I agree with the estimations made by our members. I am just adding some more information to this. there are several variables influence the cat cir rate. one of them is severity of operation or conversion.
Cat cir rate for a 50,000 BPSD FCC is
1. @30TPM for a moderate conversion level of 55 to 60%
2. approx 40 T/min for a conversion level of 70%
3. approx 50 TPM for a conversion levek of 80%
the above data is applicable for a riser FCC. If UOPs latest Rx cat tecnology riser is used, cat cir rates are much higher, arround in the range of 80 TPM for a 50000BPSD FCCU at 80% conversion level.