| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To produce a denitrating reductant composition consisting of a high-purity urea aqueous solution by efficiently removing ionic impurities from the high-concentration urea aqueous stock solution prepared by using an inexpensive raw material easily available commercially. <P>SOLUTION: The denitrating reductant composition consisting of the high-purity urea aqueous solution having 30-50 mass% urea concentration, pH≤8.0,≤500μS/cm electric conductivity and≤0.5 ppm concentration of each of Ca, Fe, Na and K is produced by making the urea aqueous stock solution of 30-50 mass% urea concentration pass continuously through a single bed column of an H-type strongly acidic cation exchange resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
