Benzene Reduction at Frontier Refinery

We are working with Frontier Refinery in Cheyenne, Wyoming to reduce benzene concentration in the gasol ine pool. Mobile Source Air Toxins, a newly implemented environmental regulation, requires all small refineries to reduce benzene content to 0.62% (v/v) by the year 2015. Current benzene content is greater than 1%. If the content is not reduced, Frontie r will be fined for failing to meet the new standards. HYSYS and Aspen Plus simulation software were used to model the process. A naphtha splitter was modeled downstream of the hydrobon unit to remove benzene precursors from the platformer feed. Three options were considered downstream of the naphtha splitter. Benzene saturation would convert benzene to cyclohexane, but would require an additional hydrogen plant. Benzene marketing would not require a high capital cost but would introduce major revenue and product loss. Alkylation would convert benzene to ethylbenzene, yielding a high octane blendstock. An economic analysis was completed for each option and alkylation proved to be the most feasible. Further work on optimization, safety and environmental considerations is currently under review. A detailed final report will be provided to Frontier