Epoxidation Process Moderator Control
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Solution Overview
Problem
The optimization of moderator concentration in catalytic oxidation of ethylene to ethylene oxide is a laborious and time-consuming process, requiring incremental adjustments by skilled operators to maintain catalyst efficiency, especially when temperature changes, and existing methods are inadequate due to linear correlations that do not accurately represent the exponential relationship between moderator concentration and temperature.
Innovation Solution
A method that correlates the change in moderator concentration with temperature using an exponential relationship (M2 = M1 * e^(r * (T2 - T1)) to maintain peak catalyst efficiency, allowing for automated or manual adjustments without the need for complex calculations or skilled expertise, where r is a constant factor between 0.001% and 100%.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If incremental trial-and-error adjustments of moderator concentration are used to optimize catalyst efficiency, then catalyst selectivity and activity can be maintained, but the process becomes laborious, time-consuming, and requires skilled operators
Solution Approach 1:
The patent implements a feedback control system where the actual moderator concentration is continuously measured and compared with the target concentration calculated from the exponential relationship with temperature. The system automatically adjusts the moderator concentration to maintain optimal catalyst efficiency, eliminating manual trial-and-error optimization and reducing dependency on skilled operators.
Solution Approach 2:
The control system automatically maintains optimal catalyst efficiency by self-adjusting the moderator concentration based on the exponential temperature relationship. The system serves itself by continuously monitoring temperature, calculating the appropriate moderator concentration, and making adjustments without requiring external skilled intervention, thereby reducing optimization time and labor requirements.
2Ease of operation
If linear correlation methods are used to adjust moderator concentration with temperature, then the control process is simple, but the accuracy of maintaining optimum catalyst performance is insufficient due to the exponential relationship between moderator concentration and temperature
Solution Approach 1:
The patent changes the mathematical model from a linear correlation to an exponential relationship between temperature and moderator concentration. This parameter change in the control strategy accurately reflects the true physical relationship, maintaining manufacturing precision while keeping the control process straightforward through automated calculation based on the exponential formula.
3Extent of automation
If automated control systems are implemented using the exponential relationship, then the need for skilled operators and iterative adjustments is reduced, but the complexity of the control system increases
Solution Approach 1:
The patent replaces manual mechanical adjustment operations with an automated electronic control system. The exponential relationship is implemented through software calculation and automatic control, substituting the need for skilled human operators with an automated system that handles the complexity internally while presenting a simple interface.
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 enables straightforward maintenance of optimum selectivity and activity across varying temperatures, reducing the need for iterative adjustments and allowing for automation, thus improving the efficiency and reliability of the catalytic process.
Implementation Method 1
reacting a feed gas composition containing an olefin, oxygen, and a halocarbon moderator having a first moderator concentration M1 in the presence of an epoxidation catalyst
Implementation Method 2
Halogen-containing compounds, especially chlorohydrocarbons, have long been used in the feed mixture for the gas phase production of ethylene oxide
Data Source
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AI summary
A method for the epoxidation of an olefin comprising reacting a feed gas composition containing an olefin, oxygen, and a halocarbon moderator having a first moderator concentration M1 in the presence of an epoxidation catalyst at a first temperature T1; increasing the first temperature to a second temperature T2; and increasing the first moderator concentration to a second moderator concentration M2, wherein the second moderator concentration is defined by: M2 = M1(1 + r)T2-T1 where in the temperature has the units of degrees Celsius, and r is a constant factor which is in the range of from 0.001% to 100%.