Kinetic Study and Modelling of n-Heptane Reforming Process over Pt/Zr-HMS/HZSM-5 Composite Catalysts

Pt/Zr(x)-HMS/HZSM-5 catalysts with various Si/Zr ratios (as x) were used for investigation of the kinetics of n-heptane reforming process under 350 - 450 oC reaction temperature, 35 to 80 ml min-1 flowing rate of hydrogen and 2 to 5 ml h-1 flowing rate of n-heptane. In the present work, two kinetics (power law and Langmuir - Hinshelwood) models were selected and examined to describe the kinetics of the n-heptane reforming process over the used catalysts. The results show that the Langmuir - Hinshelwood model provides a better fit with the experimental data and allows to determine the kinetics parameters. Among the synthesized catalysts, Pt/Zr(35)-HMS/HZSM-5 (with Si/Zr = 35) has the best performance for this process. Because this catalyst in contrast to others, based on the apparent activation energies, has a fast formation of aromatic and isomeric products, and low rate on the production of by-products, such as cracking and hydrogenolysis products.