Bimodal Polymer Scale-Up for Consistent Melt Index and Density
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Solution Overview
Problem
The challenge in scaling up bimodal polymer production from a pilot plant to a larger facility lies in maintaining consistent polymer split and properties, as current methods lack real-time measurement and are prone to uncertainties due to catalyst concentration, poisons, flow meter offsets, and reactor conditions, leading to inconsistent melt index and density.
Innovation Solution
A method involving transitioning from a dual catalyst system to a single catalyst system in a pilot plant, followed by scaling up to a larger facility, adjusting catalyst ratios, and fine-tuning reactor conditions to maintain consistent melt index and density, using techniques such as H2/C2 reactor gas ratio, C6/C2 reactor feed ratio, and reactor residence time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dual catalyst system is used to produce bimodal polymer with specific melt index and density, then the polymer properties can be controlled, but the polymer split becomes inconsistent due to multiple variables affecting each catalyst
Solution Approach 1:
The patent extracts one catalyst from the dual catalyst system, transitioning from two catalysts to a single catalyst system. This eliminates the complexity of managing multiple catalysts while maintaining the ability to produce bimodal polymer with consistent properties through a single catalyst formulation.
Solution Approach 2:
The patent changes the catalyst system parameter from dual to single catalyst, and adjusts other process parameters (H2/C2 ratio, C6/C2 ratio, residence time) to compensate and achieve the desired polymer properties without the complexity of managing multiple catalysts.
2Productivity
If pilot plant data is used to scale up to commercial production, then production capacity increases, but offsets in process conditions cause uncertainties in achieving target polymer properties
Solution Approach 1:
The patent identifies and adjusts key process parameters (H2/C2 reactor gas ratio, C6/C2 reactor feed ratio, reactor residence time) to account for scale-up offsets between pilot plant and commercial production, ensuring consistent polymer properties across different production scales.
Solution Approach 2:
The patent uses measured polymer properties (melt index, density) as feedback to adjust process conditions during scale-up, allowing real-time optimization to maintain target polymer specifications when transitioning from pilot to commercial scale.
3Manufacturing precision
If multiple process conditions are adjusted to achieve target melt index and density, then polymer properties can be optimized, but the polymer split cannot be measured in real-time to verify consistency
Solution Approach 1:
The patent replaces complex analytical measurement systems (GPC combined with TREF) with simpler, faster measurement methods suitable for manufacturing QC laboratories, enabling real-time or near-real-time verification of polymer properties without sacrificing essential measurement accuracy.
Solution Approach 2:
The patent focuses measurement efforts on key parameters (melt index, density) that can be measured quickly and reliably, rather than attempting to measure all polymer characteristics, enabling practical real-time quality control in production environments.
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
Ensures production of bimodal polymer with consistent melt index and density across different scales by stabilizing catalyst ratios and reactor conditions, addressing uncertainties in the scale-up process.
Implementation Method 1
gas phase polyethylene polymerization using a single catalyst system and/or a dual catalyst system
Implementation Method 2
the partial pressures of ethylene, hexene-1, and hydrogen, reactor temperature and residence time
Implementation Method 3
reactor temperature
Data Source
AI summary
Methods for scale-up from a pilot plant to a larger production facility of a bimodal polymer product having a density, a melt index and melt index ration are provided herein.