Cryogenic air separation is the most efficient method for the production of gaseous and liquid high-purity nitrogen, oxygen and argon. The cryogenic process can be modified to manufacture a range of desired products and mixes. Even so, cryogenic air separation typically calls for sequential steps. Our focus here is on the air pre-treatment step and the necessary impurity monitoring entailed.
Following air compression, the air pre-treatment step consists of cooling and purification to remove process contaminants, such as moisture, carbon dioxide and hydrocarbons. Temperature Swing Adsorption (TSA), which exploits the difference in adsorption capacity of adsorbents at different temperatures, or Pressure Swing Adsorption (PSA), which operates similarly via pressure variations, typically removes these impurities.
Purification is essential to this process, because harmful impurities, such as H2O, CO2 and CH4, can freeze in the downstream heat exchangers and cryogenic separation equipment. As a result, product quality can be impaired, with potential damage to the system itself. To avoid such mishaps, the Tiger Optics’ Spark and HALO analyzer families offer a user-friendly, cost-efficient high-performance solution to monitor air emitting from the TSA/PSA to ensure full contaminant removal prior to entering the heat exchangers. By coupling your Tiger analyzer with a high-purity gas stream selector, the need for multiple analyzers per contaminant can be eliminated. Due to the fast speed of response, the Spark can sample in many gas streams for accurate, real-time measurement.
The Compressed Gas Association Standard, CGA G-10.1, Commodity Specification for Nitrogen, now cites Cavity Ring-Down Spectroscopy as an approved method for moisture measurement.
CGA standards have been adopted by governmental agencies in the United States and Canada.
Based on a unanimous decision by the members of the Atmospheric Gases and Equipment Committee in August 2016, this change is welcome news to our many users in the industrial gas community. Specializing in CRDS since 2001, Tiger Optics offers a proven range of moisture analyzers for nitrogen.