Renewable diesel
The U.S. Department of Energy's Alternative Fuels Data Center describes renewable diesel as a fuel made from fats and oils that is chemically the same as petroleum diesel. In the United States it meets ASTM D975, the specification for diesel fuel oils. It can be used neat or blended in any amount with petroleum diesel. It is a hydrocarbon. The commercial route the page describes for fats, oils, and greases is hydrotreating. The page also names gasification, pyrolysis, biological sugar upgrading, catalytic conversion of sugars, and hydrothermal processing as other routes.
The same page says renewable diesel does not meet the EN 590 minimum density of 0.820 kilograms per cubic meter. It says the fuel does meet EN 15940, the European specification for paraffinic diesel. Renewable diesel is not biodiesel. Biodiesel is a mono-alkyl ester made by transesterification and, on that page, is the fuel that meets ASTM D6751 for blending.
Source: AFDC, Renewable Diesel. This page does not use the plant-capacity table on that AFDC page. The capacities in Producers come from company filings and company pages, which do not match that table.
Biodiesel
AFDC describes biodiesel as a fuel made from vegetable oils, animal fats, or recycled restaurant grease. B100 is the neat fuel. The page says it qualifies as biomass-based diesel and as an advanced biofuel under the Renewable Fuel Standard, and that it is distinct from renewable diesel. It is used in compression-ignition engines.
Source: AFDC, Biodiesel Basics. This page does not state a legal cap on the biodiesel blend percentage. The ASTM D6751 point for the blend stock is the one on the renewable-diesel page linked above.
Sustainable aviation fuel
AFDC describes sustainable aviation fuel as fuel made from non-petroleum feedstocks. It says the blend limit with conventional jet fuel is between 10 percent and 50 percent, depending on the feedstock and the pathway.
Diamond Green Diesel's 2025 financial statements say current aviation regulations allow synthetic paraffinic kerosene to be blended up to 50 percent with conventional jet fuel. The proposed section 45Z regulations define sustainable aviation fuel by ASTM D7566, or by the Fischer-Tropsch provisions of ASTM D1655 Annex A1.
Sources: AFDC, Sustainable Aviation Fuel; Diamond Green Diesel financial statements; Federal Register, February 4, 2026.