SCIENTIFIC REVIEW COMMITTEE MEETING -
May 22, 2003

MEETING HIGHLIGHTS

Marty Kay welcomed the SRC members and the audience to the meeting.  The topics listed below were discussed during the meeting.

¾    Update of Part D (Minor Source) BACT Guidelines for Emergency Diesel Engines

¾    Experience with EMx NOx Control Technology on Gas Turbines – Presentation by John Dilliott, UC San Diego

¾    Minutes of March 27th Meeting

¾    Responses to Comments from March 27th Meeting

¾    New and Updated BACT - Part B Listings

¾    Other Business

MSBACT Update for Emergency Diesel Engines

AQMD summarized that it is proposing to update the minor source BACT (MSBACT) Guidelines for emergency diesel engines to require that engines meeting U.S. EPA Tier 2 nonroad emission standards be used as they become available and to also require that cleaner natural gas engines be used for generators that are to be used in interruptible electric service programs.  Copies of the AQMD staff report on this subject were available to attendees. (Marty Kay, AQMD)

Discussion: A committee member stated opposition to the requirement for natural gas engines for generators to be used in interruptible electric service programs, stating that: (1) the 2000-2001 data that had been used in the analysis were not representative of normal conditions, (2) other districts allow use of diesel generators in declared electrical emergencies, and (3) these programs may prevent blackouts in the future, which would cause more diesel generators to operate and be more harmful to public health.  AQMD responded that use of diesel generators in interruptible programs is inappropriate in that these programs generate economic benefits for generator owners, part of which can be used to pay for cleaner generators.  Another committee member stated that in the event of a severe power crisis, a Governor’s executive order could be issued to allow more diesel generators to operate in a preventative mode, if necessary. (Martin Ledwitz, Southern California Edison Co.; Marty Kay, AQMD; Gary Rubenstein, Sierra Research)

Several audience members expressed strong concern about diesel generators without emission controls being permitted for locations that are near schools and suggested that a separate category be created in BACT with more stringent emission controls being required.  Their specific concern was about the effects of diesel particulate emissions on children’s health.  AQMD explained that this problem cannot be readily addressed in the MSBACT guidelines, which must be justified in terms of reductions in criteria pollutants.  AQMD suggested that these concerns can probably be best addressed by changes in Regulation XIV to ensure that diesel engines that are to be sited near schools are subjected to the Rule 1401 toxic screening process and that the health effects of diesel particulate are included in the analysis in each case.  A committee member noted, however, that when toxic screening analyses are performed for uncontrolled emergency diesel generators in other districts, they usually pass screening.  It was also mentioned that the State is presently formulating an Air Toxics Control Measure that will limit emissions and/or the amount of test operation of all emergency diesel generators, with special provisions for those located near schools.  It was further mentioned that AQMD Rule 431.2 requires use of ultra low-sulfur diesel fuel in all diesel engines starting June 1, 2004, which will substantially reduce diesel particulate emissions. (Audience Members; Marty Kay, AQMD; Karl Lany, SCEC; Grant Chin, CARB; Martin Ledwitz, Southern California Edison Co.)

Minutes of the March 27th Meeting

Committee members pointed out that the date of the September meeting as noted in the minutes (September 20) did not appear to be correct.  AQMD apologized for the error and stated that the correct date is September 18 and that the meeting on that date will be in Room CC2.

Regarding the new Part B listing of EMx NOx control technology on a gas turbine (UC San Diego), a committee member questioned whether the gradual decline in the sorbent activity was due to sulfur as stated in the listing.  An audience member responded that it was due to sulfur but clarified that the deactivation mechanism was masking rather than chemical as stated in the listing. (Bill Dennison, Dennison & Associates; Richard Davis, Emerachem)

Experience with EMx NOx Control Technology on Gas Turbines

John Dilliott, Energy Plant Manager for UC San Diego, gave a presentation describing his experience in operating the 26 MW gas turbine cogen plant with EMx NOx control technology, which had been the subject of a new Part B listing presented to the Committee at the March 27^th meeting.  Committee members and AQMD asked a number of questions during the presentation.  The presentation and responses to questions were supportive of the technology, indicating that EMx has been reliable and effective in controlling NOx, CO and VOC emissions below permit limits.  A number of minor problems are being worked on with close support from the vendor, Emerachem.  Mr. Dilliott noted that part of the NOx control being achieved was due to the SoLoNOx dry low-NOx combustion technology on the gas turbine, which was guaranteed to maintain NOx levels below 25 ppmvd@15%O2 while EMx was guaranteed to achieve at least 90% NOx reduction.

An audience member added that a paper will be presented at the AWMA meeting in San Diego the last week of June describing the plant’s experience with continuous measurement of NOx in the sub-2.5 ppm range. (John Prince, APG-CalCEMS)

Responses to Comments from the March 27th Meeting

AQMD stated that changes to the new Part B listings and minutes from the prior meeting that had been agreed upon at the March 27th meeting had been made, and committee or audience members could view the updated documents on AQMD’s web site.  Several comments had been made regarding the UC San Diego gas turbine listing that AQMD was to report back on; however, AQMD felt that those comments had been adequately addressed in the presentation by John Dilliott. (Howard Lange, AQMD)

New and Updated BACT Part B, Section I Listings

Aluminum Melting Furnace, Commonwealth Aluminum (A/N 361714)

This is a 240,000 lb capacity reverberatory furnace used to melt scrap beverage cans for an aluminum rolling mill, which is a continuous operation.  The furnace is RECLAIM Large Source, and the facility is also Title V.  The furnace is equipped with low-NOx, high-efficiency burners, which were installed in 1995.  There are two burners, which operate in tandem to capture heat from the furnace exhaust and utilize it to preheat the combustion air, in a manner similar to a regenerative thermal oxidizer.  One burner is the firing burner while the other functions as the furnace exhaust.  The firing direction is periodically reversed so that the firing burner becomes the exhaust and the exhaust becomes the firing burner.  Each burner is equipped with a ceramic bed.  The bed on the exhaust side is heated by the hot flue gas leaving the furnace while the bed on the firing burner is used to preheat incoming air to the burner.   In 2000, the facility applied for a RECLAIM concentration limit of 60 ppmvd@3%O2 and was granted this limit on the basis of an earlier source test which had shown a NOx level of 46 ppm.  A more recent source test, at a higher firing rate, showed a NOx level of 50 ppm.

The facility maintains fuel records for this furnace as well as for an identical furnace that is equipped with cold-air burners.  Comparisons have consistently shown this furnace to be 30 to 40 percent more efficient than the other furnace.  Mass emissions of NOx from this furnace are therefore 30 to 40 percent less than mass emissions from a furnace with cold-air burners at the same ppm level.  To achieve the same mass emissions as this furnace at its maximum permitted NOx level of 60 ppm, a furnace equipped with cold-air burners would have to be limited to 36-42 ppm, depending on what the actual efficiency advantage is.  This NOx range on this type of furnace can be achieved by using conventional low-NOx burners (see other Part B listings), but this low-NOx, high-efficiency burner system has the additional advantage of conserving fuel. (Howard Lange, AQMD)

Discussion:  There was no discussion.

Fiberglass operation, Jacuzzi Whirlpool Bath (A/N 402868)

This Title V facility manufactures showers and tubs.  The process consists of hand application of a polyester resin/fiberglass mixture in a styrene base to acrylic shapes.  The process equipment includes a mixing room, which contains mixing tanks, and a glassing room, which contains resin storage tanks, resin application booths and curing areas.  Both rooms are vented to an air pollution control (APC) system, which consists of a zeolite concentrator and a catalytic oxidizer.  The equipment was relocated from Irvine to Chino in 2002.  The mixing and glassing rooms were not physically relocated but were replaced with functionally equivalent equipment at the new site, but the APC system was physically relocated.  The APC system had been installed in 2002 at the Irvine location and had been operated for seven months prior to the move.  The permit at the new location requires the following destruction/removal efficiencies: concentrator-90%, oxidizer-95%, overall-90%.  The permit also requires that the glassing room meet U.S. EPA Method 204 criteria for a permanent total enclosure and that the zeolite and oxidation catalyst each be tested for activity on a semi-annual basis.  A source test at the Irvine location showed the following destruction/removal efficiencies: concentrator-92.7%, oxidizer-95.2%, overall-91.9%, and also showed the glassing room to meet the Method 204 criteria. (Howard Lange, AQMD)

Discussion: An audience member requested that AQMD attempt to find out the cost of the APC system.  AQMD responded that it would ask the applicant for that information but could not promise that the applicant would provide the information (Rita Loof, Radtech; Marty Kay, AQMD)

A committee member asked what was being measured in the semi-annual activity checks and what were the criteria of acceptability.  AQMD responded that these factors were not specified in the permit.  The same committee member commented that the process, when at the Irvine location, was not meeting permanent total enclosure criteria and was therefore not meeting the required destruction/removal efficiencies.  AQMD responded that the source test indicated that the permanent total enclosure and destruction/removal efficiency requirements were all met.  The facility’s consultant stated that the glassing room was not built as a permanent total enclosure but had been modified to satisfy those criteria at the time that the APC system was installed.  The committee member stated that the glassing room’s compliance with the permanent total enclosure criteria is questionable and that the zeolite concentrator can be expected to become fouled by styrene and recommended, therefore, that the listing be placed on hold pending the results of a source test at the new location.  AQMD responded that this was not necessary because a BACT determination had been made at the time of the relocation based on the process meeting the achieved-in-practice criteria at the prior location. (Anoosheh Mostafaei, Ship and Shore Environmental; Howard Lange, AQMD; Paul Engel, MFG; Marty Kay, AQMD)

A committee member asked whether there was any urea involved in this process.  AQMD responded that to the best of its knowledge urea is not used in this process.  Another committee member asked what emission controls are used in the boat building industry.  AQMD responded that those are generally smaller operations and typically have less effective controls. (Gary Rubenstein, Sierra Research; Howard Lange, AQMD; Russell Greenhouse, SCEFA; Marty Kay, AQMD)

Dryer or Oven, Fletcher Coating (A/N 385818)

This is a powder coating operation that was installed as a new process line in an existing facility.  The process is used to coat various products and operates continuously for eight hours per day.  The oven temperature is set at from 400F to 600F, depending on what coating is being applied.  The permit sets a limit on the NOx level at 30 ppmvd@3%O2, which was consistent with BACT.  Although not setting new BACT for NOx in this equipment category, the listing is significant in that it is the first listing for this equipment category of the Eclipse Winnox burner.  A source test, which was accepted by the AQMD Monitoring & Source Test Engineering group, showed a NOx level <20 ppm and a CO level of 14 ppm.  It is noted in the listing that burner turndown capability is not as great on this burner as on conventional burners, which may be a problem on some ovens. (Howard Lange, AQMD)

Discussion:  A committee member questioned whether the source test could be considered valid in that the O2 level was above 19%.  AQMD responded that it was well aware of the accuracy problem that can occur at high O2 levels, but the Monitoring & Source Test Engineering group had accepted the test and therefore apparently found the methods used to be adequate to deal with the high O2 level.  An audience member commented that this operation should be examined as possible new VOC BACT for metal coating. (Noel Muyco, Southern California Gas Co.; Howard Lange, AQMD; Rita Loof, Radtech)

New BACT Part B, Section II Listings

Flow Coater, Ball Western Can (N-2253-15-2)

This is a BACT determination for a can coating operation, which was made by the San Joaquin Valley APCD.  The coating operation was relocated from the Bay area to an existing facility in Oakdale, CA, and thus became subject to BACT.  The equipment consists of three flow coaters, which apply the coating to the metal sheets that are used to form the cans.  These three coaters are used to apply the internal can coating, i.e., the side of the sheet that will constitute the internal surface of the can.  Each flow coater is followed by a curing oven.  The coating materials that are used are relatively high in VOC content.

The Authority to Construct was issued in October 2001, and the VOC BACT determination was 95% overall control, based on use of a thermal oxidizer.  The flow coaters and ovens are all vented to a common thermal oxidizer.  The permit requires that the VOC capture system either meet the criteria for a permanent total enclosure or be tested annually for capture efficiency and that the thermal oxidizer be operated at a temperature shown in a source test to produce a 98.5 % destruction efficiency.  Annual testing of the destruction efficiency is required.

The oxidizer is rated at 8 MMBtu/hr maximum fuel input and is designed to process 36,000 scfm air flow rate.  The system was started up in June 2001.  A source test in February 2002 showed that the permanent total enclosure criteria were met and demonstrated a destruction efficiency greater than 99%.  It was determined that an operating temperature of 1400F was adequate to produce 98.5% destruction efficiency.  A second source test, in February 2003, showed a destruction efficiency greater than 98.5%.

The thermal oxidizer is a regenerative type, and due to the inherent thermal efficiency of this type oxidizer and the high VOC content of the inlet air, which is approximately 1000 ppm, it requires no auxiliary fuel once heated to temperature.  It is noted in the listing that it may be more difficult to achieve similar VOC destruction efficiency on a process coating two-part cans (e.g., aluminum beverage cans) due to the lower-VOC coating materials used on two-part cans. (Howard Lange, AQMD)

Discussion: There was no discussion.

Flow Coater, Ball Western Can Co. (N-2253-18-2)

This is a fourth coating line at the Ball Western Can plant in Oakdale.  Whereas the three coating lines at this facility that were discussed previously apply the internal coating required for all cans, this coating line is used to apply an external coating, which is required on only a portion of the total production.  This coating operation is quite different from the other three coating lines in that it employs a UV-curable coating material.  After application of the coating material, the sheets are exposed to UV light, which initiates cross-linking reactions in the coating material causing it to harden without the need for elevated-temperature curing.  This process uses a low-VOC material, and virtually no VOC is released to the surrounding air. (Howard Lange, AQMD)

Discussion:  A committee member commented that a UV-curable coating process has been used on two-part (beverage) cans by Coors for many years.

Another committee member asked whether there is any concern with regard to ozone being produced by the UV light.  An audience member responded that some UV-curable coating processes include a filter to mitigate ozone emissions, but added that very little ozone is actually produced by the UV light and ozone, due to its high reactivity, does not persist very long in the atmosphere.  A committee member added that ozone emissions in a work place are subject to stringent OSHA (Occupational Safety & Health Agency) regulations.

An audience member noted that UV-curable coatings are not used for internal can coating because there are no FDA-approved UV-curable coating materials.  The audience member also noted that there is a similar electron beam curing process, and electron beam-curable coating materials are now being evaluated by the FDA. (Katy Wolf, IRTA; Noel Muyco, Southern California Gas Co.; Rita Loof, Radtech; Bill Dennison, Dennison & Associates; Gary Rubenstein, Sierra Research; Marty Kay, AQMD)

Other Business

AQMD reiterated that the date of the September meeting has been changed to September 18 and that the meeting will be held in Room CC2.

AQMD stated that the next meeting is scheduled to take place at 1:00 p.m. July 24 in Room GB.

There was no further discussion, and the meeting was closed.

 Attachments