n-Paraffines; SO2 + O2

sec-Alkane sulfonate

Process for the production of a highly biodegradable detergent, secondary sodium alkane sulfonate, from normal paraffins (C14-C17), sulfur dioxide and oxygen.

Description: The process is based on the sulphoxidation, a chemical process where sulfur dioxide and oxygen are added to saturated straight-chain hydrocarbons where by sulphonic acids are formed: RㆍH + SO2 + 1/2 O2 --> RㆍSO3H
   A n-paraffin mixture is used; the above mentioned reaction takes place initiated by UV-radiation in a reaction vessel. The reaction is exothermic and cooling necessary.
   Sulphonic acid containing unreacted paraffin, sulphuric acid, SO2 and O2 (extract) is continuously drawn out of the reactor. Unreacted paraffins, SO2 and O2 are separated and returned into the reactor.
   Sulphuric acid formed simultaneously is separated. The extract is neutralized with 50% caustic soda solution.
   The neutralized extract is dehydrated is in an evaporator. The hydrocarbons still contained in the intermediate product are separated in a further evaporator and in a stripping column.
   Water is admixed to the alkane sulfonate melt for keeping the product in pumpable viscosity.

Raw materials and utilities (Per 1,000 kg secondary alkane sulfonate):

n-Paraffins (98%)
Sulphur dioxide (100%)     
Oxygen (99.5%)
NaOH (calc. on 100%)
Electric power
Steam (3.5 bar)
Fuel

700 kg
450 kg
120 kg
180 kg
500 kWh
3,000 kg
0.08 * 10 ⁶ kcal