Building simulations

Reactors and reaction engineering

Seven reactors, from a conversion you already know to kinetics you want to explore. Pick by what you have: a conversion, an equilibrium, or a rate.

Which reactor

Conversion reactor — you know how far each reaction goes. The simplest, and the usual first pass at a process.
Yield reactor — you know what comes out, by mass, not the reactions behind it.
Equilibrium reactor — each reaction pinned by its equilibrium constant K(T), a conversion or an extent, mixed freely.
Gibbs reactor — equilibrium predicted by minimising the free energy: no reactions to write, only the species that may form.
CSTR, PFR and Batch reactor — kinetics: a rate law, a volume or a time, and the reactor's own design equation.

Power law: r = k₀ e^(−Ea/RT) Π Cᵢ^orderᵢ, fractional orders allowed. Give k₀ per second, minute or hour, and say whether it is the rate of reaction or −r_A of the basis reactant — the form shows the units k₀ must carry for the orders you entered.
Reversible: tick it and give the reverse k₀ and Ea; its orders default to the products' coefficients.
LHHW (catalytic): kinetic factor × driving force / adsorption term, on partial pressures, fugacities or concentrations, per m³ of reactor or per kg of catalyst.
Every reaction must balance by mass; one that does not is refused, with the imbalance.

Run adiabatically, or cooled through a jacket with UA and a coolant temperature, a CSTR finds every steady state its energy balance allows and marks the middle one of three unstable.
Choose which to report: the one a cold start-up reaches, the ignited one, or the one nearest a temperature.
Analysis → Profiles draws the heat-generated and heat-removed curves, with the steady states where they cross.

A PFR reports temperature, conversion, and every species' flow and concentration along its length or volume; a batch reports them against time. Analysis → Profiles charts them and exports every series as CSV, to compare with a textbook solution.
A PFR can be a bundle of tubes cooled by a coolant, with the hot spot reported and an Ergun pressure drop along a packed bed.
A batch can be isothermal, adiabatic or jacketed, and reports its peak temperature, the peak heat the jacket must remove, and the time to a target conversion.

Case studies sweep k₀, the activation energy, a reaction order or a reverse constant, as well as any operating condition, and chart the result.
Goal seek finds the value of one that gives the conversion you want.
The reaction-engineering examples — an adiabatic CSTR and its steady states, a jacketed batch, a CSTR against a PFR, series reactions, a cooled methanol bed — are in the Examples menu.
In Dynamics, a CSTR keeps reacting through time: lose the cooling and watch it settle.

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