Isomerization of paraffin hydrocarbons using zeolites with high steam-enhanced acidity
AssigneeMobil Oil Corporation
InventorsWerner O. Haag, Rudolph M. Lago
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Abstract
A process is provided for effecting hydroisomerization of a C.sub.4 -C.sub.8 paraffin by contacting the same under hydroisomerization conditions with a catalyst comprising a porous crystalline zeolite characterized by a silica/aluminum mole ratio of greater than 12 and a constraint index within the approximate range of 1 to 12, which zeolite has undergone controlled pretreatment by contact with water to enhance the acid activity thereof, expressed as alpha, to greater than about 300. The catalyst also comprises, intimately combined therewith, a minor proportion of a Group VIII metal.
Claims23
A process for effecting hydroisomerization of a C.sub.4 -C.sub.8 paraffin which comprises contacting a feedstock containing the paraffin under hydroisomerization conditions with a catalyst comprising a porous crystalline zeolite characterized by silica/alumina mole ratio of greater than 12 and a constraint index within the approximate range of 1 to 12, which zeolite contains a minor proportion of a Group VIII metal and which zeolite has an enhanced acid activity achieved by a method comprising treating the zeolite with water under conditions of contact time, temperature and water partial pressure governed by the following relationship of treating time and water pressure at constant temperature:
- 0.01(Pt).sub.T <(Pt)<10(Pt).sub.T
- where
- (Pt).sub.T =2.6.times.10.sup.-9 e.sup.16000/T ;
- P=Water Partial Pressure, atmospheres;
- t=Treating Time, hours;
- T=Temperature, degrees K.
Dependencies are inferred from the claim text.