Packed Column Mass Transfer Correlations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for designing and optimizing packed columns for separation processes lack accurate and dependable expressions for vapor-side and liquid-side mass transfer coefficients and mass transfer area, leading to unreliable predictions when applied to chemical systems and conditions outside those used for correlation development.
Innovation Solution
Derivation of vapor-side and liquid-side mass transfer coefficient expressions and mass transfer area expressions based on a column average height equivalent to a theoretical plate (HETP), which are proportional to vapor flow rate, inversely proportional to effective packing area, and corrected for liquid and vapor-side mass transfer, using empirical data and least squares regression to optimize column height and width configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If public domain packing mass transfer correlations are used, then design calculations can be performed, but the predictions are unreliable when applied to chemical systems and column operating conditions outside of those used to develop the correlations
Solution Approach 1:
The patent transforms the mass transfer correlations by changing the fundamental parameters from empirical fitting parameters to dimensionless groups based on fundamental physical properties. The new correlations use dimensionless mass transfer coefficients (Sherwood number), Reynolds number, and Schmidt number, which are universally applicable across different chemical systems and operating conditions, resolving the contradiction between adaptability and reliability
Solution Approach 2:
The patent replaces the mechanical/empirical correlation system with a physics-based dimensionless analysis system. Instead of using empirical correlations fitted to specific experimental data, the invention uses dimensionless groups that capture the essential physics of mass transfer, enabling reliable predictions across diverse chemical systems without re-fitting parameters
2Reliability
If nonequilibrium column models are used, then more rigorous and reliable basis for assessing column performance is obtained, but the models lack accuracy, generality, and ease of use due to questionable predictive capability of underlying equipment performance correlations
Solution Approach 1:
The patent changes the parameters in nonequilibrium column models from unreliable empirical correlations to dimensionless groups based on fundamental physical properties. This substitution maintains the rigorous nonequilibrium framework while improving predictive accuracy by using universally applicable dimensionless correlations that do not depend on specific chemical systems or operating conditions
Data Source
AI summary
A method of designing or optimizing a column for a separation process includes the computer implemented steps of, in a digital processor, providing vapor-side and liquid-side mass transfer coefficient expressions and a mass transfer area expression relevant for a subject column, the vapor-side and liquid-side mass transfer coefficient expressions and the mass transfer area expression having been derived from defining a column average height equivalent to a theoretical plate HETP) as a mathematical relationship in which HETP is proportional to a vapor flow rate, is inversely proportional to effective packing area participating in mass transfer, has a first correction factor with respect to liquid-side mass transfer, and has a second correction factor with respect to vapor-side mass transfer. The expressions are further derived from reducing error of curve fitting HETP empirical data of various columns by using the defined HETP to obtain expressions for the vapor-side and liquid-side mass transfer coefficients and mass transfer area. The method also includes using the provided expressions to determine column height and column width configurations of the subject column, and outputting the determined column height and column width configurations of the subject column.