Process Description and Performance - ExSact

The ExSact process operates using two fixed bed reactors. The two reactors are operated in swing mode; while one is on-stream, the other is being regenerated. This operation ensures continual production of alkylate with minimal capital cost.

Olefin is staged to the on-stream reactor where it is reacted with isobutane. The olefin is proportionally divided to each fixed bed while an effluent recycle stream and a recycled isobutane stream enter at the reactor inlet. During fractionation excess isobutane and n-butane are removed in an isostripper, and light ends from the feeds are removed in a depropanizer, as shown in the diagram. No Acid Soluble Oils (ASOs) are produced as in liquid catalyst processes.

Regeneration occurs at elevated temperature using hydrogen. Catalyst activity is completely recovered during each regeneration cycle. The long catalyst lifetime engineered into the ExSact catalyst permits a full regeneration cycle to be executed during the on-stream time of the second reactor.