Enum SmrReaction 

pub enum SmrReaction {
    Reforming,
    WaterGasShift,
}

Which of the two independent reactions.

Variants

Reforming

CH4 + H2O <=> CO + 3 H2.

WaterGasShift

CO + H2O <=> CO2 + H2.

Implementations

impl SmrReaction

pub const BOTH: [SmrReaction; 2]

Both, in the order smr_reactions returns them.

pub fn stoichiometry(self) -> [(Species, f64); 4]

Signed stoichiometry νᵢ — negative reactant, positive product.

pub fn base_reactant(self) -> Species

The reaction’s base reactant — the species whose conversion normalises the extent.

pub fn delta_h(self) -> f64

Standard reaction enthalpy ΔH° at 298.15 K [J/mol of extent], summed from crate::species formation enthalpies.

Positive is endothermic. Nothing here is a tabulated reaction enthalpy — it is Σ νᵢ ΔH°f,ᵢ, so it cannot disagree with the species table it is built from.

pub fn delta_s(self) -> f64

Standard reaction entropy ΔS° at 298.15 K [J/(mol·K)], summed from absolute entropies as Σ νᵢ S°ᵢ.

pub fn delta_g(self, temperature_k: f64) -> f64

Standard Gibbs energy of reaction at temperature_k [J/mol], on the constant-ΔH°/ΔS° (van ’t Hoff) approximation: ΔG° = ΔH° − T ΔS°.

This is the model’s main thermodynamic approximation. Treating ΔH° and ΔS° as temperature-independent ignores the ∫Cp dT and ∫Cp/T dT corrections, which over 298 K → 1200 K are not negligible. It is the approximation EquilibriumConstant::GibbsVantHoff embodies, and it is kept because the alternative — integrating heat capacities — needs Cp(T) polynomials this crate would have to source and catalogue. Stated so a reader does not mistake the equilibrium curve for an exact one.

pub fn equilibrium_constant(self, temperature_k: f64) -> f64

Equilibrium constant Kp(T) [-] on the standard-state partial pressure basis: Kp = exp(−ΔG°(T)/(R T)), with each partial pressure referred to P° = 1 bar.

This is the thermodynamic equilibrium constant. It is not the one a concentration-basis rate law equilibrates to unless Δn = 0 — see SmrReaction::kc.

pub fn delta_n(self) -> f64

Change in mole count, Δn = Σ νᵢ [-].

+2 for reforming (1 + 1 → 1 + 3) and 0 for the shift. It is the whole reason kc exists.

pub fn kc(self, temperature_k: f64) -> f64

Equilibrium constant on the molar concentration basis, Kc = Π Cᵢ^νᵢ in (mol/m³)^Δn.

Why this is not Kp, and why getting it wrong is expensive

Reaction::net_rate evaluates k_f·ΠC^d − k_r·ΠC^r in concentrations, so the composition its rate law settles at satisfies k_f/k_r = Kc, not Kp. For an ideal gas pᵢ = Cᵢ R T, so

  Kp = Kc · (R T / P°)^Δn      =>      Kc = Kp · (P° / (R T))^Δn

For the shift reaction Δn = 0 and the two coincide. For reforming Δn = +2, and at 1123 K the factor (R T / P°)² is about 115 — so using Kp where Kc belongs would put the reforming equilibrium out by two orders of magnitude, in the direction of far too little conversion. That is not a subtle error, but it is a silent one: the reactor still converges, and still returns a plausible-looking number.

P° is 1 bar = 100 kPa, the standard state the formation data in crate::species is tabulated at.

Trait Implementations

impl Clone for SmrReaction

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SmrReaction

impl Debug for SmrReaction

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for SmrReaction

impl PartialEq for SmrReaction

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SmrReaction