Sequential Hydrothermal Liquefaction for Algae Bio-oil Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing biofuel from algae face economic viability issues due to high production costs and inefficiencies in separating high-value co-products, particularly due to the limitations of lipid extraction and hydrothermal liquefaction processes which result in low-quality bio-oils and the presence of undesirable compounds.
Innovation Solution
A two-stage process involving subcritical water extraction (SWE) followed by hydrothermal liquefaction (HTL) to selectively extract polysaccharides and bio-oils from algae biomass, optimizing reaction conditions to produce high-quality bio-oils and value-added co-products while minimizing the presence of nitrogenous compounds and bio-char.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrothermal liquefaction is used to convert algae biomass to bio-oil, then bio-oil yield increases, but bio-oil quality deteriorates due to formation of nitrogenous compounds and bio-char
Solution Approach 1:
The patent divides the hydrothermal processing into two sequential stages: a first stage at lower temperature (200-300°C) that selectively converts lipids to bio-oil while preserving quality, and a second stage at higher temperature (300-400°C) that converts remaining biomass to bio-oil. This segmentation allows optimization of both yield and quality by controlling the temperature profile across stages.
Solution Approach 2:
The patent performs preliminary extraction of lipids from algae biomass before the main hydrothermal liquefaction process. This preliminary action removes the bulk of lipid material that would otherwise require high-energy conversion, allowing the subsequent HTL process to operate at lower temperatures and produce higher quality bio-oil with fewer nitrogenous compounds and bio-char.
2Productivity
If high temperature hydrothermal liquefaction is used to maximize bio-oil production, then total bio-oil yield increases, but production of undesirable compounds increases
Solution Approach 1:
The patent segments the thermal processing into distinct temperature zones: a first hydrothermal stage at 200-300°C that produces bio-oil from lipids with minimal undesirable compounds, and a second stage at 300-400°C that processes remaining biomass. This segmentation prevents excessive formation of nitrogenous compounds and bio-char by avoiding prolonged exposure to extremely high temperatures.
Solution Approach 2:
The patent dynamically changes the temperature parameter across the two processing stages, starting at 200-300°C for lipid conversion and increasing to 300-400°C for remaining biomass conversion. This parameter change optimizes the balance between bio-oil yield and minimization of harmful compounds by matching temperature to the specific conversion requirements of different biomass components.
3Productivity
If conventional lipid extraction methods are used, then extraction efficiency improves, but separation of co-products becomes difficult
Solution Approach 1:
The patent employs hydrothermal liquefaction as a multi-functional process that simultaneously achieves lipid extraction, protein hydrolysis, and carbohydrate conversion in a single integrated system. This universality eliminates the need for separate extraction and separation units, reducing overall process complexity while maintaining high extraction efficiency through the hydrothermal environment.
Solution Approach 2:
The patent changes the physical-chemical parameters of the processing environment by using hydrothermal conditions (elevated temperature and pressure aqueous environment) instead of conventional solvent extraction. This parameter change enables selective dissolution and separation of different biomass components based on their hydrothermal stability and solubility, simplifying the separation of co-products like polysaccharides, proteins, and lipids.
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 process enhances bio-oil quality, increases bio-oil yield, and facilitates the recovery of high-value co-products like polysaccharides, reducing production costs and environmental impact by minimizing the formation of toxic compounds and bio-char, thus improving the economic viability of algal biofuel production.
Implementation Method 1
heating an aqueous mixture comprising the oleaginous biomass to a first temperature in the range of from 155 to 165° C.; maintaining said aqueous mixture comprising the oleaginous biomass at said first temperature for a first period of time
Implementation Method 2
using, in step 2, high temperature hydrothermal liquefaction of the remaining algae-biomass solids to produce bio-oils
Data Source
AI summary
Methods of producing bio-fuel and other high-value products from oleaginous biomass (e.g. algae biomass) are provided. The two-step methods use a first step of subcritical water extraction of the biomass at low temperatures to produce polysaccharides and other high value products of interest, followed by, ii) hydrothermal liquefaction of remaining solid biomass at high temperatures to produce bio-oil.