Liquid H2S scavengers are sometimes injected into pipelines transporting wet gas to reduce the H2S concentration below allowable values before reaching certain points of the system.

Experimental protocols have been developed to qualify H2S scavengers based on their efficiency and kinetics. However, it has been recognized that the overall reaction kinetics can be affected by the injection method.

A methodology was developed and implemented in a four-inch multiphase flow loop to evaluate the performance of scavenger application technologies in improving the reaction kinetics of liquid scavengers in wet gas systems.

The technical approach was based on using a fast-reacting O2 scavenger as a proxy of a liquid H2S scavenger, to assure that the overall reaction kinetics be controlled by the mass transport kinetics of the liquid scavenger and the reacting gas into the aqueous phase. Oxygen sensors were installed in different sections of the flow loop to evaluate the oxygen concentration transients both in the gas and in the aqueous phases. A kinetic model was used to select the experimental parameters and to assist in the results interpretation.

Experimental results indicated a significant improvement in the overall reaction kinetics between the scavenger and the reacting gas when using injection nozzles, compared to quills.
The methodology implemented can be used to evaluate the effect of different injection technologies in improving the overall reaction kinetics of H2S scavengers without safety concerns related to the use of large volumes of H2S in flow loops.