Amine Additives Inhibit DVB Cross-Linking in Styrene Distillation

Solution Overview

Problem

Conventional styrene production methods face challenges with insoluble polystyrene polymer fouling due to divinyl benzene cross-linking, leading to flow restrictions and reduced distillation column performance, despite the use of polymerization inhibitors which are often toxic and costly.

Innovation Solution

Introducing an additive with functional groups such as amines, alcohols, and ketones having a boiling point near that of divinyl benzene, which inhibits its cross-linking and remains effective throughout the styrene purification process, reducing insoluble polymer formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polymerization inhibitors (such as dinitrophenols or tetramethylpiperidene-1-oxyl species) are used to control styrene polymerization, then polymerization control is improved, but toxicity and cost increase

Engineering Contradiction:

Improvepolymerization controlVSAvoidtoxicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a mixed amine system comprising a primary aromatic amine and a secondary aliphatic amine that are consumed during the process to inhibit DVB crosslinking. These amines act as sacrificial inhibitors that react with DVB to form soluble adducts, replacing toxic conventional inhibitors with cheaper, less hazardous alternatives that can be readily disposed of or regenerated

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical parameters by using amines with specific boiling points (higher than styrene but lower than DVB) to achieve selective interaction with DVB. The amine selection is based on boiling point, molecular weight, and chemical reactivity parameters to optimize inhibition efficiency while maintaining processability and reducing toxicity

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional polymerization inhibitors are used to control styrene polymerization, then polymerization control is improved, but cost increases

Engineering Contradiction:

Improvepolymerization controlVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a mixed amine system comprising a primary aromatic amine and a secondary aliphatic amine that are consumed during the process to inhibit DVB crosslinking. These amines act as sacrificial inhibitors that react with DVB to form soluble adducts, replacing toxic conventional inhibitors with cheaper, less hazardous alternatives that can be readily disposed of or regenerated

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The amine system provides self-regulating inhibition where the amines automatically react with DVB as it forms, creating a self-correcting mechanism that maintains polymerization control without requiring precise dosing or complex control systems, thereby reducing operational costs

Inventive Principle:

Principle #25Self-service

3Reliability

If distillation is carried out at lower pressure and temperature with polymerization inhibitors to prevent thermal self-initiation, then polymerization control is improved, but process complexity and cost increase

Engineering Contradiction:

Improvepolymerization controlVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts DVB from the polymerization system through selective chemical reaction with amines. The amines preferentially react with DVB to form soluble adducts, effectively removing the crosslinking agent from the system and preventing insoluble polymer formation, thereby simplifying the distillation process

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The amine acts as an intermediary substance that mediates between DVB and the polymerization system. The amine reacts with DVB to form soluble intermediates that prevent crosslinking, allowing the process to proceed without complex inhibitor systems or extreme operating conditions

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If high dosages of anti-polymerization inhibitors are used, then polymerization control is improved, but formation of insoluble polymer is not eliminated and fouling persists

Engineering Contradiction:

Improvepolymerization controlVSAvoidinsoluble polymer formation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts DVB from the polymerization system through selective chemical reaction with amines. The amines preferentially react with DVB to form soluble adducts, effectively removing the crosslinking agent from the system and preventing insoluble polymer formation, thereby simplifying the distillation process

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a composite amine system combining a primary aromatic amine and a secondary aliphatic amine. This composite approach provides synergistic inhibition where the two amines work together to more effectively prevent DVB crosslinking than either amine alone, completely eliminating insoluble polymer formation

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The additive effectively reduces insoluble polymer formation and fouling in styrene production, enhancing process efficiency and extending plant run lengths while avoiding the toxicity and cost issues associated with conventional inhibitors.

Implementation Method 1

at least one chemical compound comprising one or more functional groups selected from amines, alcohols, amino-alcohols, labile C—C, esters, carbamates, aldehydes, ketones, acids, acetates, benzoates, labile hydrogen, and combinations thereof, and having a boiling point greater than or equal to 170° C. and within 10, 20, 30, 40, 50, or 60° C. of the boiling point of divinyl benzene (DVB)

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

Purification by distillation encounters challenges due to the thermal self-initiation of polymerization by styrene that can occur at a significant rate above 80° C. Styrene boils at 145° C., so distillation is generally carried out at lower pressure and temperature

Methodology Applied

Scientific EffectDistillation: Distillation

Data Source

PatentUS11661496B2Additives to remediate DVB cross-linking and insoluble polymer formation in the styrene process

Publication Date: 2023.05.30 FINA TECH INC

AI summary

A method of reducing the fouling in a process for the production of styrene, the method comprising: introducing an additive into a stream comprising styrene and byproduct divinyl benzene (DVB), wherein the additive comprises: at least one chemical compound comprising one or more functional groups selected from amines, alcohols, amino-alcohols, labile C—C, esters, carbamates, aldehydes, ketones, acids, acetates, benzoates, labile hydrogen, and combinations thereof, and having a boiling point greater than or equal to 170° C. and within 10, 20, 30, 40, 50, or 60° C. of the boiling point of divinyl benzene (DVB) (which is 195° C.), wherein the at least one chemical compound is active to inhibit divinyl benzene (DVB) crosslinking. A system for carrying out the method is also provided.