초록

The invention relates to an improved absorption-type separation and/or purification processes having dual rotary valves.

대표청구항 ▼

1. A process for separating a first compound from a mixture comprising a first compound and at least one other compound in an SMB system, said process comprising the steps of: a. providing a first feedstream, having a first concentration of said first compound and a first concentration of a second c

1. A process for separating a first compound from a mixture comprising a first compound and at least one other compound in an SMB system, said process comprising the steps of: a. providing a first feedstream, having a first concentration of said first compound and a first concentration of a second compound, to a first distributive valve, said first distributive valve fluidly connected to a second distributive valve, and to a plurality of chambers comprising an adsorptive material selective for the adsorption of said first compound or said second compound;b. providing a second feedstream having a second concentration of said first compound, different from said first concentration of said first compound, and a second concentration of a second compound, to said second distributive valve, fluidly connect to said first distributive valve, and to at least one of said chambers comprising an adsorptive material;c. introducing said first feedstream into said at least one of said plurality of chambers comprising said adsorptive material and selectively adsorbing said first or said second compound on said adsorptive material to provide a modified adsorptive material and a modified first feedstream having a third concentration of said first compound, different from said first concentration of said first compound, and a third concentration of said second compound, different from said first concentration of said first compound, withdrawing said modified first feedstream from said at least one chamber, and passing said modified first feedstream to said first distributive valve, said second distributive valve, or a combination thereof;d. introducing said second feedstream into said at least one of said plurality of chambers comprising said adsorptive material, and selectively adsorbing said first or said second compound on said adsorptive material to provide a modified adsorptive material and a modified second feedstream having a fourth concentration of said first compound, different from said second concentration of said first compound, and a fourth concentration of said second compound, different from said second concentration of said first compound, wherein said fourth concentration of said first compound and said fourth concentration of said second compound are, independently, the same or different from said third concentration of said first compound and said third concentration of said second compound, respectively, withdrawing said modified second feedstream from said at least one chamber in this step (d), and passing said modified second feedstream to said first distributive valve, said second distributive valve, or a combination thereof;e. recovering said modified first feedstream and said modified second feedstream;f. providing at least one flush comprising a desorbent material to said first distributive valve, said second distributive valve, or a combination thereof;g. contacting said modified adsorbent material from steps (c) and (d), simultaneously or step-wise, with said flush, whereby said first or said second compound is at least partially desorbed, to provide a modified flush; andh. passing said modified flush to said first distributive valve, said second distributive valve, or a combination thereof. 2. The process of claim 1, wherein said first compound is p-xylene and said second compound is selected from the group consisting of o-xylene, m-xylene, and ethylbenzene. 3. The process of claim 1, wherein step (c) and step (d) include the step of adsorbing o-xylene on said adsorbent material and wherein said first modified feedstream and said second modified feedstream comprise at least one compound selected from o-xylene, m-xylene, and ethylbenzene. 4. The process of claim 1, wherein said first feedstream in step (a) comprises at least one material selected from the group consisting of C8 aromatics, a mixture of olefins and paraffins, a mixture of normal paraffins, and fructose. 5. The process of claim 1, wherein said first feedstream in step (a) and said second feedstream in step (b) are independently selected from an equilibrium mixture of xylenes, a concentrated p-xylene stream from a selective toluene disproportionation unit, and filtrate from a crystallizer which is low in p-xylene. 6. The process of claim 1, wherein said second concentration of said first compound provided in step (a) is different from said first concentration of said first compound provided by step (b). 7. In an SMB process for separating a first compound in a feedstream from a mixture comprising a first compound and at least one other compound in said feedstream, the improvement comprising two distributive valves fluidly connected to each other and to plural adsorptive separation chambers, wherein each of said distributive valves has a separate source of feedstream, wherein said distributive valves process separate feedstreams having differing concentrations of said first compound. 8. In an SMB process using parallel rotary valves, the improvement comprising feeding a first feedstream to a first rotary valve and a second feedstream, different from said first feedstream, to a second rotary valve, and separating a predetermined product from each of said feedstreams without mixing of said feedstreams. 9. In an SMB process for separating a first compound in a feedstream from a mixture comprising a first compound and at least one other compound in said feedstream, the improvement comprising two distributive valves fluidly connected to each other and to plural adsorptive separation chambers, wherein each of said distributive valves has a source of at least one of a material selected from desorbent and flush, each of which is from a different source, whereby at least one of said plural adsorptive separation chambers is contacted with said mixture and then by said at least one of a material from each of said distributive valves.