Continuous Catalyst Activator for Chromium Valence Conversion
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Solution Overview
Problem
Current methods for converting chromium catalysts from trivalent to hexavalent state for polymerization reactions are inefficient due to reliance on extensive temperature cycling and manual processes, requiring long times and increased operational complexity.
Innovation Solution
A continuous catalyst activator system using a fluidized bed process that maintains chromium catalysts in a hexavalent state through controlled heating and gas treatment, allowing for simultaneous activation and reduction, with a controller for optimizing reactor parameters and catalyst feed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If batch processes with thermal cycling are used to convert chromium from trivalent to hexavalent state, then the conversion can be achieved, but the process time is long and operational complexity increases
Solution Approach 1:
The patent implements a continuous catalyst activation process where chromium-containing catalyst precursor is continuously fed into a fluidized bed reactor, converted to hexavalent chromium continuously, and discharged continuously. This eliminates the batch-wise heating and cooling cycles, maintaining continuous operation throughout the activation process, thereby dramatically reducing the time loss associated with thermal cycling.
Solution Approach 2:
The patent changes the operational parameters from batch-mode thermal cycling to continuous-mode controlled temperature operation. By maintaining a steady temperature in the fluidized bed reactor and continuously adjusting feed rate and gas flow, the system achieves efficient chromium valence conversion without the need for repeated heating and cooling cycles, thus improving productivity while minimizing time loss.
2Productivity
If extensive temperature cycling is used for catalyst activation, then chromium valence conversion is achieved, but operational complexity and manual intervention increase
Solution Approach 1:
The continuous operation eliminates the need for complex temperature cycling control. A single steady-state temperature control system replaces multiple heating and cooling phases, simplifying the control architecture while maintaining high activation efficiency through continuous material flow and reaction.
Solution Approach 2:
The patent replaces mechanical batch processing with automated continuous flow systems. The fluidized bed reactor with continuous feeding and discharge mechanisms, coupled with automated gas flow control and temperature regulation, reduces manual intervention and simplifies operational complexity while maintaining high productivity.
3Ease of operation
If batch processes are used for catalyst activation, then the process can be operated, but manual aspects of operation increase
Solution Approach 1:
The continuous catalyst activation process enables full automation by eliminating batch-wise manual operations. Catalyst precursor is continuously fed, converted in the fluidized bed, and discharged automatically, allowing the system to run unattended for extended periods and significantly reducing the time loss associated with batch processing cycles.
Solution Approach 2:
The continuous system is designed to maintain steady-state operation with automatic control of feed rate, gas flow, and temperature. The system self-regulates through feedback control mechanisms, minimizing the need for manual adjustment and intervention, thereby improving ease of operation while reducing overall processing time.
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 approach reduces process time, minimizes manual intervention, and achieves higher catalyst activity and polyolefin production efficiency, with the ability to store and continuously feed activated catalysts to polymerization reactors, enhancing operational efficiency and product quality.
Implementation Method 1
the catalyst is heated to a maximum temperature in the presence of at least one agent within the fluidized bed continuous catalyst activator
Implementation Method 2
The catalyst is maintained at the maximum temperature for an average hold time
Implementation Method 3
the catalyst is contacted with the at least one agent to convert a valence of at least a portion of the chromium contained within the catalyst from its trivalent state (hereinafter "Cr(III)") to a hexavalent state (hereinafter "Cr(VI)")
Implementation Method 4
After activation, the valence-converted catalyst is cooled in a presence of an oxygenating agent
Data Source
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AI summary
Methods and systems for preparing catalyst, such as chromium catalysts, are provided. The valence of at least a portion of the catalyst sent to an activator is changed from Cr(III) to Cr(VI). The catalyst is prepared or activated continuously using a fluidization bed catalyst activator.