Ethylene Oxide Reabsorption Column Pressure Optimization
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Solution Overview
Problem
The production of ethylene oxide is hindered by the formation of ethylene glycol as a by-product, which reduces the yield and purity of ethylene oxide, as it requires additional steps to manage and discharge this by-product, thereby lowering overall efficiency.
Innovation Solution
Adjusting the operation pressures of the ethylene oxide reabsorption and stripper columns to specific ranges (3 to 50 kPa gauge and 3 to 60 kPa gauge respectively) and maintaining a column bottom temperature of 101 to 110°C in the stripper column to minimize ethylene glycol production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ethylene oxide is recovered in the ethylene oxide reabsorption column, then ethylene oxide can be recovered from uncondensed gas, but water molecules attach to ethylene oxide to produce ethylene glycol as a by-product, reducing yield and purity
Solution Approach 1:
The invention changes the operating parameters of the reabsorption column, specifically setting the column top pressure to 3 to 50 kPa gauge and the column bottom temperature to 101 to 110°C. These parameter changes optimize the absorption process to recover ethylene oxide while minimizing the formation of ethylene glycol by-product, thus resolving the contradiction between recovery efficiency and yield loss.
2Stability of the object's composition
If ethylene glycol is discharged to the outside of the system or fed to an ethylene glycol production plant to prevent concentration, then by-product concentration is controlled, but the yield of ethylene oxide is lowered due to additional processing steps
Solution Approach 1:
The invention applies preliminary anti-action by optimizing the reabsorption column parameters to prevent the formation of ethylene glycol in the first place. By controlling the column top pressure to 3 to 50 kPa gauge and column bottom temperature to 101 to 110°C, the process prevents water molecules from attaching to ethylene oxide, thereby avoiding by-product formation before it occurs and eliminating the need for subsequent discharge or processing steps.
3Reliability
If conventional operating parameters are used in the ethylene oxide reabsorption column, then the process operates stably, but ethylene glycol by-product is produced, requiring additional steam and water for concentration or discharge
Solution Approach 1:
The invention changes the operating parameters from conventional values to optimized values: column top pressure set to 3 to 50 kPa gauge and column bottom temperature set to 101 to 110°C. These parameter changes maintain process stability while preventing ethylene glycol formation, thereby eliminating the need for additional steam and water consumption for by-product management.
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 the amount of ethylene glycol produced as a by-product, enhancing the yield of ethylene oxide and minimizing the need for steam and water input for its concentration or discharge, thereby improving the overall process efficiency.
Implementation Method 1
bringing the reaction product gas into contact with an absorption liquid supplied to the ethylene oxide absorption column
Implementation Method 2
supplying an ethylene oxide-containing column bottom liquid of the ethylene oxide absorption column to an ethylene oxide stripper column
Implementation Method 3
a column bottom temperature of the ethylene oxide stripper column is set to 101 to 110°C
Implementation Method 4
supplying an ethylene oxide-containing uncondensed gas discharged from the ethylene oxide purification system to an ethylene oxide reabsorption column
Data Source
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AI summary
The purpose of the present invention is to provide a means which can inhibit an ethylene oxide production process from yielding ethylene glycol as a by-product and can improve the yield of ethylene oxide. The ethylene oxide (EO) production process comprises the steps of feeding, to an EO absorption tower, an EO-containing reaction product gas produced in an ethylene oxidation step in which ethylene is subjected to catalytic vapor-phase oxidation with a gas containing molecular oxygen, in the presence of a silver catalyst, bringing the reaction product gas into contact with an absorbing liquid supplied to the absorption tower, feeding the EO-containing bottoms from the absorption tower to an EO purification system, and supplying the EO-containing uncondensed gas discharged from the purification system to an EO re-absorption tower, the re-absorption tower being operated at a pressure (tower top pressure) of 3-50 kPa gauge.