Dehydrogenation Catalyst Oxygen Removal via Supplemental Hydrogen
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Solution Overview
Problem
Dehydrogenation reactor systems face unsafe operating conditions due to excess oxygen buildup during non-normal operating conditions, such as start-up, shutdown, or system recycle, which can lead to exothermic reactions and explosions, as free oxygen does not react with hydrocarbons at lower temperatures.
Innovation Solution
Introducing supplemental hydrogen into the dehydrogenation system to combust free oxygen carried by the catalyst, ensuring oxygen is removed through a combustion reaction even at temperatures below 550°C, where natural hydrogen production is insufficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If dehydrogenation reactor operates at lower temperatures during non-normal conditions, then energy consumption is reduced, but oxygen buildup occurs leading to unsafe operating conditions
Solution Approach 1:
The patent converts the harmful effect of free oxygen buildup into a beneficial combustion reaction by introducing supplemental hydrogen. The free oxygen that would normally accumulate safely during low-temperature non-normal operations is instead utilized to combust with hydrogen, eliminating the safety hazard while maintaining low operating temperatures.
Solution Approach 2:
The patent introduces supplemental hydrogen as an intermediary substance to mediate between the free oxygen on the catalyst and the desired safe operating state. This intermediary enables the combustion reaction that removes oxygen without requiring high temperatures or hydrocarbon feeds.
2Object-affected harmful factors
If supplemental hydrogen is introduced to combust free oxygen, then oxygen buildup is eliminated, but system complexity increases
Solution Approach 1:
The system utilizes the free oxygen already present on the catalyst during non-normal operations to combust with supplemental hydrogen. The catalyst itself serves as the oxygen source, and the combustion process automatically occurs when hydrogen is introduced, requiring minimal additional control infrastructure.
3Object-affected harmful factors
If hydrogen is used to combust oxygen at low temperatures, then safety is improved, but hydrogen consumption increases
Solution Approach 1:
The patent applies partial action by introducing supplemental hydrogen only during non-normal operating conditions when free oxygen buildup is detected, rather than continuously. The hydrogen introduction is targeted and limited to the specific timeframe and conditions when oxygen removal is necessary, minimizing overall hydrogen consumption.
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
Effectively mitigates or eliminates oxygen buildup, preventing unsafe conditions by ensuring complete combustion of free oxygen, even under low-temperature non-normal operating conditions, thereby enhancing safety and process stability.
Implementation Method 1
contacting the catalyst with supplemental hydrogen, the contacting removing at least a portion of the oxygen from the catalyst by a combustion reaction
Data Source
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AI summary
According to one or more embodiments disclosed herein, methods for operating dehydrogenation processes during non-normal operating conditions, such as at start-up, shut-down, system recycle, or unit trip, are described. The methods may include contacting a feed stream with a catalyst in a reactor portion of a reactor system to form a reactor effluent stream, separating at least a portion of the reactor effluent stream from the catalyst, passing the catalyst to a catalyst processing portion and processing the catalyst, wherein processing the catalyst comprises contacting the catalyst with oxygen, passing the catalyst from the processing portion to the reactor portion, wherein the catalyst exiting the processing portion comprises at least 0.001 wt.% oxygen, and contacting the catalyst with supplemental hydrogen, the contacting removing at least a portion of the oxygen from the catalyst by a combustion reaction.