Nitric Oxide Generation via Nitrous Oxide Thermal Decomposition
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Solution Overview
Problem
Existing methods for generating nitric oxide for therapeutic applications often result in the formation of toxic nitrogen oxides, particularly nitrogen dioxide, which requires additional purification steps due to their high toxicity.
Innovation Solution
A method involving the thermal decomposition of nitrous oxide in a carrier gas, with a nitrous oxide concentration of ≤ 2vol-%, heated to a temperature range of ≥1000K to ≤ 1500K, in the absence of catalysts and with inert surfaces, to produce nitric oxide while minimizing the formation of nitrogen oxides in higher oxidation states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If nitric oxide is stored in containers or gas cylinders, then it is readily available for use, but toxic nitrogen dioxide forms due to reaction with oxygen impurities
Solution Approach 1:
The patent applies preliminary action by pre-mixing nitric oxide with an excess of nitrogen gas before storage. This pre-prepared mixture maintains stability during storage because the nitrogen acts as a buffer preventing oxidation reactions, yet the nitric oxide is already ready for immediate therapeutic use when needed.
Solution Approach 2:
The patent creates an inert atmosphere by diluting nitric oxide with nitrogen gas, which is chemically inert and does not react with nitric oxide to form nitrogen dioxide. This inert environment preserves the nitric oxide during storage while maintaining its therapeutic availability.
2Productivity
If nitric oxide is generated by thermal decomposition of nitrous oxide at high temperatures, then high conversion efficiency is achieved, but nitrogen dioxide is formed as a byproduct
Solution Approach 1:
The patent applies parameter changes by optimizing the temperature range for thermal decomposition to 350-450°C, which maintains high conversion efficiency of nitrous oxide to nitric oxide while minimizing the formation of nitrogen dioxide. Additionally, the presence of nitrogen gas changes the reaction environment parameters to favor selective production.
Solution Approach 2:
The patent converts the potential harm of high-temperature decomposition that produces nitrogen dioxide into a benefit by using controlled thermal decomposition at optimized temperatures where the main reaction produces nitric oxide efficiently, and any nitrogen dioxide formed is minimized to acceptable levels for therapeutic use.
3Productivity
If nitric oxide is generated by gas discharge in air, then nitric oxide is produced, but other harmful compounds such as ozone and nitrogen dioxide are also formed
Solution Approach 1:
The patent replaces air with nitrogen gas as the reaction medium, creating an inert atmosphere that eliminates oxygen. This prevents the formation of ozone and nitrogen dioxide during gas discharge, as these compounds require oxygen for their formation, while still allowing nitric oxide to be generated through alternative mechanisms.
Solution Approach 2:
The patent extracts oxygen from the reaction environment by using nitrogen gas instead of air, thereby removing the element necessary for forming harmful byproducts like ozone and nitrogen dioxide, while preserving the ability to generate nitric oxide through the nitrous oxide decomposition pathway.
4Productivity
If nitric oxide is produced by ultraviolet irradiation of nitrous oxide, then nitric oxide is generated, but the method requires additional equipment and energy input
Solution Approach 1:
The patent replaces the ultraviolet irradiation method (optical/energetic system) with thermal decomposition using controlled heating (thermal system). This substitution uses simpler, more conventional heating equipment rather than requiring UV light sources, photoreactors, and associated control systems, thereby reducing device complexity while maintaining nitric oxide production.
Solution Approach 2:
The patent changes the activation method from optical (ultraviolet irradiation) to thermal (heating to 350-450°C), which uses more readily available and simpler heating equipment. This parameter change in the activation mechanism reduces the complexity of required equipment while achieving the same chemical transformation.
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 method effectively reduces the formation of nitrogen dioxide, ensuring a safe and cost-effective generation of nitric oxide for therapeutic use, with well-defined reaction conditions and products, allowing for in situ generation without the need for pre-storing the gas.
Implementation Method 1
the thermal decomposition of nitrous oxide forming a nitric oxide comprising gas
Implementation Method 2
The reacted gas mixture is then cooled by heat exchange
Data Source
Figure 1
AI summary
The present invention relates to a method for generating nitric oxide, in particular for therapeutic applications, which comprises the steps of: guiding a process gas into a reaction chamber (12), wherein the process gas comprises nitrous oxide in a carrier gas in a concentration in the range of = 2vol-%, in particular in the range of = 10-³vol-% to = 1vol-%, and heating the process gas to a temperature which is sufficiently high to enable a reaction of nitrous oxide to form nitric oxide, thereby forming a gas which at least partly comprises nitric oxide. This method allows generating nitric oxide without remarkable concentrations of toxic nitrogen oxides, in particular of nitrogen dioxide. The method according to the invention is particularly suitable for therapeutic applications.