Tall oil fatty acid reaches fuel through two routes: esterified directly with methanol it feeds the methyl ester (FAME) route, and its derivatives are used in fuel lubricity and combustion additives. Fuel blend and combustion additive production is listed as an application in the TOFA 180 and TOFA 185 product data. The feedstock does not compete with the food chain.
What does tall oil fatty acid do on the fuel side?
A fatty acid shows up in the fuel chain at two different scales. The first is the volume side: the fatty acid is converted into a methyl ester and becomes a component of the fuel blend. The second is the additive side: the fatty acid or a derivative is used as a functional component dosed into the fuel at a very low level, targeting lubricity and combustion behaviour.
Both uses have a clear counterpart in the product data. The TOFA 180 application list carries fuel blend and combustion additive production; in TOFA 185 the same line reads fuel additive and combustion improver production. Together they show that a single raw material can serve both the blend and the additive side.
The free fatty acid route: esterification or transesterification?
Biodiesel chemistry has two different starting points, and the feedstock you work with decides which reaction you set up. Vegetable and animal fats are triglycerides: the fatty acids are already bound to glycerol. Converting them into methyl esters calls for transesterification, where methanol displaces the glycerol and glycerine leaves as a by-product. That route is typically run with base catalysis and is sensitive to free fatty acid in the feed.
Tall oil fatty acid is not a triglyceride; it enters the process as a free fatty acid already. The reaction needed here is not transesterification but direct esterification: the carboxyl group combines with methanol, water is released and a methyl ester forms. Removing that water drives the reaction forward. No glycerine by-product arises on this route.
The distinction has purchasing consequences too. Free fatty acid content is not an impurity here, it is the raw material itself, and it is measured directly through the acid value: min 180 for TOFA 180 and min 185 for TOFA 185 (ASTM D1980). Stoichiometry is calculated from that value. The non-reacting fraction is capped by unsaponifiables: max 6% in TOFA 180 and max 4% in TOFA 185 (ASTM D1065).
BİO BAZLI ÜRÜNLERTall Oil Fatty Acids 185 (TOFA)TOFA 185 is listed in the product data with a fuel additive and combustion improver production application, at acid value min 185 and unsaponifiables max 4%. Request a free sample for your esterification trial.Fuel lubricity additive: what builds the boundary film?
Diesel fuel also lubricates moving parts such as the fuel pump and the injectors. Desulphurisation lowers the sulphur content of the fuel and, along the way, removes part of the polar species that adhere to surfaces. Flow properties survive, but the ability to build a film on the surface weakens. The job of a lubricity additive is to bring that polar function back.
Fatty acids and fatty acid esters are suited to that job by definition. The polar carboxyl or ester end of the molecule orients to the metal surface, the long hydrocarbon tail lines up towards the fuel phase, and an adsorbed layer forms that reduces metal-to-metal contact. The mechanism works through surface activity rather than viscosity, so it acts without changing the flow properties of the fuel.
The polyol ester and base stock route on the lubricating oil side is a separate subject and is covered in the lubricant ester article on this site. On the fuel additive side the scale and the purity expectation are different: volumes are low, but the compatibility of the additive with the fuel and its storage stability are what govern.
Combustion additives and intermediate routes
A fatty acid can enter the fuel additive world as a direct component and also as an intermediate. Routes such as amidation, ethoxylation or amine salt formation produce additives with different functions from the same fatty acid chain. What those derivatives share is that they carry a polar head group together with a long hydrocarbon tail.
Unsaturation is the governing parameter here. The iodine value is min 150 in both TOFA grades (ASTM D5768), and according to the product data that level keeps reactivity predictable from lot to lot in resin, binder and fuel additive applications that rely on drying, oxidative crosslinking or dimerisation. The same unsaturation is also a variable to monitor on the storage stability side.
Why does a non-food feedstock matter?
Tall oil is a by-product of kraft pulp production. No crop is planted for it, no separate agricultural area is set aside for it, and it does not compete directly with the food chain. On the fuel side that is more than a technical property: it is a supply and positioning argument, because in programmes with a renewable content target the origin of the raw material is now part of the specification.
The second consequence is price behaviour. A stream that is a by-product of pulp production moves on different dynamics than the market for food-grade vegetable oil. The feedstock origin comparison is the subject of a separate article on this site and is not repeated here; the scope of this article is the fuel application itself.
KORKİMYA supplies these products KKDIK registered, with a Turkish Safety Data Sheet (SDS/GBF) and a per-lot certificate of analysis (CoA).
Which grade for the fuel route?
Both grades are listed with fuel applications. The choice is made on how narrow a band the esterification yield has to be held in and on the colour expectation of the finished product.
Rosin acid content is watched separately on this route: rosin acids do not take part in esterification in the same way as fatty acids and behave differently in the finished product. TOFA 185 caps that fraction at max 2%, TOFA 180 at max 3%.
Sample, validation and supply
No raw material decision on the fuel side is taken without laboratory validation. The right sequence is to run your own esterification or blending process with a sample, measure the finished product against your own acceptance criteria, and only then move to a supply agreement.
- CAS number: 61790-12-3 (TOFA grades).
- Packaging: ISO tank container 20-24 MT net for TOFA 180 and 20-22 MT net for TOFA 185; carbon steel or stainless steel tank.
- Storage: 20-40°C, closed tank or container, away from direct sunlight.
- Shelf life: 12 months, extendable to 24 months with quality control testing.
- KKDIK registered; Turkish SDS/GBF and a CoA for every lot.
Why is TOFA processed by direct esterification rather than transesterification?
Because tall oil fatty acid is not a triglyceride; it enters the process as a free fatty acid already. In vegetable and animal fats the fatty acids are bound to glycerol and transesterification is required to obtain methyl esters. With a free fatty acid the carboxyl group esterifies directly with methanol, water is released and no glycerine by-product forms.
How does a fuel lubricity additive work?
The polar end of the molecule orients to the metal surface while the hydrocarbon tail lines up towards the fuel phase, forming an adsorbed layer that reduces metal-to-metal contact. The mechanism rests on surface activity rather than viscosity, so it acts without changing the flow properties of the fuel.
Which value is esterification stoichiometry calculated from?
The acid value: min 180 for TOFA 180 and min 185 for TOFA 185 (ASTM D1980). The unsaponifiables limit (max 6% in TOFA 180 and max 4% in TOFA 185, ASTM D1065) caps the fraction that does not react.
Why is unsaturation monitored in fuel additive production?
The iodine value is min 150 in both grades (ASTM D5768). According to the product data that level keeps reactivity predictable from lot to lot in resin, binder and fuel additive applications relying on drying and oxidative crosslinking; the same unsaturation is also a variable to monitor for storage stability.
How do I get a sample and a quote?
State your route (methyl ester production, lubricity additive or intermediate synthesis), estimated annual volume and destination in the inquiry form on the product page. KORKİMYA provides a free sample for laboratory validation and a per-lot CoA.