Selection of hydrocracking catalyst

Hydrocracking is a relatively flexible processing technology that can produce liquefied petroleum gas from crude gasoline, quality petroleum products such as naphtha, gasoline, aviation kerosene, light diesel and lubricating oil from inferior heavy oil, as well as feed materials for catalytic cracking and steam cracking to produce ethylene. By changing the operating conditions such as the reaction temperature and the cutting point of the distillation column, the conversion rate and the destination product can be changed. The key of hydrocracking technology is the catalyst. The activity, selectivity, stability and mechanical strength of the catalyst have great influence on the operating level and economic benefit of the hydrocracking unit. Different kinds of catalysts with different catalytic properties are often needed for different raw materials and products with different purposes.

The main reactions in hydrocracking process include cracking, hydrogenation, isomerization, cyclization, desulfurization, denitrification, deoxygenation and demetalization. Due to the desulfurization, denitrification and deoxidation reaction respectively generated the corresponding hydrocarbon and H2S, NH3, H2O, they are easy to remove, so the hydrocracking products do not need to be refined. The chemical reaction is as follows:

R—CH—SH + H2—→R—CH2—R + H2S

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R                                     (alkane)

(mercaptan)