Insoluble Sulfur Stabilization via Methane Gas-Phase End Capping

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Solution Overview

Problem

Existing stabilizers for insoluble sulfur, particularly pre-stabilizers, are insufficient in ensuring uniform contact and reaction with sulfur, leading to slow reaction speeds and quality issues such as black spots in the final product due to their addition after quenching and potential carbonization at high temperatures.

Innovation Solution

Methane is used as an anti-reversion stabilizer added before quenching, where it is cracked into active free radicals during sulfur gasification, allowing for uniform mixing and end capping of sulfur vapor polymerization end groups, improving thermal stability and reducing reversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If pre-stabilizers are added before quenching to participate in sulfur free radicals polymerization, then the thermal stability should be improved, but the reaction speed is slow and uniform contact is insufficient

Engineering Contradiction:
Improvethermal stabilityVSAvoidreaction speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent changes the physical state parameter of the stabilizer from solid/liquid to gas phase. By using gaseous stabilizer that can be uniformly mixed with sulfur vapor before quenching, the reaction speed increases dramatically while maintaining thermal stability through end-capping of polymer chains.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies pneumatic principles by introducing gaseous stabilizer into the sulfur vapor phase. The gas-phase stabilizer flows with the sulfur vapor through the quenching zone, ensuring uniform distribution and contact throughout the polymerization process, thereby achieving both fast reaction speed and consistent thermal stability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Reliability

If stabilizer is added after quenching in the drying or oil filling process, then the contact and reaction between stabilizer and insoluble sulfur is improved, but the production efficiency decreases and environmental pollution increases

Engineering Contradiction:
Improvecontact and reaction effectivenessVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs the stabilizer addition action before quenching, when sulfur is in vapor phase. The gaseous stabilizer is introduced and mixed with sulfur vapor prior to the quenching step, allowing end-capping to occur during the rapid cooling process. This preliminary action eliminates subsequent stabilization steps, improving production efficiency while maintaining effective contact through gas-phase mixing.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If carbonium ion structure stabilizer is used in quenching liquid, then the thermal stability is improved, but black spots are formed in the product due to carbonization

Engineering Contradiction:
Improvethermal stabilityVSAvoidblack spots formation
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces complex carbonium ion structure stabilizers with simple hydrocarbon gas molecules. These short-chain hydrocarbon gases serve as effective end-capping agents without undergoing carbonization, thereby providing thermal stability without generating black spots in the final product.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent extracts the essential functional component from complex carbonium ion stabilizers - the ability to provide end-capping - and implements it through simple hydrocarbon gases. By removing the problematic carbonium ion structure while retaining the end-capping function, the patent achieves thermal stability without the harmful carbonization side effect.

Inventive Principle:
Principle #2Taking out (Extraction)

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 use of methane as a pre-stabilizer enhances the anti-reversion property and thermal stability of insoluble sulfur, reducing the formation of black spots and improving product quality by ensuring uniform contact and mixing, thus increasing production efficiency and reducing environmental pollution.

Implementation Method 1

methane is cracked into active free radicals during sulfur gasification

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 2

sulfur free radicals polymerization stage

Methodology Applied
Scientific EffectRadical polymerization: Photopolymerisation

Implementation Method 3

quenching and solidifying

Methodology Applied
Scientific EffectRapid cooling: Adiabatic Cooling

Data Source

PatentUS11427469B2Preparation method for insoluble sulfur and anti-reversion stabilizer used thereby
Publication Date: 2022.08.30 SHANDONG YANGGU HUATAI CHEM

AI summary

Provided are a preparation method for insoluble sulfur and an anti-reversion stabilizer used thereby. Methane is used as the anti-reversion stabilizer. The methane is added to liquid sulfur at sulfur gasification stage, and is cracked into active free radicals under the action of sulfur vapor active free radicals; in the quenching process of sulfur vapor mixed with methane, the active free radicals generated by methane cracking carry out end capping on insoluble sulfur end groups generated by sulfur vapor polymerization, thus completing insoluble sulfur stabilization. The methane is added at liquid sulfur gasification stage, and after sulfur gasification, the methane is mixed with sulfur vapor in a gaseous form, rather than being added to the product in a solid or liquid manner at a later stage, so that the insoluble sulfur and the stabilizer can be uniformly contacted and mixed to the greatest extent.