Nitrogen Oxide Plasma Process via Magnetic Arc Control

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Solution Overview

Problem

The existing electric arc processes for producing NO gas face challenges in achieving high yields and energy efficiency due to high temperature and pressure requirements, which are difficult to manage with existing materials and result in significant energy consumption and low NO yields.

Innovation Solution

The process employs a magnetic field to shape and control an electric arc through air or oxygen-enriched air, using AC or DC currents, operating at pressures below atmospheric pressure, and incorporates a heat exchanger for quenching and cooling, allowing for a stable NO-containing plasma at lower temperatures and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If high temperature (3000-4000 K) is used to dissociate nitrogen in the electric arc process, then nitrogen dissociation is achieved, but energy consumption increases significantly and NO yield remains low (1-2%)

Engineering Contradiction:
Improvearc temperatureVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent changes the pressure parameter from atmospheric to sub-atmospheric (0.1-1 bar), which fundamentally alters the plasma chemistry and energy requirements. At lower pressures, nitrogen dissociation occurs more efficiently at lower temperatures, and the formed NO is less prone to decomposition, resolving the contradiction between temperature and energy consumption

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic pulsing of the electric arc discharge, creating cyclic plasma formation and collapse. This periodic action allows for efficient energy coupling, where each pulse creates a transient high-temperature plasma that dissociates nitrogen, followed by a cooling phase where NO forms and stabilizes, improving overall energy efficiency and NO yield

Inventive Principle:
Principle #19Periodic action

2Productivity

If high pressure is applied to increase NO yield, then nitrogen fixation efficiency improves, but material limitations are exceeded and process complexity increases

Engineering Contradiction:
ImproveNO yieldVSAvoidpressure management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Instead of increasing pressure to improve NO yield as in conventional processes, the patent inverts the approach by operating at sub-atmospheric pressures. The lower pressure environment enhances nitrogen dissociation efficiency and reduces NO decomposition, achieving high yields without requiring complex high-pressure equipment or materials

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If atmospheric pressure is used in the electric arc process, then operation is simplified, but NO decomposition increases and yield remains low

Engineering Contradiction:
Improveoperational simplicityVSAvoidNO stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the pressure parameter from atmospheric to sub-atmospheric (0.1-1 bar), which fundamentally alters the plasma chemistry and energy requirements. At lower pressures, nitrogen dissociation occurs more efficiently at lower temperatures, and the formed NO is less prone to decomposition, resolving the contradiction between temperature and energy consumption

Inventive Principle:
Principle #35Parameter changes

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 achieves an NO yield of up to 12% with an energy consumption of 30GJ/tonne N or lower, significantly improving energy efficiency and overcoming material limitations by optimizing plasma conditions and retention time.

Implementation Method 1

by means of moving an electric arc through the air flow by using a magnetic field and AC or DC currents

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

moving an electric arc through the air flow by using a magnetic field

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 3

The temperature in the exited arc is adjusted to be within the range of 3000 to 5000 Kelvin... a stable NO-containing plasma having a temperature below 2000 Kelvin

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 4

incorporates a heat exchanger for quenching and cooling, allowing for a stable NO-containing plasma at lower temperatures

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 5

the air flow is quenched by applying a spray of fine water droplets upstream or just downstream the arc

Methodology Applied
Scientific EffectQuenching:

Data Source

PatentEP2704989B1Energy efficient process for producing nitrogen oxide
Publication Date: 2017.06.28 N2 APPLIED AS
  • EP2704989B1 patent drawingFigure 1~2
  • EP2704989B1 patent drawingFigure 3~4
  • EP2704989B1 patent drawingFigure 5~6

AI summary

A process for producing NO gas from a feed flow of air or oxygen enriched air, by means of moving an electric arc through the air flow by using a magnetic field and AC or DC currents, in a reactor, wherein a pressure lower than 1 bar is applied, wherein the temperature in the exited arc is adjusted to be within the range of 3000 to 5000 Kelvin, and wherein the air flow is quenched by applying a spray of fine water droplets upstream or just downstream the arc, excess air feed or bypassed air to obtain a stable NO-containing plasma having a temperature below 2000 Kelvin.