PROCESS FOR INCREASING HYDROGEN PARTIAL PRESSURE IN HYDROPROCESSING PROCESSES.

摘要

In a hydrocracking unit (12), the flash gases (24) from the high-pressure separator (20) are fed to the bottom of an absorption zone (70) where the entering gases are counter-currently contacted with a lean solvent (74). The lean solvent absorbs away the contained methane, ethane, propane, butanes and pentanes (C1+) from the contained hydrogen. The overhead gas stream (76) from the absorption zone typically contains hydrogen at a purity of 90 to 98 mol %, or even higher, which is fed to the recycle gas stream to provide hydrogen purity in the range of 96 to 99 mol %, thereby providing an increase in the overall efficiency of the hydroprocessor unit. The process can also be employed with hydrotreating, hydrodesulfurization, hydrodenitrogenation and hydrodealkylation reactors.