Staggered Filtration Control for Continuous Fermentation Membranes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In continuous fermentation processes, intermittent filtration methods lead to unstable feedstock concentration in the fermentation tank due to synchronized filtration and filtration-stop operations across multiple separation membrane modules, causing fluctuations in fermentation performance and potential pH imbalances, which can impair microbial activity and reduce productivity.
Innovation Solution
Implementing a method where the filtration-stop treatment timing is controlled across separation membrane modules to avoid overlap, allowing staggered filtration-stop cycles and using water or oxidizing/reducing agents for backwashing, while maintaining constant transmembrane pressure and varying the order of fermentation liquid transport to prevent membrane clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If intermittent filtration treatment is performed with multiple separation membrane modules operating in parallel, then membrane fouling is removed and filtration efficiency is maintained, but feedstock concentration becomes unstable and fermentation performance fluctuates
Solution Approach 1:
The system divides multiple separation membrane modules into different operational groups, where some modules perform filtration while others perform backwashing simultaneously. This segmentation prevents all modules from stopping filtration at the same time, maintaining continuous feedstock concentration stability while still allowing periodic cleaning of individual modules.
Solution Approach 2:
Backwashing is performed periodically on individual modules rather than simultaneously on all modules. Each module undergoes periodic backwashing in a staggered sequence, ensuring that filtration continues uninterrupted in other modules, thus maintaining both filtration efficiency and feedstock concentration stability.
2Productivity
If backwashing is performed during filtration-stop treatment, then membrane fouling is removed effectively, but washing liquid introduces pH imbalance and affects microbial activity
Solution Approach 1:
The system segments the backwashing operation to affect only one module at a time while other modules continue filtration. This minimizes the volume of washing liquid entering the fermentation system at any given moment, reducing pH imbalance impact on microbial activity.
Solution Approach 2:
The system changes the operational state of individual modules between filtration and backwashing modes in a controlled sequence. By transitioning modules through different operational parameters (filtration pressure, flow direction) sequentially rather than simultaneously, it maintains overall system stability and minimizes harmful effects.
3Productivity
If multiple separation membrane modules operate in parallel, then filtration capacity is increased, but synchronized filtration-stop operations cause feedstock concentration fluctuations
Solution Approach 1:
The parallel modules are segmented into different operational phases, with each module operating independently in terms of filtration-stop timing. This allows the system to maintain high overall filtration capacity while preventing synchronized stoppages that would cause feedstock concentration fluctuations.
Solution Approach 2:
The system prepares for backwashing by selecting which module will undergo cleaning before it is needed, allowing other modules to maintain filtration continuously. This preliminary planning ensures that filtration capacity is maintained while scheduling necessary maintenance activities.
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 stabilizes feedstock concentration, enhances fermentation productivity, and reduces membrane clogging, leading to efficient and cost-effective continuous fermentation with improved microbial activity and product recovery.
Implementation Method 1
microorganisms and culture cells are filtered with a separation membrane to recover a chemical product from a filtrate
Implementation Method 2
A cross flow filtration is adopted in which the fermentation culture liquid is transported to a hollow fiber membrane module, part of the liquid is filtered, and most of them are returned to a fermentation tank. According to shear force generated by cross flow motion, fouling on membrane surface are removed
Implementation Method 3
the membrane separation step, an intermittent filtration treatment is performed such that a filtration treatment and a filtration-stop treatment are alternately repeated
Implementation Method 4
using water or oxidizing/reducing agents for backwashing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a method for producing a chemical, wherein the separation membranes can be efficiently washed and the fermentation can be stably performed in a continuous fermentation apparatus for continuously producing a chemical by fermentation using separation membranes. The method for producing a chemical by continuous fermentation according to the present invention includes a fermentation step for converting a fermentation feedstock, through fermentation by culturing a microorganism or culture cells, into a fermented liquid containing the chemical, and a membrane separation step for collecting the chemical, as a filtrate, from the fermented liquid with the use of two or more separation membrane modules, and returning the non-filtered liquid to the fermented liquid, wherein in the membrane separation step, timing of the filtration-stop treatment for each separation membrane module is controlled when an intermittent filtration operation including alternately repeating a filtration treatment and a filtration-stop treatment is performed with plural separation membrane modules.