Copper Oxide Adsorbent for CO Removal in Ethylene Streams
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Solution Overview
Problem
Carbon monoxide (CO) deactivates oligomerization catalysts in the production of jet fuel from ethanol, requiring its removal from the ethylene stream before oligomerization to prevent catalyst poisoning and extend catalyst life.
Innovation Solution
The process involves using a copper oxide adsorbent with oxygen injection to regenerate the adsorbent and convert CO and hydrogen to CO2 and water, thereby maintaining the oxidized state of the copper and ensuring continuous removal of CO without depleting the CuO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon monoxide is removed by fractional distillation, then CO is separated from the ethylene stream, but the process becomes economically unviable due to very short catalyst life under high CO and hydrogen levels
Solution Approach 1:
The patent applies preliminary action by removing carbon monoxide from the ethylene stream before the oligomerization process begins. The copper oxide adsorbent is positioned upstream to convert CO to CO2 through oxidation reactions, preventing CO from reaching and deactivating the oligomerization catalyst. This pre-treatment ensures the catalyst operates in a CO-free environment from the start, extending catalyst life and improving process economics.
Solution Approach 2:
The patent uses a copper oxide adsorbent as an intermediary substance to remove CO from the ethylene stream. The CuO acts as a mediator that reacts with CO to form CO2, which can then be easily separated. This intermediary approach allows CO removal without directly exposing the oligomerization catalyst to CO, thereby protecting the catalyst and extending its operational life.
2Duration of action of stationary object
If oxygen is added to regenerate copper oxide adsorbent, then the adsorbent is continuously renewed and CO conversion is maintained, but oxygen must be precisely controlled to prevent it from going downstream to the product stream
Solution Approach 1:
The patent implements periodic action through a three-bed system where beds are cyclically switched between service and regeneration modes. While one bed is actively removing CO from the ethylene stream, another bed is being regenerated with oxygen. This periodic switching ensures continuous CO removal while allowing controlled oxygen introduction during regeneration periods without contaminating the product stream.
Solution Approach 2:
The patent divides the CO removal system into three separate beds, segmenting the function of CO conversion and oxygen management. This segmentation allows one bed to be in service while another is regenerated, and a third bed can be in standby or regeneration mode. The segmentation enables precise control of oxygen introduction, ensuring it only contacts the adsorbent during regeneration and not the product stream.
3Reliability
If a three-bed system is used with periodic switching, then continuous CO removal and adsorbent regeneration are achieved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing each bed to perform multiple functions at different times. Each bed can alternately serve as a CO removal bed, a regeneration bed, or a standby bed. This multi-functionality reduces the need for separate dedicated equipment for each function, as the same physical beds are reused in different operational modes, thereby managing complexity while maintaining continuous operation.
Solution Approach 2:
The patent merges the functions of CO removal, adsorbent regeneration, and standby capacity into a single integrated three-bed system. Rather than having separate systems for each function, the beds are combined and cyclically switched between modes. This merging approach achieves continuous CO removal and regeneration capabilities while consolidating equipment, thereby managing overall system 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 allows for extended operation of the ethanol to jet fuel process without catalyst reloading, improving process economics and maintaining product specifications by ensuring CO removal without oxygen being left in the product.
Implementation Method 1
carbon monoxide is removed via an oxidation reaction over a copper oxide adsorbent to produce carbon dioxide
Implementation Method 2
continuous renewal of the spent elemental copper adsorbent back to copper oxide through oxidation by the addition of oxygen
Implementation Method 3
conversion of carbon monoxide and hydrogen over available elemental copper sites to carbon dioxide and water
Data Source
AI summary
A process is provided for treating a stream comprising light olefins and carbon monoxide by passing the stream through a bed containing a copper containing material. The carbon monoxide needs to be removed in order to prevent poisoning of catalysts in downstream oligomerization reactors. This carbon containing material converts the carbon monoxide and hydrogen to carbon dioxide and water. The olefin stream is then dried and sent to an oligomerization step. There may be three beds so that the beds may alternate regeneration, reaction with CO and H2 and scavenging O2 steps.