Dual-Flow Sparging System for Algae Cultivation
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Solution Overview
Problem
Current algae cultivation systems face inefficiencies in CO2 utilization and light penetration due to inadequate mixing and self-shading, limiting maximal algae density and growth potential.
Innovation Solution
A sparging system with dual fluid flow rates and a controller to adjust flow rates based on measured parameters, combined with targeted illumination, enhances mixing and CO2 assimilation, and optimizes light distribution for high-density cultures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If gas sparging is used to create mixing in photo-bioreactors, then mixing is achieved, but CO2 biological usage is poor (about 10%) due to diluted concentration in large bubbles
Solution Approach 1:
The invention changes the parameters of bubble sparging by using fine bubbles instead of large bubbles, and operating at higher pressures (0.5-2.0 atm) to increase CO2 concentration and solubility. This transforms the sparging process from inefficient large-bubble mixing to efficient fine-bubble CO2 delivery, simultaneously achieving both mixing and high CO2 utilization.
Solution Approach 2:
The invention segments the gas delivery system into multiple fine sparging points distributed throughout the bioreactor volume, creating numerous small bubbles instead of few large bubbles. This segmentation increases the total surface area for CO2 transfer and improves both mixing efficiency and CO2 absorption by the algae culture.
2Quantity of substance
If algae culture increases in density, then biomass production increases, but light penetration decreases due to self-shading, reaching maximal light-limited concentration
Solution Approach 1:
The invention implements dynamic control of sparging intensity and pattern to adapt to changing algae density. As culture density increases and light penetration decreases, the system adjusts sparging parameters to enhance mixing and redistribute cells, ensuring continuous optimal light exposure and preventing permanent light limitation.
Solution Approach 2:
The invention maintains continuous sparging action to ensure constant mixing and light distribution throughout the culture volume. This continuous action prevents cell settling and maintains uniform cell distribution, allowing the system to sustain higher algae densities by continuously overcoming self-shading effects.
3Productivity
If ultra-high cell concentrations are used, then productivity increases, but cell damage occurs due to photo-inhibition from over-exposure to high light
Solution Approach 1:
The invention uses periodic sparging pulses to create cyclic mixing patterns that alternately expose cells to light and darkness. This periodic action prevents continuous over-exposure to high light intensities, reducing photo-inhibition while maintaining ultra-high cell concentrations through repeated redistribution of cells throughout the light field.
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
The system achieves improved CO2 utilization and light penetration, increasing algae growth rates and density by up to 20% organic carbon and maintaining optimal growth conditions in high-density cultures.
Implementation Method 1
Gas sparging (mainly air or Nitrogen enriched with CO2) is commonly used in photo-bioreactors (PBRs) in order to create the required mixing. The rising motion of the bubbles creates mixing tangential to the flow direction.
Implementation Method 2
The rising motion of the bubbles creates mixing tangential to the flow direction. Efficient mixing usually requires continuous high flow rates and large bubbles.
Implementation Method 3
About 50% of algal biomass is carbon, obtained by fixing CO2 photosynthetically, where carbon dioxide needs to be dissolved into the culture in a liquid phase.
Implementation Method 4
About 50% of algal biomass is carbon, obtained by fixing CO2 photosynthetically
Implementation Method 5
Light emitting diodes (LEDs) have the capability of providing light of specific wavelengths, for example in the visible light (e.g., blue and/or red) wavelength range.
Data Source
AI summary
Aspects of the invention are directed to a system and method of sparging an algae cultivation container. The method may include controlling at least one first sparger to distribute a first fluid into the container at a first operating flow rate; and controlling at least one second sparger to distribute a second fluid into the container at a second operating flow rate. The first operating flow rate may be adapted to allow mixing the algae in the cultivation container, and the second operating flow rate may be adapted to allow assimilation of materials in a liquid in the cultivation container.