Attendance

The handouts and audiotapes can be obtained through the Public Records Section.  There may be a fee for this service.

Welcome

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

• Minutes of May 20th Meeting
• Responses to Comments from May 20th Meeting
• New and Updated BACT - Part B Listings - AQMD Determinations
• New and Updated BACT - Part B Listings - Other Determinations
• Status Report on Proposed MSBACT for Distributed Generation
• Other Business

Minutes of the May 20th Meeting

The minutes of the May 20th meeting were approved as written.

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 Responses to Comments from the May 20th Meeting

AQMD staff stated that changes in the listings presented at the May 20th meeting that had been agreed upon at the meeting, as well as any agreed-upon changes in the minutes from the prior meeting, had been made.  Committee and audience members were advised that they could check the listings and minutes as posted on AQMD’s web site.

Staff was to report back on the following items:

1.      Regarding the refinery process heater (Chevron Products, A/N 411357), a committee member had asked what reagent is used in the SCR system.  Staff responded that aqueous ammonia is used, which was already noted in the listing.

2.      Also regarding the refinery process heater, a committee member had requested more information about the ammonia analyzer.  Staff found that the analyzer was supplied by Analytical Specialties of Houston, Texas (web site “analyzer.com”).  The analyzer is an in situ type using a tunable diode laser.  Chevron has used a similar analyzer on another heater for approximately 18 months.  Both analyzers, while not meeting full CEMS requirements, are meeting relative accuracy test audits (RATAs) every six months.  Chevron stated that the cost per analyzer is approximately $50,000 to $60,000.

Discussion: Committee members requested that staff try to find out whether the analyzer can meet other criteria normally required for CEMS certification, which are contained in 40CFR Part 60 Appendix B and the QA/QC appendix (F?), such as the 7-day drift test, etc.
(Greg Adams, Los Angeles County Sanitation Districts; Gary Rubenstein, Sierra Research)

3.      Regarding the natural gas-fired I.C. engines in Tehama County operated by NEO California Power for peaking power, staff had reported at the May meeting that the catalyst beds appeared to need cleaning, and committee members had asked staff to look into the number of hours logged on the engines as compared the normal catalyst cleaning cycle.  Staff contacted the catalyst vendor and found that the normal cleaning cycle is 6,000 to 8,000 hours, depending mainly on the rate of lube oil consumption.   Staff also learned that the cleaning procedure consists of blowing out the catalyst layers and vacuuming the dust from the bottom of the reactor housing.  It is nominally a 2-man, 4-hr operation per reactor.  Staff was unable to get information on the number of hours the engines had operated.  It was also learned that the plant has chosen to explore system adjustments that may lower the NOx before deciding on what cleaning/rotation/replacement strategy should be applied.

Discussion: A committee member suggested that staff contact Tim Hemig of NEO to obtain information on the number of hours the engines have operated.  Another committee member asked whether there was a lube oil specification limiting potential catalyst poisons such as phosphorous.  Staff was to try to obtain this information.
(Gary Rubenstein, Sierra Research; Greg Adams, Los Angeles County Sanitation Districts)

4.      A committee member had suggested that the MSBACT for particulate matter emissions from non-emergency engines, .045 g/bhp-hr, be eliminated in favor of the Clean Fuel Policy.  Staff reported that the change had been made and became effective as of the July meeting of the Governing Board.
(Howard Lange, AQMD)

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New and Updated Listings in Part B, Section I: AQMD LAER/BACT Determinations

I.C. Engine, Stationary, Non-Emergency--Snow Summit, A/N 418235

This is Engine No. 1 of two identical 2835 hp engines to be used to generate power for snow making at 8200 ft elevation.  The engines will operate during the ski season, which is usually December through March or April.  Operation is generally at night, but tends to be around the clock for an initial period in December when the snow making machines are being used to build base.  Each engine is restricted to 1600 hrs/yr.  Engine No.1 was source tested in December 2003 and was used during the 2003-2004 ski season.  Installation of Engine No.2 has been delayed.

Due to unavailability of natural gas at the location, the engines were permitted to use diesel fuel.  BACT consists of selective catalytic reduction and diesel particulate filter with the following limits: NOx-50, CO-89, VOC-39, ammonia-10, all ppmvd@15%O2, and .045 g/bhp-hr PM.  The BACT limits on NOx, CO and PM are based on maximum emissions predicted by the equipment vendors, and these limits correspond to AQMD’s MSBACT.  The ammonia limit was guaranteed by the SCR vendor.  The VOC limit corresponds to 0.15 g/bhp-hr even though the diesel particulate filter vendor predicted a maximum emission of 0.2 g/bhp-hr.  The facility requested the lower limit in order to keep their annual VOC below 4 tpy.

The engine did not meet the 0.15 g/bhp-hr limit in the December 2003 source test.  However, the facility is working with the vendor to reduce the VOC emissions to below the limit and expects to be successful.  AQMD may allow a higher VOC limit if necessary, but not higher then 0.2 g/bhp-hr, and the hrs/yr limit in the permit would be reduced accordingly to keep facility VOC below 4 tpy.  The listing will be updated when this situation is resolved.

Comparing the results of the source test to emission limits normally required of a natural gas-fired engine, CO and PM emissions are quite good whereas NOx and VOC are higher. (Howard Lange, AQMD; Marty Kay, AQMD)

Discussion: An audience member asked whether ultra low sulfur diesel fuel (i.e., less than 15 ppmw) is required in these engines.  Staff responded that as of June 1, 2004, Rule 431.2 requires that all diesel fuel purchased for stationary engines be ultra low sulfur.

An audience member questioned whether both the SCR and DPF catalysts were manufactured by Johnson Matthey.  Staff confirmed that they were.
(Audience Members; Marty Kay, AQMD; Howard Lange, AQMD)

I.C. Engine, Stationary, Non-Emergency--Tidelands Oil, A/N 405789 (Update)

This 2000 hp engine operates a water pump, which is located at an oil production field.  The engine is fueled on field gas, which is produced along with the oil and contains CO2, similar to landfill or digester gas.  This engine was listed in Part B in July 2003.  At that time the Permit to Construct had been developed but had not yet been issued.  BACT consisted of a rich-burn engine with a three-way catalyst and air/fuel ratio controller.  BACT emission limits were (ppmvd@15%O2): 9 NOx, 26 VOC and 60 CO.  These ppm limits were guaranteed by the engine manufacturer and correspond to MSBACT for non-emergency engines, which is 0.15 NOx, 0.15 VOC and 0.6 CO as g/bhp-hr.

Since July 2003, there have been a number of developments, and the listing needs to be updated.  The Permit to Construct was issued in August 2003, the unit was started up in October 2003.  The original air/fuel ratio controller proved to be unable to hold emissions within limits, and the problem was determined to be inability of the air/fuel ratio controller to keep up with rapid and substantial fluctuations in the CO2 (and thus Btu) content of the field gas.  That system was replaced with a Continental Controls system, which has a full authority fuel valve with rapid response characteristics.  This system proved successful, and the unit was source tested and the CEMS certified in December 2003.

The facility reports that the CEMS NOx has remained below one ppmvd@15%O2 essentially all the time and CO has been running in the 12-15 ppm range whenever it is checked using a portable analyzer.  The low NOx level may be partly due to the high level of CO2 in this field gas (e.g., the CO2 in the field gas at the time of the source test was determined to be about 31%) and thus may not be as readily achievable on an engine fueled by natural gas or a field gas containing less CO2.  
(Howard Lange, AQMD)

Discussion: A committee member noted that the emission control cost figure in the listing may be out of date since the control system has been replaced.  Staff agreed to try to get an up-to-date cost figure.  Another committee member asked whether it is normal for an oil field water pump engine to run at or near full load most of the time.  Staff agreed to investigate this.  A committee member asked what was formerly done with the field gas that is used by this engine.  Staff responded that it was probably flared but might have been compressed and returned to the field.  A committee member asked whether the sulfur level in the field gas reaching the engine was actually near 40 ppm as H2S, the permit limit, in view of the generally deleterious effect of sulfur on catalysts.  Staff agreed to look into this.
(Greg Adams, Los Angeles County Sanitation Districts; Karl Lany, SCEC; Philip Hodgets, Clean Air Now; Howard Lange, AQMD; Marty Kay, AQMD)

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New Listing in Part B, Section II: Other LAER/BACT Determinations

I.C. Engine, Stationary, Non-Emergency--Setton Pistachio, San Joaquin Valley Unified APCD, A/N S-512-24-0

These are two non-emergency engines, each driving a 75-kW generator for distributed generation at a pistachio farm in San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) jurisdiction.  The waste heat from the engines is directly utilized in a roasting oven.  The supplier of the engine-generator sets is Tecogen, which has supplied many such installations in California.  Tecogen purchases the engine used in its package from an engine manufacturer but has the engine customized for lower NOx emissions by substituting a larger three-way catalyst bed than the engine manufacturer would normally use.  Tecogen manufactures its own air/fuel ratio controller.

The engines started up in September 2002.  After initial debugging, the system has had significant operation for about 15 months and has had what the facility characterizes as good, essentially trouble-free, operation for about the last 12 months.  BACT limits on these engines were set at 5 NOx, 30 VOC and 70 CO, all as ppmvd@15%O2.  The NOx limit is less than half of AQMD’s NOx BACT for non-emergency engines.  The CO and VOC limits are about the same as AQMD’s BACT limits.  The low NOx limit was requested by the applicant.  These limits are enforced by a source test every two years and portable analyzer checks of NOx and CO every six months.  Tecogen will guarantee these limits for constant speed engines only.  However, this encompasses essentially all engines used to drive generators.  Tecogen estimates that the additional cost of meeting the 5 ppmvd@15%O2 NOx limit versus AQMD’s BACT limit of 0.15 g/bhp-hr (which translates to approximately 10-12 ppmvd@15%O2) is approximately 10 cents per hour for one 75-kW system (to account for shorter catalyst life).

Staff stated that this proposed listing will not be adopted at this time but will be held as a potential listing pending resolution of some issues.
(Howard Lange, AQMD; Marty Kay, AQMD)

Discussion: A committee member stated that SJVUAPCD has separate BACT categories for rich-burn and lean-burn engines and asked whether AQMD has considered doing the same.  Staff responded that this has been considered in the past, and AQMD has chosen not to go in that direction.  The same committee member noted that engines that do not run at constant speed, such as those that drive compressors and chillers, may not be able to meet these emission limits.  Another committee member expressed concern that the lower NOx limit could not be met by lean-burn engines, and engine purchasers would be forced toward rich-burn engines.  Staff responded that the listing will not be made final without being brought back before the committee, and these comments could be addressed at that time.

One of these committee members thought that the facility was required to perform annual source tests until passing two successive tests after which source testing would be required every two years.  Another committee member suggested that staff confirm the number of hours and the loads that the engines have actually logged.  Staff was to check on these matters.

The same committee member suggested that the compliance method (source test every two years and semi-annual portable monitor checks) be made part of the BACT.  Another committee member stated that more frequent portable analyzer checks and fewer source tests would result in engines being in compliance more of the time; however existing portable analyzer protocols are too onerous.  One of these committee members responded that (1) AQMD is requiring in all new engine permits semi-annual portable analyzer checks and (2) Roy Olivares is working on a portable analyzer protocol.  The first committee member wondered whether the portable analyzer protocol in Rule 1146 might be useful in this regard.  The second committee member responded that the Rule 1146 protocol is intended as a source test alternative and would not be appropriate for a frequent emissions check.
(Steve Simons, Southern California Gas Co.; Karl Lany, SCEC; Gary Rubenstein, Sierra Research; Greg Adams, Los Angeles County Sanitation Districts; Marty Kay, AQMD)

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Proposed Update of Part D, Guidelines for Non-Major Polluting Facilities (MSBACT)

New MSBACT Guideline for Distributed Generation

Staff had previously proposed new MSBACT for distributed generation (DG) equipment that would be equivalent to DG standards being proposed by CARB to take effect in 2007.  The proposal had been introduced at the March 2004 SRC meeting and noticed to the public May 10 with a comment period open until June 10.  Many comments had been received and will soon appear on the BACT Docket on AQMD’s BACT web page.

One of those comment letters, from Tecogen, had caused staff to reconsider its proposal.  Tecogen noted the SJVUAPCD permit for DG engines with NOx limited to 5 ppmvd@15%O2, the previous item in the meeting.  This I.C. engine technology, achieves both lower NOx and lower net cost than an engine complying with current MSBACT.  The lower net cost is realized because with a typical waste heat recovery credit, an engine limited to 5 ppmvd@15%O2 NOx can qualify for the PUC incentive (0.14 lb NOx per MW-hr).  This may cause fuel cell technology to fail AQMD’s incremental cost-effectiveness test for new MSBACT.  Staff is reevaluating this.

Staff is, however, concerned about continuous compliance of rich-burn I.C. engine technology.  While this technology can be tuned to achieve very low emissions for a source test, there are many parameters that tend to deteriorate over time and cause the emissions to become very high.  Parameters that tend to deteriorate include catalyst activity (due to poisoning and aging), oxygen sensor deterioration, engine spark plug wires, etc.  A summary of NOx and CO emissions from eight Tecogen engines obtained by unannounced portable analyzer checks was handed out.  Only one of these engines was in compliance.  The others had either NOx or CO out of compliance.  Uncorrected NOx levels as high as 2,995 ppmvd and uncorrected CO levels as high as 44,000 ppmvd were found.  AQMD has also tested other manufacturer’s engines and has found similar results.  Staff will be looking at ways to improve continuous compliance of rich-burn engines.
(Marty Kay, AQMD)

Discussion: A committee member suggested that a relatively inexpensive method to monitor engine emissions might be to monitor the CO only.  Another committee member suggested parametric monitoring of such items as the urea or ammonia injection rate for a lean-burn engine and, for rich-burn engines, parameters such as those followed by automobile engine diagnostic systems.  Staff responded that these are good suggestions and staff is considering concepts such as these.  However, for any monitoring method it must be apparent to the AQMD inspector when the engine is or was out of compliance.  Another committee member suggested that perhaps this could best be addressed by amending Rule 1110.2 to increase the monitoring requirements.  Staff agreed that this is a possibility.  Staff invited suggestions from engine manufacturers.
(Hal Taback, HTC; Gary Rubenstein, Sierra Research; Steve Simons, Southern California Gas Co.; Marty Kay, AQMD)

An audience member asked whether staff had monitored the first workshop in the series that is intended to produce an assessment of the proposed CARB 2007 DG standards (due in 2005) and whether staff intended to monitor the balance of this process before deciding about its DG MSBACT proposal.  Staff responded that it had monitored the first workshop and was still of the opinion that that process does not have a bearing on staff’s DG MSBACT proposal.  Staff explained that CARB’s evaluation is directed at unpermitted DG equipment, and CARB has left regulation of permitted DG equipment up to the districts.  The audience member responded that while AB 1298 required CARB to institute a certification program for unpermitted equipment only, it also required CARB to formulate guidance for all equipment.  Another audience member added that the information gathered in the assessment process might be useful to staff’s deliberations regardless of its intent.  However, a third audience member stated that if sufficient information is available now to justify the new DG MSBACT, we should not wait.  The first audience member stated that we should not go ahead with the proposed new BACT unless we are convinced that it can be maintained on a continuous basis and suggested that perhaps the new BACT should include a requirement for operator training.
(Richard Brent, Solar Turbines; Tracy Saville, TK & Co.; Martin Schlageter, Coalition for Clean Air; Marty Kay, AQMD)

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Other Business

Marty Kay announced that the date of the next meeting would be September 23 and thanked all attendees for their participation.

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

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