Effect of inhibitor on isoprene from cracking C5

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.