Sonication in a urea or melamine synthesis process

Patent metadata

Field	Value
Publication number	US-10507451-B2
Application number	US-201615563460-A
Country	US
Kind code	B2
Filing date	Mar 11, 2016
Priority date	Mar 30, 2015
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

Process and respective reactor for urea or melamine synthesis, comprising sonication treatment of at least part of a reaction liquid mass or two-phase mixture contained inside said reactor.

First claim

The invention claimed is:

1. A process for the synthesis of melamine from urea, inside a chemical reactor, said process comprising a sonication treatment of at least part of a reaction liquid mass or two-phase mixture contained inside said chemical reactor,
wherein the sonication treatment is performed in a sonication zone inside said chemical reactor,
wherein the process further comprises the circulation of a liquid phase or liquid/vapour phase through at least one reaction zone and a recirculation zone, which are arranged coaxial and concentric inside said reactor, wherein the sonication treatment is performed in at least one of said two reaction and recirculation zones, and
wherein the reaction zone is a primary reaction zone fed with urea melt.

2. The process according to claim 1 , wherein said sound waves have a frequency in the range 1 kHz to 1 MHz.

3. The process according to claim 2 , wherein said sound waves have a frequency equal to or greater than 20 kHz.

4. The process according to claim 1 , said sound waves being generated by one or more electrical or mechanical sources.

5. The process according to claim 3 , wherein said sound waves have a frequency of 20 to 40 kHz.

6. A method, comprising:
using a sonication treatment inside a reactor for melamine synthesis, wherein said sonication treatment provides transmission of sound waves to at least part of a liquid mass or two-phase mixture contained inside said reactor,
wherein the sonication treatment is performed in a sonication zone inside said reactor,
wherein the method further comprises circulating a liquid phase or liquid/vapour phase through at least one reaction zone and a recirculation zone, which are arranged coaxial and concentric inside said reactor, wherein the sonication treatment is performed in at least one of said two reaction and recirculation zones, and
wherein the reaction zone is a primary reaction zone fed with urea melt.

Assignees

• Casale Sa

Inventors

• Rizzi Enrico

Classifications

• C07C273/12

  combined with the synthesis of melamine · CPC title

• C07C273/04 Primary

  from carbon dioxide and ammonia · CPC title

• B01J19/246

  internally, i.e. the mixture circulating inside the vessel such that the upward stream is separated physically from the downward stream(s) · CPC title

• B01J19/10 Primary

  employing sonic or ultrasonic vibrations · CPC title

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title