Subcritical Water Lipid Extraction from Wet Algal Biomass
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Solution Overview
Problem
The energy-intensive steps in algae biofuel production, particularly lipid extraction and dewatering, hinder the efficiency and sustainability of algal biofuel production, and existing methods often damage co-products, making them unsuitable for further use.
Innovation Solution
The use of subcritical water extraction methods, assisted by microwaves, to extract lipids from wet algae biomass, optimizing conditions such as temperature, pressure, and residency time to separate lipids from a polar phase, while recycling water and minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional lipid extraction methods (solvent extraction, expeller press) are used on dried algal biomass, then lipid extraction efficiency is improved, but energy consumption increases significantly (nearly 85% of production energy)
Solution Approach 1:
The patent applies parameter changes by using subcritical water conditions (temperature 100-374°C, pressure maintaining water in liquid state) to fundamentally alter the extraction mechanism. This allows direct extraction from wet biomass without drying, changing both the physical state parameters and the extraction efficiency, thereby reducing energy consumption while maintaining productivity
Solution Approach 2:
The patent uses subcritical water as an intermediary solvent that enables lipid extraction from wet algal biomass. This intermediary medium allows simultaneous dewatering and extraction processes, eliminating the need for separate energy-intensive drying and extraction steps, thus resolving the energy efficiency contradiction
2Productivity
If dewatering is performed on biomass with 20% or higher loading, then processing efficiency is improved, but energy consumption becomes prohibitive
Solution Approach 1:
The patent merges the dewatering and lipid extraction processes into a single subcritical water extraction step. By combining these two previously separate operations, the system achieves both dewatering and lipid recovery simultaneously, improving processing efficiency while avoiding the prohibitive energy costs of separate dewatering operations
Solution Approach 2:
The patent changes the operational parameters by operating in the subcritical water regime where water remains liquid at elevated temperatures and pressures. This parameter change enables high biomass loading processing without the energy-intensive evaporation required in conventional dewatering, thus resolving the contradiction between processing efficiency and energy consumption
3Productivity
If chemical lysing methods are used to extract lipids, then extraction efficiency is improved, but co-products are damaged and rendered unsuitable for consumption
Solution Approach 1:
The patent uses parameter changes by controlling temperature and pressure within the subcritical water range, which provides sufficient extraction efficiency while avoiding the harsh chemical conditions that damage co-products. The physical-chemical parameters are tuned to achieve selective lipid extraction without degrading proteins, carbohydrates, and other valuable biomass components
Solution Approach 2:
The patent employs subcritical water as a gentle intermediary that facilitates lipid extraction without the harsh chemical agents used in conventional lysing methods. This intermediary approach maintains the integrity of co-products while still achieving high extraction efficiency, eliminating the harmful effects on valuable biomass components
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 bio-crude yield and extraction efficiency, preserves co-products for further use, and reduces energy consumption, making the process more sustainable and efficient.
Implementation Method 1
heating and microwaving the biomass to heat the water to a subcritical temperature and to lyse the algae in the reactor
Implementation Method 2
subcritical water extraction methods, assisted by microwaves, to extract lipids from wet algae biomass
Implementation Method 3
heating and microwaving the biomass to heat the water to a subcritical temperature
Data Source
AI summary
Methods of lipid extraction from biomass, in particular wet algae, through conventionally heated subcritical water, and microwave-assisted subcritical water. In one embodiment, fatty acid methyl esters from solids in a polar phase are further extracted to increase biofuel production.