What happens if during the catalyst sulfidation, Hydrogen flow is much higher than the target value?Oct-2022
Steve Mayo, Eurecat US Inc, firstname.lastname@example.org
Excess hydrogen flow during catalyst sulfiding is generally not problematic, especially if the gas is recycled (with amine scrubber bypassed) so that unreacted H2S is recirculated. In the case of once through gas flow, additional DMDS injection may be necessary to compensate for lower H2S content in the gas, in particular if feedstock sulfur content is low.
Jake Gotham, InSite Technical Services, email@example.com
Assuming the unit has a recycle compressor to recover hydrogen from the high pressure separator and return it to the reactor, high recycle hydrogen flow rate is unlikely to be a problem.
A small number of hydrotreaters operate with once-through hydrogen (i.e. the gas from the high pressure separator is vented into a hydrogen header or to another hydrotreater). In this case, during high temperature sulphiding, H2S is lost from the hydrotreater into the downstream system. The higher the flow-rate, the more H2S will be lost and an increased amount of DMDS will be required in order to complete the sulphiding.