Fractionation Research Inc. (FRI) has been studying distillation and distillation equipment for almost 60 years on behalf of its 70 members, each of whom pay an annual subscription fee for services. FRI possesses two industrial-size distillation columns which are located on the Oklahoma State University campus in Stillwater, Okla.
Typically one of the following three binary separation tests is run within those two columns:
1.p- and o-xylenes from 75 mm Hga to atmospheric pressure
2.cyclohexane and n-heptane near atmospheric pressure
3.isobutane and n-butane from 100 psia to 500 psia.
During test runs, the trays and packings within the columns are subjected to a very wide range of liquid/vapor and mass transfer regimes. All of the runs are logged at steady-state conditions, but steady state is maintained only long enough to collect the relevant data. The process conditions are then modified for the next test. Tests conducted include start-up, transitions within and between various modes of operations, flooding, un-flooding, setpoint changes and shutdowns.