C3 Splitter Column Propane Fraction Optimization
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Solution Overview
Problem
The existing processes for epoxidation of propene with hydrogen peroxide face challenges in efficiently using propene starting materials containing propane, leading to high energy consumption and equipment requirements due to the accumulation of propane in the process, as conventional C3 splitter columns operate with high reflux ratios and large equipment sizes.
Innovation Solution
A process is developed where propene is reacted with hydrogen peroxide in excess, with a C3 splitter column operated to provide a vapor stream enriched in propene and depleted in propane, allowing for the separation and recycling of propene with a reduced propane fraction, thereby minimizing equipment size and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional C3 splitter column is used to separate propane from propene with high purity requirements, then the propene can be recycled efficiently, but the equipment size and energy consumption increase significantly
Solution Approach 1:
The invention changes the operating parameters of the C3 splitter column by allowing a higher propane content (up to 5 mol%) in the recycled propene stream. This parameter change enables the column to operate with lower reflux ratios and reduced energy consumption while still maintaining sufficient propene conversion in the epoxidation reactor, thus resolving the contradiction between recycling efficiency and energy consumption.
2Manufacturing precision
If propene is used in molar excess relative to hydrogen peroxide to achieve high selectivity, then propene oxide selectivity improves, but propane accumulation increases in the recycle stream
Solution Approach 1:
The invention extracts propane from the recycle stream by allowing its controlled accumulation up to a defined threshold (5 mol%) and removing it through the C3 splitter column. This selective removal of the harmful component (propane) while maintaining the beneficial operating conditions (propene excess) resolves the contradiction between achieving high selectivity and preventing propane accumulation.
3Manufacturing precision
If the C3 splitter column operates with high reflux ratio to achieve complete propane removal, then propene purity in recycle stream increases, but equipment complexity and operating costs increase
Solution Approach 1:
The invention applies partial action by allowing a small amount of propane (up to 5 mol%) to remain in the recycled propene stream rather than completely removing it. This partial removal approach simplifies the C3 splitter column operation, reducing reflux ratios and operating complexity while still maintaining sufficient propene purity for effective epoxidation reaction.
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 energy consumption and equipment size of the C3 splitter column while maintaining high selectivity for propene oxide, allowing for efficient recycling and utilization of propene starting materials containing propane.
Implementation Method 1
separating propene and propane in a C3 splitter column to provide a vapor at the column top with a propane fraction of at least 0.04
Implementation Method 2
reacting propene with hydrogen peroxide in the presence of an epoxidation catalyst to provide a reaction mixture comprising propene oxide
Implementation Method 3
epoxidation of propene with hydrogen peroxide
Data Source
AI summary
In a process for the epoxidation of propene, comprising the steps of reacting propene with hydrogen peroxide, separating propene oxide and a recovered propene stream from the reaction mixture, separating propane from all or a part of the recovered propene stream in a C3 splitter column, and passing the overhead product stream of the C3 splitter column to the epoxidation step, a propane starting material with a propane fraction of from 0.002 to 0.10 is used, the epoxidation is operated to provide a propane fraction in the reaction mixture of from 0.05 to 0.20 and the C3 splitter column is operated to provide an overhead product stream which comprises a propane fraction of at least 0.04 in order to reduce the size and the energy consumption of the C3 splitter column.