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US 5,177,298 AGranted
Liquid phase adsorption process
AssigneeUop LLC
InventorsCarmen M. Yon, Joe Quock, Wim P. Reel, Henry Rastelli
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Abstract
A process for the regeneration of oxygenate containing adsorbents uses regenerant streams such as LPG and isomerate products for the desorption of oxygenate compounds. The process discloses arrangements for the integration of regenerant treatment into the adsorption scheme and for the enhancement of the isomerate product. The integrated flowscheme can be used to remove sulfur and water from contaminated regenerants or to deliver the oxygenates into the gasoline pool.
Claims16
A process for the continuous liquid phase adsorption of oxygenates from an oxygenate-containing liquid hydrocarbon feedstock with a regenerant stream comprising hydrocarbons and at least 10 wt. ppm sulfur compounds, said process comprising:
- (a) passing the feedstock to a first of at least two fixed adsorbent beds containing a solid adsorbent having selectivity for the adsorption of oxygenates and recovering from the first bed a product having a lower concentration of oxygenates than the liquid hydrocarbon feedstock;
- (b) terminating the passage of said feedstock into the first adsorbent bed and passing said feedstock to a second adsorbent bed said second adsorbent bed initially containing a sweet regenerant in the liquid phase;
- (c) passing said feedstock into said second adsorbent bed, displacing sweet regenerant in liquid phase from said second adsorbent bed and passing the displaced regenerant to said first adsorbent bed while recovering treated product from said first adsorbent bed;
- (d) passing an untreated liquid regenerant to a third adsorbent bed containing a solid adsorbent for the removal of sulfur compounds and recovering a sweet regenerant;
- (e) heating at least a portion of said sweet regenerant;
- (f) passing a portion of said sweet regenerant in vapor phase to said first adsorbent bed to desorb oxygenates from the adsorbent, and recovering a spent sweet regenerant vapor containing oxygenates;
- (g) passing a portion of said sweet regenerant in vapor phase to a fourth adsorbent bed containing a solid adsorbent for the removal of sulfur compounds to desorb sulfur compounds from said fourth adsorbent bed and recovering a spent, sour regenerant vapor;
- (h) cooling and filling said first adsorbent bed by passing sweet regenerant in the liquid phase to said first adsorbent bed and recovering sweet regenerant;
- (i) terminating the flow of regenerant to the fourth adsorbent bed and terminating the flow of regenerant to the first adsorbent bed and reversing the process cycle of steps (b) to (h) for said first and second, and said third and fourth adsorbent beds.
6 more elements
A process for the continuous liquid phase adsorption of trace amounts of oxygenates from an oxygenate containing liquid hydrocarbon feedstock with a regenerant stream comprising a wet liquified petroleum gas (LPG) stream having at least 10 wt. ppm sulfur compounds, said process comprising:
- (a) passing the feedstock to a first of at least two fixed adsorbent beds containing a solid adsorbent having selectivity for the adsorption of oxygenates and recovering from the first bed a product having a lower concentration of oxygenates than the liquid hydrocarbon feedstock;
- (b) terminating the passage of said feedstock into the first adsorbent bed said second adsorbent bed initially containing a sweet regenerant in liquid phase;
- (c) passing said feedstock into said second adsorbent bed, displacing sweet liquid regenerant in liquid phase from the second adsorbent bed, passing the displaced regenerant to said first adsorbent bed while recovering treated product from said first adsorbent bed for the duration of the regenerant displacement;
- (d) passing a portion of an untreated liquid regenerant stream to a third adsorbent bed containing a solid adsorbent for the removal of sulfur compounds and water and recovering a first dry, sweet regenerant;
- (e) draining the displaced liquid regenerant from said first adsorbent bed and recovering a first liquid regenerant stream in a first separator;
- (f) passing at least a portion of said untreated liquid regenerant stream and at least a portion of said first liquid regenerant stream from said first separator to said third adsorbent bed, recovering a second dry, sweet regenerant and superheating said second dry, sweet regenerant;
- (g) passing a major portion of the superheated dry sweet regenerant to said first adsorbent bed to desorb oxygenates from the adsorbent and recovering a spent sweet regenerant vapor containing oxygenates;
- (h) passing a minor portion of the superheated dry sweet regenerant to a fourth adsorbent bed containing a solid adsorbent for the removal of sulfur compounds to desorb sulfur compounds and water from said fourth adsorbent bed and recovering a spent sour regenerant vapor;
- (i) condensing said spent sweet regenerant vapor, passing the condenser vapor to said first separator and recovering a first hydrocarbon phase comprising sweet regenerant and oxygenates and an aqueous phase comprising oxygenates;
- (j) recycling a portion of said first hydrocarbon phase to provide additional regenerant;
- (k) cooling and filling said first adsorbent bed by passing dry, sweet regenerant in the liquid phase to the bottom of said first adsorbent bed and from said first adsorbent bed to said first separator;
- (l) condensing the spent sour regenerant vapor of step (h), passing the condensed sour liquid to a second condensor and recovering the condensed sour liquid as a by-product;
- (m) terminating the flow of regenerant to the fourth adsorbent bed and terminating the flow of regenerant to the first adsorbent bed and reversing the process cycle of steps (b) to (l) for said first and second, and said third and fourth adsorbent beds.
10 more elements
Dependencies are inferred from the claim text.