Control of the Merox© NGL sweetening process

If unprocessed natural gas contains higher hydrocarbon fractions (C3+), natural gas liquids (NGLs) can be recovered as a commercial product using, e.g., cryogenic fractionation processes. If the condensed liquids contain impurities of sulfur compounds known as mercaptans, the NGL should be ‘sweetened.’ In the Merox© process, ‘sour’ components are extracted and oxidized with excess air to form alkyl disulfides. Process gas analyzers are used to monitor the oxidation process by measuring the oxygen level in the excess air vent behind the disulfide separator.