Method for producing solid urea by granulation

Inactive Publication Date: 2018-07-05
CASALE SA
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0018]The superior quality of the product arises from the improved granule structure. The invention allows obtain a more uniform granule structure owing to the elimination of the water evaporation generating porosity in the internal layers of the granule.
[0019]The elimination of the formaldehyde gives rise to dual benefit because it eliminates a costly item and a source of concern in terms of ecological and environmental impact.
[0020]The invention provides a technique for obtaining solid urea in granule form which is free from formaldehyde. The invention therefore enables urea producers to provide a product which has a mechanical strength equivalent to or superior to the granules which are nowadays available, but has the advantage of containing no formaldehyde and of being regarded as an environmentally friendly product. Formaldehyde-free urea is thus available at lower costs compared to the known processes for the production of technical urea.
[0021]An aspect of the invention is also a method for revamping existing plants with a prilling section. These plants already have an evaporation section designed to reach a high concentration

Problems solved by technology

3-4%), worsens the qu

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for producing solid urea by granulation
  • Method for producing solid urea by granulation

Examples

Experimental program
Comparison scheme
Effect test

Example

[0028]FIG. 1 shows a schematic urea plant comprising a synthesis section US and a recycling section UR. The recycling section UR provides an aqueous solution of urea SOL containing about 70% by weight of urea.

[0029]Said solution passes through evaporation section EV inside which the water is removed, obtaining a urea melt UM containing more than 98%, for example 99.7%, by weight of urea. Said urea melt UM, without the addition of formaldehyde, is fed to a granulation section GS, obtaining granules of urea U.

[0030]FIG. 2 shows an example of revamping of a plant in which the urea melt UM is originally fed to a prilling section PS which produces urea prills P. At least a part UM′ of said urea melt UM is fed to a granulation section GS which is arranged parallel to the prilling section PS, also in this case without the addition of formaldehyde.

[0031]In some embodiments, the UM stream is directed entirely towards the new granulation section GS, i.e. the production of prills P is disconti...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Percent by massaaaaaaaaaa
Percent by massaaaaaaaaaa
Percent by massaaaaaaaaaa
Login to view more

Abstract

Method for producing solid urea by granulation, wherein the granulation is fed with liquid urea having a purity greater than 98% by weight and not containing formaldehyde.

Description

FIELD OF APPLICATION[0001]The invention relates to the field of the production of solid urea.PRIOR ART[0002]Solid urea is produced mainly by prilling or granulation.[0003]Prilling involves cooling droplets of liquid urea falling inside a tower by means of counter-flowing air. The solids thus formed are termed prills. Granulation involves spraying liquid urea onto granules inside a proper granulator, for example in a fluid bed; the liquid forms a layer which solidifies, thus increasing the size of the granule. Both techniques are known to persons skilled in the art and are described in the literature, for example in Meessen, “Urea”, Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag, 2010.[0004]Granulation offers a series of recognized advantages and is considered to be superior to prilling. It is well-known that the prills have a certain fragility essentially due to the rapid cooling of the droplets which creates a porous structure. The solid product obtained by granul...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B01J2/16C05C9/00
CPCB01J2/16C05C9/005B01J2/00C05C9/00C07C273/14C07C273/16
Inventor BEDETTI, GIANFRANCO
Owner CASALE SA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap