Technology Transfer Network - Air Toxics Web Site
Stationary Internal Combustion Engines
- Proposed Amendments to NSPS for Stationary Compression Ignition Internal Combustion Engines
- On October 30, 2015, EPA proposed amendments that would allow operators to temporarily override features that shutdown the engine when NOx emission control equipment is not operating during an emergency situation where there is a risk to human life. The amendments would align requirements for stationary compression ignition engines with requirements for the same engines used in nonroad vehicles. This action also would revise the criteria for defining remote areas of Alaska to align with those in the air toxics standards for stationary reciprocating internal combustion engines. See proposed amendments and summary fact sheet.
- Court Decision on Petitions for Review
- On May 1, 2015, the U.S. Court of Appeals for the District of Columbia Circuit issued a decision granting in part and denying in part petitions for review of the RICE NESHAP and NSPS emergency engine regulations in Delaware v. EPA (Nos. 13-1093, 13-1102 and 13-1104) (D.C. Cir.).
- On July 15, 2015, the EPA filed an unopposed petition for panel rehearing of the vacatur of the 100 hours for maintenance checks and readiness testing. In response to the petition for panel rehearing, on July 21, 2015, the court amended the May 1, 2015 decision to specify that the decision would vacate only those portions of the regulations addressed to emergency demand response, and would leave in effect the provisions that allow emergency engines to operate for maintenance checks and readiness testing. EPA also filed an opposed motion for a stay of the court's mandate until May 1, 2016. On August 14, 2015, the court granted EPA’s motion to stay issuance of the court’s mandate until May 1, 2016.
- The Court's decision and EPA’s filings are available on the Technical Info page.
- Motion for Voluntary Remand
- On June 30, 2015, the EPA filed a motion for voluntary remand without vacatur of EPA’s final decision on the reconsideration of the conditions in 40 CFR 60.4211(f)(3)(i), 60.4243(d)(3)(i) and 63.6640(f)(4)(ii) for operation for up to 50 hours per calendar year in non-emergency situations as part of a financial arrangement with another entity (79 FR 48072, August 15, 2014).
On September 23, 2015, the court granted EPA’s motion for a voluntary remand without vacatur. See the Technical Info page.
- On June 30, 2015, the EPA filed a motion for voluntary remand without vacatur of EPA’s final decision on the reconsideration of the conditions in 40 CFR 60.4211(f)(3)(i), 60.4243(d)(3)(i) and 63.6640(f)(4)(ii) for operation for up to 50 hours per calendar year in non-emergency situations as part of a financial arrangement with another entity (79 FR 48072, August 15, 2014). On September 23, 2015, the court granted EPA’s motion for a voluntary remand without vacatur. See the Technical Info page.
What Are Stationary Internal Combustion Engines?
Stationary Internal Combustion Engines use pistons that alternatively move back and forth to convert pressure into rotating motion. They're commonly used at power and manufacturing plants to generate electricity and to power pumps and compressors. They are also used in emergencies to produce electricity and pump water for flood and fire control. The U.S. Environmental Protection Agency (EPA) has recently finalized new air quality regulations that place requirements on owners and operators of a wide variety of stationary engines.
Why Does EPA Regulate Stationary Engines?
Stationary Internal Combustion Engines are common combustion sources that collectively can have a significant impact on air quality and public health. The air toxics emitted from stationary engines include formaldehyde, acrolein, acetaldehyde and methanol. Exposure to these air toxics may produce a wide variety of health difficulties for people including irritation of the eyes, skin and mucous membranes, and central nervous system problems. Engines also emit the conventional air pollutants created when fuel is burned including carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and particulate matter (PM). The health effects of these pollutants include a range of respiratory (breathing) issues, especially asthma among children and seniors.
How Does EPA Regulate Stationary Engines?
EPA air quality requirements for stationary engines differ according to:
- whether the engine is new or existing, and
- whether the engine is located at an area source or major source and whether the engine is a compression ignition or a spark ignition engine. "Spark ignition" engines are further subdivided by power cycle - i.e., two vs. four stroke, and whether the engine is "rich burn" (burning with a higher amount of fuel as compared to air) or "lean burn" (less fuel compared to air) engine.
Several regulations have expanded the number and type of stationary RICE that must comply with federal requirements. These include:
- National Emission Standard for Hazardous Air Pollutants (NESHAP) for Reciprocating Internal Combustion Engines (RICE) – 40 Code of Federal Regulations Part 63, Subpart ZZZZ ("the RICE rule")
- New Source Performance Standards (NSPS) - Standards of Performance for Stationary Spark Ignition Internal Combustion Engines - 40 CFR Part 60 Subpart JJJJ – "the Spark Ignition NSPS rule"
- Standards of Performance for Stationary Compression Ignition Internal Combustion Engines - 40 CFR Part 60 Subpart IIII - "the Compression Ignition NSPS rule"
The rule Does Not Apply to:
- Motor vehicles, or to non-road engines, which are:
- self-propelled (tractors, bulldozers)
- propelled while performing their function (lawnmowers)
- portable or transportable (has wheels, skids, carrying handles, dolly, trailer or platform). Note: a portable non-road engine becomes stationary if it stays in one location for more than 12 months (or full annual operating period of a seasonal source)
- Existing emergency engines located at residential, institutional, or commercial area sources, used or obligated to be available ≤15 hr/yr for emergency demand response, and not used for local reliability. Engine must meet Subpart ZZZZ emergency engine operational requirements:
- Unlimited use for emergencies (e.g., power outage, fire, flood)
- Emergency engines may operate for 100 hr/yr for any combination of the following:
- emergency demand response (in situations when a blackout is imminent – either the reliability coordinator has declared an Energy Emergency Alert Level 2 as defined in the North American Reliability Corporation (NERC) Reliability Standard; or there is a deviation of voltage or frequency of 5 percent or greater below standard voltage or frequency);
- 50 hr/yr of the 100 hr/yr allocation can be used for:
- non-emergency situations if no financial arrangement
- local reliability as part of a financial arrangement with another entity if specific criteria met (existing RICE at area sources of HAP only)
- peak shaving until May 3, 2014 (existing RICE at area sources of HAP only) if part of a peak shaving (load management) program with the local distribution system operator and the power is provided only to the facility or to support the local distribution system
The rule Applies to:
- Engines >500 Horsepower (HP) at major source of HAP:
Existing engines if constructed before December 19, 2002
New engines if constructed on or after December 19, 2002
Reconstructed engines if reconstruction began on or after December 19, 2002
- Engines ≤500 HP located at major source of HAP and engines of all horsepower located at an area source of HAP:
Existing engines if constructed before June 12, 2006
New engines if constructed on or after June 12, 2006
Reconstructed engines if reconstruction began on or after June 12, 2006