Chemical Engineering: PBR Reactor Problem to solve with polymath or matlab

I have to find out the Efective Diffusion, Constant Reaction Rate, Efficieny Factor and another properties of the catalyst. The information that is given o me is a couple of runs with 2 different diameter particles as a function of the volumetric flow. I have the concentration of the reactant in the bed, density of particle and liquid, viscosity, diffusstion coeficient and area of the bed (but not the volume or lenght). So, how would you start with the problem? Will give specific details once I awarded the miniproject. thanks