Abstract: Factors affecting the conversion and selectivity of n-heptane hydroisomerization over rare earth modified MCM-41 catalysts were investigated by orthogonal experimental design. Test results showed that the six factors affecting isoheptane selectivity were in the order of reaction temperature > rare earth type in modified support > H2 flow rate > phosphomolybdic acid content in catalyst > Ni content in catalyst > reduction temperature; factors affecting the conversion of n-heptane were in the order of reaction temperature > Ni content in catalyst > H2 flow rate > phosphomolybdic acid content in catalyst > reduction temperature > rare earth type in modified support. The orthogonal test results were further optimized as follows: using La-MCM-41 support, catalyst having Ni mass fraction of 5% and phosphomolybdic acid mass fraction of 20%, H2 flow rate of 120 mL/min, reaction temperature of 300℃ and reduction temperature of 370℃, under such conditions the conversion of n-heptane was 13.5%, and isoheptane selectivity reached 68%.

Key words: rare earth , catalyst, phosphomolybdic acid, n-heptane, hydroisomerization