Steam Methane Reforming Reactor

Reformer Conditions

Temperature 850 °C

Pressure 10 bar

Steam : Carbon ratio 3.0

Flow speed 1.0×

Live Equilibrium

CH4 + 2H2O ⇌ CO2 + 4H2

CH4 conversion

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H2 yield

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Equilibrium constant K_p(T)

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How it works

~95% of the world's hydrogen is made this way. Natural gas (CH4) reacts with steam over a nickel catalyst — endothermic and mole-increasing — then the reformer's CO is pushed on through the water-gas-shift step to make more H2. Lumped together the plant behaves like one overall equilibrium:

CH4 + 2H2O ⇌ CO2 + 4H2      ΔH° ≈ +165 kJ/mol (endothermic)

ΔG°(T) = ΔH° − TΔS°,  Kp(T) = exp(−ΔG°/RT)

Basis 1 mol CH4 fed, extent ξ mol converted, S = steam/carbon:
 n(CH4)=1−ξ  n(H2O)=S−2ξ  n(CO2)=ξ  n(H2)=4ξ   Δn = +2

Kp(T) = [y_CO2 · y_H2⁴ / (y_CH4 · y_H2O²)] · P^Δn

Temperature — the reaction is endothermic, so K_p rises steeply with T (Arrhenius/van 't Hoff): hotter reformer, more conversion. This is why real furnaces run the tubes at 700–1000 °C.
Pressure — the reaction makes more gas moles than it consumes (Δn = +2), so by Le Chatelier's principle higher pressure suppresses conversion even though industrial plants still run pressurised (15–30 bar) for downstream compression economics.
Steam : Carbon ratio — excess steam pulls the equilibrium toward products and also suppresses carbon (coking) deposits on the catalyst; real plants use S/C ≈ 2.5–4.
Every frame solves Kp(T)/P² = y-ratio(ξ) for ξ by bisection, then colours the flowing gas: reactant molecules that haven't reached their (randomly assigned) conversion point along the tube stay blue; the ξ-fraction that do convert turn amber as they pass it.

CH4 / H2O (reactants) CO2 / H2 (products)

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Steam Methane Reforming: Hydrogen Production Equilibrium