Stock-Solution Concentration at Critical Transmembrane Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods struggle to select an optimal molecular weight cut-off for ultrafiltration membranes, leading to leakage of useful components to the filtrate side or low filtration flux, and there is a need to improve the recovery rate of concentrated components.
Innovation Solution
The method involves filtering raw liquid through an ultrafiltration membrane at a transmembrane pressure equal to or higher than the critical pressure, with a molecular weight cut-off to weight average molecular weight ratio of 0.05 to 0.30, using an external pressure type hollow fiber membrane, and optimizing operational conditions to enhance rejection and recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a separation membrane with a molecular weight cut-off greater than the minimum molecular weight of the component to be concentrated is used, then the filtration flux is improved, but the useful component leaks to the filtrate side
Solution Approach 1:
The invention changes the pressure parameter from conventional low pressure to high pressure (equal to or higher than the critical pressure of the membrane). This parameter change enables the use of membranes with larger molecular weight cut-off values (higher productivity) while preventing component leakage through the enhanced rejection effect at critical pressure
Solution Approach 2:
The invention applies preliminary anti-action by pre-establishing the high pressure condition (at or above critical pressure) before filtration begins. This preliminary pressure application creates a strong rejection field that prevents useful components from leaking through the membrane pores, countering the leakage tendency that would otherwise occur with higher molecular weight cut-off membranes
2Reliability
If a separation membrane with a molecular weight cut-off smaller than the useful component to be concentrated is used, then the rejection rate is improved, but the filtration flux becomes low
Solution Approach 1:
The invention changes the pressure parameter to high pressure (at or above critical pressure), which enhances the rejection mechanism. This allows membranes with smaller molecular weight cut-off values to achieve even better rejection rates while maintaining acceptable filtration flux through the high pressure-driven flow
3Reliability
If an optimal molecular weight cut-off membrane is selected based on the molecular weight of the useful substance, then the recovery rate increases, but it is difficult to always select the optimal membrane from commercially available options
Solution Approach 1:
The invention changes the operating pressure parameter to high pressure (at or above critical pressure), which fundamentally alters the membrane separation mechanism. This parameter change enables the use of membranes with molecular weight cut-off values that are larger than the minimum required, expanding the range of commercially available membranes that can achieve high recovery rates
Solution Approach 2:
The invention introduces dynamics by making the membrane selection less rigid and more flexible. Instead of requiring a precise match between membrane cut-off and component molecular weight, the high pressure condition dynamically enhances rejection across a broader range of membrane types, making selection easier
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
This approach increases the recovery rate of concentrated components by improving the rejection rate and maintaining efficient filtration flux.
Implementation Method 1
membrane filtration using a hollow fiber membrane module
Implementation Method 2
a relation between a molecular weight of a component to be concentrated and a molecular weight cut-off of the separation membrane is important
Implementation Method 3
filtering the raw liquid through the ultrafiltration membrane at a transmembrane pressure equal to or higher than a critical pressure
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention addresses the problem of providing a method that is for producing a concentrated solution of a stock solution using an ultrafiltration membrane, and that increases the recovery rate of useful components intended to be concentrated. The present invention pertains to a method for producing a concentrated solution of a stock solution using an ultrafiltration membrane, and involves, when A/B which is the ratio of the molecular weight cut-off (MWCO) A of the ultrafiltration membrane with respect to the weight-average molecular weight (Mw) B of a solute in the stock solution is 0.05-0.30, filtering the stock solution through the ultrafiltration membrane at a transmembrane pressure higher than or equal to the critical pressure of the ultrafiltration membrane.