초록 ▼

The present invention is directed to a cascade catalytic hydrotreating/dewaxing process, wherein a hydrocarbon feedstock containing waxy components is treated. The hydrotreating phase precedes the dewaxing phase in order to remove contaminants, such as nitrogen and sulfur, from the feedstock to prol

The present invention is directed to a cascade catalytic hydrotreating/dewaxing process, wherein a hydrocarbon feedstock containing waxy components is treated. The hydrotreating phase precedes the dewaxing phase in order to remove contaminants, such as nitrogen and sulfur, from the feedstock to prolong the life of the catalyst used in the subsequent dewaxing step. A conventional hydrotreating catalyst is used. The dewaxing catalyst is a Zeolite Beta catalyst. The cascade process is conducted with or without interstage gas separation. The treatment occurs in the same or in separate reactors. The ratio of hydrotreating catalyst to dewaxing catalyst is greater than 1:2. This sequence of treatments enhances distillate yields and lowers processing and capital costs.

대표청구항 ▼

In a process for dewaxing a waxy hydrocarbon feedstock containing waxy paraffins, normal paraffins, slightly branched paraffins, sulfur and nitrogen compounds over a dewaxing catalyst containing Zeolite Beta alone in a reactor of specified volume, the improvement comprising: (a) substituting a porti

In a process for dewaxing a waxy hydrocarbon feedstock containing waxy paraffins, normal paraffins, slightly branched paraffins, sulfur and nitrogen compounds over a dewaxing catalyst containing Zeolite Beta alone in a reactor of specified volume, the improvement comprising: (a) substituting a portion of the said dewaxing catalyst in said reactor volume with a hydrotreating catalyst to form a distinct hydrotreating zone and a dewaxing zone, the ratio of the catalyst in the hydrotreating zone to the catalyst in the dewaxing zone being at least 1:2, but less than 2:1 to maintain a specified reactor volume; (b) subjecting said feedstock to hydrotreating by contacting said feedstock with the hydrotreating catalyst in said hydrotreating zone operated at hydrotreating conditions sufficient to remove at least a portion of said sulfur and nitrogen compounds from the feedstock; (c) subjecting said hydrotreated feedstock to catalytic dewaxing without changing the hydrogen partial pressure by contacting said feedstock with the dewaxing catalyst in the dewaxing zone containing Zeolite Beta and a hydrogenation/dehydrogenation component; and (d) recovering a distillate having a reduced pour point compared to said feedstock at higher yield and with reduced hydrogen consumption than a process using the said dewaxing catalyst alone.