Nitrogen
(information)
Known Methods of Extraction
### **Primary Industrial Methods** 1. **Fractional Distillation of Liquid Air**: - Air is liquefied and separated into its components (e.g., nitrogen, oxygen, argon) by fractional distillation at cryogenic temperatures. 2. **Pressure Swing Adsorption (PSA)**: - A non-cryogenic method where nitrogen is separated from air using adsorbents like zeolites under varying pressures. 3. **Membrane Separation**: - Specialized polymer membranes allow nitrogen to pass while retaining other gases like oxygen and argon. 4. **Cryogenic Air Separation**: - A large-scale industrial process where air is cooled to cryogenic temperatures to isolate nitrogen. 5. **Vacuum Swing Adsorption (VSA)**: - Similar to PSA but operates under vacuum conditions to enhance nitrogen purity and reduce energy consumption. --- ### **Secondary and Alternative Methods** 6. **Chemical Absorption**: - Air is passed through solutions that absorb oxygen or carbon dioxide, leaving nitrogen-rich gas. 7. **Carbon Molecular Sieves (CMS)**: - CMS materials selectively adsorb oxygen, allowing nitrogen to remain in the gas phase. 8. **Cold Trap Method**: - Air is cooled to condense water vapor and oxygen, leaving behind gaseous nitrogen. 9. **Distillation of Ammonia**: - Nitrogen is isolated by decomposing ammonia (NH₃) into nitrogen and hydrogen gases through heating. 10. **Plasma Arc Process**: - Nitrogen is extracted by ionizing air and separating the nitrogen ions from other gases. --- ### **Laboratory-Scale Methods** 11. **Thermal Decomposition of Azides**: - Sodium azide (NaN₃) is heated to decompose into pure nitrogen gas and sodium metal. 12. **Decomposition of Ammonium Dichromate**: - Heating ammonium dichromate (NH₄)₂Cr₂O₇ produces nitrogen, water, and chromium(III) oxide. 13. **Reaction of Nitrites with Acids**: - Sodium nitrite (NaNO₂) reacts with acids to release nitrogen gas. 14. **Decomposition of Urea**: - Urea is decomposed under heat or with acids to release nitrogen gas as a byproduct. --- ### **Emerging and Sustainable Methods** 15. **Direct Air Capture for Nitrogen**: - New technologies selectively capture nitrogen from ambient air for industrial or localized use. 16. **Biological Nitrogen Extraction**: - Nitrogen-fixing bacteria are used in controlled environments to produce nitrogen gas. 17. **Electrochemical Air Separation**: - Applying an electric field to air selectively separates nitrogen and oxygen ions. --- ### **Extraction from Waste Streams** 18. **Recovery from Exhaust Gases**: - Nitrogen is captured from industrial exhaust streams containing nitrogen-rich emissions. 19. **Separation from Fertilizer Production**: - Nitrogen is recovered during the synthesis of ammonia or other nitrogen-based fertilizers. 20. **Cryogenic Recycling**: - Nitrogen is recovered from used cryogenic systems or processes in industrial plants.