PHA Isolation via Alkyl Alcohol Pre-Cleaning and Chlorinated Hydrocarbon Extraction
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Solution Overview
Problem
Existing methods for isolating polyhydroxyalkanoates (PHAs) from biomass result in low purity and large particle sizes due to thermal degradation and contamination with undesired biomass components, especially when using chlorinated hydrocarbon extraction agents, which also extract non-PHA components and lead to high moisture content in the precipitated form.
Innovation Solution
A method involving initial extraction with an alkyl alcohol-based agent to remove contaminants, followed by chlorinated hydrocarbon extraction and subsequent precipitation in a circulation loop with controlled temperature and turbulence, achieving high purity and small particle sizes through multiple stages of extraction and filtration, with the option of recycling solvents to reduce costs and enhance yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chlorinated hydrocarbon extraction agents are used to extract PHAs from biomass, then extraction efficiency is improved and thermal degradation is avoided due to low temperature operation, but purity of the isolated PHA deteriorates because other biomass components are also extracted and co-precipitate with PHA
Solution Approach 1:
The extraction process is divided into two sequential stages: first using an alkyl alcohol-based extraction agent to remove contaminants, then using a chlorinated hydrocarbon to extract PHA. This segmentation allows each extraction agent to perform its optimal function without the drawbacks of the other, resolving the contradiction between extraction efficiency and purity.
Solution Approach 2:
The alkyl alcohol-based extraction is performed as a preliminary action before the main PHA extraction. This preliminary extraction removes undesired biomass components that would otherwise co-precipitate with PHA, ensuring high purity in the final product while maintaining efficient PHA extraction in the subsequent stage.
2Manufacturing precision
If conventional solvents such as carbonates or higher alcohols are used for PHA extraction, then purity may be maintained, but thermal degradation occurs because extraction must take place at higher temperatures
Solution Approach 1:
The invention changes the chemical parameters of the extraction agent from conventional solvents (carbonates, higher alcohols) to alkyl alcohol-based agents with specific chain lengths (2-4 carbon atoms). This parameter change allows extraction to proceed at lower temperatures (below PHA degradation threshold) while maintaining effective extraction and purity.
3Loss of energy
If precipitation is performed without sufficient water turbulence, then energy consumption is reduced, but particle size of PHA becomes too large requiring additional disintegration
Solution Approach 1:
The precipitation process uses dynamic water circulation with controlled turbulence instead of static precipitation. The circulating water creates optimal turbulence that controls particle growth during precipitation, producing smaller PHA particles that do not require additional disintegration while avoiding excessive energy consumption.
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 method achieves polyhydroxyalkanoate purity exceeding 99% with a yield of 97% and particle sizes of approximately 1 mm, significantly improving upon existing methods by reducing thermal degradation and contamination, and eliminating the need for further disintegration of particles.
Implementation Method 1
by means of an extraction agent based on alkyl alcohol having 2 to 4 carbon atoms in the chain, which is added to the biomass in a weight ratio from 1:0.5 to 1:5
Implementation Method 2
polyhydroxyalkanoates are extracted by means of the extraction agent based on chlorinated hydrocarbon
Implementation Method 3
the extraction agent is removed from this extract and polyhydroxyalkanoates precipitate
Implementation Method 4
polyhydroxyalkanoates precipitate from the extract
Implementation Method 5
insufficient water turbulence during precipitation leads to the formation of large particles of PHA
Data Source
AI summary
A method of isolation of polyhydroxyalkanoates from biomass pre-cleans the biomass in a first extraction process by extracting components of the biomass other than polyhydroxyalkanoates. In a second extraction process, polyhydroxyalkanoates are extracted from a solid phase of the biomass obtained in the first extraction process by adding an extraction agent to pre-cleaned biomass based on chlorinated hydrocarbon, carrying out the extraction for 5 to 90 minutes at a temperature in the range of 20 to 120° C., separating the extract containing the polyhydroxyalkanoates from the extraction solution, and feeding the extract to a circulation loop filled with water having a temperature from 20 to 120° C. or a mixture of water and from up to 20% by weight of the extraction agent based on chlorinated hydrocarbon used for the extraction of polyhydroxyalkanoates, wherein the extraction agent is removed from this extract and polyhydroxyalkanoates precipitate.