Plural stage reforming with catalysts having a skewed distribution of a platinum-group metal and rhenium

摘要

A process for reforming naphthene and paraffin-containing hydrocarbon feeds to increase their aromatic content is disclosed which involves the use of a series of reaction zones containing a supported platinum-group metal catalyst and a supported rhenium catalyst, wherein the distribution of catalytically effective platinum-group metal and rhenium among the series of reaction zones is skewed. The ratio of the percent by weight of the supported platinum-group metal in the catalyst in at least one of the earlier reaction zones of the series of reaction zones to that in the catalyst in at least one of the later reaction zones is in the range of about 1.5 to 10, and preferably in the range of about 2 to about 6. The percent by weight of supported rhenium based on the catalyst in the first zone is preferably less than about 10 percent by weight. Broadly, in the skewed distribution of supported platinum-group metal and rhenium, the ratio of the platinum-group metal to rhenium in the earlier zones is greater than about 1.5, and the ratio of platinum-group metal to rhenium in the later zones is less than about 1.