US 4,338,101 AGranted

Process and apparatus for recovering hydrocarbons from inert gas-hydrocarbon vapor mixtures

AssigneeJohn Zink Company

InventorWillard N. Tuttle

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Abstract

A process and apparatus for recovering hydrocarbons from inert gas-hydrocarbon vapor mixtures wherein the mixture is caused to flow through a bed of solid adsorbent whereby the hydrocarbons are removed from the mixture and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced. A second bed of solid adsorbent having hydrocarbons previously adsorbed thereon is regenerated by evacuating the bed and the inert gas-hydrocarbon vapor mixture produced by the evacuation is contacted with a liquid absorbent whereby a major portion of the hydrocarbons are absorbed therefrom and recovered. The evacuation of the beds is accomplished using a vacuum pump with an integral cooling jacket for cooling the pump as well as the fluids pumped thereby attached thereto. A cooling medium such as the rich liquid absorbent produced in the process is caused to flow through the vacuum pump cooling jacket thereby cooling the pump and the inert gas-hydrocarbon mixture pumped thereby.

Claims21

Dependent claims

A process for recovering hydrocarbons from an inlet inert gas-hydrocarbon vapor mixture comprising the steps of:

(a) flowing said inlet mixture through a first bed of solid absorbent having an affinity for hydrocarbons whereby hydrocarbons are adsorbed on said bed and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced;
(b) removing said substantially hydrocarbon-free inert gas from said bed of adsorbent;
(c) evacuating a second bed of solid adsorbent having hydrocarbons and inert gas adsorbed thereon by vacuum pumping with a vacuum pump having a cooling jacket for cooling said pump and fluids pumped thereby attached thereto whereby a major portion of said hydrocarbons are desorbed from said bed and a hydrocarbon-rich inert gas-hydrocarbon mixture is produced;
(d) separating hydrocarbons which condense from said inert gas-hydrocarbon mixture from said mixture prior to pumping said mixture with said vacuum pump;
(e) passing a cooling medium through said cooling jacket of said vacuum pump to thereby cool said pump and said inert gas-hydrocarbon mixture pumped thereby;
(f) contacting the inert gas-hydrocarbon mixture produced in step (c) and pumped by said vacuum pump in an absorber with a lean liquid absorbent having an affinity for hydrocarbons whereby a major portion of the hydrocarbons are removed therefrom thereby producing a hydrocarbon-rich liquid absorbent stream and a residue gas stream comprised of inert gas and a minor portion of hydrocarbons;
(g) combining said residue gas stream produced in step (f) with said inlet inert gas-hydrocarbon mixture of step (a) whereby hydrocarbons contained therein are adsorbed on said first bed of solid adsorbent;
and
(h) periodically changing the flow patterns of said inlet inert gas-hydrocarbon mixture and changing the bed of solid adsorbent being evacuated whereby when the beds through which the inlet inert gas-hydrocarbon mixture is flowing becomes loaded with adsorbed hydrocarbons, the inlet inert gas-hydrocarbon mixture is caused to flow through the bed which has just been regenerated.

6 more elements

A process for recovering hydrocarbons from an inlet air-hydrocarbon vapor mixture comprising the steps of:

(a) flowing said inlet mixture through a first bed of activated carbon whereby said hydrocarbons in said mixture are adsorbed on said bed and a residue gas stream comprisesd of substantially hydrocarbon-free air is produced;
(b) venting said substantially hydrocarbon-free air to the atmosphere;
(c) evacuating a second bed of activated carbon having hydrocarbons adsorbed thereon with a vacuum pump having a cooling jacket for cooling said pump and fluids pumped thereby attached thereto whereby a major portion of said hydrocarbons are desorbed from said bed and a hydrocarbon-rich air-hydrocarbon vapor mixture is produced;
(d) separating hydrocarbons which condense from said air-hydrocarbon mixture from said mixture prior to pumping said mixture with said vacuum pump;
(e) introducing a quantity of hydrocarbon-free air into said second bed while continuing to evacuate said bed whereby additional hydrocarbons are stripped from said bed and additional air-hydrocarbon vapor mixture is produced;
(f) contacting the air-hydrocarbon mixture produced in steps (c) and (e) and pumped by said vacuum pump in an absorber with a lean liquid absorbent having an affinity for hydrocarbons whereby a major portion of the hydrocarbons are removed therefrom;
(h) passing at least a portion of said hydrocarbon-rich liquid absorbent stream produced in step (f) through said cooling jacket of said vacuum pump to thereby cool said pump and said air-hydrocarbon mixture pumped thereby;
and
(i) periodically changing the flow pattern of said inlet air-hydrocarbon mixture and changing the bed of activated carbon being evacuated and stripped whereby when the bed through which the inlet air-hydrocarbon mixture is flowing becomes loaded with adsorbed hydrocarbons, the inlet air-hydrocarbon mixture is caused to flow through the bed which has just been evacuated and stripped.

6 more elements

Apparatus for recovering hydrocarbons from an inert gas-hydrocarbon vapor mixture comprising:

(a) a pair of adsorbers containing beds of solid adsorbent having an affinity for hydrocarbons and having inlet and outlet connections on opposite sides of said beds;
(b) first conduit means connected to the inlet connections of said adsorbers for conducting said inert gas-hydrocarbon vapor mixture to said adsorbers and for evacuating said adsorbers;
(c) valve means disposed in said first conduit means for selectively causing said inert gas-hydrocarbon vapor mixture to flow through one or the other of said adsorbers;
(d) second conduit means connected to the outlet connections of said adsorbers for withdrawing residue gas from said adsorbers;
(e) second valve means disposed in said second conduit means for selectively causing residue gas to be withdrawn from one or the other of said adsorbers;
(f) a vacuum pump having a suction connection and a discharge connection and having a cooling jacket for cooling said pump and the fluids pumped thereby attached thereto, said cooling jacket having a cooling medium inlet connection and a cooling medium outlet connection;
(g) means connected to the cooling medium inlet and cooling medium outlet connections of said vacuum pump heat exchanger for circulating a cooling medium therethrough;
(h) third conduit means connected between the suction connection of said vacuum pump and said first conduit means;
(i) third valve means disposed in said third conduit means for selectively communicating one or the other of said adsorbers with the section connection of said vacuum pump;
(j) liquid knockout means disposed in said third conduit means;
(k) an absorber for contacting an inert gas-hydrocarbon vapor mixture with a liquid absorbent having an inert gas-hydrocarbon vapor mixture inlet connection, a residue gas outlet connection, a lean liquid absorbent inlet connection and a rich liquid absorbent outlet connection;
(l) fourth conduit means connected between the inert gas-hydrocarbon vapor mixture inlet of said absorber and the discharge connection of said vacuum pump;
and
(m) fifth conduit means connected between the residue gas outlet connection of said absorber and said first conduit means.

11 more elements

Dependencies are inferred from the claim text.