Integrated Ethylene Process Oxygen Removal
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Solution Overview
Problem
The integration of steam cracking and ethane oxidative dehydrogenation (ODH) processes poses safety and product specification risks due to the introduction of unconverted oxygen into the steam cracker process, which can lead to explosion hazards and undesired trace chemistry.
Innovation Solution
A process is developed that integrates a steam cracker configuration with an ODH configuration, where unconverted oxygen, carbon monoxide, and acetylene from the ODH effluent are removed by oxidation into carbon dioxide in an oxidation unit located downstream of the ODH unit and upstream of the carbon dioxide removal unit in the steam cracker configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If unconverted oxygen from ODH effluent is fed to the steam cracker configuration, then the productivity of ethylene production is improved, but safety risks and explosion hazards increase
Solution Approach 1:
The harmful unconverted oxygen is extracted and removed from the ODH effluent stream before it enters the steam cracker configuration. This is achieved by introducing a separate oxidation unit that selectively removes oxygen through oxidation of carbon monoxide and acetylene, thereby eliminating the explosion hazard while preserving the beneficial components (ethylene and unconverted ethane) for further processing
Solution Approach 2:
An oxidation unit is introduced as an intermediary component between the ODH configuration and the steam cracker configuration. This intermediary unit performs the function of removing unconverted oxygen by oxidizing carbon monoxide and acetylene into carbon dioxide, which is then subsequently removed in the carbon dioxide removal unit, thus mediating the safe integration of the two processes
2Productivity
If unconverted oxygen from ODH effluent is fed to the steam cracker configuration, then the productivity of ethylene production is improved, but product specification quality deteriorates due to undesired trace chemistry
Solution Approach 1:
The unconverted oxygen that causes undesired trace chemistry is extracted and removed from the effluent stream before it can interfere with subsequent ethylene conversion processes. The oxidation unit selectively targets and removes oxygen through the oxidation of carbon monoxide and acetylene, ensuring that only purified streams enter the steam cracker configuration and maintain product specification quality
Solution Approach 2:
The oxidation unit performs preliminary removal of unconverted oxygen and conversion of carbon monoxide and acetylene into carbon dioxide before the effluent enters the steam cracker configuration. This preliminary action prevents the formation of undesired trace chemistry products and ensures that the subsequent ethylene conversion processes operate with high-quality feedstock
3Reliability
If an oxidation unit is added to remove unconverted oxygen, carbon monoxide and acetylene, then safety risks are reduced, but device complexity increases
Solution Approach 1:
The oxidation unit is integrated into the existing process configuration by merging it with the carbon dioxide removal unit. The oxidation unit converts carbon monoxide and acetylene into carbon dioxide, which is then removed in the same carbon dioxide removal unit that already exists in the steam cracker configuration. This merging approach reduces the number of separate units required and simplifies the overall process configuration while maintaining safety
Solution Approach 2:
The carbon dioxide removal unit is designed to perform multiple functions: it removes carbon dioxide produced from the oxidation of carbon monoxide and acetylene in the oxidation unit, as well as carbon dioxide from the steam cracker process itself. This multi-functionality reduces the need for separate dedicated units for each removal function, thereby reducing device complexity
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 effectively removes unconverted oxygen before it enters the back-end distillation section of the steam cracker, thereby reducing safety and integrity risks, and results in a more efficient and affordable ethylene production process with lower energy demand and capital expenditure.
Implementation Method 1
removing unconverted oxygen, carbon monoxide and acetylene from at least a portion of the stream coming from the ODH unit by oxidation of carbon monoxide and acetylene into carbon dioxide in an oxidation unit
Implementation Method 2
subjecting a stream comprising saturated hydrocarbons to steam cracking conditions in the steam cracker unit, resulting in a stream comprising water, unconverted ethane, ethylene, acetylene, hydrogen, methane, carbon monoxide, carbon dioxide and C3+ hydrocarbons
Implementation Method 3
subjecting a stream comprising ethane and oxygen to oxidative dehydrogenation (ODH) conditions in the ODH unit, resulting in a stream comprising unconverted ethane, ethylene, acetylene, unconverted oxygen, water, carbon monoxide and carbon dioxide
Data Source
AI summary
The invention relates to a process for the production of ethylene in an integrated configuration comprising (i) a steam cracker configuration which comprises a steam cracker unit, a water condensation unit and a carbon dioxide removal unit and (ii) an oxidative dehydrogenation (ODH) configuration which comprises an ODH unit and a water condensation unit, wherein an effluent coming from the ODH configuration, which effluent comprises unconverted ethane and ethylene, is fed to the steam cracker configuration at a position which is downstream of the steam cracker unit, and wherein unconverted oxygen, carbon monoxide and acetylene are removed from at least a portion of the stream coming from the ODH unit by oxidation of carbon monoxide and acetylene into carbon dioxide in an oxidation unit which is located at a position (a) which is downstream of the ODH unit, and (b) which is downstream of the steam cracker unit and upstream of the carbon dioxide removal unit of the steam cracker configuration.