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Hubei Fertilizer Successfully Uses Gas Chromatography to Determine Argon Content in Product Oxygen Author/Source: Sinopec News Network Date: 2020-08-13 Clicks: 6 Recently, the analysis technician studio at Hubei Fertilizer Company, led by Yang Jiangping, successfully applied gas chromatography to determine the argon content in product oxygen. Experimental results show that this method is simple and efficient, with detection results available within 5 minutes; it has high sensitivity, capable of detecting argon at a concentration of 50 ppm in oxygen; and it offers high analytical accuracy, with a relative standard deviation of less than 3% when six parallel measurements are taken on the same sample. In Hubei, coal-based gas production for fertilizer manufacturing uses the technology of oxidizing pulverized coal with pure oxygen, while a large amount of industrial oxygen is produced through air separation via the cryogenic method. Since the boiling points of oxygen and argon are close to each other, impurities of argon inevitably mix in during the production of pure oxygen. This results in a decrease in the concentration of the useful components in the syngas in the ammonia synthesis tower, leading to increased energy consumption during powder coal gasification. Therefore, accurately determining the argon content in the oxygen of the product is of great significance for guiding process optimization and ensuring the optimal performance of the equipment. The standard analytical method for industrial oxygen uses a copper-ammonia solution to absorb the oxygen in the gas, and the oxygen concentration is determined based on the decrease in gas volume. This method is cumbersome to operate and subject to many interfering factors, which affect the accuracy of analysis and prevent precise determination of the argon content. Studio members are focusing on the more widely applied gas chromatography method to help drive continuous progress and achieve better results. To separate oxygen and argon more effectively, they came up with an innovative approach: passing the gas through a nickel conversion furnace first, converting the resulting oxygen into water, and then separating the water from argon in a chromatography column to determine the argon content. To improve conversion efficiency, they pooled their ideas to modify the nickel conversion furnace by adding another parallel tube filled with catalyst nickel, and retrieved samples from the site to analyze the argon content in the oxygen product using a chromatograph. Through repeated experiments, they obtained spectra of high-purity oxygen, demonstrating the high efficiency of the conversion furnace; the oxygen in the sample was completely converted into water as it passed through the furnace, with the argon content ranging from 0.35% to 0.5%. The detection time was reduced significantly from over 90 minutes to just 5 minutes. This method can monitor the argon content in the oxygen of products, guide process optimization adjustments, reduce the inert gas content in ammonia synthesis towers, and improve the conversion efficiency of liquid ammonia; it is a relatively advanced analytical technique for determining argon in oxygen.