Patent benchmark: gas fermentation to single-cell protein (JP2024028821A)

The gas-fermentation process class JP2024028821A describes: hydrogen-oxidizing chemolithoautotrophic bacteria (the patent names Cupriavidus necator and Rhodococcus opacus strains) fixing CO2 using H2 as the electron donor to grow single-cell protein biomass. Built here with real physics closing two genuine gaps this session's fact-check found missing: gas-liquid mass transfer (Henry's-law dissolution + a volumetric kLa driving the H2 dissolution rate) and chemolithoautotrophic growth stoichiometry (McCarty's electron-balance method combining the H2-oxidation, O2-reduction, and C5H7O2N cell-synthesis half-reactions) -- not a Monod-on-dissolved-substrate shortcut repurposed for a gas feed. Honesty note, stated plainly: JP2024028821A is a prophetic patent with zero disclosed numerical yields, rates, or operating conditions, so unlike the methyl-lactate benchmark, there is no published number here to validate against -- this demonstrates the real capability (a genuinely mass-transfer-limited fermenter, exactly the regime a real gas-fermentation plant is designed around) rather than replicating a claimed result. The reactor's kLa and Henry's-law constant are illustrative order-of-magnitude values (a real design would fit kLa to measured aeration/agitation data), and the synthesis electron fraction fs=0.4 sits in the literature-typical 0.3-0.6 range for aerobic hydrogen-oxidizing bacteria.