摘要 |
Ferric chloride (FeCl3), a known chlorination and polymerization catalyst for 1,3-butadiene ("BD"), can nevertheless be effectively used in a packed or trayed quench tower, operating under essentially anhydrous conditions, without plugging it. Essentially all BD from a crude stream of vinyl chloride (VCl), is removed within a hold-up time of 6 minutes. The speed of removal is note-worthy because less than half the stoichiometric amount of chlorine required to chlorinate the BD is used. The BD is preferentially chlorinated, the time being too short to chlorinate a substantial amount of chloroprene and monovinylacetylene. Only a portion of the BD is removed by chlorination, the remainder being removed by polymerization catalyzed by 100-200 ppm anhydrous FeCl3. For such speed and effectiveness without plugging the quench tower, the amount of BD in the effluent stream is required to be controlled to no more than 100 ppm, based on the weight of 1,2-dichloroethane (ethylene dichloride or "EDC") in the stream.
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