Abstract: The n-C₅/C₆ isomerization catalysts were prepared by using the industrialized mordenite molecular sieves. The performance and hydro-isomerization process conditions such as reaction temperature, reaction pressure, liquid hourly space velocity and the ratio of hydrogen to oil for isomerization of n-C₅/C₆ alkanes over catalyst were investigated in the fixed-bed microreactor. The results showed that the optimum isomerization conditions were as follows: a reaction temperature of 280 ℃, a reaction pressure of 2 MPa, a liquid hourly space velocity of 1.0 h-1, a hydrogen/oil molar ratio of 2.77. Under these conditions, the once through isomerization rates of n-pentane and n-hexane were 67.3% and 85.2%, respectively. The liquid yield was 96%. When the topped oil from commercial reforming unit was used as raw material, the once through isomerization rates of n-pentane and n-hexane were 67.5% and 85.7%, respectively. The selectivity of C₆ was 19.9%. The results of 600 h long-period evaluation test using topped oil as raw material showed that the isomerization performance of the catalyst was stable.

Key words: mordenite, C5 and C6 alkanes, isomerization, reforming topped oil