Blue hydrogen: SMR + water-gas-shift + CO2 capture

A low-carbon (blue) hydrogen train: steam-methane reforming converts natural gas + steam to syngas (CH4 + H2O <=> CO + 3H2) at 1123 K, a water-gas-shift reactor converts the CO with more steam to extra H2 + CO2 (CO + H2O <=> CO2 + H2), the gas is cooled, the process water knocked out, and 96% of the CO2 is captured as a pure stream for sequestration/EOR (the CCS that makes the hydrogen 'blue'). Both reactors are solved to real chemical equilibrium (partial-pressure basis) rather than a fixed conversion. Honesty notes: the reforming/shift Keq values are the representative high-temperature equilibrium magnitudes (~85% CH4 conversion at 1123 K, near-complete CO shift at 620 K), not fitted to one plant; CO2 capture is modeled as a component separator (a real unit uses an amine or physical-solvent loop -- see the 'mixed-amine-acid-gas-treating' showcase for the rigorous MDEA/PZ chemistry, which needs its own electrolyte thermo package and so can't share this flowsheet's gas EoS); and the ~4% residual CH4 slip in the product is real (a plant polishes it with a PSA -- see 'psa-h2-purification').