Okla. Admin. Code § 252:100-31-2
The following words or terms, when used in this subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Alternative fuel" means fuel derived from any source other than petroleum, natural gas, or coal. Alternative fuel includes, but is not limited to, biogas, waste-derived fuel, recycled tires, tire-derived fuel, and wood fuel as defined in OAC 252:100-19-1.
"Black liquor solids" means the dry weight of the solidsthat enter the recovery furnace in the black liquor.
"Digester system" means each continuous digester or each batch digester used for the cooking of wood in white liquor, and associated flash tank(s), blow tank(s), chip steamer(s), and condenser(s).
"Fossil fuel-fired steam generator" means a furnace or boiler used in the process of burning fossil fuel for the primary purpose of producing steam by heat transfer.
"Kraft pulp mill" means any pulp mill process facility that produces pulp from wood by cooking (digesting) wood chips in a water solution of sodium hydroxide and sodium sulfide (white liquor) at high temperature and pressure. Regeneration of the cooking chemicals through a recovery process is also considered part of the kraft pulp mill.
"Lime kiln" means a unit used to calcine lime mud, which consists primarily of calcium carbonate, into quickline, which is calcium oxide.
"Multiple-effect evaporator system" means the multiple-effect evaporators and associated condenser(s) and hotwell(s) used to concentrate the spent cooking liquid that is separated from the pulp (black liquor).
"Petroleum and natural gas process equipment" means the process equipment used to convert crude petroleum and/or natural gas into refined products. Petroleum and natural gas process equipment includes, but is not limited to, distillation columns, treating columns, catalytic cracking units, catalytic reforming units, sulfur removal equipment, petroleum coke units, flares, heat exchangers, reboilers, jet ejectors, compressors, recompressors, and any other auxiliary equipment pertinent to the process.
"Petroleum and natural gas process facility" means a facility that is engaged in converting crude petroleum and/or natural gas into refined products. Petroleum and natural gas process facilities include petroleum refineries and natural gas processing plants (as defined in 40 CFR § 60.631) , but do not include petroleum and natural gas production, gathering, and transportation facilities.
"Recovery furnace" means either a straight kraft-recovery furnace or a cross-recovery furnace, and includes the direct-contact evaporator for a direct-contact furnace.
"Smelt-dissolving tank" means a vessel used for dissolving the smelt collected from the recovery furnace.
"Sulfur recovery unit" means a process device that recovers elemental sulfur from acid gas.
"Sweetening unit" means a natural gas processing device that removes hydrogen sulfide and carbon dioxide from the gas stream.
"Total reduced sulfur" or "TRS" means the sum of the compounds hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide.
Okla. Admin. Code § 252:100-31-2