Ethylene Polymerization Catalyst Component with Controlled Particle Size
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Solution Overview
Problem
Current catalyst systems for ethylene polymerization, particularly in the slurry process, face challenges in achieving high catalytic activity, uniform particle diameter, narrow particle size distribution, and good hydrogen response, which are essential for producing ethylene homopolymers and copolymers with desired properties.
Innovation Solution
A catalyst component is prepared by reacting a magnesium complex with a titanium compound, an alcohol compound, and a silicon compound, optionally including an organic aluminum compound, in a solvent system containing an organic epoxy compound and an organophosphorus compound, to form a catalyst with improved activity and particle morphology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a magnesium compound is dissolved in a solvent to form a homogeneous solution, then the solution can be combined with a titanium compound to precipitate solids comprising magnesium and titanium, but the particle size and particle size distribution of the catalyst particles are controlled fully through the precipitation process which is a process of recrystallizing magnesium-containing support and of which stable control is difficult
Solution Approach 1:
The patent applies preliminary action by pre-forming magnesium support particles with controlled size and morphology before titanium compound impregnation. The magnesium support is prepared in advance with specific particle characteristics, then titanium compounds are loaded onto this pre-formed support structure. This separates the particle formation step from the catalyst activation step, making particle size control more stable and predictable.
Solution Approach 2:
The patent segments the catalyst preparation into distinct steps: first preparing magnesium support particles with controlled morphology, then separately impregnating with titanium compounds. This segmentation allows independent optimization of support particle characteristics and catalyst active component loading, improving overall manufacturing precision.
2Ease of manufacture
If organic substance such as phthalic anhydride is used as precipitator to facilitate the precipitation of solids, then the precipitation process can be facilitated, but the presence of an anhydride may adversely affect the catalyst and a large amount of titanium tetrachloride is required
Solution Approach 1:
The patent extracts and removes the harmful anhydride precipitator from the system. Instead of using phthalic anhydride or similar organic precipitators that can adversely affect catalyst activity, the invention employs alternative precipitation methods or agents that do not interfere with catalyst performance. This eliminates the harmful factor while maintaining the ease of precipitation.
Solution Approach 2:
The patent replaces expensive and harmful titanium tetrachloride (used as precipitator) with more economical and environmentally friendly alternatives. By using disposable or regenerable precipitation agents that do not require large amounts of toxic TiCl4, the process becomes both easier to manufacture and safer for the catalyst.
3Manufacturing precision
If an active component of a catalyst is supported directly on an inert support, then particulate catalysts having uniform particles can be obtained, but the loaded amount of an active component on a support is limited and thereby a lower Ti content and lower polymerization activity
Solution Approach 1:
The patent employs composite materials by combining magnesium support particles with titanium compounds to form a composite catalyst structure. Rather than using simple inert supports with limited loading capacity, the magnesium-titanium composite allows higher titanium content while maintaining uniform particle morphology. The composite structure provides both structural integrity and increased active component capacity.
Solution Approach 2:
The patent changes the support material parameter from conventional inert supports to magnesium-based supports, which have different physical and chemical properties that enable higher titanium loading. By adjusting the support composition and characteristics, the system achieves both uniform particle distribution and increased titanium content for higher polymerization activity.
4Ease of manufacture
If a large amount of titanium tetrachloride is required, then the precipitation process can proceed, but the production cost of the catalyst increases and the problem of environmental pollution is aggravated
Solution Approach 1:
The patent replaces expensive titanium tetrachloride (used as precipitator) with more economical alternatives. By using cheaper precipitation agents or methods, the process remains easy to manufacture while significantly reducing titanium tetrachloride consumption, thereby lowering production costs and environmental pollution.
Solution Approach 2:
The patent converts the harmful and expensive role of titanium tetrachloride as precipitator into a beneficial use only where necessary. By eliminating its use as precipitator and retaining it only as essential catalyst active component, the invention reduces overall TiCl4 consumption while maintaining catalyst functionality. This transforms a harmful practice into a more sustainable process.
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 resulting catalyst exhibits high catalytic activity, good hydrogen response, and a narrow particle size distribution, making it suitable for ethylene polymerization, especially in the slurry process, while reducing the need for excessive titanium tetrachloride and avoiding the use of harmful precipitators like phthalic anhydride.
Implementation Method 1
the solution is combined with a titanium compound and optionally an electron donor compound, to precipitate solids comprising magnesium, titanium, and optionally the electron donor compound
Implementation Method 2
a magnesium compound, for example magnesium dichloride, is dissolved in a solvent to form a homogeneous solution
Data Source
AI summary
The present invention relates to a catalyst component for ethylene polymerization, which comprises a reaction product of a magnesium complex, at least one titanium compound, at least one alcohol compound, at least one silicon compound, and optionally an organic aluminum compound. The silicon compound is an organic silicon compound having a general formula R1xR2ySi(OR3)z, in which R1 and R2 are independently a hydrocarbyl or a halogen, R3 is a hydrocarbyl, 0≤x≤2, 0≤y≤2, 0≤z≤4, and x+y+z=4. The present invention further relates to a method for the preparation of the catalyst component and to a catalyst comprising the same. The catalysts according to the invention have virtues such as high catalytic activity, good hydrogen response, and narrow particle size distribution of polymer, and are especially suitable for a slurry process of ethylene polymerization and a combined process of ethylene polymerization, which requires a high activity of catalyst.