CRE Design Equation Reference Card (PDF)

Chemical Reaction Engineering (CRE) centers on predicting how chemical reactions proceed in real reactors and how to design equipment to achieve desired conversion, selectivity, and yield. The core methodology relies on combining four pillars: the general mole balance (accounting for accumulation, input, output, and generation), the rate law (expressing reaction rate as a function of concentration, temperature, and catalyst properties), stoichiometry (relating species concentrations via reaction coefficients), and energy balances (for non-isothermal cases). The reference card distills these into context-specific design equations—such as the CSTR design equation (V = F_{A0}X / -r_A) or the PFR differential form (dX/dV = -r_A / F_{A0})—each annotated with standard assumptions (e.g., no pressure drop in PBRs, negligible axial dispersion, well-mixedness in CSTRs). It often includes auxiliary relationships like the Arrhenius equation for temperature dependence, conversion–concentration transformations, and definitions of key parameters (e.g., space time τ, Damköhler number). Practitioners use it not only for exam preparation and homework but also as a verification scaffold during process simulation, pilot-scale design, and troubleshooting of industrial reactors—ensuring consistency between first-principles modeling and empirical correlations.