| 摘要 |
<p>PURPOSE:To drastically enhance adsorption performance by previously allowing ammonia to be adsorbed to an adsorbent or previously adding ammonia to a gaseous raw material, in a method for removing the trace quantity of carbon dioxide contained in the gaseous raw material utilized for the producing process of a semiconductor, while using the adsorbent. CONSTITUTION:An adsorbent which selectively adsorbs carbon dioxide and ammonia is equipped to the insides of main adsorption towers 11, 12. Gaseous ammonia is passed through an ammonia circulation passage 30 from an ammonia storage tank 34 and introduced into the main adsorption tower 11, and adsorbed to the adsorbent. Thereafter, a gaseous raw material such as air is introduced into the reactor 10 of a copper oxide catalyst and the combustible components contained therein are converted into carbon dioxide and water. Thereafter, these are introduced into the main adsorption tower 11 at normal temp. and brought into contact with the adsorbent. Thereby carbon dioxide contained in the gaseous raw material is selectively adsorbed to the adsorbent. The concn. of carbon dioxide in the outlet side of the adsorption tower 11 is stably held at low concn. Thereafter, ammonia is desorbed from the adsorbent in an auxiliary adsorption tower 21 and recovered into the ammonia storage tank 34. Further purification and recovery of gas can be continuously performed by alternately utilizing two sets of adsorption towers in this equipment.</p> |
