| 摘要 |
An upgrading process for paraffinic naphthas subjects a full range naphtha to hydrocracking over a zeolite beta hydrocracking catalyst to effect a selective, partial hydrocracking in which the higher molecular weight n-paraffinic components of the naphtha are hydrocracked preferentially to the lower molecular weight components with concurrent isomerization of n-paraffins to isoparaffins, to form a hydrocracked effluent which comprises isobutane, C5 to C7 paraffins and relatively higher boiling naphthenes and paraffins. The hydrocracked effluent is split to remove the isobutane and the C5 and C7 paraffins with the balance of the higher boiling components being used as a reformer feed. Removal of the C5 and C7 paraffins permits improved reformer operation with the production of a higher octane product. The isomerization of the paraffins which occurs in the hydrocracking step provides a C5 to C7 paraffinic fraction which is of relatively higher octane number because of the shift to isoparaffins, permitting this component to be used as a gasoline blending component. |
