A co processing combining a first selective catalytic bed consisting of {HEAD ~ only one metal element} selected from {TAIL ~ group VIB metals} and of at least one conventional hydrotreating bimetallic catalytic bed 
selected from
A co processing combining a first selective catalytic bed consisting of { HEAD ~ only one metal element } selected from { TAIL ~ group VIB metals } and of at least one conventional hydrotreating bimetallic catalytic bed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH