Adsorption process
AssigneeShell Oil Company
InventorRobert P. Bannon
Life of this patent
Estimating the term…
Abstract
A continuous, cyclic, vapor-phase adsorption process for the separation of normal paraffins from a hyrocarbon feed mixture, providing improved efficiency of separation and continuity of product flows. For purposes of this process, a continuous flow of the feed mixture and a continuous flow of an eluent are passed in repetitions of a particular sequence of six process steps to at least three molecular sieve adsorbent beds.
Claims7
An improved process for using three molecular sieve adsorbent beds to effect the resolution of a continuous flow of a vapor-phase hydrocarbon feed mixture containing normal paraffins and non-normal paraffin hydrocarbons into an adsorbate product fraction comprising normal paraffins and a raffinate product fraction comprising non-normal paraffin hydrocarbons, which process comprises repeated sequential performance of the following steps:
- step one, in which
- the feed mixture is passed through a first adsorbent bed,
- effluent is withdrawn from the first bed and passed through a second adsorbent bed
- a continuous flow of eluent is passed through a third adsorbent bed,
- adsorbate product is withdrawn as an effluent from the third bed, and
- raffinate product is withdrawn as an effluent from the second bed;
- step two, in which
- the feed mixture is passed through the second bed,
- the eluent flow is passed through the third bed,
- effluent from the third bed is withdrawn and divided into an adsorbate product fraction, which contains between 60 and 95 volume percent of the effluent from the third bed, and a purge fraction which contains between 5 and 40 volume percent of the effluent from the third bed,
- the purge fraction is passed through the first bed,
- effluent from the first bed is withdrawn and is passed through the second bed, and
- raffinate product is withdrawn as effluent from the second bed;
- step three, in which
- the feed mixture is passed through the second bed,
- effluent is withdrawn from the second bed and passed through the third bed,
- the eluent flow is passed through the first bed,
- adsorbate product is withdrawn as an effluent from the first bed, and
- raffinate product is withdrawn as an effluent from the third bed;
- step four, in which
- the feed mixture is passed through the third bed,
- the eluent flow is passed through the first bed,
- effluent from the first bed is withdrawn and divided into an adsorbate product fraction, which contains between 60 and 95 volume percent of the effluent from the first bed, and a purge fraction which contains between 5 and 40 volume percent of the effluent from the first bed,
- the purge fraction is passed through the second bed,
- effluent from the second bed is withdrawn and is passed through the third bed, and
- raffinate product is withdrawn as effluent from the third bed;
- step five, in which
- the feed mixture is passed through the third bed,
- effluent is withdrawn from the third bed and passed through the first bed,
- the eluent flow is passed through the second bed,
- adsorbate product is withdrawn as an effluent from the second bed, and
- raffinate product is withdrawn as an effluent from the first bed;
- and
- step six, in which
- the feed mixture is passed through the first bed,
- the eluent flow is passed through the second bed,
- effluent from the second bed is withdrawn and divided into an adsorbate product fraction, which contains between 60 and 95 volume percent of the effluent from the second bed, and a purge fraction, which contains between 5 and 40 volume percent of the effluent from the second bed,
- the purge fraction is passed through the third bed,
- effluent from the third bed is withdrawn and is passed through the first bed, and
- raffinate product is withdrawn as effluent from the first bed.
Dependencies are inferred from the claim text.