HydroThane STP CSP stands for Chemical Scrubbing Process. In principle, the removal of H2S is based on the transfer of gaseous hydrogen sulphide to the water phase:

H₂S (g) <-> H₂S (l)

followed by the reaction of dissolved hydrogen sulphide with hydroxide (caustic):

H₂S (l) + OH^- <-> HS^- + H₂O
HS^- + OH^- <-> S^2- + H₂O

HydroThane STP CSP has the following characteristics:

- Low consumable usage
- Standardized skid mounted unit
- Compact and robust construction
- Low capital investment

Because of the pre-scrubber, the pH in main scrubber can be lower than in the normal single systems, what results in:

- less CO₂ consumption due to lower pH in main scrubber
- less precipitation of solid salts and thus less chance of clogging
- Simple operation and maintenance