If the user needs nitrogen purity greater than 99.99%, a JQC carbon purifier can be installed on the basis of the SN oxygen generator to produce 99.9995% nitrogen. This series of products uses alkaline catalysts for deoxidation, does not require the consumption of hydrogen sources, and reacts with the residual oxygen in nitrogen to produce carbon dioxide, and then uses pressure swing adsorption technology to remove carbon dioxide and water, and obtains high-purity nitrogen after filtration. The technical indicators of high-purity nitrogen can reach O₂≤3Ppm, CO2≤4PPm, and dew point≤-60℃.