Dual-Pressure Nitric Acid Plant Tail Gas Split to Eliminate Air Compression
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Solution Overview
Problem
Existing nitric acid production plants face high energy consumption and equipment revamping challenges, particularly due to the need for air and NOx gas compressors, leading to bottlenecks and significant costs.
Innovation Solution
A dual pressure nitric acid production system that recirculates tail gas and uses oxygen-rich gas from a high-pressure water electrolyzer to supply oxygen to the ammonia converter and NOx gas compressor, eliminating the need for an air compressor and optimizing ammonia conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If air compressor and NOx gas compressor are used in dual pressure nitric acid production, then ammonia conversion and nitric acid production are achieved, but power consumption increases and equipment complexity increases
Solution Approach 1:
The patent merges the functions of air compression and NOx gas compression into a single dual-stage compressor system. The first stage compresses air to intermediate pressure for ammonia oxidation, and the second stage compresses the resulting NOx gases to final pressure for absorption, eliminating the need for separate compressors and reducing overall power consumption.
Solution Approach 2:
The dual-stage compressor serves multiple functions: it acts as both an air compressor for the ammonia converter and an NOx gas compressor for the absorption tower. This multi-functional design reduces equipment count and simplifies the overall system while maintaining dual pressure operation capabilities.
2Productivity
If air compressor and NOx gas compressor are used in dual pressure nitric acid production, then ammonia conversion and nitric acid production are achieved, but device complexity increases
Solution Approach 1:
The patent merges the functions of air compression and NOx gas compression into a single dual-stage compressor system. The first stage compresses air to intermediate pressure for ammonia oxidation, and the second stage compresses the resulting NOx gases to final pressure for absorption, eliminating the need for separate compressors and reducing overall power consumption.
Solution Approach 2:
The dual-stage compressor serves multiple functions: it acts as both an air compressor for the ammonia converter and an NOx gas compressor for the absorption tower. This multi-functional design reduces equipment count and simplifies the overall system while maintaining dual pressure operation capabilities.
3Reliability
If traditional dual pressure system with separate compressors is used, then ammonia oxidation and NOx absorption are achieved, but equipment revamping costs increase
Solution Approach 1:
The patent merges the functions of air compression and NOx gas compression into a single dual-stage compressor system. The first stage compresses air to intermediate pressure for ammonia oxidation, and the second stage compresses the resulting NOx gases to final pressure for absorption, eliminating the need for separate compressors and reducing overall power consumption.
Solution Approach 2:
The dual-stage compressor serves multiple functions: it acts as both an air compressor for the ammonia converter and an NOx gas compressor for the absorption tower. This multi-functional design reduces equipment count and simplifies the overall system while maintaining dual pressure operation capabilities.
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
Reduces power consumption, minimizes emissions, and simplifies the plant setup by removing the air compressor, while maintaining optimal ammonia conversion efficiency.
Implementation Method 1
ammonia is first oxidized in an ammonia burner on platinum gauzes (commonly called ammonia converter) or cobalt balls, producing nitric oxide
Implementation Method 2
nitric oxide, following cooling, is then oxidized to nitrogen dioxide (NO2) and further to dinitrogen tetroxide N2O4 (g) in an oxidation section
Implementation Method 3
cooling of nitrogen oxide gases is accomplished first through the use of a waste heat recovery system, then through the use of a cooler condenser in which condensed nitric acid is separated
Implementation Method 4
By absorption in water, following compression through a NOx gas compressor, nitrogen dioxide and dinitrogen tetroxide are converted to nitric acid and nitric oxide
Data Source
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AI summary
The present disclosure discloses a system for producing nitric acid at reduced power, the system being a standard dual pressure nitric acid plant characterised in that the system further comprises means for splitting a tail gas stream into a first tail gas stream, in fluid communication with an oxygen-rich gas upstream the ammonia mixing unit, and a second tail gas stream, and means for adjusting the amount of tail gas being split into the first tail gas stream and the second tail gas stream, such that an air compressor is not required for operating the nitric acid plant. The present disclosure further relates to a method for operating the system, to the use of the system of the disclosure for performing the method of the disclosure and to a method for revamping a standard dual pressure nitric acid plant into the system of the disclosure.