New equations improve vapor pressure calculations for different conditions

The Korea Institute of Civil Engineering and Construction Technology introduced the vapor pressure equation. It addresses the limitations of the Lee-Kesler method, a widely used method in the field of thermodynamics, and provides a versatile and comprehensive solution for vapor pressure calculations across a variety of conditions.

The research was published in the journal Chemical Engineering Communications.

The Lee-Kesler method is a reliable calculation method in chemical process design, especially when predicting vapor pressure based on material properties. By referring to non-central factors, we account for non-ideal behavior and provide stable and accurate results even near critical points.

Due to its simplicity, requiring only non-central factors and critical properties, it is recommended as an alternative to Antoine’s equation, which relies on extensive material-specific temperature data. However, limitations in temperature range and accuracy at low temperatures have long been a challenge.

Dr. Lee Jaiyeop of KICT developed this new equation. This represents a significant improvement, achieving an impressive average error rate of 0.49%, slightly better than the 0.50% of the Lee-Kesler method. In a study of 76 substances, it outperformed the Lee-Kesler method in 45 cases.

Most notably, at low temperatures below 0.7, the average error rate of the equation was shown to be 0.57%, compared to 0.72% for the Lee-Kesler method. This increased accuracy at relatively low temperatures could be particularly valuable in cryogenic environments such as Antarctica or the lunar surface, or other extreme environments.

A key advancement is its extended temperature range. The Lee-Kesler method is limited to calculations at reduced temperatures of approximately 0.7, whereas the new equation is applicable over a wide range of 0.25 to 0.95. This flexibility makes it suitable for materials with limited experimental data and addresses data-dependency challenges faced by other methods. The result is a more adaptable and efficient computing environment for engineers and researchers.

This equation is internationally recognized as a significant extension of the Antoine and Lee-Kesler methods. Its potential applications span various fields such as energy, pharmaceuticals, and environmental monitoring. Its precision and versatility make it a valuable tool for addressing high pressure and low temperature challenges in industrial operations.

Additionally, the equation is designed to seamlessly integrate with IoT-based monitoring systems. This compatibility enables real-time data analysis and process optimization, which is expected to improve productivity and safety across the industry. By bridging theoretical innovation and practical application, this new approach promises to establish a new benchmark in vapor pressure calculations.

Dr. Lee said, “This research not only sets a new benchmark, but also introduces an innovative tool to the chemical engineering community.”

He said that it is expected that the industry will make great progress with its introduction. As its influence grows, this breakthrough equation will leave a lasting mark across a variety of fields.