Soybean Acid Oil

About This Product

Soybean acid oil is recovered from soybean soapstock, the alkaline residue separated when crude soybean oil is neutralised with caustic soda. Acidulation with sulphuric acid converts those soaps back into free fatty acids, which are drawn off as a dark, viscous oil layer. As a fuel feedstock it combines a regulatory advantage with a technical liability. The advantage is classification: as a refining residue it counts as a waste or residue stream under RED II and comparable schemes, attracting stronger incentives than virgin soybean oil while trading at a discount to it. The liability follows from composition. Soybean oil is dominated by linoleic acid, which carries two double bonds, plus a smaller alpha-linolenic fraction carrying three, and the acid oil inherits that profile. Every double bond is an oxidation site, so the resulting methyl ester has poor storage stability and needs substantial antioxidant treatment to hold an induction period. Free fatty acid, typically well above 50 percent, also rules out alkali transesterification and requires an acid esterification step, and residual sulphate must be controlled for hydrotreating. It is routed to biodiesel through pre-esterification, to renewable diesel by hydrotreating, and into industrial soap, animal feed energy and oilfield chemicals. Bio Green Fuels supplies soybean acid oil to specification on free fatty acid, iodine value, moisture and impurities, sulphur and residual sulphate, and unsaponifiable matter.