| 摘要 |
<p>PURPOSE:To prevent the material for forming the pipe line from corrosion by a method wherein when methanol is transferred under pressure over a long distance, the water content of the methanol (solution) is adjusted to a required range in proportion to the formic acid radical content of the methanol and the ratio of the formic acid radical with respect to the water is maintained such that the methanol does not contain more than 3wt% of the formic acid radical. CONSTITUTION:The present invention has been made on the base of the recognition that carbon steel and low alloy steel commonly used for making the pipe line are liable to stress corrosion crackings due to a small quantity of formic acid present in methanol. Therefore, according to the present invention, the following requirements must be satisfied: (1) That the water content of the methanol is in the order of 0-35wt% when the formic acid radical is in the order of less than 0.05wt% (2) That the water content of the methanol is in the order of 0.5-2wt% when the formic acid radical content of the methanol is in the order of 0.05-2wt%; and (3) That the water content of the methanol is in the order of 0-35wt% when the formic acid radical content of the methanol is in the order of 2-3wt%, provided that the ratio of the formic acid radical with respect to the water is maintained to such extent that no more than 3wt% of the formic acid radical is contained in the methanol.</p> |
