Blended Textile Waste Liquor Separation by Polyester Precipitation
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Solution Overview
Problem
Existing methods for recycling blended textile wastes containing both cellulose and polyester components fail to effectively separate and treat the waste liquor produced during alkaline pulping, leading to high chemical oxygen demand and metal content, making it unsuitable for conventional wastewater treatment.
Innovation Solution
A method involving the evaporation of waste liquor to precipitate polyester degradation products, allowing for a two-phase separation of solid and aqueous phases, enabling the solid phase to be utilized independently and reducing the burden on wastewater treatment by processing the aqueous phase separately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wastewater treatment is applied to waste liquor from alkaline pulping of blended textile waste, then treatment capacity is exceeded, but chemical oxygen demand and metal content are excessively high
Solution Approach 1:
The patent extracts and removes harmful substances (polyester degradation products and metals) from the waste liquor through precipitation and filtration processes before the treated water enters conventional wastewater treatment, thereby reducing the chemical oxygen demand and metal content that would otherwise overwhelm treatment capacity
Solution Approach 2:
The patent converts harmful polyester degradation products and metals in the waste liquor into beneficial precipitates that can be separated and disposed of, transforming the waste stream from a treatment burden into a manageable byproduct while protecting downstream treatment systems
2Quantity of substance
If blended textile waste containing polyester is subjected to alkaline pulping, then cellulose extraction is achieved, but significant polyester degradation products contaminate the waste liquor
Solution Approach 1:
The patent selectively extracts polyester degradation products from the waste liquor through precipitation processes, separating them from the cellulose-rich stream while maintaining high cellulose recovery efficiency in the filtrate
Solution Approach 2:
The patent changes physical-chemical parameters such as pH, temperature, and concentration to control the precipitation of polyester degradation products while keeping cellulose in solution, enabling selective separation based on differential solubility properties
3Manufacturing precision
If waste liquor is evaporated to precipitate polyester degradation products, then two-phase separation is achieved, but energy consumption increases
Solution Approach 1:
The patent optimizes evaporation parameters including temperature, pressure, and concentration rates to achieve precise precipitation of polyester degradation products while minimizing energy input through controlled phase changes and heat recovery mechanisms
Solution Approach 2:
The patent utilizes controlled phase transitions during evaporation to selectively precipitate polyester degradation products at specific concentration thresholds, enabling efficient two-phase separation with optimized energy utilization through staged evaporation processes
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
Enables the recovery of high-purity cellulose raw material and reduces the environmental impact by minimizing chemical oxygen demand in wastewater treatment, with the solid phase being incinerated for thermal energy and the aqueous phase treated to recover alkaline solution.
Implementation Method 1
water is evaporated from the waste liquor in order to precipitate the polyester degradation product from the waste liquor
Implementation Method 2
obtain a two-phase mixture having an aqueous phase and a solid phase that includes the polyester degradation product
Data Source
AI summary
The invention relates to a method for the treatment and utilization of waste liquor containing at least polyester degradation products and originating from an alkaline pulping process for the extraction of cellulose raw material from blended textile waste which contains at least a cellulose component and a polyester component. In order to make the method environmentally friendlier and more resource-efficient, it is proposed that the method comprises the following steps: the evaporation of water from the waste liquor in order to precipitate the polyester degradation product from the waste liquor and to obtain a two-phase mixture having an aqueous phase and a solid phase including the polyester degradation product, b) the separation of the solid phase from the liquid phase, and c) the thermal/energetic utilization of the solid phase.