Mobile Support Microalgae Culture for Light Management

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Solution Overview

Problem

Current microalgae production methods, especially in suspension and mobile support systems, are energy-intensive and yield modest results, particularly at high light intensities due to inefficient light exposure and harvesting processes.

Innovation Solution

A process where the total duration of phases in the shade is greater by 50% than the total duration of exposure to light, with a mobile support system circulating in a loop, ensuring microalgae receive less than 50% of the average light intensity during exposure, and utilizing specific species like Botryoccocus sp. and Chlorella sp., to optimize growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If microalgae are grown in suspension with continuous stirring to ensure light exposure, then each cell can be exposed to light intermittently, but the installation becomes very energy-consuming

Engineering Contradiction:
Improvelight exposureVSAvoidenergy consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The support moves dynamically between illuminated and shaded zones, allowing microalgae to experience alternating light exposure without continuous stirring. The cyclic motion of the support through different light zones replaces the need for continuous mechanical agitation, reducing energy consumption while maintaining effective light exposure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The microalgae on the support undergo periodic cycles of light exposure and shade. The support is moved through illuminated zones and shaded zones in regular intervals, creating a periodic light regime that maintains photosynthetic activity without requiring continuous energy input for stirring.

Inventive Principle:
Principle #19Periodic action

2Productivity

If microalgae are grown on mobile support with maximized light exposure to optimize growth, then light intensity is maximized, but the yield remains modest especially in strong light

Engineering Contradiction:
Improvegrowth optimizationVSAvoidlight intensity
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

Instead of continuous strong light exposure, the microalgae experience periodic cycles of high light intensity followed by shade periods. This periodic action prevents photoinhibition and allows recovery phases, maintaining high productivity even under strong light conditions by alternating between intensive light exposure and rest periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The light intensity parameter is dynamically changed by moving the support between illuminated and shaded zones. The system transitions from constant high light intensity to variable light intensity with distinct phases, optimizing photosynthetic efficiency by preventing saturation and photodamage while maintaining high overall productivity.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If harvesting is performed by centrifugation to separate microalgae from medium, then separation is achieved, but significant energy is consumed

Engineering Contradiction:
ImproveharvestingVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The microalgae accumulate naturally on the support surface during circulation, and the support itself serves as a harvesting mechanism. By lifting or removing the support from the culture medium, microalgae are automatically separated without requiring external centrifugal force, making the harvesting process self-service and energy-efficient.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The support acts as a carrier that extracts microalgae from the liquid medium through physical removal. Instead of using centrifugation to separate cells from medium, the system extracts the supported biofilm directly from the culture, achieving separation through simple physical extraction rather than energy-intensive mechanical separation.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enhances microalgae yield, particularly at high light intensities, by balancing light exposure and shade periods, reducing energy consumption, and facilitating easier harvesting while maintaining high photosynthetic efficiency.

Implementation Method 1

exploiting the ability of micro-algae to capture light energy to fix inorganic carbon (mainly in the form of carbon dioxide or bicarbonate)

Methodology Applied
Scientific EffectPhotosynthesis: Photosynthesis

Data Source

PatentEP3022283B1Method and unit for producing microalgae
Publication Date: 2019.10.09 SORBONNE UNIVERSITE
  • EP3022283B1 patent drawingFigure 1~2
  • EP3022283B1 patent drawingFigure 3~4
  • EP3022283B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing microalgae on a support (14) that is movably mounted essentially in an aqueous medium contained in a tank (12), said method comprising a succession of phases in which the microalgae developing on the support (14) are exposed to sunlight and phases in the shade, the light intensity received in the shade being less than 50% of the average light intensity received during the sunlight exposure phases. The total length of the shade phases is more than 50% longer than the total length of the sunlight exposure phases.