Continuous Process Vent

{
  "id": "MLC-T-ENV-006467",
  "term": "Continuous Process Vent",
  "field": "Environment",
  "definition": "1. Process vent containing greater than 0.005 weight percent total organic HAP from a continuous unit operation within an affected source. The total organic HAP weight percent is determined after the last recovery device, as described in § 63.115(a), and is determined as specified in § 63.115(c).\n\n2. Process vent from a continuous unit operation within an affected source. Process vents that are serving as control devices are not subject to additional control requirements.\n\n3. Point of discharge to the atmosphere (or the point of entry into a control device, if any) of a gas stream if the gas stream has the characteristics specified in § 63.107(b) through (h), or meets the criteria specified in § 63.107(i), except:(1) The reference in § 63.107(e) to a chemical manufacturing process unit that meets the criteria of § 63.100(b) means an MCPU that meets the criteria of § 63.2435(b);(2) The reference in § 63.107(h)(4) to § 63.113 means Table 1 to this subpart;(3) The references in § 63.107(h)(7) to §§ 63.119 and 63.126 mean tables 4 and 5 to this subpart; and(4) For the purposes of § 63.2455, all references to the characteristics of a process vent (e.g., flowrate, total HAP concentration, or TRE index value) mean the characteristics of the gas stream.(5) The reference to “total organic HAP” in § 63.107(d) means “total HAP” for the purposes of this subpart FFFF.(6) The references to an “air oxidation reactor, distillation unit, or reactor” in § 63.107 mean any continuous operation for the purposes of this subpart.(7) A separate determination is required for the emissions from each MCPU, even if emission streams from two or more MCPU are combined prior to discharge to the atmosphere or to a control device.Dedicated MCPU means an MCPU that consists of equipment that is used exclusively for one process, except that storage tanks assigned to the process according to the procedures in § 63.2435(d) also may be shared by other processes.\n\n4. “Process vent” as defined in § 63.101 in subpart F of this part, except:(1) The reference in § 63.107(e) to a chemical manufacturing process unit that meets the criteria of § 63.100(b) means a CMPU that meets the criteria of § 63.11494(a) and (b);(2) The reference in § 63.107(h)(2) to subpart H means § 63.11495(a) for the purposes of this subpart;(3) The reference in § 63.107(h)(4) to § 63.113 means Tables 2 and 3 to this subpart;(4) The reference in § 63.107(h)(7) to § 63.119 means Table 5 to this subpart, and the reference to § 63.126 does not apply for the purposes of this subpart;(5) The second sentence in the definition of “process vent” in § 63.101 does not apply for the purposes of this subpart;(6) The references to an “air oxidation reactor, distillation unit, or reactor” in § 63.107 means any continuous operation for the purposes of this subpart;(7) Section § 63.107(h)(8) does not apply for the purposes of this subpart; and(8) A separate determination is required for the emissions from each CMPU, even if emission streams from two or more CMPU are combined prior to discharge to the atmosphere or to a control device.\n\n5. Vent from a continuous PVCPU operation through which a HAP-containing gas stream has the potential to be released to the atmosphere except that it is required by this subpart to routed to a closed vent system and control device and has the following characteristics:(1) The gas stream originates as a continuous flow from any continuous PVCPU operation during operation of the PVCPU.(2) The discharge into the closed vent system and control device meets at least one of the following conditions:(i) Is directly from any continuous operation.(ii) Is from any continuous operation after passing solely (i.e., without passing through any other unit operation for a process purpose) through one or more recovery devices within the PVCPU.(iii) Is from a device recovering only mechanical energy from a gas stream that comes either directly from any continuous operation, or from any continuous operation after passing solely (i.e., without passing through any other unit operation for a process purpose) through one or more recovery devices within the PVCPU.\n\n6. (8) On and after August 12, 2023, § 63.107(h)(3) applies unless the fuel gas system supplies a flare of which 50 percent or more of the fuel gas burned in the flare is derived from an MCPU that has processes and/or equipment in ethylene oxide service, or produces olefins or polyolefins. (9) On and after August 12, 2023, § 63.107(h)(9) no longer applies. (10) On and after August 12, 2023, § 63.107(i) no longer applies. Instead, a process vent is the point of discharge to the atmosphere (or the point of entry into a control device, if any) of a gas stream if the gas stream meets the criteria specified in this paragraph. The gas stream would meet the characteristics specified in § 63.107(b) through (g) of subpart F, but, for purposes of avoiding applicability, has been deliberately interrupted, temporarily liquefied, routed through any item of equipment for no process purpose, or disposed of in a flare that does not meet the criteria in § 63.11(b) of subpart A or § 63.2450(e)(5) as applicable, or an incinerator that does not reduce emissions of organic HAP by 98 percent or to a concentration of 20 parts per million by volume, whichever is less stringent. (11) Section 63.107(d) does not apply to continuous process vents in ethylene oxide service.",
  "references": [
    "40 CFR 63.1312 (CFR 2013)",
    "40 CFR 63.1402 (CFR 2013)",
    "40 CFR 63.2550 (CFR 2013)",
    "40 CFR 63.11502 (CFR 2013)",
    "40 CFR 63.12005 (CFR 2013)",
    "85 FR 49084; 40 CFR 63.255 (CFR 2021)"
  ],
  "url": "https://mlchart.com/terminology/environment/continuous-process-vent/"
}