Renewable diesel & SAF: HEFA hydrotreating train

The HEFA (Hydroprocessed Esters and Fatty Acids) pathway to sustainable aviation fuel and renewable diesel from fats/oils/greases: a triglyceride feed (triolein) plus a large hydrogen excess is hydrodeoxygenated (HDO) to n-paraffins + propane + water, the paraffins are hydrocracked/isomerized toward the jet range, the H2-rich recycle gas and the HDO process water are knocked out, the light ends are stabilized, and a two-column fractionation splits the product into light naphtha, a jet-range SAF cut, and renewable-diesel bottoms. Honesty notes: the databank carries no lauric/oleic assay, so the FOG feed is modeled as triolein hydrodeoxygenating to n-octadecane (real HDO stoichiometry: triolein + 15 H2 -> 3 n-C18 + propane + 6 H2O); the hydrocracking lump (n-C18 -> n-C12 + n-C6) is illustrative, not a fitted kinetic network; and the n-/iso-paraffin distinction that actually sets the jet freeze-point spec is NOT resolved (the databank carries n-paraffins, not the specific branched isomers) — the train computes real material/energy balances and a real fractionation, not a validated freeze-point. A 3-phase water knockout is modeled as a component separator (the real unit gravity-decants the sour water).