PHA Extraction Using Non-Halogenated Solvents and Steam Evaporation
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Solution Overview
Problem
Current methods for extracting polyhydroxyalkanoates (PHAs) from bacterial cellular biomass using halogenated solvents are aggressive to the environment and human health, and existing non-halogenated solvents often result in thermal degradation and high energy consumption, limiting the production of high-purity, high-molecular-weight biopolymers.
Innovation Solution
A process utilizing non-halogenated solvents such as methyl formiate, ethyl formiate, and propyl valerate for extracting PHAs from bacterial cellular biomass, involving rapid heating, agitation, and steam evaporation to minimize thermal exposure and energy consumption, while achieving high purity and molecular weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If halogenated solvents are used for extracting PHAs, then extraction efficiency is improved, but environmental harm and human health risks increase
Solution Approach 1:
The patent changes the chemical composition parameter of the solvent from halogenated to non-halogenated compounds, specifically using esters such as ethyl formiate, propyl formiate, butyl formiate, isoamyl formiate, ethyl propionate, isoamyl propionate, ethyl butyrate, isoamyl butyrate, ethyl valerate, and isoamyl valerate. This substitution maintains extraction efficiency while eliminating the harmful environmental effects associated with halogenated solvents
Solution Approach 2:
The patent employs readily available, biodegradable ester solvents that can be easily disposed of or degraded in the environment, replacing persistent halogenated solvents. These esters are derived from natural sources and exhibit short environmental lifetimes, thus reducing long-term environmental contamination
2Object-affected harmful factors
If conventional non-halogenated solvents are used for extracting PHAs, then environmental harm is reduced, but thermal degradation of PHAs occurs
Solution Approach 1:
The patent optimizes the temperature parameter during extraction to range between 40-80°C, with preference for 50-70°C. This controlled temperature regime prevents thermal degradation of the PHA polymer chains while maintaining sufficient solubility for effective extraction. The specific temperature range was selected to balance extraction efficiency with polymer integrity preservation
Solution Approach 2:
The patent employs a rapid extraction procedure that minimizes the exposure time of PHAs to solvent and temperature. By conducting the extraction in a shortened time frame, the process reduces cumulative thermal stress on the polymer, thereby preventing degradation while still achieving thorough extraction
3Productivity
If conventional extraction processes are used, then PHAs can be recovered, but energy consumption increases
Solution Approach 1:
The patent changes the operational parameters of the extraction process, specifically operating at moderate temperatures (40-80°C) rather than high temperatures. This parameter modification significantly reduces the energy input required for heating and maintains extraction effectiveness, thereby lowering overall energy consumption while achieving PHA recovery
Solution Approach 2:
The patent implements a continuous extraction process where the solvent continuously contacts the biomass, maximizing extraction efficiency in a single pass. This continuous action reduces the need for repeated extraction cycles and associated energy inputs for multiple heating and processing steps
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 effectively recovers PHAs with molecular weights above 300,000 Da and high purity (>99%), reducing environmental impact and energy usage, making it suitable for industrial-scale production.
Implementation Method 1
submitting the cellular biomass to concomitant operations of injection of PHA solvent, vigorous agitation and rapid heating in the interior of a reactor in order to promote rupture of the wall of the biomass cells and dissolution of the PHA contained in the latter
Implementation Method 2
submitting the cellular biomass to concomitant operations of injection of PHA solvent, vigorous agitation and rapid heating
Implementation Method 3
submitting the cellular biomass to concomitant operations of injection of PHA solvent, vigorous agitation and rapid heating
Implementation Method 4
submitting the solution of PHA solvent enriched with PHA to operations of agitation and washing with water and/or steam at a temperature which is sufficient and appropriate to promote the removal, through evaporation, of substantially all PHA solvent
Data Source
AI summary
A process for extracting and recovering polyhydroxyalkanoates (PHAs) from cellular biomass comprising the steps of: extracting the polyhydroxyalkanoate with at least one non-halogenated solvent which is non-aggressive to the environment; heating the cellular biomass, in order to form a suspension comprising PHA solvent with the dissolved PHA and insoluble residues; recovering the solvent enriched with PHA; injecting the PHA-enriched solvent in a vapor flow in order to rapidly promote the complete precipitation of PHA in water, while processing the solvent evaporation; depleting the residual solvent; separating the purified PHA particles from the suspension and drying them.