Filter-Free Ti3+ MgCl2 Catalyst for Olefin Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnesium-titanium catalysts for olefin polymerization are not sufficiently active to allow for the use of catalyst residues in polyolefins without causing quality issues, such as degradation and oxidation, and face challenges in scaling up due to filtration requirements.
Innovation Solution
Development of a filter-free procatalyst system using a Ti3+ complex on a delta form MgCl2 support, prepared without filtration or washing steps, with specific mole ratios of magnesium, titanium, and aluminum components, and an aluminum alkyl activator, enabling high-temperature solution polymerization for increased comonomer incorporation and molecular weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional magnesium-titanium catalysts are used for olefin polymerization, then the catalyst can be prepared and used, but the catalyst activity is insufficient and catalyst residues cause polymer quality problems such as degradation and oxidation
Solution Approach 1:
The invention changes the oxidation state parameter of titanium from traditional Ti(IV) to Ti(III), and optimizes the Mg/Ti molar ratio to 5-10. These parameter changes create a highly active catalyst system where at least 60% of titanium is in the +3 oxidation state, significantly improving catalyst activity while reducing residual catalyst impurities that cause polymer degradation and oxidation.
Solution Approach 2:
The invention creates a composite catalyst system comprising magnesium halide support, Ti(III) active centers, and aluminum alkyl/co-catalyst components. This composite structure with specific stoichiometric ratios (Al/Ti = 0.7-3.0) produces a synergistic effect that enhances catalyst activity and selectivity, enabling high polymerization activity while minimizing harmful residual catalyst in the polymer product.
2Manufacturing precision
If filtration and washing steps are included in catalyst preparation, then catalyst purity can be improved, but the process complexity and difficulty of scaling up increase
Solution Approach 1:
The invention extracts and eliminates the filtration and washing steps from the traditional catalyst preparation process. By optimizing the in-situ formation process with specific reagent ratios and addition sequences, the catalyst slurry is prepared directly in its final form without requiring separation operations, thereby simplifying the process while maintaining catalyst quality.
Solution Approach 2:
The catalyst preparation process is designed to be self-cleaning, where the reaction conditions and reagent ratios are optimized such that the catalyst forms directly in a clean, filter-free state. The in-situ generated catalyst slurry requires no external filtration or washing assistance, making the process inherently simple and easily scalable.
3Reliability
If filtration steps are required in catalyst preparation, then catalyst quality can be maintained, but the scaling up to commercial volumes becomes difficult
Solution Approach 1:
The invention implements a continuous in-situ catalyst preparation and polymerization process where the catalyst is generated directly in the polymerization reactor. This continuous process eliminates batch filtration operations, allowing for seamless scaling from laboratory to commercial production while maintaining consistent catalyst quality. The process flows continuously without interruption for filtration or washing.
4Strength
If high temperature solution polymerization is used to increase comonomer incorporation and molecular weight, then polymer properties are improved, but catalyst activity requirements increase
Solution Approach 1:
The invention employs Ti(III) instead of traditional Ti(IV) and uses high Mg/Ti ratios (5-10) to create a catalyst system with exceptionally high activity. This parameter change enables the catalyst to maintain high productivity even under high temperature solution polymerization conditions (up to 100°C), where comonomer incorporation and molecular weight are enhanced.
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 solution achieves high catalyst activity with reduced residual titanium and halogen impurities, facilitating the production of polyolefins with improved properties and simplifying the scaling process by eliminating filtration steps.
Implementation Method 1
Ti3+ complex of the formula TiCl3*[[R4]a[R5O]bAlX3-c]d... for polymerization of ethylene and α-olefins
Implementation Method 2
adding an aluminum alkyl activator to the reactor in a molar ratio of about 1 to about 10 relative to the amount of procatalyst
Data Source
AI summary
The various embodiments provide, a magnesium titanium polymerization procatalyst, and methods for making and using the same.