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

• June SRC Meeting Minutes
• BACT Listings Under Public Review
• New BACT - Part B Listings
• Other Business

Following are the responses to comments presented at the last meeting.

A protocol for continuously monitoring ammonia slip from a gas turbine at Sithe Mystic Development LLC in Massachusetts is under development. Facility has been discussing with several CEMS vendors, but has not made a decision on a specific technology. Complete protocol will be finalized before start up in 2002. AQMD staff will update the BACT listing to include this information. (Knut Beruldsen)

Emergency ICEs operated less than 200 hours/yr are exempt from emission limits in Rule 1110.2. However, facility must monitor and keep records of engine's operating hours to demonstrate compliance with the 200-hour limit. (Knut Beruldsen)

• To make the technology universal, Catalytica is working side by side with various turbine manufacturers. In general, if one or two manufacturers can produce low NOx products that meet the need of the applicants, it is possible that the NOx limit achieved will be imposed on other manufacturers.
• Because large size turbines are generally designed for a specific need, LAER should be considered on a case-by-case basis. Small size turbines are generally sold as package. Therefore, BACT may not need to be determined on a case-by-case basis.

Part C of the District LAER/BACT Guidelines states that a control technology found in any regulatory document will be considered achieved-in-practice (AIP) if it meets all of the AIP criteria. Part A states that a control technology may be considered AIP if it meets all of the AIP criteria. AQMP staff will revisit the wordings in Part A and C for consistency. (Deanna Haines, Pom Pom Ganguli)

AQMD staff has not received substantial public comments for the CO2 plant at BOC Group, and the refinery heater at CENCO refinery, and has not yet completed the review. Following information was provided at the meeting:

A commentor has recommended that BACT/LAER determination for this CO2 plant should reflect either 1) a control efficiency requirement, or 2) a maximum allowable hydrocarbon concentration. Permit limit for this CO2 plant addresses this concern by requiring a control efficiency of 95% for hydrocarbon, or a maximum allowable hydrocarbon concentration of 25 ppmv measured as methane. (Audience)

The applicant has requested District staff to consider a more stringent NOx limit (<7ppmv) in exchange for a less stringent ammonia limit (>5 ppmv). Internal discussion is still going on to address whether or not the 5-ppmv ammonia slip limit should be relaxed.

To put the subject in perspective, AQMD staff highlighted the following information:

• NOx is a criteria pollutant regulated under federal NSR whereas ammonia is a pollutant regulated under District NSR but not federal NSR.
• SCR using ammonia injection is an established control technology such that there is no need for a 6-month operation to demonstrate achieved-in-practice.
• The effectiveness of the catalyst degrades with time. In order to maintain a required NOx limit, more ammonia is injected at the end of life of the catalyst. Because of that, ammonia slip tends to increase. The District has source test data to show that ammonia slip below 2 ppmv can be achieved at the beginning of the catalyst life. However, the District has less information regarding catalyst degradation, and the increase of ammonia slip as a function of time.
• The performance of the SCR catalyst in refinery gas application may be different than that in natural gas application.
• The ammonia slip and NOx limits for a gas turbine with SCR at Sithe Mystic Development LLC in Massachusetts are 2 ppmv. Even though the system has not yet been built, the catalyst design and feedback control are expected to be far superior to five years ago.

SRC members shared the following information:

• Type of ammonia vaporization and delivery system could influence the ammonia slip. Los Angeles County Sanitation District originally had an ammonia vaporization system where the aqueous ammonia solution was atomized at the nozzle. This system did not work well. The facility finally switched to a vaporizing system where aqueous ammonia solution is atomized and mixed with a carrier gas way upstream of the nozzle, and injected into the ductwork.
• Type of design and application could affect the ammonia slip level. Carson Cogen plant in Sacramento has a combined cycle turbine and a peaking turbine equipped with SCRs. The ammonia injection system for the peaking unit is designed differently than for the combined cycle unit. They were both designed to meet a 5ppmv ammonia slip. However, the peaking unit consistently has a slip of about 10 ppmv. On the other hand, the slip measured for the combined cycle unit is in the neighborhood of 1 ppmv to 2 ppmv at the start of the catalyst life, and 3 ppmv to 5 ppmv after 7 years of operation.
• Type of fuel burned could affect the degradation of the catalyst. Annual source tests for an oil-fired internal combustion engine operated at 6000 hours to 7000 hours a year in Hawaii show that there is a gradual degradation of the catalyst and the rate of degradation accelerates with time. The system recently completed a 7-year life cycle. After three years of operation, this system barely passed a limit of 20-ppmv ammonia slip. It is suspected that catalyst degradation occurs more rapidly with oil-fired than with gas-fired units.
• Because the catalyst degradation is gradual, an annual source test of ammonia slip may be sufficient to provide adequate warning to the facility to replace the catalyst in time and stay in compliance.
• San Diego Naval Base recently receives a modified permit for an approximately 7-year old SCR system where the ammonia slip limit is raised from 20 to 50 ppmv.

Copies of the new BACT listings for three screen printing operations were provided to the SRC members and the audience. AQMD staff highlighted the following information:

• The screen printing equipment at New Age Graphics Inc. and Giant Merchandising is used to print images on fabrics. BACT requirements are met by using low VOC plastisols and water based inks.
• The screen printing equipment at Coyle Reproductions, Inc. is used to print posters, banners, brochures etc. BACT requirements are met by using UV curable inks.

District staff and SRC members shared the following understanding about the use of RTO to control chlorinated compounds:

• Chlorinated (or Halogenated) compounds form acids (e.g. Hydrochloric acid) when oxidized. The acids are corrosive, and can severely attack the control device's casing and downstream exhaust piping/stack if these devices are not constructed with corrosion resistant materials.
• Chemical poisoning of the catalysts may occur. The chlorinated compounds, which usually have very high decomposition temperatures, tightly bind to the catalysts, and even though the process is physical adsorption in nature, the desorption time may not be sufficient to completely remove the compounds.

Following information is provided:

• Recommendation from Bill Wong to improve the clarity of the LAER/MSBACT Guidelines was acknowledged. AQMD staff will develop an Introduction Section to clearly explain and lead the readers through the BACT/LAER process. The terminology LAER will now be used to address BACT for major sources, and MSBACT to address BACT for minor sources.
• AQMD staff has received requests to include 1) the use of UV products for screen printing operations; and 2) the use of Catalytica catalysts for gas turbines into the MSBACT Guidelines. AQMD staff will be looking into the applicability of UV products across a whole spectrum of the screen printing industry and its cost effectiveness. Catalytica is a promising technology for gas turbines and will be considered for MSBACT after it becomes achieved-in-practice.
• At the initialization of the MSBACT Guidelines, as long as a technology is proven to be achieved-in-practice, cost effectiveness is not a factor. However, cost effectiveness analysis must be provided to the Governing Board for information purposes. If the cost effectiveness becomes extremely high, the Governing Board may ask staff to reevaluate its recommendation.
• The transfer of BACT from Part B to Part D is not automatic. Before imposing the requirement on minor sources, staff has to make a determination that BACT is applicable to most of the sources in that category. For example, even though UV inks are listed for a certain screen printing application in Part B, staff must consider whether or not UV products are applicable to various substrates and application (e.g. fabrics, paper, plastics, silk to make T-shirts, poster, banners, etc.)
• A cost effectiveness methodology is included in Part C of the MSBACT Guidelines. Capitals cost as well as annual operating cost will be used to determine cost effectiveness. Annual cost savings will be considered if appropriate and justified.
• BACT for boilers is listed under Part D of the MSBACT Guidelines. NOx limit is 9 ppmv (with low-NOx burner) or 7 ppmv (with SCR) for boilers ³ 20 mmbtu/hr. For boilers < 20 mmbtu/hr, NOx limit is 12 ppmv. Concerns were raised at the meeting to whether or not 12 ppmv is achieved-in-practice for small boilers. AQMD staff will take a close look into this issue, and update the SRC members and the audience in the next meeting.
• (Rita Loof, Katy Wolf, Audience, Pom Pom Ganguli)

• Proposed NSR Rule is scheduled for September Board Hearing.

There was no further discussion and the meeting was closed. Steve Oliva of Catalytica Combustion Systems gave a technical presentation on the XONON catalytic combustion technology for gas turbines. The next SRC meeting is scheduled for August 24, 2000, in Conference Room GB (Note that this is now scheduled for September 7, 2000). Meeting information is available on the AQMD web page.