40 CFR 60.641 - Definitions.
Natural gas means a naturally occurring mixture of hydrocarbon and nonhydrocarbon gases found in geologic formations beneath the earth's surface. The principal hydrocarbon constituent is methane.
Onshore means all facilities except those that are located in the territorial seas or on the outercontinental shelf.
Reduced sulfur compounds means H2S, carbonyl sulfide (COS), and carbon disulfide (CS2).
Sulfur recovery unit means a process device that recovers element sulfur from acid gas.
Sweetening unit means a process device that separates the H2S and CO2 contents from the sour natural gas stream.
Total SO2 equivalents means the sum of volumetric or mass concentrations of the sulfur compounds obtained by adding the quantity existing as SO2 to the quantity of SO2 that would be obtained if all reduced sulfur compounds were converted to SO2 (ppmv or kg/dscm (lb/dscf)).