{"data":{"id":"us/40-cfr-60.641","jurisdiction":"us","citation":"40 CFR 60.641","heading":"Definitions.","body":"All terms used in this subpart not defined below are given the meaning in the Act and in subpart A of this part.\nAcid gas means a gas stream of hydrogen sulfide (H2S) and carbon dioxide (CO2) that has been separated from sour natural gas by a sweetening unit.\nNatural 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.\nOnshore means all facilities except those that are located in the territorial seas or on the outercontinental shelf.\nReduced sulfur compounds means H2S, carbonyl sulfide (COS), and carbon disulfide (CS2).\nSulfur production rate means the rate of liquid sulfur accumulation from the sulfur recovery unit.\nSulfur recovery unit means a process device that recovers element sulfur from acid gas.\nSweetening unit means a process device that separates the H2S and CO2 contents from the sour natural gas stream.\nTotal 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)).\nEThe sulfur emission rate expressed as elemental sulfur, kilograms per hour (kg/hr) [pounds per hour (lb/hr)], rounded to one decimal place.\nRThe sulfur emission reduction efficiency achieved in percent, carried to one decimal place.\nSThe sulfur production rate, kilograms per hour (kg/hr) [pounds per hour (lb/hr)], rounded to one decimal place.\nXThe sulfur feed rate from the sweetening unit (i.e., the H2S in the acid gas), expressed as sulfur, Mg/D(LT/D), rounded to one decimal place.\nYThe sulfur content of the acid gas from the sweetening unit, expressed as mole percent H2S (dry basis) rounded to one decimal place.\nZThe minimum required sulfur dioxide (SO2) emission reduction efficiency, expressed as percent carried to one decimal place. Zi refers to the reduction efficiency required at the initial performance test. Zc refers to the reduction efficiency required on a continuous basis after compliance with Zi has been demonstrated.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES","Subpart LLL—Standards of Performance for SO2 Emissions From Onshore Natural Gas Processing for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"1d0aea8a2833a2e6b18984e5c985ddfa5d3f96dc3c3f87b71282a5c11d55ff4e","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-60.640","next":"us/40-cfr-60.642"},"notice":"GroundRules: Original legal text. Not legal advice."}