Hydrogen peroxide (H2O2) has proved its efficiency when it is used as an oxidant in chemical scrubbing towers. The important H2O2 decomposition in basic solutions has been investigated and slowed down by addition of a stabiliser: poly-alpha-hydroxyacrylic acid. The objective of this work is to implement this alternative in a laboratory scrubbing pilot. H2S and CH3SH removals were studied in order to characterise the performances of the process. The consumption of reactants (H2O2 and NaOH) was quantified in continuous working with recycling of the scrubbing solution or not. Using hydrogen peroxide in a scrubbing tower gave quite satisfactory results for hydrogen sulphide, and encouraging ones for methylmercaptan. Hydrogen peroxide decomposition observed was economically acceptable, even if compared with the chlorine process. However, sodium hydroxide consumption was found important because of the carbon dioxide competitive absorption. (c) 2006 Elsevier Ltd. All rights reserved.