Ethylene Polymerization Feed Temperature and Solvent Rate Optimization
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Solution Overview
Problem
Current polymerization processes for ethylene-alpha-olefin polymers face challenges in energy and catalyst utilization, particularly in large-scale production, where pre-cooling to low temperatures results in high energy consumption and inefficient catalyst use.
Innovation Solution
A polymerization process that involves supplying a feed containing ethylene and alpha-olefin in a solvent to a reactor at a first temperature above -80°C, then decreasing the temperature and solvent and catalyst feed rates to increase polymer concentration and catalyst efficiency, while maintaining polymer production rates and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the feed temperature is decreased to increase polymer yield, then the polymer concentration increases, but the energy consumption increases dramatically
Solution Approach 1:
The patent changes the feed temperature parameter from conventional low temperatures (-80°C or lower) to a higher range (-30°C to +50°C), thereby reducing energy consumption for pre-cooling while maintaining acceptable polymer yield through optimized catalyst and solvent parameters
Solution Approach 2:
The patent applies preliminary cooling to the feed before it enters the reactor, but at moderate temperatures only, rather than extreme low temperatures. This preliminary action is sufficient to control the exothermic polymerization reaction while avoiding dramatic energy consumption
2Quantity of substance
If the feed temperature is decreased to improve polymer yield, then the polymer concentration increases, but the catalyst utilization decreases
Solution Approach 1:
The patent changes multiple parameters simultaneously: feed temperature (increased to -30°C to +50°C), solvent type (changed to ethers, esters, or carbon dioxide), and catalyst selection (specific Ziegler-Natta or metallocene catalysts), thereby improving catalyst utilization while maintaining polymer yield
3Quantity of substance
If the solvent feed rate is decreased to increase polymer concentration, then the polymer concentration increases, but the heat removal capability decreases
Solution Approach 1:
The patent changes the solvent type parameter from conventional hydrocarbons to ethers, esters, or carbon dioxide, which have different thermal properties. This allows for effective heat removal even at lower solvent feed rates, enabling higher polymer concentrations while maintaining temperature control
Solution Approach 2:
The patent uses modified solvents (ethers, esters, or carbon dioxide) as intermediaries that facilitate both heat removal and polymerization control, allowing the system to achieve high polymer concentration without sacrificing thermal management capability
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 improves energy and catalyst utilization by reducing energy consumption and catalyst usage, with increased polymer concentration and efficiency, and minimizes changes to existing polymerization plants and polymer attributes.
Implementation Method 1
the heat of polymerization usually needs to be removed, for example, by using cooled solvent
Data Source
Figure 1
AI summary
The present invention relates to a polymerization process of producing ethylene- alpha-olefin polymer. The polymerization process comprises supplying at a feed temperature a feed containing ethylene, at least one alpha-olefin and optionally, a diene in a solvent, the solvent is supplied at a solvent feed rate; supplying at a catalyst feed rate a catalyst to a reactor, and contacting the feed with the catalyst to produce a reaction mixture containing the polymer. The present invention also relates to processes for improving the energy utilization of polymerization processes, wherein the process comprises decreasing the feed temperature, decreasing the solvent feed rate, and decreasing the catalyst feed rate.