Ammonia Synthesis System With Buffer Tank Flow Stabilization
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Solution Overview
Problem
Existing ammonia synthesis systems face challenges with flow rate variability due to renewable energy sources, leading to non-uniform flow rate distribution, temperature deviations within catalyst beds, and compressor surge phenomena, which affect yield and stability.
Innovation Solution
The system includes a buffer tank in the feed recirculation line, an expander, and a flow regulating device to stabilize compressor operation, along with microwave heating and distributed gas supply to maintain uniform flow and temperature across catalyst beds, and a heat exchanger for efficient energy management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a water electrolyzer powered by renewable energy is used to produce hydrogen, then green ammonia production is achieved, but flow rate variability occurs due to temporal variability of renewable energy
Solution Approach 1:
The buffer tank stores excess regeneration stream when flow rate is high, preparing it for later use when flow rate decreases, thereby preventing compressor surge and maintaining stable operation during renewable energy variability
Solution Approach 2:
The buffer tank acts as an intermediary between the ammonia separation device and the compressor, decoupling their operations and allowing the compressor to maintain stable flow rate regardless of upstream variability
2Use of energy by moving object
If the flow rate of raw material is decreased, then energy consumption is reduced, but non-uniform flow rate distribution at the front end of catalyst bed occurs
Solution Approach 1:
The distribution device divides the gas flow into multiple streams that are distributed across different regions of the catalyst bed, ensuring uniform flow rate distribution even at low overall flow rates
Solution Approach 2:
The distribution device creates locally optimized flow conditions at the front end of the catalyst bed, ensuring that each region receives appropriate flow rate regardless of the overall system flow rate
3Productivity
If the ammonia synthesis system operates at high flow rate, then productivity is improved, but temperature deviation between central and outer parts of catalyst bed increases
Solution Approach 1:
The microwave heating device divides the heating function into multiple zones corresponding to different regions of the catalyst bed, allowing independent temperature control of central and outer parts to maintain uniformity during high productivity operation
Solution Approach 2:
The microwave heating device applies localized heating to specific regions of the catalyst bed, compensating for temperature deviations and maintaining uniform temperature distribution across the catalyst bed during high flow rate operation
4Adaptability or versatility
If the flow rate of raw material changes substantially, then adaptability is improved, but compressor surge phenomenon occurs
Solution Approach 1:
The buffer tank pre-stores regeneration stream during high flow rate periods, making it available to prevent compressor surge before it occurs during flow rate decreases, thereby maintaining compressor stability while allowing system adaptability
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
The system stabilizes compressor operation, maintains uniform flow and temperature distribution, enhances yield, and optimizes energy use, thereby improving overall efficiency and catalyst lifespan.
Implementation Method 1
a microwave heating device for emitting microwaves to each of the two or more catalyst beds
Implementation Method 2
a heat exchanger for efficient energy management
Implementation Method 3
An expander may be installed upstream from the buffer tank in the feed recirculation line
Data Source
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AI summary
A ammonia synthesis system, an operation method thereof, and an ammonia synthesis method are provided. The system includes a compressor for compressing mixed gas; a feed supply line for supplying the mixed gas to the compressor; an ammonia synthesis reactor for synthesizing ammonia by feeding the mixed gas compressed by the compressor into the reactor; an ammonia separation device for separating syngas produced by the ammonia synthesis reactor into ammonia and a regeneration stream; a feed recirculation line for recirculating the regeneration stream to the feed supply line; and a buffer tank installed in the feed recirculation line.