| 摘要 |
A process for preparing vinyltoluene comprising passing ethyltoluene through a dehydrogenation zone to form vaporous crude vinyltoluene, adding from about 50 to about 100 parts per million by weight of a polymerization inhibitor such as a nitrated phenol to the vaporous crude vinyltoluene at a temperature between about 200 DEG and about 300 DEG C., condensing the vaporous crude vinyltoluene, maintaining the pH of the aqueous phase of the condensed crude vinyltoluene at a value between about 5.5 and about 6.5 sufficient to maintain the inhibitor in the organic phase of the condensed crude vinyltoluene, adding a second portion of polymerization inhibitor to the condensed crude vinyltoluene until the inhibitor concentration totals about 500 parts per million by weight relative to the vinyltoluene content of the crude vinyltoluene, filtering the condensed crude vinyltoluene to remove seed polymer, and distilling the condensed crude vinyltoluene to recover substantially pure vinyltoluene; and apparatus for carrying out said method.
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