| abstract |
The present invention relates to processes for isomerizing normal paraffin hydrocarbons to produce products containing non-normal hydrocarbons using a zeolite beta catalyst that has been activated in order to enhance its catalytic properties. In accordance with the present invention, the zeolite beta catalyst is activated at a temperature effective to substantially reduce the concentration of strong acid species, i.e., hydronium cations, without substantially reducing the concentration of weak acid species, i.e., hydroxoaluminum cations, both of said strong acid species and weak acid species being initially present on the catalyst prior to activation. In addition, the isomerization step is preferably conducted at a temperature at least 300 DEG C. lower than the activation temperature. Additional treatment steps that are preferably performed prior to the activation step described above include a calcining step wherein a synthesized zeolite beta catalyst containing a templating agent is calcined at a temperature in the range of from about 200 DEG to 1000 DEG C. in order to remove a substantial portion of the catalyst templating agent and an ion-exchanging step wherein the calcined catalyst is ion-exchanged with a salt solution containing at least one hydrogen forming cation selected from NH4+ and quaternary ammonium. |