Your plant is considering the installation of a new railcar tank unloading facility. The facility will
unload nominal 25,000-gal tank cars containing either pure butadiene or cyclohexane. The unloading
system will be equipped with an emergency shutdown system with remotely operated block
valves. The unloading operation will be done by computer control. The railcars are inerted with nitrogen
to a pressure of 40 psig, and the railcar relief system has a set pressure of 75 psig. The unloading
operating instructions are written and have been reviewed by the corporate technical staff.
A reactive chemicals review has already been completed on the proposed facility. Combustible gas
detectors will be located at the unloading station. A deluge system will be installed at the unloading
site with an excellent water supply. A diking system will surround three sides of the facility, with
any spills directed to a covered impounding area.
Determine the Dow F&EI for this operation, and determine the minimum spacing from adjacent
units.
Solution