Stretford process

The Stretford process was developed during the late 1950s to remove hydrogen sulfide (H2S) from town gas.

It was the first liquid phase, oxidation process for converting H2S into sulfur to gain widespread commercial acceptance.

The process uses reduction-oxidation (redox) chemistry to oxidise the H2S into elemental sulfur, in an alkaline solution containing vanadium as an oxygen carrier.

By 1987, about 170 Stretford plants had been built worldwide, and more than 100 were still operating in 1992, capable of removing 400,000 tons of sulfur per year.

[4] The first US plant was commissioned in 1971 at Long Beach, California, to process the gas from offshore oil wells.