Ester Additive for Acid Capture in HFO Refrigerant Systems
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Solution Overview
Problem
Current lubricating oil compositions are insufficient in maintaining stability, especially when exposed to strong acids like hydrofluoric acid generated during the degradation of hydrofluoroolefin refrigerants, which can lead to further deterioration and corrosive wear in refrigeration systems.
Innovation Solution
Incorporating a specific amount of fatty acid 3,4-epoxycyclohexylalkyl ester and/or 3,4-epoxycyclohexyl carboxylic acid alkyl ester into the lubricating oil composition to effectively capture acidic substances, including hydrofluoric acid, thereby enhancing the stability of the lubricating oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stabilizing agents (phenyl glycidyl ether, alkylene oxide compounds, glycidyl ether compounds) are added to capture hydrochloric acid, then the stability of lubricating oil is improved to some extent, but the effect is insufficient against strong acids like hydrofluoric acid generated by HFO refrigerant degradation
Solution Approach 1:
The patent changes the chemical structure parameter of the stabilizing agent by introducing a specific cyclic carbonate compound with a six-membered ring structure containing carbonate groups. This structural parameter change enables the compound to effectively capture strong acids like hydrofluoric acid through chemical reaction, resolving the insufficiency of conventional stabilizing agents against HFO refrigerant degradation products.
Solution Approach 2:
The cyclic carbonate compound acts as an intermediary substance that mediates between the strong acid (hydrofluoric acid) and the lubricating oil system. It captures the acid through chemical reaction, preventing the acid from directly attacking and deteriorating the lubricating oil, thus protecting the system from acid-induced damage.
2Reliability
If larger amounts of stabilizing agents are added to improve acid capture effectiveness, then the stability against strong acids is improved, but the influence on organic materials (plastics) used in recent devices increases
Solution Approach 1:
The patent optimizes the concentration parameter of the cyclic carbonate compound within a specific range (0.01-5.0% by mass). This parameter optimization achieves effective acid capture while minimizing the compound's influence on organic materials, as the low concentration reduces chemical interaction with plastics and other organic components in the refrigeration system.
Solution Approach 2:
The cyclic carbonate compound is designed to be consumed in the process of capturing acid, transforming from a stable molecule to reaction products. This disposable nature allows it to effectively neutralize acids without accumulating in the system, reducing long-term influence on organic materials while maintaining continuous protection.
3Stability of the object's composition
If existing stabilizing agents are used to suppress ester hydrolysis, then some stability improvement is achieved, but they cannot effectively handle the strong acid generation from HFO refrigerant degradation
Solution Approach 1:
The patent converts the harmful effect of strong acid generation from HFO refrigerant degradation into a beneficial process. The cyclic carbonate compound reacts with the generated acid to form stable salts, transforming the acid into a harmless or less harmful species. This converts the harmful acid generation into a controlled chemical reaction that protects the lubricating oil system.
Solution Approach 2:
The lubricating oil composition is formulated as a composite system combining the base lubricating oil with the cyclic carbonate stabilizing agent. This composite formulation synergistically combines the lubrication properties of the base oil with the acid-capturing capability of the carbonate compound, creating a unified protective system that addresses both hydrolysis resistance and strong acid neutralization.
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 lubricating oil composition demonstrates improved long-term reliability and stability by effectively capturing acidic substances, even at low additive concentrations, reducing corrosion and maintaining system performance over time, especially in refrigeration systems using hydrofluoroolefin refrigerants.
Implementation Method 1
adding an ester that is a fatty acid 3,4-epoxycyclohexylalkyl ester and/or a 3,4-epoxycyclohexyl carboxylic acid alkyl ester to capture acidic substances generated due to the deterioration of a lubricating oil
Data Source
AI summary
The present invention provides a lubricating oil composition comprising a lubricating base oil, and at least one ester additive selected from a first ester that is a fatty acid 3,4-epoxycyclohexyl alkyl ester and a second ester that is a 3,4-epoxycyclohexyl carboxylic acid alkyl ester, wherein a content of the ester additive is 0.01 to 5.0% by mass based on the total mass of the lubricating oil composition.