| 摘要 |
<PICT:0900627/III/1> Crude dilute ethyl alcohol is fed by a pipe 1 to a washing tower 2 to which, at a slightly lower level, water is supplied from a rectification column 12, the water having a raised temperature, e.g. 95 DEG -100 DEG C., and a pH value adjusted to between 8 and 12 by addition of alkali. Volatile resin-forming impurities are thus driven off to a condenser 3, and the dilute alcohol from the foot of the tower 2 is passed by a pipe 9 to the rectification column 12, which is of conventional design, the purified alcohol being withdrawn through a pipe 18. Vapours evolved from the top of the column 12 are condensed in condenser 13 and returned in part to the column by pipe 14, the remainder passing to tower 2 by way of pipe 15. A pump 16 delivers water from the base of the column 12 to a point near the top of the tower 2. The impurities condensed in condenser 3 may be returned in part to the tower 2 by a pipe 4, and the remainder may be passed to a second washing tower 6 to which water is supplied from the column 12 by pipe 17. The liquid from the foot of the tower 6 may be supplied to the tower 2 by means of a pump 10, and the vapours from tower 6 may be passed to a condenser 7 and thence to a separator 8. The process is particularly applicable to the refining of ethyl alcohol obtained by the catalytic hydration of ethylene, but may be applied also to ethyl alcohol produced by fermentation. |
