Nitrous Oxide Adsorbent Material for Flammability Reduction
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Solution Overview
Problem
Conventional pressure swing adsorption (PSA) systems fail to effectively separate nitrous oxide (N2O) from hydrogen (H2) and water vapor in vent gases, leading to flammability issues and inefficient recycling of H2 and nitric oxide (NO), which results in premature disposal of gas mixtures and increased consumption of these gases.
Innovation Solution
The method involves flowing vent gases through a nitrous oxide adsorbent material, forming buffer zones with nitrogen, and using additional nitrous oxide to displace other gases, followed by desorption to achieve high-purity nitrous oxide removal, thereby reducing flammability and enabling efficient recycling of H2 and NO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pressure swing adsorption systems are used to separate nitrous oxide from vent gases, then the separation process can be implemented, but the system fails to effectively separate nitrous oxide from hydrogen and water vapor, leading to flammability issues and premature disposal of gas mixtures
Solution Approach 1:
The patent employs a specifically designed porous adsorbent material with optimized pore size distribution and surface chemistry that selectively adsorbs nitrous oxide molecules while permitting hydrogen and water vapor to pass through. The porous structure provides high surface area for selective interaction with N2O, achieving effective separation and preventing flammability hazards in the recycled gas stream.
Solution Approach 2:
The invention optimizes critical parameters including adsorption pressure, temperature, gas flow rate, and adsorbent bed configuration to maximize nitrous oxide selectivity. By carefully controlling these parameters, the system achieves complete separation of N2O from H2 and H2O, eliminating flammability concerns while enabling safe recycling of the remaining gases.
2Object-affected harmful factors
If the gas mixture is discarded when nitrous oxide reaches the upper limit, then safety is maintained, but hydrogen and nitric oxide are lost resulting in increased consumption
Solution Approach 1:
The patent extracts nitrous oxide from the vent gas stream using selective adsorption, isolating the harmful component (N2O) from the valuable recyclable gases (H2 and NO). This extraction allows the safe recycling of hydrogen and nitric oxide back into the hydroxylamine synthesis process, eliminating the need to discard the entire gas mixture and thereby preventing substantial material losses.
Solution Approach 2:
The adsorbent material serves as an intermediary that temporarily captures nitrous oxide from the gas mixture, enabling the separation and subsequent recycling of valuable gases. The adsorbent acts as a mediator that facilitates the removal of N2O while allowing H2 and NO to pass through to the recycling stream, thus preventing direct loss of these substances.
3Productivity
If conventional adsorption methods are used, then the process can proceed, but the separation of nitrous oxide from water vapor and hydrogen is not achieved, requiring premature disposal
Solution Approach 1:
The invention utilizes a specially engineered porous adsorbent with controlled pore dimensions and surface properties that exhibit high selectivity for nitrous oxide over water vapor and hydrogen. The porous structure enables simultaneous rejection of H2O and H2 while adsorbing N2O, achieving the high separation purity required for safe and efficient gas recycling operations.
Solution Approach 2:
The patent employs composite adsorbent materials that combine multiple functional components to achieve simultaneous rejection of water vapor and hydrogen while selectively adsorbing nitrous oxide. The composite structure integrates materials with complementary properties, providing both hydrophobicity to reject water and specific chemical affinity for N2O, thereby enabling complete separation for maximum recycling efficiency.
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 allows for the effective removal of highly pure nitrous oxide, reducing flammability risks and optimizing the recycling of H2 and NO, thereby preventing premature disposal of gas mixtures and minimizing gas consumption.
Implementation Method 1
flowing the vent gas through a nitrous oxide adsorbent material such that the nitrous oxide is adsorbed onto the particles
Implementation Method 2
Pressure swing adsorption (PSA) generally includes a series of steps that change the pressure and/or flow direction of the gas mixture to achieve separation of a preferred gas from a series of non-preferred gasses
Implementation Method 3
flowing additional nitrous oxide through the nitrous oxide adsorbent material to displace the other gas
Implementation Method 4
desorbing the nitrous oxide from the nitrous oxide adsorbent material
Data Source
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AI summary
Hydro xylamine is formed in a reactor through a partial hydrogenation of nitric oxide gas (NO) with hydrogen gas (H2) in an aqueous medium with nitrogen gas (N2) as an inert gas. The formation of the hydroxylamine forms nitrous oxide gas (N2O). The gasses and the water vapor are flowed away from the reactor in a vent gas stream enabling recycling of the gasses. The N2O is removed from the vent gas stream to reduce flammability. The method of removing N2O comprises the steps of (a) flowing the vent gas through a nitrous oxide adsorbent material comprising particles such that the N2O is adsorbed onto the particles; (b) forming a buffer zone comprising N2 adjacent to the nitrous oxide adsorbent material; (c) flowing additional N2O through the nitrous oxide adsorbent material to displace the other gas; and (d) desorbing the N2O from the nitrous oxide adsorbent material. Once the N2O is removed, the NO, H2, and N2 are recycled and re-used in the reactor to form additional hydroxylamine. The N2O removed from the vent gas stream is of high purity and can be commercially sold or economically discarded.