| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing high-purity urea water excellent in transparency and also suitable as a source of ammonia in an NOx reduction catalyst for internal combustion engine exhaust treatment using urea containing an impurity which becomes a cloudy component when producing urea water as a raw material urea. SOLUTION: The method for producing high-purity urea water is provided which uses filtration means including a filtering medium having turbidity of urea water after the cloudy component is removed is 5 degrees (kaoline) or lower such as a membrane filter or a cartridge filter the pore diameter of which is 10μm or smaller as a removal means of the cloudy component. COPYRIGHT: (C)2011,JPO&INPIT |
