Economic Optimization and Hazard Analysis of a Hydrofluoric Acid Catalyzed Alkylation Process

A hydrofluoric acid catalyzed alkylation process was modeled using four series/parallel reactions starting with propylene and isobutane.  A target of 5,000 barrels per day of 95% pure 2,2-dimethylpentane was specified.  The product was also defined to contain less than 1% of heavies (1-nonene and 2,2-dimethyl-octane).  The system was modeled using the process simulator ChemCAD and priced using cost equations from Turton, Bailie, Whiting and Shaeiwitz (2012).  Both topological and parametric optimizations were considered.  The recycle streams increased the complexity of the simulator significantly, but were required to accurately model the concentration build-up in the system.  The impact of reactor residence time, separator recycle purity, and feed ratio on the economics will be presented.  Process hazards will be identified and suggestions to mitigate hazards will be presented.