Ammoniated Alcohol Neutralization for Polyol Acid Value Reduction
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Solution Overview
Problem
Recycled polyol waste from polyurethane (PU) or polyisocyanurate (PIR) products often has a high acid value, which affects the curing profile and mechanical properties of new PU or PIR products, limiting its application and requiring additional processing to reduce acidity.
Innovation Solution
A process involving the solubilization of ammonia in a distillable alcohol to form an ammoniated solution, which is then chemically reacted with polyol waste to reduce its acid value, achieving an upgraded stabilized polyol composition suitable for direct use in PU or PIR formulations without the need for corrosive acids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polyol waste is used directly in PU or PIR formulations, then the recycling process is simple and cost-efficient, but the high acid value adversely affects curing profile, demolding time, and foam properties
Solution Approach 1:
The patent introduces an intermediary treatment step using alkaline substances (such as KOH, NaOH, or Ca(OH)2) to neutralize the acidic components in polyol waste before it is used in PU or PIR formulations. This intermediary neutralization process removes the harmful acidic impurities while preserving the valuable polyol components, enabling the waste polyol to be successfully recycled without adversely affecting curing profile, demolding time, or foam properties.
2Quantity of substance
If polyol waste with high acid value is used for PU product preparation, then the quantity of recyclable material is maximized, but terminal-acid groups form amide bonds with polyisocyanates leading to carbon dioxide formation and undesirable bubble formation
Solution Approach 1:
The patent converts the harmful acidic components in polyol waste into beneficial neutral salts through alkaline neutralization. The acid groups that would otherwise react with polyisocyanates to form carbon dioxide and cause bubble formation are neutralized by alkaline substances, transforming them from harmful impurities into harmless or beneficial components in the final foam product.
3Productivity
If polyol waste is recycled without additional processing, then the process is environmentally friendly and cost-efficient, but the acid value remains higher than fresh polyol, limiting application latitude
Solution Approach 1:
The patent changes the chemical parameter (acid value) of polyol waste through alkaline neutralization treatment. By adjusting the pH and neutralizing the acid groups, the treated polyol achieves acid values comparable to fresh polyol, thereby expanding its adaptability and versatility for use in various PU and PIR applications without sacrificing recycling efficiency.
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 process effectively reduces the acid value of polyol waste to levels comparable to fresh polyol, enhancing reactivity and allowing for the production of high-quality PU or PIR products with improved mechanical properties, while being environmentally friendly.
Implementation Method 1
Chemically reacting the solution of ammoniated distillable alcohol with the provided polyol (waste polyol) to reduce its acid value
Implementation Method 2
Chemically reacting the solution of ammoniated distillable alcohol with the provided polyol (waste polyol)
Data Source
AI summary
The present invention relates to a method for reducing the acid value in a provided polyol to obtain an upgraded stabilized polyol composition, said method comprising following process steps:Solubilizing ammonia in a distillable alcohol having a boiling point lower than 200° C. with formation of an ammoniated distillable alcohol;Providing a polyol having a predefined acid value;Chemically reacting the ammoniated distillable alcohol with the provided polyol;Removing the distillable alcohol by distillation at a temperature comprised between 120 and 220° C.; andObtaining an upgraded stabilized polyol composition having an acid value lower than the predefined acid value of said provided polyol.