New direction in the hydroprocessing of gasoline fractions: integration of C5-C6 and C7-paraffin hydrocarbons isomerization processes
In this work catalytic studies on the isomerization of individual hydrocarbons (n-heptane, n-hexane) and their mixtures (mass ratios of n-heptane / n-hexane are 70/30, 50/50, 30/70) on Pt/WO3-ZrO2 catalysts were carried out. In table 1 the main reaction parameters of n-heptane, n-hexane and their mixtures isomerization reactions on catalyst Pt/WO3-ZrO2 with tungsten oxide content of 15 wt.% are shown (the data are given at the reaction temperatures, allowing to achieve the highest yields of C7 isomers). It is seen that in the presence of a tungstated zirconia catalyst, the octane number of isomerate when using individual n-heptane as a feed is 54 (RON), for n-hexane – 73 (RON). The octane number of isomerate obtained in isomerization of n-heptane / n-hexane mixtures is 62-68 (RON) depending on feed composition. RON for mixtures of С7 isomerate and С6 isomerate is also 62-68 (RON).
Thus, the results of the isomerization of n-heptane / n-hexane mixtures show that the isomerization of C5-C7 hydrocarbons can be carried out by using only one catalyst in one technological unit. The octane number of the isomerate of the joint isomerization reaction is not inferior to the octane characteristics of the mixed component obtained by separate isomerization of C6 and C7 hydrocarbons.