Rotating Disc Extraction Apparatus for Microalgal Lipid Recovery
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Solution Overview
Problem
Current methods for extracting lipids from microalgae are inefficient due to short retention time and high solvent requirements, particularly when using solvents like hexane or methanol, which are not effectively dissolved in water, leading to high separation costs.
Innovation Solution
An extraction apparatus with a chamber and rotation discs that increases retention time between microalgal lipids and solvent, improving solubility and reducing the impact of water content, featuring a shaft with rotation discs and a depositor to enhance extraction efficiency and solvent recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If liquid-solid extraction technique is used to extract lipids from microalgae, then extraction can be achieved, but retention time between lipids and solvent is short and extraction efficiency is low
Solution Approach 1:
The patent applies dynamics by rotating the disc stack at controlled speeds (50-500 rpm) to create continuous motion between solvent and biomass. This rotation dynamically adjusts the contact pattern, preventing stagnant zones and maximizing extraction efficiency while maintaining adequate retention time through controlled rotational speed.
Solution Approach 2:
The continuous rotation of the disc stack ensures uninterrupted contact between extraction solvent and microalgae biomass. The solvent continuously flows over the rotating discs, maintaining constant extraction action without idle periods, thereby improving productivity while preserving sufficient retention time through sustained contact.
2Productivity
If solvents like hexane or methanol are used for extraction, then lipid extraction can be performed, but solvent separation costs are high due to high solvent-to-microalgae ratio requirements
Solution Approach 1:
The patent transitions from traditional batch extraction to a continuous counter-current extraction process using a multi-disc rotating stack. This dimensional change in process configuration allows solvent to flow through multiple stages in series, achieving better extraction efficiency with reduced solvent quantity by utilizing the vertical stacking and rotational movement of extraction stages.
Solution Approach 2:
The system enables solvent recovery by separating the extract stream from the spent solvent stream. The raffinate outlet allows spent solvent to be discharged for recycling, while the extract outlet collects the lipid-solvent mixture. This separation facilitates solvent recovery and reuse, reducing the total quantity of solvent required for continuous operation.
3Productivity
If microalgae cell walls are ruptured to extract lipids, then lipid availability increases, but water content impact on extraction increases
Solution Approach 1:
The patent segments the extraction process into multiple stages using a stack of discs (typically 3-10 discs). Each disc provides a separate extraction zone, allowing progressive extraction of lipids from ruptured cell walls. This segmentation enables efficient lipid release from cell walls while managing water content effects through distributed extraction zones rather than a single overwhelmed stage.
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
Significantly enhances lipid extraction efficiency from microalgae by increasing retention time and solubility, reducing solvent usage, and lowering production costs through improved solvent recycling and cell rupture mechanisms.
Implementation Method 1
The rotation discs are juxtaposed at the first end of the shaft, and each of the rotation discs has at least one opening. The biological substance moves downward and sequentially passes through the opening of each of the rotation discs.
Implementation Method 2
An extraction solvent is injected into the chamber through the extraction solvent injection entrance, such that the extraction solvent and the biological substance are reversely contacted to generate an extract and a raffinate.
Data Source
AI summary
An extraction apparatus capable of continuously and efficiently extracting a biological substance is provided. Multiple rotation discs are utilized in the extraction apparatus to significantly improve the efficiency of extracting the biological substance by using an extraction solvent. Specifically, when the extraction solvent is applied to extract lipids from microalgae, retention time of the microalgae in the extraction solvent can be significantly increased, and solubility of the microalgal lipids in the extraction solvent can be improved. Hence, the efficiency of extracting the lipids from the microalgae by using the extraction solvent can be enhanced. On the other hand, owing to the improvement of the efficiency of extracting the lipids from the microalgae, the amount of the extraction solvent can be reduced, and production costs can be reduced as well.