(129b) FCC Gasoline Hydrodesulfurization and U.L.S.G

The USEPA Tier 3 regulation becomes effective in January, 2017.  The  most attractive options for satisfying the new regulation will involve some combination of the following requirements:  least additional octane loss, least capital investment, fastest implementation time, least additional plot space requirement, sufficient availability.  This discussion will solely consider selective hydrodesulfurization technology and how it can be utilized to satisfy the new regulation.  As will hopefully be made clear in the discussion, it is not often a trivial matter for selective hydrodesulfurization technology designed for the present regulation to be operated so that the new regulation can be satisfied.  If minimum additional mono-olefin loss and minimum additional hydrogen consumption have a high priority, then the mercaptan recombination reaction must receive very careful consideration.