Reaction Engineering Expert

Before Starting

1. Homogeneous or heterogeneous reaction?
2. Which reactor type? (batch, CSTR, PFR, packed bed)
3. Isothermal or non-isothermal operation?

Core Expertise Areas

Reaction Kinetics

Rate law: r = k times CA to power alpha times CB to power beta. Arrhenius equation: k = A times exp of negative Ea over RT. Elementary vs non-elementary: rate law derived from mechanism not stoichiometry. Conversion: X = moles reacted over moles fed. Selectivity: desired product formed over total product formed.

Ideal Reactor Design

Batch: dX over dt = negative rA over CA0, closed system, time-dependent. CSTR: V = FA0 times X over negative rA at exit, well-mixed, steady state. PFR: dFA over dV = rA, plug flow, axial concentration gradient. Levenspiel plot: 1 over negative rA vs X, area gives reactor volume. CSTR in series: approaches PFR performance as number of CSTRs increases.

Non-Isothermal Reactors

Energy balance: heat generated equals heat removed at steady state. Adiabatic temperature rise: delta T = negative delta H times CA0 times X over rho Cp. Multiple steady states: CSTR energy and mole balance can intersect multiple times. Runaway: temperature sensitivity, Damkohler number determines stability.

Heterogeneous Catalysis

Langmuir-Hinshelwood: adsorption, surface reaction, desorption steps. Effectiveness factor: ratio of actual rate to rate without diffusion limitation. Thiele modulus: phi = L times sqrt k over De, large means diffusion limited. Packed bed reactor: pressure drop from Ergun equation, catalyst deactivation.

Best Practices

• Collect kinetic data at multiple temperatures to determine Ea
• Check for mass and heat transfer limitations before fitting intrinsic kinetics
• Design for worst case temperature for safety analysis
• Validate lab kinetics at pilot scale before full scale design

Common Pitfalls

Pitfall	Fix
Ignoring heat effects for exothermic reactions	Always include energy balance for non-isothermal design
External diffusion limitation in kinetic studies	Use differential reactor or high flow rate
Wrong residence time distribution	Characterize RTD with tracer experiment before design
Catalyst deactivation not accounted for	Include deactivation kinetics in design equations

Related Skills

• process-design-expert
• separation-processes-expert
• safety-engineering-expert