Investigation of benzene and cycloparaffin containing hexane fractions skeletal isomerization on Pt/sulphated metal-oxide catalyst

The most valuable components of gasoline are iso- and cycloparaffins, because their utilization leads to lower environmental and human biological risk, than aromatic and olefin hydrocarbons. Light naphtha fractions (C-5-C-7) of different type crudes contain different amount of benzene and cycloparaffins. In most case their separation is not economical, thus the quality improvement (desulphurization, benzene saturation, isomerization) of these components has to be carried out with the others. In case of high benzene concentration "two step process" (benzene saturation and isomerization) is recommended. Benzene and cycloparaffins can significantly modify the isomerization mechanism. Hence the aims of our experiments were to investigate the isomerization of binary and multicomponent feeds on Pt/sulphated metal-oxid (Pt/SO42-/MOx) in a large scale reactor system. During the experiments we studied the isomerization of binary and multicomponent mixtures and how they influenced each other's isomerization. The process parameters were: 160-200 degrees C; 20-30 bar; LHSV:1.0-4.0 h(-1) and H-2/hydrocarbon molar ratio 1.0:1.0-2.0:1.0. We concluded that the enhanced benzene and cycloparaffin concentration has disadvantageous effects on isomerization efficient, even the optimal process parameters were different at the investigated range depending on the applied feed. The stability and long term application of the investigated catalyst was confirmed.