SRC Meeting #7 Highlights

SCIENTIFIC REVIEW COMMITTEE MEETING NO. 12

December 16, 1999

MEETING HIGHLIGHTS


	SRC Members
Greg Adams		Deanna Nichols (for Deanna Haines)
Bob Giorgis (not present)		Ron Wilkniss
Martin Ledwitz		Karl Lany (not present)
Robert Anderson (not present)		Stan Romelczyk (not present)
Larry Felix (not present)		Hal Taback (not present)
Ted Guth		Bill Dennison
Katy Wolf		Steve Barhite
Ed Camarena (not present)		Robert Zweig (not present)
James Provenzano (not present)		Gary Rubenstein (not present)


	Attendees
Frank Rice		Rita Loof
Larry Ashton		Andy Wales
Richard Freet		Mark Mueller
Greg Danenhauer		Steve Hernandez
James Harber		Jerry Kraim
Lee Wallace		Kevin Williams
Harold Derus		Omar Rivera
Viji Sadasivan		Joyce Clark
Jim Waggoner		Jim Donnelly
Matt Brueck		Peter Gebhard
Charles Botsford		Jon Sullivan (via telephone)

	AQMD Staff
Pom Pom Ganguli		Knut Beruldsen
Hemang Desai		Lee Lockie
Mike Mills		Roy Olivares
Sean Cullins		Lou Yuhas
Bill Wong

The handouts and audiotapes can be obtained through the Public Records Section of the Chief Prosecutor’s Office. There may be a fee for this service.

Overview

Pom Pom Ganguli welcomed the SRC members and the audience to the twelfth SRC meeting of 1999. The topics listed below were discussed during the meeting.

Minutes from the October and November SRC meetings

Public comments received regarding BACT for a new CO2 plant

New BACT determinations for the following categories of equipment: Dryer or Oven – Others, Direct and Indirect Fired; Heater – Other Process (new category); and Boilers

Report on discussions regarding achieved in practice criteria

Greg Adams requested clarification regarding Marty Kay’s response to Ed Cancilla’s comment included on page 9 of the November minutes. Marty commented that since the boiler at Corcoran State Prison is listed in the EPA’s RACT/BACT/LAER clearinghouse, it is considered achieved in practice, and that for these cases a detailed review of achieved in practice reliability and effectiveness data is not required. Steve Barhite responded to Greg by stating that as a matter of policy, a review of achieved in practice reliability and performance data has not been required when a BACT determination is based on an emissions limit that is contained in a valid permit. Pom Pom Ganguli commented that the District recently contacted EPA regarding this issue and that staff is currently awaiting a written response from EPA.

The SRC meetings for next year will be moved to the last Thursday of the month. A schedule of the meeting dates and times will be provided in the near future.

Response to Items pending from November SRC Meeting

Item: Why wasn’t an airless degreaser required for the system included in Application Number 356147? Is the vapor degreaser equivalent to an airless system?

Response: An airless system was not required for the following reasons: (1) the vapor degreaser will be located in a totally enclosed room that will be vented to a carbon adsorper, and (2) an airless or airtight system using isopropyl alcohol (IPA) is not achieved in practice due to its high flammability.

Item: Did the fire pump engine included in Application Number 359091 have add-on controls when it went in for UL certification?

Response: No. The engine was purchased several years ago, and the controls were put on recently. For this application, UL certification was not an issue.

Item: Is the BACT trigger 1 pound/day or 30 pounds/month?

Response: BACT is triggered by any emissions increase, and an emissions increase is defined by the District as 1 pound/day. In certain cases, particularly for VOC equipment, a different source category may be defined for equipment with emissions less than 30 pounds/month, for the application of a less stringent control requirement.

Discussion of issues

Batch Vapor Degreaser

An airless or airtight degreaser is required as BACT as long as the parts can be placed under vacuum. Also, it is more dangerous to use IPA in a vapor degreaser than in an airless system. Therefore, the District should require an airless/airtight system for this application. (Katy Wolf)

District staff could not find any examples of airless systems using IPA. Given that BACT is determined on a case-by-case basis, for this application, staff determined that it is not technically feasible to require an airless system. (Pom Pom Ganguli)

I think the technical feasibility analysis should be reassessed because (1) Serec has used IPA in airless degreasing systems, and (2) it is safer to use IPA in an airless system (than in an open top system) because there is no air/solvent interface, which greatly reduces the risk of explosion or fire. (Peter Gebhard)

The proposed system (a vapor degreaser in a totally enclosed room vented to a carbon adsorber) will not be as effective in reducing emissions as an airless system. The control system will not capture all the emissions. I thought BACT was use of an airless or airtight system unless there are sound technical reasons why they can’t be used. I haven’t heard any good technical reasons why an airless system could not be used. (Katy Wolf)

Staff has already completed the technical analysis and issued the permit to construct for this application. However, I would like Peter Gebhard to submit any data he has regarding the use of IPA in an airless degreaser so that this information can be used by District staff when making future BACT determinations. (Pom Pom Ganguli)

I would like further discussion of this issue based on the technical arguments presented at this meeting. I don’t believe the flammability issue is a good reason to preclude the requirement for an airless degreasing system. This BACT determination sets a bad precedent in that it goes against the BACT determination established last year for this category of equipment. (Katy Wolf)

When the District updated the BACT Guidelines for degreasing systems last year, I thought the intent of the guidelines was to encourage the design and use of airless or airtight systems (which significantly reduce uncontrolled emissions), and not encourage the use of secondary control systems such as this one. I don’t believe the use of a vapor degreaser in an enclosed room is consistent with what the District published in BACT Guidelines (last year) for this category of equipment. (Peter Gebhard)

You are partially correct. The general BACT determination for this category of equipment is an airless/airtight system. For example, if the applicant could have used a solvent that is commonly used in airless systems, then the District would have required an airless system. However, since the applicant needed to use IPA (which to staff’s knowledge is not achieved in practice in airless systems), staff made an alternative BACT determination based on the available technical information. At this point, since there is still disagreement, I would suggest that you set up a separate meeting with the permitting team to exchange technical information both for future purposes and possibly to resolve this application. (Pom Pom Ganguli)

Are the controlled emissions from the vapor degreaser equivalent to what would be emitted from an airless system? (Greg Adams)

I don’t believe so. This is a less stringent level of control based on the infeasibility of using an airless system. (Pom Pom Ganguli)

Comments Received Regarding BACT for a New CO2 Plant

The public notice of intent to establish new BACT for a CO2 plant was distributed on November 19, 1999. As of this time, no comments have been submitted to the District regarding the proposed BACT requirement. Any comments received by staff in the next few days will be discussed at the next SRC meeting.

New BACT Listings

Dryer or Oven – Others, Direct and Indirect Fired (A/N 360365)

The applicant received a permit to operate a 3.7 MMbtu/hour oven that will be used to cure powder coatings. They are using a Maxon Cyclomax low-NOx burner and the BACT requirements are 30 ppm @ 3% oxygen for NOx, and use of Regulation XI compliant materials for VOC. The cost of the Cyclomax burner was approximately $4,000.

Heater – Other Process (A/N 347641)

This is a new category that was derived from the boiler equipment category. The applicant received permits to construct three identical 6.5 MMbtu/hour hot oil heaters that are used to heat triethylene glycol to 450 degrees Fahrenheit. The heaters use a Powerflame low-NOx burner and the BACT requirements are 20 ppm NOx @ 3% oxygen and 50 ppm CO @ 3% oxygen.

Boilers (A/Ns 362396, 360389, 347790, 352348, and 355513)

Santa Monica Beach Hotel received permits to construct two identical 4.3 MMbtu/hour Clayton water-tube boilers that will be used to supply hot water at the hotel. The boilers will be equipped with Clayton burners and the BACT requirements are 12 ppm @ 3% oxygen for NOx, and 100 ppm @ 3% oxygen for CO. Each boiler cost approximately $50,000.

Disneyland Resorts received permits to construct four identical 8.5 MMbtu/hour Cleaver-Brooks boilers that will be used to supply hot water to the hotel. The boilers will be equipped with Alzeta burners and the BACT requirements are 12 ppm @ 3% oxygen for NOx, and 50 ppm @ 3% oxygen for CO. For this example, a notice of intent to establish a new BACT was distributed for a 30-day public comment period on December 16, 1999. A copy of the public notice is included in the handouts.

Children’s Hospital received permits to construct three boilers that will be used to supply hot water and steam. The boilers range in size from 24.2 to 33.9 MMbtu/hour. The boilers will be equipped with Coen burners and the NOx emissions will be further controlled by SCR equipment. The BACT requirements are 7 ppm @ 3% oxygen for NOx, 50 ppm @ 3% oxygen for CO, and 5 ppm @ 3% oxygen for ammonia slip (including when the boiler is operating with Amber 363 backup fuel). The installed cost for each Peerless SCR system was approximately $175,000.

Coca-Cola received permits to construct two identical 31.5 MMbtu/hour boilers that will be used to supply steam for sanitation. The boilers will be equipped with Coen burners and the NOx emissions will be further controlled by SCR equipment. The BACT requirements are 7 ppm @ 3% oxygen for NOx, 50 ppm @ 3% oxygen for CO, and 5 ppm @ 3% oxygen for ammonia slip. The installed cost for each Peerless SCR system was approximately $150,000. For this example, a notice of intent to establish a new BACT was distributed for a 30-day public comment period on December 16, 1999. A copy of the public notice is included in the handouts. A public notice is required because the District doesn’t have an example of a boiler in this size range that is controlled with SCR to 7 ppm NOx. The basis for the 7 ppm NOx limit is technology transfer, specifically, the reforming furnace at TOSCO Refining Company.

General Dyeing & Finishing received a permit to construct a 13.5 MMbtu/hour Kewanee boiler that will be used to supply high pressure steam. The boiler will be equipped with an Energy & Environment, Inc. ultra low-NOx burner. The applicant requested a 5 ppm NOx limit in order to avoid emission offset requirements. The boiler is listed in Section III because at this time, 5 ppm NOx @ 3% oxygen is not considered achieved in practice for this category of equipment. The cost of the burner was approximately $41,000. The boiler will be source tested at three different loads to verify compliance with the 5 ppm NOx permit limit.

Discussion of issues

Oven

The District needs to be aware that the Cyclomax burner can’t meet the turndown ratio required for many oven applications, especially in the textile industry. Perhaps the District could create separate source categories for applications (such as powder coating curing applications) where the Cyclomax or other low-NOx burners are achieved in practice. (Steve Hernandez)

In making the changeover from a standard Ovenpak burner to a Cyclomax burner the maximum turndown ratio goes from 40/1 to 15/1. It is more difficult to establish a minimum flame in the Cyclomax burner, and it is also more difficult to achieve low NOx emissions at low fire. At higher firing rates there are no problems in achieving 30 ppm NOx. Some tenter frame applications (where delicate fabrics are used) require firing rates below 50,000 Btu/hour, and in order to assist these customers, Maxon has developed a Cyclomax burner (rated at 0.4MMBtu/hour) that can turndown to 25,000 Btu/hour. (Matt Brueck)

Question to Maxon, will the Cyclomax burner meet 30 ppm at low fire for this application? (Pom Pom Ganguli)

These ovens are typically source tested at high fire conditions, and the NOx emissions are below 30 ppm. If source tests are performed while processing delicate fabrics that require high turndown, there could be some problems in meeting the 30 ppm limit. (Matt Brueck)

The actual NOx emissions from ovens are typically low and the stack oxygen levels are high. Given these conditions, requiring a NOx limit corrected to 3% oxygen may not be the best way to go. Perhaps the District could specify a mass emissions limit (e.g., pounds/hour) for this category of equipment. (Steve Hernandez)

So noted. Please submit written comments and we will discuss this issue with permitting staff. (Pom Pom Ganguli)

Does the 30 ppm NOx limit apply to all ovens regardless of size? (Jerry Kraim)

BACT is determined on a case-by-case basis. This particular oven is rated at 3.7 MMbtu/hour. (Pom Pom Ganguli)

Heater – Other Process

Hot oil heaters run a little differently than boilers (e.g., higher stack temperatures) and I currently have some projects where we can’t hit 12 ppm NOx with a low-NOx burner. However, 20 ppm NOx (or just below that) can be achieved with a low-NOx burner, and I appreciate the District’s efforts in recognizing the distinction between a boiler and a hot oil heater. (Steve Hernandez)

NOx is a function of time at a high temperature. Since the flue gas cools quicker in a boiler it is easier to achieve lower NOx emissions for this type of equipment. For thermal fluid heaters you typically heat the fluid to greater than 450 degrees Fahrenheit resulting in higher flue gas temperatures and higher NOx emissions. (Greg Danenhauer)

So noted. (Pom Pom Ganguli)

Boilers

At what size rating are add-on controls required for boilers? (Audience)

BACT is determined on a case-by-case basis. Presently, for boilers rated below around 20 MMbtu/hour add-on controls are not being required. (Pom Pom Ganguli)

The boiler operators at Disneyland will be required to monitor boiler operation and load (for at least six months) in order to obtain achieved in practice reliability data. The District should take a more active role in collecting this information since it will require a significant level of effort. (Charles Botsford)

If you think the recordkeeping requirements are too onerous, you can submit written comments to the permitting team. (Pom Pom Ganguli)

Since you are establishing new BACT, why are the small boiler examples listed in Section I? (Deanna Nichols)

The examples for the small boilers are based on the achieved in practice operation in Corcoran, California. Achieved in practice BACT determinations are placed in Section I. The reason a public notice was distributed was because the basis for the BACT determination was a permit issued outside the District. This was the first case where the District applied a 12 ppm NOx limit to boilers with this size rating. (Pom Pom Ganguli)

There appears to be superfluous information included in the comments section for the Disneyland BACT listing. Much of the information appears to be irrelevant to the BACT determination. (Ron Wilkniss)

Staff will look into this. (Pom Pom Ganguli)

By the time a District listing gets to the EPA’s RACT/BACT/LAER clearinghouse, the listing is somewhat streamlined and non-essential information is not included in the listing. (Steve Barhite)

Question to Peerless, how will you comply with the 5 ppm ammonia slip limit when the catalyst gets old? (Pom Pom Ganguli)

Initially there will be very little ammonia slip from the SCR equipment. At some point in time when the ammonia slip reaches 5 ppm, the operator will be required to change out the catalyst. The 5 ppm limit is a point of concern for the applicant because it requires them to change out the catalyst more frequently than if they had a higher limit (e.g., 20 ppm). (James Harber)

The BACT listing for Children’s Hospital states that the expected catalyst life is 5-7 years. Is that estimate based on a 5 ppm ammonia slip emission limit? (Ron Wilkniss)

Yes. About 95% of the SCR systems we have seen that were installed in the late eighties/early nineties still have their original catalyst. Based on our experience, we feel that 5-7 years is a reasonable, conservative estimate of catalyst life (for boilers operated 100% of the time). The boilers at Children’s Hospital will run less than 50% of the time; therefore, for this particular case, the expected life of the catalyst should be even longer than 5-7 years. (James Harber)

Section 2G of the BACT listing for Children’s Hospital should be updated to reflect that the boilers operate less than 50% of the time. (Ron Wilkniss)

Staff will look into this. (Pom Pom Ganguli)

For Children’s Hospital, is the NOx analyzer only used when a boiler is operating with Amber 363 fuel, is it a Rule 218 analyzer, and are there one or three analyzers? (Greg Adams)

The NOx analyzers are in use whenever the boilers are in operation (regardless of fuel type), they are not subject to Rule 218 requirements, and there are three analyzers (one for each SCR system). (Sean Cullins)

The District requested that we install a NOx analyzer for each SCR system, and there is feedback control. However, our position is that we can comply with the permit limits without feedback control. (James Harber)

Does the $175,000 cost include the NOx analyzer? (Greg Adams)

No. (James Harber)

The cost for each NOx analyzer is approximately $80,000 (Steve Hernandez)

For Children’s Hospital, have you tested the units while running on Amber 363 fuel? I haven’t seen NOx emissions at 7 ppm for equipment burning this fuel. (Pom Pom Ganguli)

No, we haven’t tested the equipment yet. In fact, we were hoping for a 40 ppm NOx limit when burning Amber 363 fuel. (James Harber)

What is Amber 363? (Ron Wilkniss)

It is a fuel manufactured by Shell that is similar to diesel and it has a very low sulfur content. (Audience)

Is it correct to assume that the NOx analyzer at Children’s Hospital is something short of a CEMS? (Ron Wilkniss)

The NOx analyzer is a CEMS but you don’t have the maintenance required that you would for a certified CEMS. (Steve Hernandez)

The District should include language in the comments section that indicates that the CEMS is not certified. (Ron Wilkniss)

So noted. (Pom Pom Ganguli)

For the SCR systems at Children’s Hospital, the NOx emissions are primarily controlled by a feed forward control system. If at some point in the future it is established that the NOx and ammonia slip emissions are adequately controlled, are there any provisions to have the requirement for the feedback control system removed. (Audience)

You would have to work that out with the engineering and compliance team. (Pom Pom Ganguli)

This is relevant to the District’s monitoring, recordkeeping, and reporting group’s efforts, and perhaps the requirement for an expensive NOx analyzer needs to be looked at for these types of applications. Maybe we could discuss this example with the other group. (Greg Adams)

So noted. (Pom Pom Ganguli)

The public notice for the Coca-Cola operation states that the basis for the 5 ppm ammonia slip BACT determination is consistency with the ammonia slip limitation applied to new gas turbine projects that use SCR to control the NOx emissions. For gas turbines, the ammonia emissions are corrected to 15% oxygen not 3% oxygen. As a matter of policy, should the District be comparing ammonia slip from a boiler to ammonia slip from a gas turbine given the different characteristics of the exhaust streams)? By requiring such a stringent ammonia slip limit you are drastically increasing the cost of the SCR system. (Charles Botsford)

You are welcome to submit written comments during the public review period. (Pom Pom Ganguli)

For the boiler at General Dyeing & Finishing, are there any toxics monitoring requirements? (Greg Adams)

I’m not sure. Staff will get back to you regarding this issue. (Pom Pom Ganguli)

Other Business

Report on Discussions regarding Achieved in Practice Criteria

A small subgroup of the SRC along with personnel from EPA and ARB met last week to discuss possible revisions to the District’s achieved in practice criteria. In addition, CAPCOA is concerned about this topic and a subcommittee has been established to look into the issues. There needs to be consistent application of achieved in practice criteria between the different air districts and CAPCOA has scheduled a meeting with District staff to facilitate this effort. Also, if the NSR reform defines achieved in practice criteria, then District’s criteria will have to be consistent with this criteria.

Preliminary Draft Boiler Guidance, Rev. 4

The draft boiler guidance is not ready yet. Note that guidance will not be issued to permitting staff before the SRC has had a chance to review and comment on the document. The guidance document should be available in January.

Permitting Advisory for Boilers

Deanna Haines and Deanna Nichols prepared a permitting advisory for boilers and copies were provided at the meeting. This item will be discussed in more detail at the next meeting.

Discussion of issues

An item that has come up concerns when one agency looks at a permitting decision made by another agency. Is it appropriate for one agency to verify the working of a particular permit that has been issued under LAER by a different agency? There are concerns that the District could be heading down this path. (Pom Pom Ganguli)

The District should provide a clear description of what a vendor needs to do in order to satisfy achieved in practice criteria when demonstrating a new technology. Do you expect a case-by-case determination that goes through the SRC? (Ted Guth)

The EPA is hesitant to provide a guidance document that specifies rigid achieved in practice criteria because the air districts across the country need the flexibility to make these kinds of decisions based on their knowledge of the facilities located within their jurisdictions. However, if someone approaches the District, up front, and says that they would like their new technology deemed achieved in practice, then it appears that the SRC (or some other similar group) would be a good committee to turn to regarding the specifics for that particular case. The SRC could develop some general guidelines (on a case-by-case basis) that a facility would need to follow in order to generate adequate data. The EPA is also interested in those cases where the facility may not be specifically out to promote/demonstrate a new technology as achieved in practice (e.g., the Section III boiler operation discussed earlier in this meeting). We have to think of a way to include data generated for these cases in the process because it’s just as valid as data generated through the up front process. That’s a quick summary of EPA’s direction at the present time. (Steve Barhite)

The focus appears to be on add-on control equipment. The EPA/District criteria needs to be flexible enough to account for process modifications or reformulations as means of achieving BACT. (Bill Dennison)

The District tries to accomplish this by setting emission limits (e.g., the old 9 ppm NOx limit for large boilers) for equipment categories rather than specifying control technologies. The reason the District opened the achieved in practice debate is two fold: (1) language is included in the NSR reform (the District provided comments), and (2) the District’s recent experience is that the six months at 50% load reliability criteria is too tight for many applications. Many viable control technologies may not pass this criteria. What works well for an industrial boiler may not work well for a degreaser or spray booth. It’s a tough situation, the EPA wants flexibility while the equipment vendors want more guidance. The District’s goal is to provide achieved in practice criteria that satisfies both groups. (Pom Pom Ganguli)

When referencing BACT determinations from other air districts it is important to consider the monitoring requirements. The District may require a CEMS whereas the other agency may specify a less stringent monitoring requirement. This issue is very important to industry. (Martin Ledwitz)

I concur with Sempra Energy’s comments (i.e., Deanna Haines) that the achieved in practice criteria should hold the equipment vendor to the same standard that an operator subject to AQMD enforcement would have to meet. Otherwise, I’m optimistic we can come up with a revised achieved in practice criteria shortly after the next meeting. (Greg Adams)

At this time, EPA is not in favor of providing explicit achieved in practice criteria applicable to all categories of equipment. They seem to favor a more general approach that may include an up front case-by-case analysis when necessary. (Pom Pom Ganguli)

I think a general achieved in practice criteria similar to what the District already has along with use of up front meetings to work out details/exceptions (when necessary) should work. The six months and 50% load criteria was meant to be a general guideline and not a hurdle to establishing a new technology. (Steve Barhite)

My experience with this issue is that the six months and 50% load criteria was intended by EPA to be the minimum for establishing a new technology. (Lee Wallace)

EPA does not feel that periodic excursions below 50% load should automatically eliminate a technology from being considered achieved in practice. Load issues can be resolved through an up front meeting with the equipment operator. (Steve Barhite)

What are the data requirements for a facility that voluntarily accepts a permit limit that may subsequently establish a new BACT limit (e.g., the Section III BACT determination discussed earlier in this meeting)? (Lee Wallace)

That is a good question. Since the applicant has an enforceable permit limit they don’t need to satisfy the District’s achieved in practice criteria. However, there needs to be some level of assurance that the technology is effective and reliable. We can follow up on this question at the next meeting. (Pom Pom Ganguli)

Since BACT determinations may result from technology transfer, it is important to note the reliability demonstration because a technology that has only been subject to sporadic operation at partial load (e.g., a merchant power plant) may not hold up as well when subject to continuous operation at maximum load. (Ron Wilkniss)

So noted. (Pom Pom Ganguli)

There was no further discussion and the meeting was closed. The next meeting is scheduled for January 27, 2000, in Room CC2. Note that meeting information is available on the AQMD web page.