裂解C_5中异戊二烯阻聚剂的作用

EFFECT OF INHIBITOR ON ISOPRENE FROM CRACKING C_5

为了减少裂解C5馏分分离过程中异戊二烯（IP）的聚合损失,可以加入阻聚剂来缓减其聚合程度。在IP-正己烷溶液中分别加入亚硝酸钠、4-羟基-2,2,6,6-四甲基-1-氧代哌啶四氟硼酸盐和自制阻聚剂（摩尔比1∶1的氧代铵盐和相应的羟基胺化合物的混合物）,探讨它们对IP热聚合的阻聚效果。考察了反应时间、反应温度、IP初始质量分数和阻聚剂的加入量在自制阻聚剂对IP的阻聚过程中的影响。结果表明,3种阻聚剂中效果最好的是自制阻聚剂。随着反应时间的延长,阻聚剂逐渐消耗,IP损失率也随之增大;温度越高,IP损失率的增加速率也逐渐增大;随着IP初始质量分数的增大,IP损失率也逐渐增大,高浓度的IP需要加入更多的阻聚剂;当自制阻聚剂的质量分数在0.15%~0.30%范围,对IP具有较好的阻聚效果。

Isoprene（IP） in cracking C5 fraction can often auto-polymerize during the separation process.Several types of inhibitors can be applied to weaken the auto-polymerization.Sodium nitrite,4-OH-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate and a self-made inhibitor（1∶1 mixture of the oxoammonium salt and the corresponding hydroxylammonium salt）,were selected to be as the poloymerization inhibitors used in IP-hexane solution.The effects of some parameters,such as reaction time,reaction temperature,the initial mass fraction of IP and the addition amount of inhibitor on the loss rate of IP in the polymerization reaction were further studied with the self-made inhibitor as the polymerization inhibitor.The results demonstrated that the self-made inhibitor was the best one among the three inhibitors.The inhibitor gradually consumed and loss rate of IP increased with the increase of reaction time and reaction temperature.The loss rate of IP also increased with the increase of initial mass fraction of IP,so that initial mass fraction of IP needed more inhibitor added.Self-made inhibitor achieved obvious inhibition effect with the mass fraction range of 0.15%-0.30% on the loss rate of IP in IP-hexane solution when polymerization reaction happened.