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WO1996013316A1 - Procede et appareil pour la preparation de monocristaux a macropores ouverts a partir d'une solution - Google Patents

Procede et appareil pour la preparation de monocristaux a macropores ouverts a partir d'une solution Download PDF

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Publication number
WO1996013316A1
WO1996013316A1 PCT/HU1995/000046 HU9500046W WO9613316A1 WO 1996013316 A1 WO1996013316 A1 WO 1996013316A1 HU 9500046 W HU9500046 W HU 9500046W WO 9613316 A1 WO9613316 A1 WO 9613316A1
Authority
WO
WIPO (PCT)
Prior art keywords
solution
crystal
gas
desalting agent
crystallizer
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.)
Ceased
Application number
PCT/HU1995/000046
Other languages
English (en)
Inventor
Tiborné PÉTERFI
Zsuzsanna HALÁSZ
Zoltán RÉPÁSY
László SZOTYORI
Oszkár BORLAI
Judit Filka
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.)
Magyar Tudomanyos Akademia Mueszaki Kemiai Kutato Intezet
Magyar Tudomanyos Akademia
Original Assignee
Magyar Tudomanyos Akademia Mueszaki Kemiai Kutato Intezet
Magyar Tudomanyos Akademia
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 Magyar Tudomanyos Akademia Mueszaki Kemiai Kutato Intezet, Magyar Tudomanyos Akademia filed Critical Magyar Tudomanyos Akademia Mueszaki Kemiai Kutato Intezet
Publication of WO1996013316A1 publication Critical patent/WO1996013316A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0004—Crystallisation cooling by heat exchange
    • B01D9/0013—Crystallisation cooling by heat exchange by indirect heat exchange
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/005—Selection of auxiliary, e.g. for control of crystallisation nuclei, of crystal growth, of adherence to walls; Arrangements for introduction thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0059—General arrangements of crystallisation plant, e.g. flow sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0063—Control or regulation

Definitions

  • the invention relates to a process and apparatus for the preparation of open macropore individual crystals from solution by using a desalting agent in gas state.
  • the Hungarian patent application No. P 92 01070 discloses a process and apparatus for the preparation of open macropore individual crystals from solution by using a desalting agent in gas state. According to this specification the process is carried out by absorbing a homogeneously distributed desalting agent in gas state in the solution containing the crystals, which solution may contain also a surface-active agent. While continuously renewing the contact surfaces a crystallization occurs after reaching the limit of oversaturation.
  • the apparatus for implementation of the process comprises: a double-walled solution container provided with solution inlet; one or more series- and/or parallel-connected crystallizers(s) joining to the said solution container, fitted with gas inlet and supplementary gas inlet, outlets for gas, mother liquor and crystals as well as heat- exchanger; a recycling pipe leading therefrom to the solution container; a saturator joining to the gas inlet, having an inlet for the desalting liquid; optionally a container for the desalting liquid; and a gas heater.
  • An embodiment of the apparatus comprises a pipe connecting the gas inlet of the crystallizer with the gas saturator.
  • a disadvantage of the known process referred to is that in addition to the open macropore individual crystals, poreless or mostly closed pore or less porous crystals with an unusual small size are formed in an amount of 20-30 %, wherein the volume proportion of the void part manifested by the pores is less than 1 20, furthermore loss of the desalting agent leaving with the solution as well as that of the substance forming the crystals occur The loss of desalting agent is high and makes the process expensive and uneconomic In addition, the discarded solution causes a considerable environmental pollution
  • the object of the invention is to develop a process and apparatus for the preparation of open macropore individual crystals from a solution by using a desalting agent, in gas state by eliminating or considerably reducing the disadvantages mentioned above
  • the invention is based on the recognition that, if the desalting agent to be absorbed in the solution of the crystal-forming substance is transformed into gas-form from a solution containing at least 1 % by weight of crystal-forming substance, no poreless or significantly less poreless or mostly closed pore or less porous crystals containing a void volume proportion of lower than 1 2 are obtained vis understand the known process, wherein the desalting agent is transformed into gas-form from a pure desalting agent or a solution thereof, which is free from the crystal-forming substance.
  • An other recognition of this invention is that is more easy to strip out the desalting agent from a solution containing the crystal-forming substance than from a solution free from these crystals.
  • the solution leaving the crystallizer containing the desalting agent and more than at least 1 % by weight, preferably more than 5 % by weight of crystal-forming substance is re-cycled for preparing the desalting agent in gas state, practically without employing fresh desalting agent; whereas the remaining solution, which contains crystal-forming substance and is practically free from desalting agent, is recycled for dissolution of the crystal-forming substance.
  • a closed liquid circuit can be developped, the loss of desalting agent is reduced to a negligible amount, that of crystal-forming substance practically to zero.
  • the environmental pollution can be eliminated and both the yield and quality of the open macropore crystals are unexpectedly improved.
  • the essence of the invention is that the desalting agent is transformed into gas-form from a solution containing more than at least 1 % by weight, preferably more than 5 % by weight of crystal-forming substance; furthermore, the solution separated from the crystals formed, containing crystal-forming substance and desalting agent is recycled to transform the desalting agent into gas- form and the solution leaving therefrom is recycled to dissolve the crystal-forming substances.
  • the desalting agent is transformed into gas-form by vaporization and/or evaporation by using a earner gas
  • a closed gas circuit is used namely, the gas leaving during crystallization is not emitted but, in form of a carrier gas, is led through the solution of the desalting agent
  • the gas leaving du ⁇ ng crystallization is led as a earner gas through the solution of the desalting agent
  • the interface between the desalting agent in gas form and the solution of the crystal-forming substance should be renewed by constant stirnng, which may be performed by bubbling the gas mixture of the desalting agent and earner gas through the solution of crystal-forming substance and by continuous regeneration of the interface by means of gas bubbles
  • the solution of crystal-forming substance is stined and the interface between the desalting agent in gas form and the solution is continuously renewed by utilizing the bubbles of the introduced gas mixture of the desalting agent and earner gas
  • the apparatus shown on Figure 1 which can be operated continuously or periodically consists of a single- or double-walled solution container 1 provided with a stiner, heat-exchanger a temperature-sensing unit and a -regulating device, a concentration- measuring and -regulating device which are not illustrated on the drawing.
  • the solution container 1 is connected with one or more series- and/or parallel-connected crystallizer(s) 3 by means of one or more solution-outlet pipe 21, which is (are) equipped with a pump 7 and/or a mechanically or automatically operated liquid closing unit 17.
  • the solution container 1 is provided with a stirrer, a solution inlet 29 and/or a feeder for the crystal-forming solid substance and liquid.
  • the single- or double-walled crystallizer 3 have a heat- exchanger and an organ controlling and regulating the oversaturation.
  • a connecting pipe 37 which may be regulated by closing unit 13, leads from crystallizer 3 to crystal separator 4 optionally including a crystal-outlet 28 equipped with a closing unit.
  • the crystal separator 4 is connected through the mother liquor outlet pipe 22 to a device 5 adjusting concentration of the desalting agent.
  • the adjusting device 5 is provided with a feeder 19 for the desalting agent, with a pipe 27 recycling the crystal-forming solid substance into the solution container 1; and with a device measuring and regulating the concentration of the desalting agent.
  • the crystal separator 4 or optionally the device 5 adjusting the concentration of the desalting agent is connected through the pipe 23 provided with a pump 6 and closing unit 14 with a single- or double- walled evaporator 2 of the desalting agent.
  • This evaporator 2 is equipped with heat-exchanger, a device for measuring and regulating the liquid level as well as a device for measuring and regulating the temperature.
  • the evaporator 2 is connected with the solution container 1 through pipe 24 recycling the solution, which pipe has a closing unit 12.
  • the evaporator 2 is further connected with crystallizer 3 through gas outlet 25 wherefrom gas pipe 26, equipped with splash head 9 and 11, liquid seal 10, pump 8 and gas inlet 10, recycling to the evaporator 2 of the desalting agent
  • gas pipe 26 equipped with splash head 9 and 11, liquid seal 10, pump 8 and gas inlet 10, recycling to the evaporator 2 of the desalting agent
  • the liquid pipe 20 leads from the splash heads 9 and 10 to the feeder 19 of the desalting agent
  • An embodiment of the apparatus according to the invention compnses in crystallizer 3 an organ controlling and regulating the oversaturation, said organ switching on in an adjusted sequence and intervals at an adjustable value of oversaturation and switching off at an other adjustable value thereof the individual operation of the solution inlet 29 and/or feeder of the solid, crystal-forming substance and liquid and/or the individual operation of stock pumps and/or the individual operation of gas inlet and/or closing units and/or the individual operation of devices for measuring and regulating the concentration and temperature, and/or organs regulating heat- exchangers
  • a preferred embodiment of the apparatus of invention consists of controlling a regulating organ for oversaturation, adjusted according to the difference between two time points of oversaturation, regulating the individual operation of solution inlet 29 and/or feeder of the solid, crystal-forming substance and liquid, individual operation of stock and/or gas inlet and/or individual operation of closing units and/or the individual operation of devices measunng and regulating the temperature and concentration of the crystallizer solution and/or individual operation of the heat- exchangers
  • Another embodiment of the apparatus according to the invention is provided with an organ controlling and regulating the oversaturation on the basis of measurement of density and/or refractive index or measurement of the differences between densities and/or refractive indices.
  • Another embodiment of the apparatus according to the invention includes a controlling organ regulating the oversaturation on the basis of optical measurement.
  • a still further possible embodiment of the apparatus according to the invention contains both a crystallizer 3 and/or an evaporator 2 for the desalting agent with a foam-layer.
  • Another embodiment of the apparatus according to the invention includes in crystallizer 3 and/or evaporator 2 of the desalting agent one or more cylindrical insert(s) and/or statical stirring element(s) with a diameter smaller than the half thereof for regulation of stirring.
  • the apparatus is operated in the following manner:
  • the solution of crystal-forming substance or the solid crystal- forming substance and solvent are introduced through solution inlet 29 or through the feeder of crystal-forming solid substance and liquid to the container 1.
  • the temperature of solution is adjusted by using a device measuring and regulating the temperature, as well as a heat-exchanger.
  • the concentration of the solution is adjusted by using a device measuring and regulating the concentration.
  • the dissolution of an occasional solid substance and the homogenity of the solution is promoted by stirring.
  • the solution prepared is introduced through p ⁇ e(s) 21 by pump 7 into one or more crystalhzer(s) 3
  • at least two senes-connected crystallizers 3 are used
  • the solution of the crystal-forming substance is constantly stirred in a bubble- or foam- layer by the mixture of desalting gas and earner gas, whilst the desalting agent is absorbed and the crystals are separated
  • the solution containing the crystals is led to the crystal separator 4 through the conncecting pipe 37, which is regulated by a closing unit 13
  • the size and porosity of the separated crystals are influenced by a device measunng and regulating the oversaturation, if desired, the temperature is also regulated by a heat- exchanger
  • the crystal separator 4 which may be a pe ⁇ odically or continuously operating pressure filter or a sedimentator, the crystals are separated from the solution containing the desalting agent and the crystal-forming substance being in equihbnum therewith The crystals are separated through
  • the desalting agent solution is mixed with this gas in a foam- or bubble-layer in the evaporator 2 of desalting agent.
  • the level and temperature of the evaporator are adjusted by using a heat-exchanger, by means of the device 33 measuring and regulatingt the liquid level as well as device 32 measuring and regulating the temperature. From evaporator 2 of the desalting agent the solution which became poor in desalting agent is recycled to the solution container 1 through the recycling pipe 24 equipped with closing unit 12; and a new solution of the crystal- forming substance is prepared by utilizing is.
  • the solution of crystal-forming substance and the desalting agent dissolved therein circulate in a closed circuit in the apparatus and the possible losses should only be supplemented in a known manner through the solution inlet 29 or feeder for crystal-forming solid substance and liquid or through feeder 19 of the desalting agent.

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

Abstract

Procédé et appareil pour la préparation de cristaux à macropores ouverts à partir d'une solution, à l'aide d'un agent de dessalement sous forme gazeuse, la transformation de l'agent de dessalement en gaz étant effectuée à partir d'une solution renfermant au moins 1 % en poids, et de préférence plus de 5 % en poids, d'une substance de formation de cristaux. On recycle les solutions renfermant la substance de formation de cristaux et l'agent de dessalement afin de transformer l'agent de dessalement en gaz, tandis qu'on recycle la liqueur-mère en sortie dans la solution de la substance de formation de cristaux. L'appareil pour la mise en oeuvre du procédé comporte un réservoir (1), un évaporateur (2) pour l'agent de dessalement, un cristalliseur (3), un séparateur de cristaux (4) et éventuellement un dispositif de régulation de la concentration de l'agent de dessalement. La solution renfermant la substance de formation de cristaux s'écoule en circuit fermé du réservoir (1) au cristalliseur (3), et de là au séparateur de cristaux (4) et éventuellement au dispositif (5) de régulation de la teneur en agent de dessalement. Ensuite, elle s'achemine jusqu'à l'évaporateur (2) depuis le dispositif de régulation (5) ou directement depuis le séparateur de cristaux (4), avant d'être recyclée dans le réservoir (1) pour la solution. Le mélange de l'agent de dessalement sous forme gazeuse et du gaz vecteur s'écoule en circuit fermé de l'évaporateur (2) au cristalliseur (3), avant de retourner dans ledit évaporateur (2).
PCT/HU1995/000046 1994-10-28 1995-09-27 Procede et appareil pour la preparation de monocristaux a macropores ouverts a partir d'une solution Ceased WO1996013316A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
HU9403106A HU9403106D0 (en) 1994-10-28 1994-10-28 Process and apparatus for producing opened makroporouos unique crystals from solution
HUP9403106 1994-10-28

Publications (1)

Publication Number Publication Date
WO1996013316A1 true WO1996013316A1 (fr) 1996-05-09

Family

ID=10985712

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/HU1995/000046 Ceased WO1996013316A1 (fr) 1994-10-28 1995-09-27 Procede et appareil pour la preparation de monocristaux a macropores ouverts a partir d'une solution

Country Status (2)

Country Link
HU (1) HU9403106D0 (fr)
WO (1) WO1996013316A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4453959A (en) * 1982-02-25 1984-06-12 Bishkin D Bruce Crystal washing and purification method
EP0180796A2 (fr) * 1984-11-05 1986-05-14 Hugo Petersen Ges. für verfahrenstechn. Anlagenbau mbH & Co KG Procédé de cristallisation par refroidissement

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4453959A (en) * 1982-02-25 1984-06-12 Bishkin D Bruce Crystal washing and purification method
EP0180796A2 (fr) * 1984-11-05 1986-05-14 Hugo Petersen Ges. für verfahrenstechn. Anlagenbau mbH & Co KG Procédé de cristallisation par refroidissement

Also Published As

Publication number Publication date
HU9403106D0 (en) 1995-01-30

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