White spirit – is a narrow hydrocarbon fraction with the boiling temperature 140-220°C. Concentration of sulfur compounds in white spirit should not exceed 0.1% wt. Therefore, white spirit production is often based on hydrotreated kerosene with complex additives to prevent yellowing.
White spirit is used as a solvent for oil paints, so special requirements are forwarded on its smell. Odor source in white spirit are mercaptans (RSH) and aromatics.
Mercaptan removal from white spirit is possible with alkaline oxidative treating. In this case, malodorous mercaptan compounds are converted to inert disulfides:
2RSH + 0.5O2 → RSSR + H2O
Removal of aromatic compounds (concentration may be up to 25%) is carried out using polar solvents (water solutions of glycols and polar aprotic solvents), however, this method is accompanied by the necessity to regenerate large amounts of solvent and does not completely remove the odor in white spirit production.
