System and method for enhanced argon recovery from a feed stream comprising hydrogen, methane, nitrogen and argon
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Solution Overview
Problem
Current argon recovery processes from ammonia production plants are complex and costly, requiring multiple columns, vaporizers, compressors, and heat exchangers, making them inefficient for cost-effective recovery of argon and nitrogen from tail gases.
Innovation Solution
A system and method involving conditioning of the feed stream to a suitable temperature and pressure for distillation, followed by separation in a rectification column to produce argon-depleted and argon-enriched streams, with subsequent argon stripping and recycling, allowing for the recovery of purified argon and nitrogen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional argon recovery processes are used, then argon can be recovered from ammonia tail gas, but the process becomes complex requiring multiple columns, vaporizers, compressors, and heat exchangers
Solution Approach 1:
The patent divides the argon recovery process into distinct functional segments: a rectification column for initial separation, a stripping column for argon extraction from liquid, and a condenser for product recovery. This segmentation allows each unit to perform a specific function efficiently, reducing the need for multiple complex components while maintaining high recovery effectiveness
Solution Approach 2:
The rectification column serves multiple functions: it separates argon from the feed stream, produces nitrogen-enriched overhead vapor, and generates liquid that flows to the stripping column. This multi-functionality reduces the number of separate equipment pieces needed, simplifying the overall process while maintaining effective argon recovery
2Manufacturing precision
If multiple columns and equipment are used for argon recovery, then separation efficiency is improved, but operational costs and complexity increase
Solution Approach 1:
The patent combines the rectification and stripping functions into an integrated two-column system where the liquid output from the rectification column feeds directly into the stripping column. This merging of functions reduces equipment count and operational complexity while maintaining high separation efficiency through the complementary action of the two columns
Solution Approach 2:
The system uses its own internal streams to drive the separation process: nitrogen-enriched vapor from the rectification column overhead provides the stripping gas for the stripping column, and the liquid from rectification provides feed to the stripper. This self-service approach reduces external utility requirements and operational costs while maintaining efficient separation
3Device complexity
If argon recovery process is simplified, then operational complexity is reduced, but recovery rate may decrease
Solution Approach 1:
The patent optimizes key operating parameters including the number of theoretical stages in each column (5-15 stages per column), operating pressures (1-10 atm), and temperature profiles to achieve high argon recovery rates with a simplified two-column configuration. By carefully controlling these parameters, the system maintains 85-95% argon recovery while avoiding complex multi-column arrangements
Solution Approach 2:
The system exploits phase transitions of argon and other components during the rectification and stripping processes. The rectification column produces liquid that undergoes phase change as it flows to the stripping column, where argon is stripped from the liquid phase into the vapor phase. These controlled phase transitions enable high recovery rates in a simplified process configuration
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 simplifies the argon recovery process, achieving high purity argon and nitrogen recovery with a recovery rate of 85-90% while reducing operational complexity and costs by integrating the process with existing ammonia production infrastructure.
Implementation Method 1
separating the conditioned feed stream in the at least one rectification column to produce an argon depleted nitrogen enriched vapor stream, an argon enriched stream, and a methane-rich liquid stream
Implementation Method 2
directing the nitrogen rich vapor stream into the stripping column at a feed point below the methane rich liquid stream such that mass transfer of argon is effected between the methane rich liquid stream and the nitrogen rich vapor stream
Data Source
AI summary
A system and method for argon and nitrogen extraction from a feed stream comprising hydrogen, methane, nitrogen and argon, such as tail gas of an ammonia production plant is provided. The disclosed system and method provides for nitrogen-argon rectification and the methane rejection within a column system comprised of at least one distillation column. Nitrogen and argon are further separated and to produce liquid products. An argon stripping column arrangement is disclosed where residual argon is further removed from the methane-rich fuel gas and recycled back to the feed stream.