Prepolymerized Catalyst Component for Olefin Polymerization
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Solution Overview
Problem
Gas-phase polymerization processes face issues with reactor throughput limitations due to particle entrainment, catalyst aging, and unloading difficulties, particularly in plants without prepolymerization units, leading to increased maintenance costs and production losses.
Innovation Solution
A prepolymerized catalyst component with a specific molar ratio of Mg/Ti and internal donor to Mg, using alkyl esters of aromatic dicarboxylic acids, is developed, which includes ethylene polymerization up to 50 g per g of solid catalyst component, optimizing particle size and porosity for improved activity and handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas mass flow rate is increased to maximize reactor throughput, then production efficiency improves, but particle entrainment increases causing maintenance costs and production losses
Solution Approach 1:
The patent changes the physical parameters of the catalyst particles through controlled prepolymerization, increasing particle size and density to specific ranges (0.3-0.5 g/cm³ density, 50-150 μm size) that allow higher gas velocities without entrainment, thus resolving the contradiction between throughput and particle loss
2Productivity
If catalyst activity is increased to improve productivity, then polymerization efficiency improves, but catalyst fragmentation increases leading to fines formation
Solution Approach 1:
The patent applies preliminary action by performing prepolymerization before the main polymerization process, where catalyst particles are pre-coated with a polymer layer that strengthens them and prevents fragmentation during high-activity polymerization, thus maintaining both high productivity and low fines formation
3Reliability
If prepolymerization unit is added to prevent catalyst aging, then catalyst activity is maintained, but plant complexity and investment cost increase
Solution Approach 1:
The patent merges the prepolymerization function into the catalyst formulation itself by incorporating internal electron donors and optimizing the Mg/Ti ratio, allowing the catalyst to maintain activity without requiring a separate prepolymerization unit, thus reducing plant complexity while maintaining reliability
4Adaptability or versatility
If prepolymerized catalyst is stored for later use, then flexibility in production scheduling improves, but catalyst aging reduces activity
Solution Approach 1:
The patent performs preliminary action by incorporating stabilizing components (internal electron donors) during catalyst preparation that prevent aging during storage, allowing the catalyst to be stored without significant activity loss while maintaining production scheduling flexibility
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 enhances catalyst activity and minimizes unloading issues, achieving higher reactor throughput and maintaining polymerization efficiency while reducing fines formation and storage-related losses, even in plants without prepolymerization units.
Implementation Method 1
a pre-polymerized catalyst component for the polymerization of olefins CH2＝CHR... comprising a solid catalyst component characterized by comprising Mg, Ti and an electron donor (ID) selected from the alkyl esters of aromatic dicarboxylic acids
Implementation Method 2
said solid catalyst component containing an amount of ethylene polymer up to 50 g per g of said solid catalyst component
Data Source
AI summary
Prepolymerized catalyst component for the polymerization of olefins CH2═CHR, wherein R is hydrogen or a C1-C12 hydrocarbyl group, comprising a solid catalyst component characterized by comprising Mg, Ti halogen and an electron donor (ID) selected from the alkyl esters of aromatic dicarboxylic acids in such an amount that the molar ratio ID/Mg ranges from 0.025 to 0.07 and the Mg/Ti molar ratio is higher than 13, said prepolymerized catalyst component containing an amount of ethylene pre-polymer up to 50 g per g of said solid catalyst component.