摘要 |
PROBLEM TO BE SOLVED: To provide a novel high-purity urea water and method for producing the same, in which the methylene urea that is suspected to be a clogging causative substance of the pipe which introduces urea water into SCR catalyst in the adoption of urea SCR process, is reduced.SOLUTION: Such a high-purity urea water is obtained from a granular urea to which formaldehyde is added as an anti-solidification agent and the methylene urea concentration is 10 ppm or less in terms of aldehyde conversion value measured by chromotropic acid absorption spectrometry. |