Is the hydrogen consumption high in the isobutylene hydrogenation reaction?
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Is a large amount of hydrogen required to hydrogenate isobutylene into alkanes? Another study shows that the hydrogenation efficiency appears to be quite high. A certain research institute used the unpolymerized C4 fraction from a polyisobutylene plant as raw material and employed nickel-based catalysts for full hydrogenation experiments. The experimental conditions were: reaction temperature of 140°C, reaction pressure of 1.0 MPa, and a hydrogen to olefin ratio of 200:1; the hydrogenation saturation rate of the olefins could approach 100%
I analyzed the 1:1 addition reaction; a larger amount of hydrogen facilitates complete reaction of isobutylene. Furthermore, the large amount of hydrogen can create a passivation environment, suppressing the auto-polymerization reaction of isobutylene. Excess hydrogen will definitely be separated from isobutylene, with the hydrogen being recycled. There is also the issue of catalyst selection, which is determined by the reaction conditions; therefore, the amount of hydrogen consumed cannot be calculated based solely on the feedstock, and a comprehensive consideration is required. The unprofessional analysis by non-experts is for reference only. There is still a difference between research and production!
Because I’ve seen that in some units, hydrogenation is carried out on the C4 fraction without hydrogenating isobutylene; instead, the remaining butadiene and butenes are hydrogenated. It seems strange to me, and I wonder if it’s because a high hydrogen load is required for the hydrogenation of isobutylene
Maybe, but it might be related to the structure of straight-chain alkanes and branched-chain alkanes; the straight-chain ones are unstable and prone to hydrogenation. The ratio of our C4 hydrogenation reactors is approximately 3:1.
Is isobutylene present in the main components of your C4? What is the content level?
Very few. Mainly cis-trans butane migration and n-butane isobutane