Caustic scrubbing is a technology that has been used for the removal of H2S from exhaust gases in different industries for many years. Improvements in design and control strategies, favorable prices for caustic compared with other non-regenerable H2S scavenging chemicals, and the potential for sales value for the NaHS (sodium bisulfide) product have made caustic scrubbing an economic and viable option for some refinery streams.

The scrubbing of hydrogen sulfide (H2S) using sodium hydroxide (NaOH) solution is an established technology and has been applied in a variety of industries.