Online monitoring of polymerization inhibitors for control of undesirable polymerization

Patent metadata

Field	Value
Publication number	US-9656930-B2
Application number	US-201614993950-A
Country	US
Kind code	B2
Filing date	Jan 12, 2016
Priority date	Feb 12, 2013
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

Disclosed herein are systems and methods for monitoring and controlling a nitroxide-based polymerization inhibitor in vinyl-based monomers. A dosage of the nitroxide-based polymerization inhibitor is provided in the vinyl-based monomers. A residual concentration of the nitroxide-based polymerization inhibitor is measured substantially in real time, and an optimized dosage of the nitroxide-based polymerization inhibitor is provided in response to the measured residual concentration.

First claim

What is claimed is:

1. A system for monitoring and controlling undesirable polymerization in vinyl-based monomers, comprising:
a fast flow sampling loop; and
a control module connected to the fast flow sampling loop, the control module being capable of controlling sample conditioning and measuring a residual concentration of a nitroxide-based polymerization inhibitor in the vinyl-based monomers substantially in real time.

2. The system of claim 1 , wherein after the fast flow sampling loop resides a continuous stirred tank reactor, and wherein the control module is capable of measuring the residual concentration of the nitroxide-based inhibitor in the continuous stirred tank reactor.

3. The system of claim 1 , further comprising a nitroxide-based polymerization inhibitor dosing pump that is connected to the control module, wherein the control module selectively activates the nitroxide-based polymerization inhibitor dosing pump so as to control the undesirable polymerization of the vinyl-based monomers during manufacture and purification thereof.

4. The system of claim 1 , further comprising a non-nitroxide-based retarder dosing pump.

5. The system of claim 1 , wherein the nitroxide-based polymerization inhibitor includes 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl.

6. The system of claim 1 , wherein the fast flow sampling loop is configured to obtain a sample slipstream and to condition the sample slipstream before flowing the conditioned sample slipstream to the control module.

7. The system of claim 6 , further comprising a check valve that facilitates moving the sample slipstream toward a predetermined direction.

Assignees

• Ecolab Usa Inc

Inventors

• Colorado Jr Ramon
• Lewis Vincent E
• Geiger Robert A
• Hancock Jessica M
• Neilson Andrew R

Classifications

• C08F2/38 Primary

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title

• C08F2438/02

  Stable Free Radical Polymerisation [SFRP]; Nitroxide Mediated Polymerisation [NMP] for, e.g. using 2,2,6,6-tetramethylpiperidine-1-oxyl [TEMPO] · CPC title

• B01J2219/00164

  controlling the flow · CPC title

• B01J2219/00254

  Formation of unwanted polymer, such as "pop-corn" · CPC title

• C07C7/20 Primary

  Use of additives, e.g. for stabilisation · CPC title