Method and apparatus for producing ammonia synthesis gas
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Solution Overview
Problem
Existing ammonia synthesis processes produce significant CO2 emissions due to the combustion of waste fluids containing high carbon monoxide and methane content, which are not effectively managed.
Innovation Solution
A multi-stage cryogenic separation process using liquid nitrogen washing columns and thermally insulated enclosures to separate and recycle carbon monoxide and methane back into the reformer, reducing their presence in combustion gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If waste fluid containing high carbon monoxide and methane content is combusted to provide heat for the reformer, then energy requirement is met, but CO2 emissions increase significantly
Solution Approach 1:
The patent recovers carbon monoxide and methane from the waste fluid by separating them through cryogenic distillation columns. These recovered components are then recycled back to the reformer inlet instead of being combusted, thereby maintaining energy production while significantly reducing CO2 emissions from combustion.
Solution Approach 2:
The patent converts the harmful effect of high CO2 emissions from combusting waste fluid into a benefit by recycling the carbon monoxide and methane back to the reformer. This transforms the waste stream into a valuable feedstock, reducing emissions while maintaining process energy requirements.
2Object-generated harmful factors
If multiple separation columns are added to reduce CO and methane content in waste fluid, then CO2 emissions are reduced, but device complexity increases
Solution Approach 1:
The patent segments the separation process into multiple specialized columns: a first column for initial separation, a second column for hydrogen-rich gas production, a third column for carbon monoxide enrichment, and a fourth column for methane enrichment. This segmentation allows each column to be optimized for specific separation tasks, achieving high purification efficiency while maintaining manageable operational complexity.
Solution Approach 2:
The patent introduces a new dimension to the separation process by implementing a multi-column cryogenic distillation system operating at different temperature and pressure levels. This dimensional approach enables simultaneous separation of multiple components (hydrogen, carbon monoxide, methane, carbon dioxide) that cannot be achieved with a single separation stage.
3Object-generated harmful factors
If carbon monoxide and methane are recycled to the reformer inlet, then CO2 emissions are reduced, but process configuration becomes more complex
Solution Approach 1:
The patent merges the waste fluid treatment stream with the fresh feed stream at the reformer inlet. The separated and purified carbon monoxide and methane from the cryogenic columns are combined with the original waste fluid or fresh feed, creating a unified optimized feed mixture that reduces CO2 emissions while simplifying the overall process configuration by integrating recycling loops into the existing reformer system.
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
Significantly reduces CO2 emissions by recycling valuable components and minimizing their combustion, enhancing the efficiency and environmental impact of ammonia synthesis.
Implementation Method 1
the mixture being cooled and separated in a cryogenic separation unit in a thermally insulated enclosure
Implementation Method 2
a thermally insulated enclosure
Implementation Method 3
liquid nitrogen scrubbing column to produce at the top of the column a first gas which is the ammonia synthesis gas
Implementation Method 4
the liquid is separated in a second separation column to produce a second column top gas enriched in hydrogen and a second liquid depleted in hydrogen and enriched in methane and argon
Data Source
Figure 1~2
AI summary
In a process for producing an ammonia synthesis gas, a gaseous mixture containing hydrogen, argon, carbon monoxide, carbon dioxide and methane comes from a reformer (R) associated with a combustion unit (H), the mixture (1) being treated to remove the carbon dioxide it contains before being cooled (3,5) and separated in a cryogenic separation unit in a thermally insulated enclosure (CB), the mixture being separated to provide a liquid (21) which is vaporized and sent as fuel to the combustion unit (H) having been purified of carbon monoxide and/or methane.