Reciprocating Internal Combustion Engines (RICE) | Region 10 | US EPA

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Reciprocating Internal Combustion Engines (RICE)

New Federal Regulations are Applying to Reciprocating Internal Combustion Engines

RICE use pistons that alternatively move back and forth to convert pressure into rotating motion, like an automobile engine does. They are also commonly refered to as generators. They're frequently used at utility power and manufacturing plants to generate electricity and to power pumps and compressors. RICE are also used in emergencies to produce back up 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 RICE.

On January 14, 2013, EPA signed final revisions to the 2010 RICE National Emissions Standards for Hazardous Air Pollutants (NESHAP) (PDF) to reflect new technical information submitted by stakeholders after the 2010 standards were issued. The updates will ensure that the standards are cost-effective, achievable, and protective, while continuing to provide significant emission reductions. In this action, we addressed several petitions for consideration and legal challenges. We have created a fact sheet with more information about the amendments (PDF) and a Emergency Engine Specific Fact Sheet (PDF) regarding amendments relevant for emergency engine types.

Additional background on the rule development and other RICE rule information can be found on the National Technology Transfer Network site for the NESHAP rule.

Why are we regulating RICE?

RICE 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. RICE 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 do we 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 which include:

What do these regulations apply to?

The RICE NESHAP rule part 63, Subpart ZZZZDOES NOT apply as described here:

  1. 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 (a shorter time period if a seasonal source).
  2. Existing emergency engines located at residential, institutional, or commercial area sources. These engines must meet Subpart ZZZZ definition of emergency engine and maintain the following operation limitations to retain emergency engine status (new engines subject to NSPS have slightly different emergency restrictions):
    • There are no limits on hours of operation for emergency service,
    • Maintenance checks & readiness testing limited to 100 hours a year,
    • 50 hours a year allowed for non-emergencies (counts towards the 100 hours a year maintenance & testing limit)
    • Engine cannot be used for peak shaving or as part of financial arrangement with another entity, except 15 of the 50 non-emergency hrs/yr can be used for on-demand response in emergency situations (e.g., imminent blackout)
    • Engines under 500 horsepower (HP), located at a major source, and installed prior to June 12, 2006, have no limit on maintenance/testing hours,
    • Engines over 500 HP, located at a major source, and installed prior to June 12, 2006 do not have the allowance for 15 hours of on-demand response

The RICE NESHAP rule Part 63, subpart ZZZZ applies to existing engines as described here. New engines are subject to New Source Performance Standards (NSPS) rules, described further below:

  1. Engines greater than 500 HP at a major source of Hazardous Air Pollutants (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
  2. Engines less than or equal to 500 HP at a major source of HAP and engines or 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
Determining RICE Rule Compliance Requirements

RICE Rule requirements are complex – but they are similar for several groups of engines, as summarized in the tables below.

Key Definitions for Terms Used in Compliance Summary Tables Below:
CI: Compression Ignition (diesel)
SI: Spark Ignition (gas including natural gas, landfill gas, gasoline, propane, etc.)

  • 2SLB: 2-stroke lean burn
  • 4SLB: 4-stroke lean burn
  • 4SRB: 4-stroke rich burn
  • LFG/DG: landfill gas/digester gas

Notes:

  • 2-stroke: power cycle completed in 1 revolution of crankshaft
  • 4-stroke: power cycle completed in 2 revolutions of crankshaft
  • Lean burn: higher air/fuel ratio (fuel-lean)
  • Rich burn: lower air/fuel ratio (fuel-rich)
  • Major Source: facility wide potential emissions of greater than 10 tons per year of any single Hazardous Air Pollutant (HAP) or greater than 25 tons per year of all HAPs combined.
Existing Non-emergency Engines Compliance Requirements
  • SI 100 - 500 HP at major source
  • SI > 500 HP at area source that are 4SLB or 4SRB and are used >24 hours/year
  • CI ≥ 100 HP at major source
  • CI > 300 HP at area source (see additional requirements)
  • Initial emission performance test
  • Subsequent performance testing every 8,760 hours of operation OR 3 years for engines >500 HP (5 years if limited use)
  • Operating limitations - catalyst pressure drop and inlet temperature for engines >500 HP
  • Notifications (Refer to Tools box)
  • Semiannual compliance reports (annual if limited use)

In addition for CI >300 HP:

  • Ultra low sulfur diesel (except rural Alaska)
  • Crankcase emission control requirements
Other Existing Engines Management Practice Compliance Requirements
  • All Engines < 100 HP at major source
  • Emergency/black start
    • ≤500 HP at major source
    • All at area source
  • CI ≤ 300 HP non-emergency at area source
  • SI ≤ 500 HP non-emergency at area source
  • SI 2SLB > 500 HP non-emergency at area source
  • SI LFG/DG > 500 HP non-emergency at area source
  • SI 4SLB or 4SRB > 500 HP non-emergency at area source and are used ≤24 hours/year
  • Option 1: Change oil/filter, inspect air cleaner or spark plugs, hoses/belts on prescribed schedule

OR

  • Option 2: May use oil analysis program instead of prescribed oil change frequency
Must complete Option 1 or 2 above, AND:
  • Operate/maintain engine & control device per manufacturer’s instructions or owner-developed maintenance plan
  • Emergency engines must have a non-resettable hour meter and record hours of operation and document hours spent in emergency or non-emergency operation. If engines used for demand response, keep record of notification of emergency situation and time operated.
  • Keep records of maintenance
  • Notifications not required
New Engines Compliance Requirements
  • SI 4SRB > 500 HP new non-emergency at major source
  • SI 2SLB  > 500 HP new non-emergency at major source
  • SI 4SLB > 250 HP new non-emergency at major source
  • CI > 500 HP new non-emergency at major source
  • Initial emission performance test
  • Subsequent performance testing semiannually (may reduce frequency to annual)
  • Operating limitations - catalyst pressure drop and inlet temperature
  • Notifications (Refer to Tools box)
  • Semiannual compliance reports
Existing SI 4S RB Engines at Major Source Compliance Requirements

SI 4SRB > 500 HP operating >24 hrs/yr

  • Initial emission performance test
  • Subsequent performance testing semiannually (may reduce frequency to annual)
  • Operating limitations - catalyst pressure drop and inlet temperature
  • Notifications (Refer to Tools box)
  • Semiannual compliance reports
Other New Engines Compliance Requirements
Emergency/limited use >500 HP new at major source
  • Initial notification only (Refer to Tools box)
Non-emergency LFG/DG >500 HP new at major source
  • Initial notification
  • Monitor/record fuel usage daily
  • Annual report of fuel usage
Emission Standards

CO = carbon monoxide     CH20 = formaldehyde

NOTE: Limits bold-italicized below are expected to require emissions control retrofit

HP Existing RICE at Major Sources
Non-emergency Emergency
CI SI 2SLB SI 4SLB SI 4SRB SI LFG/DG
<100 Work practice standards Work practice standards
100-300 230 ppm CO 225 ppm CO 47 ppm CO 10.3 ppm CH2O 177 ppm CO
300-500 49 ppm CO or 70% CO reduction
>500 23 ppm CO or 70% CO reduction No standards (2004 rule) No standards (2004 rule) 350 ppb CH2O or 76% CH2O reduction (2004 rule) No standards (2004 rule) No standards (2004 rule)
HP Existing RICE at Area Sources
Non-emergency Emergency or Black start
CI SI 2SLB SI 4SLB SI 4SRB SI LFG/DG
≤300 Mgmt practice standards Mgmt practice standards Mgmt practice standards Mgmt practice standards Mgmt practice standards Mgmt practice standards
300-500 49 ppm CO or 70% CO reduction*
>500 23 ppm CO or 70% CO reduction 47 ppm CO or 93% CO reduction* 2.7 ppm CH2O or 76% CH2O reduction**
*Except engines in rural Alaska
**If engine used >24 hrs/yr
HP New RICE at Major Sources
Non-emergency Emergency
CI SI 2SLB SI 4SLB SI 4SRB SI LFG/DG
≤250 Comply with CI NSPS Comply with SI NSPS Comply with SI NSPS Comply with SI NSPS Comply with SI NSPS Comply with CI/SI NSPS
250-500 14 ppm CH2O or 93% CO reduction (also comply with SI NSPS)
>500 580 ppb CH2O or 70% CO reduction (also comply with CI NSPS) 12 ppm CH2O or 58% CO reduction (also comply with SI NSPS) 350 ppb CH2O or 76% CH2O reduction (also comply with SI NSPS) No standards (also comply with SI NSPS) No standards (also comply with CI/SI NSPS)
Notes: New limited use engines >500 HP at major sources are not required to meet any emission standards under the NESHAP. New engines may also be subject to the NSPS.
How to Determine RICE New Source Performance Standards Compliance Requirements

The NSPS rules include two alternative compliance approaches:

  1. Operators comply by purchasing an engine certified by the manufacturer.
  2. Operators comply by meeting emission limits for an engine not certified by the manufacturer.

If you own or operate a Compression Ignition engine you are subject to the NSPS at 40 CFR 60, Subpart IIII if the engine was:

  • Constructed (ordered) after July 11, 2005, and manufactured after April 1, 2006 (July 1, 2006 for fire pump engines), or
  • Modified or reconstructed after July 11, 2005.
  • Except for engines > 30 liters per cylinder (l/cyl) displacement, performance testing is not required - you achieve compliance by:
    • purchasing a new engine that has been certified by EPA, and
    • installing, configuring, operating, and maintaining the engine per the manufacturer’s instructions.

If you own or operate a Spark Ignition engine you are subject to the NSPS at 40 CFR 60, Subpart JJJJ if the engine was:

  • Constructed (ordered) after 6/12/2006 and the engine is or has been:
    • rated greater than 500 HP manufactured on/after 7/1/2007 (except lean burn greater than or equal to 500 HP but less than 1,350 HP),
    • lean burn rated equal to or above 500 HP and below 1,350 HP manufactured on/after 1/1/2008,
    • rated less than 500 HP manufactured on/after 7/1/2008,
    • emergency engines rated greater than 25 HP manufactured on/after 1/1/2008, or
    • modified/reconstructed after 6/12/2006.
  • For the following Spark Ignition engines manufactured on/after July 1, 2008, the engine manufacturer is required to certify that the engine meets emission limits. As the owner or operator of the engine you can comply by purchasing a certified engine, and operating it according to manufacturer’s instructions. These SI engine types include:
    • engines rated under or equal to 25 HP,
    • gasoline non-emergency engines rated greater than 25 HP, and
    • rich burn LPG engines rated greater than 25 HP.
  • For other Spark Ignition engines, EPA made it optional for the manufacturer to certify that their engines meet the applicable emission limits. Owners or operators can comply either by purchasing an engine that the manufacturer has voluntarily certified, or by conducting performance testing to demonstrate that the engine meets the applicable emission limits.

For more information on applicable NSPS emission limits, which engines must be certified by manufacturers, and which engines can be voluntarily certified by the manufacturer, visit the Combustion Portal.

Reduced NESHAP Requirements in Remote Alaska

Under the NESHAP rule, existing Compression Ignition (CI) stationary RICE located in remote areas of Alaska are exempt from:

  • the requirement to use ultra low sulfur diesel fuel (fuel that meets requirements listed in 40 CFR 80.510(b)),
  • crankcase ventilation systems requirements, and
  • numerical carbon monoxide limitations.

Review a map of the Federal Aid Highway System and Railbelt grid in Alaska (PDF) (1 page, 633K)

These exempt RICE must meet the same management practices as CI RICE less than or equal to 300 HP instead.

Amendments related to remote Alaska are final:

On January 14, 2013, EPA signed final revisions to the 2010 RICE NESHAP (PDF) to reflect new technical information submitted by stakeholders after the 2010 standards were issued. For more information about the amendments we have prepared a fact sheet giving an overview (PDF).



URL: http://yosemite.epa.gov/R10/airpage.nsf/Enforcement/rice_rules

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