4 The record articles

RICE MACT Series Part 2: Continuing Through the Labyrinth – Emission Limits and Operating and Testing Requirements

Posted: January 19th, 2012

Author: All4 Staff 

Reintroduction and Review – The Twists and Turns of Where We’ve Been

All4 Inc. (ALL4) published the first article in our RICE MACT (Reciprocating Internal Combustion Engines Maximum Achievable Control Technology) Series covering applicability and exemptions in the July 2009 issue of 4 The Record.  Important information from that first RICE MACT article is briefly summarized below:

  • 40 CFR Part 63, Subpart ZZZZ – National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Stationary Reciprocating Internal Combustion Engines (RICE), commonly known as the RICE MACT, applies to any piece of equipment driven by a stationary RICE located at a major or area source of hazardous air pollutants (HAP).
  • Originally promulgated on June 15, 2004, applicability of the RICE MACT has been expanded once via revisions promulgated on January 18, 2008 to include stationary RICE that are either (1) located at an area source of HAP emissions and constructed or reconstructed after June 12, 2006, or (2) have a site rating of less than or equal to 500 horsepower located at a major source of HAP emissions and that were constructed or reconstructed after June 12, 2006.
  • Revisions proposed on February 25, 2009 would expand the applicability of the RICE MACT to include all stationary RICE located at an area source of HAP, stationary RICE with a site rating less than or equal to 500 horsepower located at a major source of HAP that were constructed or reconstructed before June 12, 2006, and stationary RICE with a site rating of greater than 500 horsepower located at a major source of HAP that were constructed or reconstructed before December 19, 2002.
  • The RICE MACT is rife with terms, acronyms, and definitions, the most noteworthy of which are the definitions of existing, new, and reconstructed stationary RICE.  Designation of a stationary RICE as new, existing, or reconstructed is especially important as the applicable requirements for each are different.
  • There are no engine size applicability thresholds under the RICE MACT.
  • While the RICE MACT technically applies to any stationary RICE located at either a major or area source of HAP, certain types of RICE are exempt from any requirements.  However, if and when the revisions proposed on February 25, 2009 are promulgated final, fewer RICE will be exempt.

Emissions and Operating Limitations – You Must Restrict Yourself in the Labyrinth

The RICE MACT limits emissions of HAP via surrogate emission limits for formaldehyde or carbon monoxide (CO).  Currently (i.e., including the final promulgated January 18, 2008 revisions but not the February 25, 2009 proposed revisions), the RICE MACT includes emissions limits for the following RICE:

  • An existing, new, or reconstructed Spark Ignition (SI), Four (4) Stroke Rich Burn (4SRB) stationary RICE with a site rating greater than 500 horsepower (HP) located at a major source of HAP emissions.
  • A new or reconstructed Two (2) Stroke Lean Burn (2SLB) stationary RICE with a site rating greater than 500 HP located at a major source of HAP emissions.
  • A new or reconstructed Four (4) Stroke Lean Burn (4SLB) stationary RICE with a site rating greater than 500 HP or with a site rating between 250 HP and 500 HP located at a major source of HAP emissions that was manufactured on or after January 1, 2008.
  • A new or reconstructed Compression Ignition (CI) stationary RICE with a site rating greater than 500 HP located at a major source of HAP emissions.

For context, the definitions of existing, new, and reconstructed stationary RICE as they apply to the RICE MACT are provided below:

  • Existing Stationary RICE means the following:
    • A stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions if construction or reconstruction commenced before December 19, 2002.
    • A stationary RICE with a site rating of less than or equal to 500 brake HP located at a major source of HAP emissions and any stationary RICE located at an area source of HAP emissions if construction or reconstruction commenced before June 12, 2006.
  • New Stationary RICE means the following:
    • A stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions if construction was commenced on or after December 19, 2002.
    • A stationary RICE with a site rating of equal to or less than 500 brake HP located at a major source of HAP emissions and any stationary RICE located at an area source of HAP emissions if construction commenced on or after June 12, 2006.
  • Reconstructed Stationary RICE means the following:
    • A stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions if it meets the definition of reconstruction in §63.2 and reconstruction commenced on or after December 19, 2002.
    • A stationary RICE with a site rating of equal to or less than 500 brake HP located at a major source of HAP emissions and any stationary RICE located at an area source of HAP emissions if it meets the definition of reconstruction in §63.2 and reconstruction commenced on or after June 12, 2006.

Facilities subject to the RICE MACT are given the option to demonstrate compliance by reducing formaldehyde or CO emissions by a specific percentage or by limiting the concentration of formaldehyde or CO in the RICE exhaust.  In either case, the emission limits are intended to be met through the use of emissions control equipment including Non-Selective Catalytic Reduction (NSCR) for SI 4SRB RICE and catalytic oxidation for 2SLB, 4SLB, and CI RICE.  Demonstrating compliance with an emission limit through the use of emissions control equipment necessitates operating limits to ensure proper operation of the emissions control equipment.  Emission and operating limits for the four (4) types of RICE listed above are as follows:

Emission Limits:

Operating Limits:

It is important to note that existing 2SLB, 4SLB, CI RICE, stationary RICE that combust landfill or digester gas equivalent to 10% or more of the gross heat input of the RICE on an annual basis, and existing limited use and emergency stationary RICE do not have applicable emission limitations under the current RICE MACT.

However, as discussed in more detail in Part 1 of the RICE MACT series and as mentioned above, the February 25, 2009 proposed revisions would expand the applicability of the RICE MACT and, as a result, the types of RICE that would be subject to emissions and/or operating limits.  The proposed revisions would expand emissions and operating limits as follows:

  1. RICE that have emissions and operating limits under the current RICE MACT would continue to be subject to those emissions limits and would receive additional, less stringent emissions limits that would apply only during periods of startup, shutdown, and malfunction (SSM).
  2. RICE not currently subject to any emissions and/or operating limits would receive emissions and operating limits for periods of normal operation, and less stringent emissions limits that would apply only during periods of SSM.

The less stringent SSM emissions limits that would apply to RICE that are already subject to existing emissions and operating limits under the current RICE MACT are provided below:

RICE not currently subject to any emissions and/or operating limits that would receive emissions and operating limits for periods of normal operation and less stringent emissions limits that would apply only during periods of SSM if the February 25, 2009 proposed revisions to the RICE MACT are promulgated final are presented below broken out into the categories in which they would be limited:

RICE Located at a Major Source of HAP Emissions:

RICE Located at an Area Source of HAP Emissions:

Too long to list in greater detail here, the specific emissions and operating limits for the RICE that would receive emissions and operating limits if the February 25, 2009 proposed revisions to the RICE MACT are promulgated final can be found in the March 5, 2009 Federal Register.  Similar to the current RICE MACT, emissions limits would include reducing formaldehyde or CO emissions by a specific percentage or limiting the concentrations of formaldehyde or CO in RICE exhaust to a specific concentration.  Operating limits would include regular maintenance of RICE components (i.e., changing oil and filter, replacing sparkplugs, etc.), and/or visually inspecting RICE components (i.e., inspecting all hoses, belts, air cleaners, etc.).

 Testing Requirements – You Must Prove your Mettle in the Labyrinth (Regularly)

The existing RICE MACT requires that testing be performed on stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions, and SI 4SLB stationary RICE with a site rating of greater than or equal to 250 and less than or equal to 500 brake HP located at a major source of HAP emissions.  However, if the February 25, 2009 proposed revisions are promulgated final, all stationary RICE, regardless of engine size or whether they are located at a facility that is considered a major or area source of HAP emissions, would be required to conduct an initial performance test unless a performance test has been conducted within the last two (2) years, the test has been accepted by the U.S. EPA Administrator, and no process or equipment changes have been made since the test was performed.

Initial performance tests would need to be conducted between 180 and 240 days after the compliance date specified for a particular type of stationary RICE.  The number of days within which an initial performance test would need to be conducted differs depending upon the RICE engine size and whether the RICE meets the definition of existing, new, or reconstructed.

2SLB, 4SLB, and CI stationary RICE demonstrating compliance by reducing CO emissions would need to measure CO and O2 at the inlet and outlet of the control device with a portable CO and O2 analyzer.  4SRB stationary RICE demonstrating compliance by reducing formaldehyde emissions would need to measure O2, moisture, and formaldehyde at the inlet and outlet of the control device.  All other stationary RICE demonstrating compliance by limiting the concentration of formaldehyde or CO in the stationary RICE exhaust would need to determine the moisture content and concentration of O2, CO, or formaldehyde, as appropriate, at the RICE exhaust.

While all RICE subject to an emissions limit would be required to conduct an initial performance test if no previous test exists, only certain engine sizes would be required to conduct subsequent, regular performance tests.  Currently, the RICE MACT requires 2SLB, 4SLB, and CI stationary RICE demonstrating compliance by reducing CO emissions; 4SRB stationary RICE with a brake horsepower ≥ 5,000 HP demonstrating compliance by reducing emissions of formaldehyde; and all other stationary RICE demonstrating compliance by limiting the concentration of CO or formaldehyde in the RICE exhaust to conduct a semiannual subsequent performance test.  After a RICE has tested in compliance for two (2) consecutive semiannual tests, the frequency of testing may be reduced to annually.  However, if an annual performance test indicates that a RICE is not in compliance with an applicable emission limit, the semiannual performance testing must be resumed.

If the February 25, 2009 proposed revisions are promulgated final, 2SLB, 4SLB, reconstructed CI, stationary RICE > 500 HP located a major source of HAP emissions, and 4SRB RICE ≥ 5,000 HP located at a major source of HAP emissions would be required to conduct semiannual performance tests.  Existing non-emergency stationary RICE with a site rating > 500 HP would need to conduct subsequent performance tests every 8,760 hours of operation or every three (3) years, whichever comes first.  The revised RICE MACT would retain the compliant testing frequency provisions.

Look for future RICE MACT updates in 4 The Record after the February 25, 2009 proposed revisions are promulgated final.

Every three (3) years, whichever comes first.  The revised RICE MACT would retain the compliant testing frequency provisions.

Look for future RICE MACT updates in 4 The Record after the February 25, 2009 proposed revisions are promulgated final.

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