Sustainable aviation fuel

technology

Liquid hydrocarbon fuel chemically close enough to kerosene to be burned in existing engines and moved through existing pipelines and hydrant systems — a drop-in replacement, certified for blending up to fifty per cent under current specifications. The category covers routes with very different properties: hydroprocessed esters and fatty acids made from used cooking oil, tallow and vegetable oils, which is nearly all of current production and is limited by feedstock; alcohol-to-jet; gasification and Fischer–Tropsch synthesis of residues and wastes; and synthetic power-to-liquid fuel made from electrolytic hydrogen and captured carbon dioxide, which is unconstrained by feedstock and is several times the price of fossil kerosene. The practical position in the mid-2020s was that sustainable aviation fuel accounted for a fraction of one per cent of global jet fuel use while policy attempted to force the curve — the European Union's ReFuelEU Aviation regulation imposed a two per cent blending obligation from 2025 rising in steps toward mid-century, with a sub-mandate specifically for synthetic fuel so that the cheap feedstock route could not satisfy the whole requirement. The honest summary is that the sector's only near-term lever is a fuel that is scarce and expensive, and that the mandate structure is an attempt to buy down that cost by guaranteeing demand — the same mechanism that worked for solar, applied to a technology with no comparable manufacturing learning curve. Not a place.

A technology is not a place. Drawing it on a map would assert something about the world that no stored fact supports.