Trap-Type Carbon Replenishing Device for Microalgae Culture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for supplementing carbon dioxide in open pond microalgae cultivation, such as direct aeration and gas-cover systems, suffer from low absorption efficiency and increased energy consumption due to high flow resistance, and existing trap-type carbon supplement devices do not fully utilize their volume for gas-liquid exchange.
Innovation Solution
The gas distributor in the trap-type carbon supplement device is moved from the bottom to the culture solution inlet, allowing CO2 bubbles to flow with the culture solution through the downcomer and riser regions, increasing gas-liquid contact time and reducing flow resistance by utilizing both sides of the partition plate for exchange, thereby enhancing CO2 absorption efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If CO2 is directly aerated into the open pond in a bubbling way, then the construction is simple and operation is easy, but the absorption efficiency of CO2 is very low (only 13%-20% is absorbed) due to very short residence time of bubbles in the culture solution
Solution Approach 1:
The invention divides the gas-liquid exchange process into multiple stages by introducing a trap-type container with partition plates that create separate downcomer and riser regions. This segmentation allows bubbles to be distributed across multiple pathways, increasing the total gas-liquid contact area and residence time while maintaining the simplicity of the overall open pond system.
Solution Approach 2:
The trap-type container is embedded into the open pond bottom, creating a nested structure where the downcomer and riser regions are integrated within the existing pond infrastructure. This nesting approach enhances CO2 absorption efficiency without requiring separate, complex external systems, thus maintaining construction simplicity while improving productivity.
2Productivity
If a hollow fiber membrane is used to enhance gas-liquid mass transfer, then the absorption efficiency of CO2 is improved, but the cost is high and the hollow fiber membrane is prone to be fouled
Solution Approach 1:
The invention replaces expensive hollow fiber membranes with simple, inexpensive trap-type container structures made of basic materials. The partition plates and downcomer/riser regions are designed to be easily constructed and maintained, eliminating the need for costly membrane materials while achieving comparable or superior CO2 absorption efficiency through optimized fluid dynamics.
Solution Approach 2:
The invention extracts the gas-liquid exchange function from complex membrane-based systems and implements it through simple trap-type container structures with partition plates. This extraction eliminates the fouling problem associated with hollow fiber membranes while maintaining effective CO2 absorption through gravity-driven flow and extended residence time in the downcomer and riser regions.
3Quantity of substance
If a gas-cover system is used to transfer CO2 into the culture solution through the water surface, then CO2 can be supplied to the culture solution, but the specific interfacial area for gas-liquid exchange is small and the mass transfer rate is lowered down due to accumulation of oxygen and nitrogen in the gas-cover
Solution Approach 1:
The invention segments the gas-liquid exchange interface by introducing multiple trap-type containers with partition plates, creating numerous smaller exchange surfaces throughout the water column. This segmentation dramatically increases the total interfacial area available for CO2 transfer, overcoming the limited surface area problem of single-layer gas-cover systems and maintaining high mass transfer rates by preventing gas accumulation.
4Productivity
If the depth of the trap-type carbon supplement device is increased to prolong gas-liquid contact time, then CO2 absorption efficiency is improved, but the flow resistance increases and energy consumption increases
Solution Approach 1:
The invention transitions from a single-vertical-dimension approach to a multi-dimensional configuration by introducing partition plates that create horizontal downcomer and riser regions within the trap-type container. This dimensional change allows gas-liquid contact time to be prolonged through horizontal flow paths while maintaining manageable vertical depths, thereby reducing flow resistance and energy consumption compared to simply increasing overall device depth.
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 configuration prolongs gas-liquid contact time, reduces the depth of the carbon supplement device, and decreases energy consumption by ensuring that both sides of the partition plate function as gas-liquid exchange regions, leading to improved CO2 absorption efficiency and lower electrical energy usage.
Implementation Method 1
the absorption efficiency of the CO2 is very low- only 13%-20% of the CO2 is absorbed
Implementation Method 2
CO2 bubbles to flow with the culture solution through the downcomer and riser regions
Implementation Method 3
allowing CO2 bubbles to flow with the culture solution through the downcomer and riser regions
Implementation Method 4
both sides of the partition plate function as gas-liquid exchange regions
Data Source
AI summary
The invention relates to the field of microalgae culture and specifically relates to a trap-type carbon supplement device and carbon supplement method for cultivating microalgae in an open pond. The trap-type carbon supplement device for cultivating microalgae in an open pond, comprises a trap-type container, a partition plate and a gas distributor, wherein the gas distributor is positioned at the culture solution inlet of the trap-type carbon supplement device; the thickness of the trap-type carbon supplement device on the side of the culture solution inlet is 0.5-2 times of the depth of the culture solution in the open pond; the gap between the lower end of the partition plate and the bottom of the trap-type container is 0.5-2 times of the thickness of the trap-type carbon supplement device on the side of the culture solution inlet; the upper end of the partition plate is higher than the wall of the trap-type container; and the width of the partition plate is matched with the trap-type container. The carbon supplement device of the invention can make the gas-liquid contact time longer and reduce the depth of the trap-type container, therefore it can reduce the flow resistance of the liquid in the carbon supplement device and save energy consumption.