Process for increasing hydrogen partial pressure in hydroprocessing processes

In a process for hydrogenating a feedstream in a hydroprocessing reactor, the feedstream comprising a heavy hydrocarbon liquid component and a hydrogen gas input component, the hydrogen gas input component comprising a recycle gas stream and a makeup gas stream, the reactor producing an effluent liquid stream and a separate effluent gas stream, the effluent gas stream comprising unreacted hydrogen and methane and heavier hydrocarbons, the improvement comprising:

• a) cooling the separated effluent gas stream to a temperature in the range of +30° F. (−1.1° C.) to −40° F. (−40° C.);
• b) contacting the cooled effluent gas stream with a leak liquid solvent stream comprising C4 to C5 hydrocarbon components in an absorption zone to absorb the methane and heavier hydrocarbon from the effluent gas stream to produce a hydrogen-rich gas stream containing 90 to 99 mol % hydrogen and a rich liquid solvent stream;
• c) recovering the hydrogen-rich gas stream from the absorption zone;
• d) adding the hydrogen-rich gas stream to the hydroprocessing reactor feedstream as the recycle gas stream;
• and
• e) flashing the rich liquid solvent stream in at least one flashing stage to produce the lean liquid solvent stream comprising C4 to C5 hydrocarbon components present in the separated effluent gas stream for contacting the cooled effluent gas stream in step (b), and to produce a methane and heavier hydrocarbon gas product stream.