Aceite de maíz de destilería — Frequently Asked Questions

Crude corn oil comes from the germ separated in corn milling and is refined for food. Distillers corn oil is recovered from the stillage of dry-grind ethanol plants after the grain has been cooked, fermented and distilled. That history gives DCO higher FFA, a darker colour and more sulphur and unsaponifiables, and it is not intended for food use.

Typically about 5–15 % as oleic acid, depending on the ethanol plant's conditions and on how long the oil has been stored. That is too high for direct alkaline transesterification, so biodiesel producers pretreat it, while HVO and SAF units accept the FFA and concentrate on removing contaminants.

Ethanol plants commonly use sulphuric acid to control pH, and fermentation contributes sulphur compounds. Some of that sulphur follows the oil through evaporation and centrifugation. For biodiesel, which has a 10 mg/kg product limit, set a sulphur cap and consider ester distillation; hydrotreating removes sulphur but consumes extra hydrogen.

It can. Some plants add oil-recovery aids to improve centrifuge separation, and antifoams or cleaning chemicals can be present in trace amounts. Ask whether recovery aids were used, and include parameters such as unsaponifiable matter and, for HVO, nitrogen and silicon in your specification so their effect on pretreatment is visible.

It is not named in Annex IX. Several schemes discuss it as a residue of ethanol production, but the category accepted and any incentives vary by Member State and by road or aviation route. Confirm the classification and certificate scope with your certification body before contracting, and ask for traceability to the originating ethanol plant.

Your FFA basis, MIU and unsaponifiable limits, iodine value range, sulphur and phosphorus caps, the conversion route, volume, packaging (road tanker, ISO tank, flexitank or bulk), delivery point and Incoterm, and the sustainability documentation your market requires. Mention any sensitivity to recovery-aid residues so it can be checked against the lot information.