DE837095C - Process for the production of urea - Google Patents

Process for the production of urea

Info

Publication number
DE837095C
DE837095C DEB1959A DEB0001959A DE837095C DE 837095 C DE837095 C DE 837095C DE B1959 A DEB1959 A DE B1959A DE B0001959 A DEB0001959 A DE B0001959A DE 837095 C DE837095 C DE 837095C
Authority
DE
Germany
Prior art keywords
urea
crystallization
production
acetylenediurea
melt
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.)
Expired
Application number
DEB1959A
Other languages
German (de)
Other versions
DE1610169U (en
Inventor
Dr Wilhelm Geisel
Dr Walter Michelitsch
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.)
BASF SE
Original Assignee
BASF SE
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 BASF SE filed Critical BASF SE
Priority to DEB1959A priority Critical patent/DE837095C/en
Application granted granted Critical
Publication of DE837095C publication Critical patent/DE837095C/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
    • C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
    • C07C273/14—Separation; Purification; Stabilisation; Use of additives
    • C07C273/16—Separation; Purification

Landscapes

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

Description

Verfahren zur Herstellung von Harnstoff Gegenstand des Patents 832 745 ist ein Verfahren zur Gewinnung von Harnstoff in groben Kristallen aus wässerigen Lösungen, wobei man die Kristallisation in Gegenwart geringer Mengen von Glyoxal-Harnstoff-Kondensationsprodukten, insbesondere von Acetylendiharnstoff, vornimmt. Läßt man den Harnstoff aus Lösungen mit solchen Zusatzstoffen langsam auskristallisieren, so scheidet sich der Harnstoff in Form derber, breiter Kristalle aus.Process for the production of urea the subject of patent 832 745 is a process for obtaining urea in coarse crystals from aqueous Solutions, whereby the crystallization in the presence of small amounts of glyoxal-urea condensation products, especially of acetylenediurea. Leaving the urea out of solutions slowly crystallize out with such additives, so the urea separates in the form of coarse, broad crystals.

Es wurde nun gefunden, daß ein Zusatz der genannten Stoffe auch dann erhebliche Vorteile bietet, wenn man die Kristallisation in an siA bekannter Weise nach weitgehender Verdampfung des Lösungswassers durch Erstarrenlassen, vorzugsweise Verspritzen, der Harnstoffschmelze vornimmt. Der in dieser Weise durch Versprühen der Schmelze mit Luft erhaltene Harnstoff besteht zu einem großen Teil aus kleinen Kugeln mit glatter Oberfläche und im übrigen aus Teilchen von weniger ausgeprägter Form. Ein in der gleichen Weise, aber ohne die genannten Zusatzstoffe hergestellter Harnstoff weist einen wesentlich geringeren Gehalt an kugelförmigen Teilchen auf und backt leichter zusammen, so daß er vor dem Gebrauch häufig zunächst zerkleinert werden muB. Der nach dem vorliegenden Verfahren gewonnene Harnstoff lagert sich viel lockerer und läßt sich, falls sich beim Lagern Brocken gebildet haben sollten, leicht durch Druck mit der Hand oder Schaufelschlag zerkleinern.It has now been found that the substances mentioned can also be added There are considerable advantages if the crystallization is carried out in a manner known at SiA after extensive evaporation of the water of solution by allowing it to solidify, preferably Splash, which makes urea melt. Made in this way by spraying The urea obtained from the melt with air consists to a large extent of small Spheres with a smooth surface and otherwise made up of less pronounced particles Shape. One made in the same way, but without the additives mentioned Urea has a much lower content of spherical particles and cakes more easily, so it is often chopped up first before use must be. The urea obtained by the present process settles much more loosely and can be opened if lumps are formed during storage should have, lightly crushed by hand pressure or a shovel strike.

Beispiel Eine Harnstoffschmelze, .die wenige Prozent Wasser enthält, wird mit geringen Mengen Acetylendiharnstoff versetzt, so daß auf 99,8 Teile Harnstoff 0,2 Teile Acetylendiharnstoff kommen. Die Schmelze wird mittels eines Luftstromes unter Anwendung von 15000 ms Luft auf 5 m3 Harnstoff in der Stunde versprüht. Der so erhaltene Harnstoff besteht zu etwa 850o aus kugeligen Teilchen und weist eine ausgezeichnete Lagerfähigkeit auf. Nach 16 Wochen beträgt der Zertrümmerungsdruck der gelagerten Masse o,7 at, der Zertrümmerungsdruck eines in der gleichen Weise, jedoch ohne Zusatz von Acetylendiharnstoff hergestellten Harnstoff 2,6 at und der Zertrümmerungsdruck eifies durch Kristallisation aus seiner wässerigen Lösung, ebenfalls ohne Zusatzstoff, hergestellten Harnstoffs. 1,7 at.EXAMPLE Small amounts of acetylenediurea are added to a urea melt which contains a few percent water, so that there are 0.2 parts of acetylenediurea for every 99.8 parts of urea. The melt is sprayed by means of an air stream using 15000 ms of air to 5 m3 of urea per hour. The urea obtained in this way consists of about 850 ° of spherical particles and has an excellent shelf life. After 16 weeks, the crushing pressure of the stored mass is 0.7 atm, the crushing pressure of a urea produced in the same way, but without the addition of acetylenediurea, is 2.6 atm and the crushing pressure eifies through crystallization from its aqueous solution, also without an additive, of urea . 1.7 at.

Claims (1)

PATEN T A l I S P R l# C. 11: Weitere Ausbildung des Verfahrens gemäß Patent 832 745 zur Gewinnung von Harnstoff aus seinen wässerigen Lösungen durch Kristallisation in Gegenwart geringer Mengen von Glyoxal-Harnstoff-Kondensationsprodukten, dadurch gekennzeichnet, daß man die Kristallisation nach weitgehender Verdampfung des Lösungswassers durch Erstarrelilassen, vorzugsweise Verspritzen, der Harnstoffschmelze vornimmt. PATEN TA l ISPR l # C. 11: Further development of the process according to patent 832 745 for the recovery of urea from its aqueous solutions by crystallization in the presence of small amounts of glyoxal-urea condensation products, characterized in that the crystallization is carried out after extensive evaporation of the Dissolving water by allowing it to solidify, preferably spraying, which melts the urea.
DEB1959A 1950-02-08 1950-02-08 Process for the production of urea Expired DE837095C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEB1959A DE837095C (en) 1950-02-08 1950-02-08 Process for the production of urea

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEB1959A DE837095C (en) 1950-02-08 1950-02-08 Process for the production of urea

Publications (1)

Publication Number Publication Date
DE837095C true DE837095C (en) 1952-04-21

Family

ID=6952507

Family Applications (1)

Application Number Title Priority Date Filing Date
DEB1959A Expired DE837095C (en) 1950-02-08 1950-02-08 Process for the production of urea

Country Status (1)

Country Link
DE (1) DE837095C (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1013644B (en) * 1955-01-14 1957-08-14 Stamicarbon Process for the production of coarse-grained urea
DE1156783B (en) * 1958-12-17 1963-11-07 Ici Ltd Process for the production of fine-grained, non-caking and free-flowing urea
US4216290A (en) * 1974-05-22 1980-08-05 Agfa-Gevaert N.V. Coating of viscous aqueous gelatin compositions on a continuous web support
DE3702133A1 (en) * 1987-01-24 1988-08-04 Meteor Siegen Apparat Schmeck Photosensitive film

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1013644B (en) * 1955-01-14 1957-08-14 Stamicarbon Process for the production of coarse-grained urea
DE1156783B (en) * 1958-12-17 1963-11-07 Ici Ltd Process for the production of fine-grained, non-caking and free-flowing urea
US4216290A (en) * 1974-05-22 1980-08-05 Agfa-Gevaert N.V. Coating of viscous aqueous gelatin compositions on a continuous web support
DE3702133A1 (en) * 1987-01-24 1988-08-04 Meteor Siegen Apparat Schmeck Photosensitive film

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