A hydrocarbon desulfurization system employing regenerable solid sorbent particulates in a fluidized bed desulfurization reactor. The sulfur-loaded sorbent particulates are continuously withdrawn from the reactor and transferred to a regenerator. A novel solids transport mechanism provides for the safe and effective transfer of the sulfur-loaded sorbent particulates from the high pressure hydrocarbon environment of the reactor to the low pressure oxygen environment of the regenerator.