Experimental studies and modelling of a simplified CIP system using ozone and linear alkylbenzenesulfonate

• Degradation of alkylbenzenesulfonate by ozone in a cleaning device has been modeled.
• A new model considering ozone and surfactant has been synthesised and tested.
• The detergency with surfactant and ozone was similar to experiments without ozone.
• Ozone reduces the surfactant toxicity without affecting the washing effectiveness.

The degradation of linear alkylbenzenesulfonate by ozone in a simplified CIP system has been explained considering jointly a first-order kinetic model for the ozone decomposition reaction in aqueous solutions and a first-order kinetic model for the reaction of ozone and homologues of linear alkylbenzenesulfonate (LAS). The kinetic constants found for the homologues of LAS at the same temperature are similar and show good dependence on temperature (0.960 < r2 < 0.995) following the Arrhenius equation, indicating that ozone has similar affinity for the different alkyl chain homologues.The cleaning of soiled substrate using LAS solutions and ozonated LAS solutions has also been analysed. Under these experimental conditions, the detergency was almost the same without affecting the washing effectiveness. However, a degradation of the surfactant is obtained when ozone is used, reducing the toxicity of the washing solutions. This indicates that LAS could have potential as a surfactant in CIP system with ozone.