k = 0.0141; //lb.mol/atm.lb cat.h
FA0 = 1.08; //lb.mol/h
FB0 = 0.54; // lb.mol/h
FI = 2.03; // lb.mol/h
bita0 = 0.0775; // atm/ft 
Ac = 0.01414; // ft^2
phi = 0.45;
rhoc = 120; // lb cat/ft^3
P0 = 10; // atm
X = 0.6;