How they are made
- Splitting. Soapstock is heated and treated with sulphuric acid: the soaps break down and the fatty acids are released in free form.
- Settling. The mixture separates into a fatty layer and acid water, and the water is drained off.
- Washing and drying. The fatty phase is washed free of residual acid and dried to a moisture content of about 1%.
The result is unrefined, or crude, fatty acids. If a purer product is needed, they are additionally distilled — that is a separate product with a different price.
Parameters
| Parameter | What it shows | Typical value |
|---|---|---|
| Fatty acid content | how much of the main substance the product contains | from 95% |
| Acid value, mg KOH/g | how much of the acid is free; the higher it is, the more complete the splitting | 180–200 |
| Iodine value, g I₂/100 g | degree of unsaturation: high in sunflower fatty acids because of linoleic acid | 120–140 |
| Moisture | water left after drying | up to 1% |
| Unsaponifiable matter | ballast: waxes, sterols, hydrocarbons | up to 2.5% |
Who buys them
- Soap plants — the base for laundry soap and detergents.
- Ore processing plants — collector-type flotation reagents for ore beneficiation. In East Kazakhstan, with its mining industry, this is a significant source of demand.
- Feed mills — an energy supplement in compound feed for cattle and poultry.
- Chemical plants — alkyd resins, lubricants, stearates.
Transport
Fatty acids are shipped in bulk in rail tank cars and tank trucks. They thicken at low temperatures, so heated tank cars are needed in winter.