Process for recovering hydrocarbons from inert gas-hydrocarbon vapor mixtures

An improved process for recovering hydrocarbon vapors from an inlet inert gas-hydrocarbon vapor mixture comprising the steps of:

• (a) flowing said inlet mixture through a first bed of solid adsorbent having an affinity for hydrocarbon vapors whereby hydrocarbon vapors are adsorbed on said bed and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced;
• (b) venting said substantially hydrocarbon-free inert gas to the atmosphere;
• (c) evacuating a second bed of solid adsorbent having hydrocarbon vapors adsorbed thereon with an ejector operated by a lean absorbent motive liquid from a separate process or storage having an affinity for said hydrocarbon vapors whereby a major portion of said hydrocarbon vapors is desorbed from said bed and a major portion of said desorbed hydrocarbon vapors is absorbed in said motive liquid thereby forming a hydrocarbon-rich absorbent motive liquid and an inert gas-non-absorbed hydrocarbon vapor mixture commingled with said hydrocarbon-rich motive liquid;
• (d) separating said inert gas-non-absorbed hydrocarbon vapor mixture from said hydrocarbon-rich absorbent motive liquid;
• (e) recycling said separated inert gas-non-absorbed hydrocarbon vapor mixture to said inlet inert gas-hydrocarbon vapor mixture prior to when said inlet mixture flows through said first bed of solid adsorbent wherein hydrocarbon vapors are being adsorbed in accordance with step (a);
• and
• (f) periodically changing the flow pattern of said inlet inert gas-hydrocarbon vapor mixture and changing the bed of solid adsorbent being evacuated whereby when the bed through which the inlet inert gas-hydrocarbon vapor mixture is flowing becomes loaded with adsorbed hydrocarbon vapors, the inlet inert gas-hydrocarbon vapor mixture is caused to flow through the bed which has just been evacuated and the bed loaded with adsorbed hydrocarbon vapors is caused to be regenerated.

An improved process for recovering hydrocarbon vapors from an inlet inert gas-hydrocarbon vapor mixture comprising the steps of:

• (a) flowing said inlet mixture through a first bed of solid adsorbent having an affinity for hydrocarbon vapors whereby hydrocarbon vapors are adsorbed on said bed and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced;
• (b) venting said substantially hydrocarbon-free inert gas to the atmosphere;
• (c) evacuating a second bed of solid adsorbent having hydrocarbon vapors adsorbed thereon with an ejector operated by a motive liquid whereby a major portion of said hydrocarbon vapors is desorbed from said bed and an inert gas and hydrocarbon-rich vapor mixture commingled with said motive liquid is produced;
• (d) separating said inert gas and hydrocarbon-rich vapor mixture from said motive liquid;
• (e) periodically changing the flow pattern of said inlet inert gas-hydrocarbon vapor mixture and changing the bed of solid adsorbent being evacuated whereby when the bed through which the inlet inert gas-hydrocarbon vapor mixture is flowing becomes loaded with adsorbed hydrocarbon vapors, the inlet inert gas-hydrocarbon vapor mixture is caused to flow through the bed which has just been evacuated and the bed loaded with adsorbed hydrocarbon vapors is caused to be regenerated;
• (f) contacting said inert gas and hydrocarbon-rich vapor mixture separated in accordance with step (d) with a lean liquid absorbent whereby a major portion of said hydrocarbon vapors in said mixture is absorbed in said lean liquid absorbent;
• (g) separating the resulting rich liquid absorbent from the remaining inert gas and non-absorbed hydrocarbon vapors;
• (h) conducting said rich liquid absorbent to a point of further processing or storage;
• and
• (i) recycling the remaining inert gas and non-absorbed hydrocarbon vapors separated in step (g) to said inlet inert gas-hydrocarbon vapor mixture prior to when said inlet mixture flows through said bed of solid adsorbent wherein hydrocarbon vapors are being adsorbed in accordance with step (a).

An improved process for recovering hydrocarbon vapors from an inlet inert gas-hydrocarbon vapor mixture comprising the steps of:

• (a) flowing said inlet mixture through a first bed of solid adsorbent having an affinity for hydrocarbon vapors whereby hydrocarbon vapors are adsorbed on said bed and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced;
• (b) venting said substantially hydrocarbon-free inert gas to the atmosphere;
• (c) evacuating a second bed of solid adsorbent having hydrocarbon vapors adsorbed thereon with an ejector operated by a lean absorbent motive liquid from a separate process or storage having an affinity for said hydrocarbon vapors whereby a major portion of said adsorbed hydrocarbon vapors is desorbed from said bed and a major portion of said desorbed hydrocarbon vapors is absorbed in said motive liquid thereby forming a hydrocarbon-rich absorbent motive liquid and an inert gas-non-absorbed hydrocarbon vapor mixture commingled with said hydrocarbon-rich motive liquid;
• (d) separating said hydrocarbon rich motive liquid from said inert gas-non-absorbed hydrocarbon vapor mixture;
• (e) conducting said hydrocarbon rich motive liquid to said separate process or storage;
• (f) recycling said separated inert gas-non-absorbed hydrocarbon vapor mixture to said inlet inert gas-hydrocarbon vapor mixture prior to when said inlet mixture flows through said bed of solid adsorbent wherein hydrocarbon vapors are being adsorbed in accordance with step (a);
• and
• (g) periodically changing the flow pattern of said inlet inert gas-hydrocarbon vapor mixture and changing the bed of solid adsorbent being evacuated whereby the bed through which the inlet inert gas-hydrocarbon vapor mixture is flowing becomes loaded with adsorbed hydrocarbon vapors, the inlet inert gas-hydrocarbon vapor mixture is caused to flow through the bed which has just been evacuated and the bed loaded with adsorbed hydrocarbon vapors is caused to be regenerated.