Solvent Purification for Elastomeric Blends
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Solution Overview
Problem
Current solvent purification technologies for elastomeric blends are inadequate for reuse in both anionic and Ziegler-Natta polymerization processes, as they fail to effectively remove contaminants like ethanol and unreacted monomers, leading to difficulties in controlling polymerization reactions and molecular-weight distribution, and are economically unfavorable.
Innovation Solution
A process involving pre-washing with acid or basic aqueous solutions, followed by liquid-liquid separation and azeotropic distillation, with water fed countercurrently, and subsequent adsorption on zeolites or activated aluminas to produce a polymer-grade solvent suitable for use in both types of polymerization processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solvent purification technologies are used, then the purification process is simpler and less expensive, but the solvent cannot be effectively reused in both anionic and Ziegler-Natta polymerization processes due to insufficient removal of polar contaminants and unreacted monomers
Solution Approach 1:
The purification process is divided into multiple sequential stages: pre-washing with aqueous solution, liquid-liquid separation, azeotropic distillation, and adsorption. Each stage targets specific contaminants, progressively purifying the solvent to meet the stringent requirements for reuse in both anionic and Ziegler-Natta polymerization processes.
Solution Approach 2:
Different purification methods are applied at different stages to address specific contaminant types. Pre-washing removes water-soluble impurities, azeotropic distillation targets polar substances like alcohols and ethers, and adsorption on zeolites or activated aluminas removes remaining traces. This localized approach ensures comprehensive purification while optimizing process efficiency.
2Manufacturing precision
If conventional purification methods are used, then the process is less complex, but contaminants like ethanol and unreacted monomers are not effectively removed, leading to poor control of polymerization reactions and molecular-weight distribution
Solution Approach 1:
The solvent undergoes comprehensive purification before being reused in polymerization processes. Pre-washing with aqueous solutions removes polar contaminants in advance, and azeotropic distillation further eliminates trace polar substances and unreacted monomers. This preliminary purification ensures that the solvent meets the high precision requirements for controlling both anionic and Ziegler-Natta polymerization reactions.
Solution Approach 2:
The purification process utilizes changes in physical and chemical parameters to separate contaminants. Azeotropic distillation exploits differences in volatility and azeotropic composition, while adsorption on zeolites or activated aluminas utilizes surface area and pore structure to selectively adsorb polar substances. These parameter changes enable effective removal of contaminants that conventional methods cannot eliminate.
3Adaptability or versatility
If conventional purification technologies are used, then the operational costs are lower, but the solvent cannot be reused in both types of polymerization plants, leading to economic unfavorability
Solution Approach 1:
The purification process is designed to produce a universal solvent that can be reused in both anionic and Ziegler-Natta polymerization processes. By implementing comprehensive purification steps including pre-washing, liquid-liquid separation, azeotropic distillation, and adsorption, the process removes all contaminants that would interfere with either polymerization type, making the solvent universally applicable across different production plants.
Solution Approach 2:
The purification process exploits phase transitions to separate and remove contaminants. Azeotropic distillation utilizes vapor-liquid phase equilibrium to separate polar substances from the hydrocarbon solvent. Adsorption on zeolites or activated aluminas involves phase transition from liquid to adsorbed state on the porous material surface. These phase transitions enable effective contamination removal while producing a high-purity solvent suitable for reuse in both polymerization 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
This process effectively removes polar and water-soluble contaminants, enabling the reuse of the solvent in both anionic and Ziegler-Natta polymerization processes, improving reaction control and reducing economic and operational challenges.
Implementation Method 1
feeding said solvent to a liquid-liquid separation column; wherein in step (b), water is fed in countercurrent to said liquid-liquid separation column
Implementation Method 2
feeding the stream leaving the head of said liquid-liquid separation column to an azeotropic distillation column
Implementation Method 3
feeding the stream withdrawn laterally (side-withdrawal) from said azeotropic distillation column to an adsorption section
Data Source
AI summary
Process for the purification of the solvent deriving from the production of an elastomeric blend comprising the following steps: (a) optionally, subjecting said solvent to a pre-washing (2) in the presence of at least one acid or basic aqueous solution; (b) feeding said solvent to a liquid-liquid separation column (7); (c) feeding the stream leaving the head of said liquid-liquid separation column (7) to an azeotropic distillation column (21); (d) feeding the stream withdrawn laterally (side-withdrawal) from said azeotropic distillation column (21) to an adsorption section (34a/b); Said process allows to obtain a polymer grade solvent having a quality suitable for being used indifferently and contemporaneously in various types of production plants of elastomeric (co)polymers, i.e. in plants wherein an anionic (co)polymerization is carried out, and also in plants wherein a Ziegler-Natta (co)polymerization is carried out.