Hydroconversion effluent separation process

Claim 1

A process for separating gases from a hydroconversion zone reaction effluent comprising: (a) effecting a hot high pressure separation of the effluent by reducing the temperature of the effluent to produce a first gas phase comprising hydrogen, contaminant gases, and gaseous hydrocarbons and a first liquid phase comprising hydrocarbons, and separating the first gas phase from the first liquid phase; (b) effecting a cold high pressure separation of the first gas phase by reducing the temperature of the first gas phase to form a first hydrogen-rich gas product and a second liquid phase, and separating the second liquid phase from the first hydrogen-rich gas; (c) effecting a hot low pressure separation of the first liquid phase by reducing the pressure of the first liquid phase to form a second gas phase comprising hydrogen and gaseous hydrocarbons and a third liquid phase comprising hydrocarbons, and separating the second gas phase from the third liquid phase; (d) effecting a cold low pressure separation of the second gas phase by reducing the temperature thereof to form a second hydrogen-rich and a fourth liquid phase comprising hydrocarbons, and separating the fourth liquid phase from the second hydrogen-rich gas; (e) recycling the second hydrogen-rich gas to the hydroconversion zone; (f) subjecting said first hydrogen-rich gas product to the removal of contaminants comprising H 2 S to produce a hydrogen-rich, contaminant-removal treated gas and recycling a first portion of said hydrogen-rich, contaminant-removal treated gas to the hydroconversion zone; (g) purifying a second portion of said hydrogen-rich, contaminant-removal treated gas to obtain a purified hydrogen-rich gas of at least 95 volume percent hydrogen, wherein the purification is carried out using membranes to separate the purified hydrogen-rich gas from the first hydrogen-rich gas; and (h) recycling the purified hydrogen-rich gas to the hydroconversion zone.