Feedstock Pre-treatment & Refining
Pretreatment sits between the collection of a waste or residue and its conversion into biodiesel, HVO or SAF. Facilities that settle, filter, dry, degum, bleach, esterify or blend feedstocks buy material that is out of specification for direct processing and upgrade it into consistent, contaminant-controlled feed. For these buyers the useful question is not whether a feedstock is clean, but which contaminants it carries and whether the plant can remove them economically.
What the process needs from the feedstock. Settling and filtration handle free water and solids. Water degumming and acid degumming remove hydratable and non-hydratable phosphatides. Bleaching with activated earths removes residual phosphorus, metals, soaps and colour bodies; for HVO feed, additional adsorbents and fine filtration may be needed to reach low mg/kg levels of metals, silicon and chloride. Where the output goes to a biodiesel plant, high free fatty acid (FFA) feedstocks are esterified with methanol over an acid catalyst, glycerolysed, or deacidified by steam stripping.
Key specification parameters. The core set is FFA, moisture, impurities and unsaponifiable matter (MIU), iodine value, phosphorus, calcium, magnesium, iron, sodium, potassium, chlorine, nitrogen, sulphur and polyethylene. Each parameter maps to a unit operation: MIU to settling and filtration, phosphorus and metals to degumming and bleaching, FFA to esterification or stripping, and chloride and polyethylene to specialist adsorption or filtration. Measuring the incoming range, not only an average, lets you size chemical and bleaching-earth consumption realistically.
Recommended feedstock types. Used cooking oil of variable grade, soybean, rapeseed, sunflower and soapstock acid oils, distillers corn oil, PFAD and PKFAD are typical pretreatment inputs. Crude palm, palm kernel, soybean, rapeseed and sunflower oils need conventional degumming and refining steps before conversion. Caustic soda for neutralisation and cleaning is usually purchased alongside.
Documentation and blending. Sustainability status travels with the material, not with the molecules. When waste oils and crop-based oils are blended, the mixture is physically uniform but the sustainability claims are not, so each input must be accounted for separately under the mass-balance rules of your certification scheme. Keep lots with different classifications apart until they are booked, ask for the certificate scope with your quotation, and agree which party's analysis governs acceptance.
Handling and shipping. Many pretreatment inputs arrive in heated ISO tanks, flexitanks or road tankers. Acid oils are corrosive and may contain residual mineral acid, so check tank linings, gaskets and hoses. Agree sampling points, retained-sample periods and a referee laboratory before the first delivery. With variable residues, a clear acceptance procedure prevents most commercial disputes, and trend data from every delivery helps you adjust chemical dosing before a difficult lot reaches the plant.
Products for Feedstock Pre-treatment & Refining
Crude Sunflower Oil
Crude sunflower oil is supplied in two distinct types for fuel use. Standard high-linoleic seed gives good cold flow but weak oxidation stability; high-oleic seed reverses both, and the two are not interchangeable in a specification.
Used Cooking Oil (UCO)
Used cooking oil is the highest-value waste feedstock in the biofuel market, qualifying under RED II Annex IX for double counting. Frying degrades it, so free fatty acid, polymer content and moisture are confirmed per source.
Crude Soybean Oil
Crude soybean oil is the dominant biodiesel feedstock in the Americas. Its high linoleic content gives good cold-flow properties but the weakest oxidation stability of the major feedstocks, so antioxidant treatment is standard.
Crude Rapeseed Oil
Crude rapeseed oil is the reference biodiesel feedstock in Europe. Its high oleic and low saturated content give rapeseed methyl ester the best cold-flow behaviour of any major FAME, which is why it dominates in temperate markets.
Crude Palm Oil
Crude palm oil is the highest-yielding biodiesel feedstock per hectare of any oil crop. Its saturated profile gives an unusually high cetane number and excellent oxidation stability, at the cost of poor cold-flow behaviour.
Crude Palm Kernel Oil
Crude palm kernel oil comes from the seed of the oil palm fruit, not the pulp, and is a lauric oil. Its short C12 and C14 chains give the highest cetane number and the lowest cloud point of the palm-derived fuel feedstocks.
Soapstock Acid Oil
Soapstock acid oil is the generic acidulated refinery residue, made from whatever oils a refinery was processing. It is the cheapest fatty feedstock available and the most variable, so it is always bought against a lot analysis.
Distillers Corn Oil
Distillers corn oil is recovered from the stillage of dry-mill ethanol plants, after the starch has already been fermented. Because it is a residue rather than a crop, it qualifies as a waste-based feedstock under most incentive schemes.
Soybean Acid Oil
Soybean acid oil is the acidulated soapstock from soybean refining. It is the cheapest route to a soybean-derived ester, but its high polyunsaturate content gives the resulting fuel poor oxidation stability.
Rapeseed Acid Oil
Rapeseed acid oil is recovered by acidulating the soapstock from rapeseed oil refining. As a residue stream it qualifies as waste-based feedstock, and its high free fatty acid content routes it to acid esterification rather than the alkali process.
Sunflower Acid Oil
Sunflower acid oil is the acidulated soapstock from sunflower oil refining. It is generally paler and lower in phosphatides than soybean or rapeseed acid oil, which makes it marginally cleaner to process.
Palm Fatty Acid Distillate (PFAD)
Palm Fatty Acid Distillate (PFAD), rich in free fatty acids, is an abundant and low‑cost feedstock converted via esterification and transesterification into biodiesel (FAMEs) or hydrotreated renewable diesel (HVO), making it a critical waste‑derived resource for sustainable energy production.
Palm Kernel Fatty Acid Distillate (PKFAD)
PKFAD is the deodoriser distillate from palm kernel oil refining, rich in lauric and myristic acids. As a processing residue at high free fatty acid content, it is a low-cost esterification feedstock for biodiesel and renewable diesel.
Need a Custom Solution?
Contact our team to discuss your specific requirements for the Feedstock Pre-treatment & Refining industry.