectly arranged on the outer side wall of the shell side cylinder;
the upper sealing head (1006) is covered on the top of the shell pass cylinder body, and a reactor feeding hole (1008) or a reactor discharging hole (1009) is formed in the upper sealing head;
the lower end enclosure (1007) is covered at the bottom of the shell pass cylinder body, and a reactor discharge port or a reactor feed port is arranged on the lower end enclosure;
and the feeding distribution plate (1010) is arranged between the top surface or the bottom surface of the shell side cylinder body and the feeding hole of the reactor.
2. The manufacturing apparatus according to claim 1, wherein a return pipe (2004) for mixing a raw material of the reaction solution is further connected to the first return tank; the bottom of the acrolein separation column is provided with a steam heat exchanger (2005).
3. The apparatus according to claim 1, wherein the first and second mixers are static mixers in the form of a pipe; the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are filler type fixed bed reactors, wherein the first-stage hydrogenation reactor is provided with a water cooling jacket communicated with a cooling water supply pipe (3009).
4. The production apparatus according to claim 1, wherein the hydrogen outlets of the second condenser and the third condenser are connected to a hydrogen compressor (4007), respectively.
5. The production apparatus according to claim 1, wherein the knock-out pot is in the form of a series of multistage knock-out pots.
6. The manufacturing apparatus of claim 1, wherein:
spring supports (1019) are respectively arranged at two ends of each row tube, inert ceramic balls (1020) are filled at the inner ends of the spring supports, and catalysts are filled between the inert ceramic balls at the two ends;
the number of the inner fins is 2-16, and the fin ratio is 1.3-4.0;
the area ratio of the edge annular non-pipe distribution area to the central circular non-pipe distribution area is 1-1.5: 1.
7. The manufacturing apparatus of claim 1, wherein: one or more pairs of annular channels (1011) are arranged on the circumference of the outer side wall of the shell pass cylinder; media withdrawing through holes (1016) are uniformly distributed on the circumference of the outer side wall of the shell pass cylinder body corresponding to the annular channel; wherein:
scheme provided with a pair of annular channels: the two annular channels are respectively arranged on the outer side wall of the shell side cylinder body close to the top surface and the bottom surface, and the media withdrawing inlet and the media withdrawing outlet are respectively arranged on one annular channel;
scheme with many pairs of annular passageways: the plurality of pairs of annular channels are sequentially arranged along the axial direction of the shell pass cylinder, and the media withdrawing inlet and the media withdrawing outlet are respectively arranged on one annular channel in each pair; and shell side intermediate clapboards (1017) are arranged at the adjacent and opposite annular passages in the shell side cylinder body for isolation.
8. The manufacturing apparatus as set forth in claim 7, wherein:
a plurality of media withdrawing inlets or media withdrawing outlets are arranged on the outer side of the annular channel along the circumferential direction, and a feeding baffle (1018) is arranged between each media withdrawing inlet and the shell side cylinder; the feeding baffle is arc-shaped or splayed;
distribution plate through holes (1022) are uniformly distributed in the areas of the feed distribution plate, which do not correspond to the edge annular non-pipe distribution area and the central circular non-pipe distribution area;
the upper end enclosure and the lower end enclosure are of a spherical cap type.
9. The manufacturing apparatus of claim 1, wherein: the acrolein separation tower comprises a tower body (100), wherein a tower top gas phase outlet (101), a feed inlet (102) and a tower bottom liquid phase outlet (103) are respectively arranged at the top, the side and the bottom of the tower body, and the tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates (104) and a plurality of efficient guide tower plates (105) are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates (106) are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered way to form a baffling channel;
guide holes (107) are distributed on the high-efficiency guide column plate, guide plates (108) protruding upwards are arranged at the edges of the guide holes, and a hole seam opening formed by the guide holes and the guide plates is consistent with the flow direction of a liquid phase on the high-efficiency guide column plate where the guide holes and the guide plates are located;
the guide three-dimensional spray tray comprises a tray (109) and a cap (110); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole (111) and a guide hole; each big hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with a sieve pore (112), and the top and the bottom of the side wall of the cap cover are respectively provided with an upper end slit (113) and a lower end slit (114) in the circumferential direction; the edge of the guide hole is provided with a guide plate protruding upwards, and a slot opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are positioned;
the guide composite three-dimensional jet tower plate comprises a tower plate, a cap and a filler (115); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the filler is filled at the top of the cap cover, sieve holes are distributed on the side wall of the cap cover, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.
10. The manufacturing apparatus of claim 9, wherein:
the section of the guide plate is in an arc shape with an inner arc surface facing the guide hole;
the distribution density of the guide holes on the efficient guide tower plate close to the side wall of the tower body is greater than that of the center of the efficient guide tower plate;
the filler is metal perforated plate corrugated filler or metal perforated wire mesh filler.
11. The manufacturing apparatus of claim 9, wherein:
the number of the efficient guide tower plates accounts for 10-40% of the total number of the tower plates;
the number of the guide three-dimensional jet tower plates accounts for 5-35% of the total tower plates;
the number of the guide composite three-dimensional jet tower plates accounts for 15-70% of the total tower plates;
the aperture ratio of the efficient guide tower plate is 5-15%;
the aperture ratio of the guide three-dimensional jet tower plate is 5-20%, and the aperture of the upper aperture of the cap cover is 3-15 mm;
the aperture ratio of the guide composite three-dimensional jet column plate is 5-20%, the aperture of the upper aperture of the cap cover is 3-15 mm, and the thickness of the filler accounts for 20-40% of the height of the cap cover.
12. The manufacturing apparatus of claim 9, wherein: the upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir (116) and a down-flow guide plate (117); wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.
13. A method for preparing a 1, 3-propanediol raw product solution by using the production apparatus according to any one of claims 1 to 12, characterized by comprising the steps of:
1) the acrolein reaction liquid enters a hydration reactor from the bottom for hydration reaction, and the hydration reaction liquid flowing out from the top enters an acrolein separation tower;
2) after the acrolein is separated by the acrolein separation tower, condensing acrolein steam at the tower top, refluxing a part of the condensed acrolein steam to the acrolein separation tower, returning a part of the condensed acrolein steam to the reaction liquid raw material blending system, and collecting and separating a 3-hydroxypropionaldehyde solution at the tower bottom of the acrolein separation tower to enter a first-stage hydrogenation reactor;
3) mixing the 3-hydroxypropionaldehyde solution with hydrogen, then feeding the mixture into a first-stage hydrogenation reactor from the top to perform first-stage hydrogenation reaction, and feeding the obtained reaction liquid into a preheater after the reaction is finished;
4) preheating the reaction liquid, mixing the preheated reaction liquid with another strand of hydrogen, entering a secondary hydrogenation reactor from the top for secondary hydrogenation reaction, and obtaining a mixed solution containing 1, 3-propylene glycol and hydrogen after the reaction is finished;
5) the mixed solution enters a gas-liquid separation tank for gas-liquid separation, hydrogen separated from the top of the gas-liquid separation tank is recycled after being condensed, and the separated solution obtained at the bottom enters a dehydrogenation separation tower;
6) after separation in the dehydrogenation separation tower, gas-phase components in the solution are discharged from the top of the tower, condensed and separated to obtain light components and hydrogen, the hydrogen is recycled, and the light components are collected; the 1, 3-propylene glycol crude product solution is discharged from the bottom of the tower and sent to a 1, 3-propylene glycol refining device.
14. The process according to claim 13, wherein in step 1), the concentration of the acrolein reaction solution is 8 to 20% by weight, the reaction temperature is 30 to 90 ℃, the operation pressure is 0.0 to 0.4MPa, and the space velocity is 0.5 to 2 hours-1。
15. The process according to claim 13, wherein in step 2), the overhead temperature of the acrolein separation column is 40 to 65 ℃, the absolute operating pressure is 5 to 40kPa, and the overhead reflux ratio is 1 to 10: 1.
16. The method of claim 13,
in the step 3), the step (c),the molar ratio of the 3-hydroxypropionaldehyde to the hydrogen is 10-40:1, the primary hydrogenation reaction temperature is 40-110 ℃, the operation pressure is 3-14MPa, and the space velocity is 5-20h-1；
In the step 4), the molar ratio of the supplemented hydrogen to the hydrogen in the step 3) is 1:5-1:1, the temperature of the secondary hydrogenation reaction is 80-140 ℃, the operating pressure is 3-14MPa, and the space velocity is 5-20h-1。
17. The method according to claim 13, wherein in the step 5), the gas-liquid separation pressure is 0 to 13 MPa.
18. The process of claim 13, wherein in step 6), the dehydrogenation-separation column has an overhead temperature of 40 to 100 ℃, an operating pressure of atmospheric pressure, and an overhead reflux ratio of 1 to 10: 1.
CN202110114490.8A 2021-01-27 2021-01-27 Preparation device and method of 1, 3-propylene glycol crude product solution Active CN112920016B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110114490.8A CN112920016B (en) 2021-01-27 2021-01-27 Preparation device and method of 1, 3-propylene glycol crude product solution

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110114490.8A CN112920016B (en) 2021-01-27 2021-01-27 Preparation device and method of 1, 3-propylene glycol crude product solution

Publications (2)

Publication Number Publication Date
CN112920016A CN112920016A (en) 2021-06-08
CN112920016B true CN112920016B (en) 2022-07-08

Family

ID=76167360

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110114490.8A Active CN112920016B (en) 2021-01-27 2021-01-27 Preparation device and method of 1, 3-propylene glycol crude product solution

Country Status (1)

Country Link
CN (1) CN112920016B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004182622A (en) * 2002-12-02 2004-07-02 Asahi Kasei Chemicals Corp Method for manufacturing 1,3-propanediol
CN1874980A (en) * 2003-10-07 2006-12-06 国际壳牌研究有限公司 Process for the production of 1,3-propanediol by catalytic hydrogenation of 3-hydroxypropanal in the presence of a hydration co-catalyst
CN101041614A (en) * 2007-04-26 2007-09-26 上海华谊丙烯酸有限公司 Method for preparing 1,3-methyl glycol by catalytic hydrogenation of 3-hydroxy propanal
CN202186949U (en) * 2011-07-06 2012-04-11 上海焦化有限公司 Two-step hydrogenization process system for preparing neopentyl glycol
CN106588567A (en) * 2016-11-08 2017-04-26 上海华谊能源化工有限公司 Preparation method of 1,3-propylene glycol through hydrogenation of 3-hydroxyl propionaldehyde
CN108358750A (en) * 2018-03-23 2018-08-03 王鹏飞 The preparation method of 1,3-PD
CN110204422A (en) * 2019-07-01 2019-09-06 宁波环洋新材料股份有限公司 A method of 1,3- propylene glycol is prepared by methacrylaldehyde

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004182622A (en) * 2002-12-02 2004-07-02 Asahi Kasei Chemicals Corp Method for manufacturing 1,3-propanediol
CN1874980A (en) * 2003-10-07 2006-12-06 国际壳牌研究有限公司 Process for the production of 1,3-propanediol by catalytic hydrogenation of 3-hydroxypropanal in the presence of a hydration co-catalyst
CN101041614A (en) * 2007-04-26 2007-09-26 上海华谊丙烯酸有限公司 Method for preparing 1,3-methyl glycol by catalytic hydrogenation of 3-hydroxy propanal
CN202186949U (en) * 2011-07-06 2012-04-11 上海焦化有限公司 Two-step hydrogenization process system for preparing neopentyl glycol
CN106588567A (en) * 2016-11-08 2017-04-26 上海华谊能源化工有限公司 Preparation method of 1,3-propylene glycol through hydrogenation of 3-hydroxyl propionaldehyde
CN108358750A (en) * 2018-03-23 2018-08-03 王鹏飞 The preparation method of 1,3-PD
CN110204422A (en) * 2019-07-01 2019-09-06 宁波环洋新材料股份有限公司 A method of 1,3- propylene glycol is prepared by methacrylaldehyde

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
丙烯醛水合加氢制1,3-丙二醇;徐泽辉等;《石油炼制与化工》;20011218;第32卷(第12期);第21-24页 *
丙烯醛水合加氢制1,3-丙二醇的研究;王玫等;《甘肃科技》;20070615;第23卷(第06期);第64-66页 *

Also Published As

Publication number Publication date
CN112920016A (en) 2021-06-08

Similar Documents

Publication Publication Date Title
US4714592A (en) Radial flow catalytic reactor including heat exchange apparatus within the bed
EP1447129A2 (en) Improved multiphase mixing device with staged gas introduction
CN111569454B (en) Built-in micro-interface oxidation system and method for preparing terephthalic acid from p-xylene
CN112920031B (en) Method for separating and recycling acrolein in process of preparing 1, 3-propylene glycol
CN100465147C (en) Fractionating tower for separating acrylic aldehyde from 3-hydroxypropionaldehyde solution
CN102516036B (en) Process method for preparing methyl tert-butyl ether by differential reaction rectification and equipment for same
CN112920016B (en) Preparation device and method of 1, 3-propylene glycol crude product solution
WO2022105300A1 (en) Enhanced micro-interface reaction system and method for preparing formic acid by carbon dioxide hydrogenation
CN112920020B (en) Refining production line and method of 1, 3-propylene glycol
CN216170039U (en) Energy-saving and carbon-reducing mixed butyraldehyde separation system
CN206886993U (en) A kind of device energy-saving for carbonate device
CN215139719U (en) Nitrogen oxide reaction tower
CN202808647U (en) Crude methanol synthetic system
CN210963995U (en) Efficient catalytic rectifying tower for esterifying ethylene glycol and acetic acid
CN116020350A (en) Reactor for synthesizing carbonic ester, system and method for synthesizing carbonic ester
CN109232516B (en) Multifunctional membrane synthesis trioxymethylene and DMM 3-8 Apparatus and method of (2)
CN112500269B (en) Device system and method for cooling CDON mixture prepared by CDOL dehydrogenation
CN214973866U (en) Reaction device for preparing 3-hydroxypropionaldehyde by acrolein hydration
CN112808178B (en) Reaction device and method for preparing 3-hydroxypropionaldehyde by acrolein hydration
CN112705114A (en) Heat exchange type multiphase reactor, application method thereof and light gasoline etherification method
CN211345270U (en) Cooling device in acrylic acid production process
CN217473543U (en) Pool-membrane reaction separation tower
CN117658771A (en) Method for preparing alcohols by continuous hydrogenation of reaction thermal coupling
CN217646378U (en) Tube-plate combined radial vinyl acetate reactor
CN210205937U (en) Rectifying tower for separating N, N-dimethyl propionamide-3-methyl ether

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
CB02 Change of applicant information

Address after: 311200 29 Chenghu Road, Yaqian Town, Xiaoshan District, Hangzhou City, Zhejiang Province

Applicant after: Zhejiang Hengyi Petrochemical Research Institute Co.,Ltd.

Applicant after: Zhejiang University

Address before: 311200 29 Chenghu Road, Yaqian Town, Xiaoshan District, Hangzhou City, Zhejiang Province

Applicant before: ZHEJIANG HENGLAN TECHNOLOGY Co.,Ltd.

Applicant before: Zhejiang University

CB02 Change of applicant information
GR01 Patent grant
GR01 Patent grant