| 摘要 |
There is disclosed a process for continuously preparing ethylene glycol, which comprises (1) a first step of contacting a gas containing carbon monoxide and an ester of nitrous acid with a solid catalyst of platinum group metal series in the gaseous phase thereby to obtain a product containing a diester of oxalic acid, (2) a second step of condensing the product of the first step thereby to separate a non-condensed gas containing nitrogen monoxide formed by the catalytic reaction of the first step from a condensed liquid containing the diester of oxalic acid, (3) a third step of contacting the non-condensed gas of the second step with a gas containing molecular oxygen and an alcohol, and recycling the resulting gas containing an ester of nitrous acid to the first step, (4) a fourth step of contacting the condensed liquid of the second step containing the diester of oxalic acid and hydrogen with a catalyst for hydrogenation in the gaseous phase thereby to obtain a product containing ethylene glycol, (5) a fifth step of distilling the product of the fourth step thereby to distill out the alcohol and to obtain ethylene glycol, and (6) a sixth step of recycling the alcohol of the fifth step as an alcohol source for the third step.
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