SCIENTIFIC REVIEW COMMITTEE MEETING -
May 23, 2002

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.

Marty Kay welcomed the SRC members and the audience to the meeting. Pom Pom Ganguli announced that he would no longer be participating in the SRC meetings due to a change in his assignment at the AQMD. Marty Kay expressed his appreciation for Dr. Ganguli’s leadership in the BACT area, and the committee responded with a round of applause. Dr. Ganguli bid farewell and left the meeting at that point. The topics listed below were discussed during the meeting.

• Minutes of January 24th Meeting
• Responses to Comments from January 24th Meeting
• New BACT - Part B Listings
• Public Notice of New Major Source BACT
• Other Business

 Minutes of the January 24th Meeting

A committee member commented that, with regard to the new BACT listings for emergency diesel engines, which are based on EPA Tier 2 standards for nonroad engines, a problem may arise if a stationary engine permit would contain the Tier 2 emission limits (as my be inferred from the BACT listings) with the engine also being subject to a source test requirement. This was thought to be a potential situation in a Title V permit, where periodic testing is frequently required. Since EPA nonroad standards are weighted averages of emissions measured in various operating modes, a single-mode source test, e.g., a full-load test, may find emissions exceeding the Tier 2 limits. It was decided that AQMD would look into what source testing requirements might be required on an emergency diesel engine under a Title V permit. (Greg Adams, Los Angeles County Sanitation Districts; Gary Rubenstein, Sierra Research; Karl Lany, SCEC; Marty Kay, AQMD)

The same committee member noted that on page 5, line 3 of the minutes, the statement that BACT can be based on a technology included in a "state implementation plan" should actually read "approved state implementation plan". Another committee member stated that for BACT to be based on a requirement in an approved state implementation plan, the requirement must also have been actually applied to at least one source. (Greg Adams, Los Angeles County Sanitation Districts; Gary Rubenstein, Sierra Research)

 Responses to Comments from the January 24th Meeting

The committee had requested that AQMD attempt to find out the efficiency with which the organic chemicals were removed from the water by the air stripper. AQMD queried the plant on this matter, but the plant did not have the required data The only performance monitoring of the stripper is periodic measurment of the residual levels of the major chemicals in the stripped water.

The committee had also requested that AQMD attempt to obtain information on the fuel used in the thermal oxidizer and the secondary emissions (e.g., NOx and CO) from the thermal oxidizer. It was determined that the fuel is natural gas, and this information has been added to the listing. Information on the secondary emissions was not available.

It had been asked whether the 1.25% VOC claimed to be in the air exiting the stripper could be realistic in that it seemed to be too close to flammability limits of typical organic compounds. AQMD checked flammability limits for the major organics in the system and found them all to be above 1.25%. Furthermore, since the 1.25% was measured using EPA Method 25, the stated VOC concentration was expressed as methane. This inflates the stated concentrations for species containing more than one carbon atom, thus adding an additional margin of safety. In discussing this potential hazard with the plant, it was learned that the VOC concentration is continuously monitored and the system is set up to trip if the flammability limit is approached too closely. (Howard Lange, AQMD)

The committee had requested that AQMD attempt to obtain information on the VOC concentration and constituents entering the thermal oxidizer, the fuel used in the thermal oxidizer and the secondary emissions (e.g., NOx and CO) from the thermal oxidizer. This information, with the exception of the VOC constituents, was obtained from the permitting agency and has been added to the listing. (Howard Lange, AQMD)

This listing was based on a thermal oxidizer permitted at 98.9% destruction efficiency. However, it was noted in the listing that the owner had applied for a permit modification to reduce the required destruction efficiency to 96.5% just prior to the plant going out of business. It was decided that AQMD would attempt to obtain more information and then make a decision whether or not to proceed with this listing. Extensive information was obtained from the owner including the most recent three annual source tests. AQMD’s analysis of the data in these reports indicated that the oxidizer could not have consistently met a permit condition any stricter than 95% destruction efficiency or 20 ppm VOC in the exit gas. AQMD concluded that this degree of control did not seem to be exceptional and that the listing should therefore not be pursued further. (Howard Lange, AQMD)

The committee had requested that AQMD attempt to obtain information on the fuel used for the oxidizer, the VOC concentration and constituents in the inlet gas to the oxidizer and the secondary emissions from the oxidizer. This information was requested from the plant and the permitting agency. However, the only information available was that the fuel is natural gas. This information has been added to the listing. (Howard Lange, AQMD)

 Burnoff Furnace – Haskell of Pittsburgh (CO-224)

AQMD was to find out whether a minimum destruction efficiency is required in its permits for burnoff furnaces. It was learned that AQMD requires a minimum 95% destruction efficiency but does not require a test. This is in addition to prior existing BACT of 1400F minimum interior temperature and 0.3 sec minimum residence time. (Howard Lange, AQMD)

This part of the meeting was prefaced with a notification of the committee that, at the request of a board member, the title of Section II of the BACT Part B listings was being changed from "Non-AQMD BACT Determinations" to "Other BACT Determinations". The board member felt that the former title may be misinterpreted to imply that Section II listings do not apply within the AQMD. (Marty Kay, AQMD)

This facility has multiple presses and curing ovens producing printed cotton goods. Rule 1130.1 allows up to 400 g/l (less water and exempt solvents) VOC in inks for screen printing, and prior BACT for screen printing was 0.625 lb/gal (approximately 75 g/l) VOC in inks (as applied). This facility is permitted at 50 g/l or less VOC in inks (as applied). The facility makes up its own inks on site using low-VOC ingredients.

Discussion: A committee member, noting that the 50 g/l limit was considered to be the lowest measurable VOC level in ink, pointed out that one AQMD rule, Rule 1122, has a VOC limit of 25 g/l and that some VOC limits in other AQMD rules, such as 1171, are being lowered to 25 g/l. The committee member requested that AQMD staff present notify the appropriate permitting team of this apparent inconsistency. (Katy Wolf, IRTA)

One operation that occurs at this facility is mirror manufacture. In this process, a flow coater or roller coater is used to apply coating to the back of the mirror, after silvering has been applied. The coated products from either coater are conveyed to an electric oven. The permit for this facility requires compliance with Rules 1145 and 1171 and venting of the coaters and oven to a thermal oxidizer with 90% overall control efficiency, which is consistent with prior Part B BACT. A source test found the VOC control system to be achieving 100% collection efficiency and 97.1% destruction efficiency.

The thermal oxidizer used in this case is a regenerative type, which captures most of the heat in the exhaust gas by passing it through a pebble bed and reuses this heat to preheat the inlet gas entering the oxidizer. Because the oxidizer requires very little supplemental fuel to maintain its temperature, secondary emissions are very low. Only .03 lb/hr NOx is produced versus approximately 60 lb/hr VOC destroyed. (Howard Lange, AQMD; Marty Kay, AQMD)

 Ink Jet Printer – Metromedia Technologies (A/N 327543)

This facility uses multiple large-scale ink jet printers to print outdoor billboards. The printed materials are air dried. High-VOC inks are used in order to withstand the outdoor conditions to which the billboards are exposed and to permit proper functioning of the ink jet printers. The primary VOC emitted from the process is methyl-isobutyl-ketone (MIBK), which is used as the ink thinner. The permits require that the ink jet printers comply with Rules 1171 and 442 and be enclosed in permanent total enclosures vented to control equipment with overall control efficiency of 85.5% or more. Rule 1171 requires either 50 g/l or less VOC in cleanup materials or an adequate degree of VOC control. Rule 442, an older VOC/coatings rule, was invoked in this case because the ink jet printers do not fit any printer definition in Regulation XI. Therefore, the permitting team is particularly interested in having BACT established for this type of printer.

The VOC control device used in this case is an adsorber in which the VOC-laden gases flow upward through multiple trays of fluidized sorbent. The sorbent flows downard tray-to-tray and is collected at the bottom, where it is air lifted back to the top of the device by a heated air stream. The hot air lift also acts as a desorber. After separation from the sorbent, the hot air passes through a condenser, where its VOC content is condensed and collected in drums for transport off site. A source test found the control system to be achieving 89% collection efficiency (some VOC escapes because the air drying is done outside the permanent total enclosure) and 98% removal efficiency. (Howard Lange, AQMD)

Discussion: A committee member asked whether the Rule 1171 requirement of 50 g/l or less VOC in cleaning materials was specifically included in the permit conditions. AQMD agreed to check the permit and report back.. (Katy Wolf, IRTA)

A committee member commented that, in Item 5.A.A1 of the listing, the second sentence was not clear, and the following sentence was agreed upon: "Total VOC emissions from the facility not to exceed 2400 lb in any calendar month using a mass balance calculation based on the total VOC inputs to the facility and the total amount of VOC collected." It was also pointed out that the word "fluidized" was misspelled in item 5.B.B2. (Greg Adams, Los Angeles County Sanitation Districts)

This facility has ten extrusion lines producing flat stock. Five lines extrude acrylonitrle butadiene styrene (ABS) resin, and the other five extrude polyethylene, ploypropylene and ploystyrene. The extruder barrels operate under vacuum and are vented to thermal oxidizers. The five ABS extruders are vented to one oxidizer, and the other five extruders are vented to a second oxidizer. The facility permits require that the oxidizer temperatures be 1400F or above. The applicant cited studies by other organizations showing that venting the extruder barrel captures 95% of the VOC emissions. The thermal oxidizer supplier guaranteed 99% destruction efficiency.

The facility is subject to Rule 1171 (Solvent Cleaning Operations), but no other Regulation XI rules apply. Part D of the BACT Guidelines list "ESP or mist filter" as BACT for polystyrene extrusion.

The facility permits also require that cleanup materials be zero-VOC. In discussions with facility staff, it was learned that the zero-VOC cleanup material used is Easy-Off Heavy Duty Oven and Grill Cleaner. AQMD attempted to contact the manufacturer of this item to verify that it is indeed zero-VOC. However, the manufacturer has thus far not responded. (Howard Lange, AQMD)

This refinery has replaced a conventional coke storage and handling system, which handled the coke in dry form, with a wet system. The wet system slurries the coke with water at the point of production and conveys it via sluices to the storage area, where it is stored wet in specially designed bins called hydrobins. The hydrobins are designed to allow the coke to settle out of the water and to reclaim the water via overflows. The water is sent to a clarifier and returned to the process. The wet coke is loaded into trucks similarly to what was done with the dry coke. Coke storage and handling is subject to Rule 1158 (Storage, Handling and Transport of Petroleum Coke), which consists of numerous dust control measures. The wet storage and handling system produces much less dust than the conventional dry system. Calculations performed by the permit engineer indicated that the conversion reduced particulate emissions by approximately 200 lb/day. (Howard Lange, AQMD)

Discussion: A committee member asked how the new system reduces electric power consumption. An audience member, representing Ultramar, responded that pumps that were added for the new system draw less power than the conveyors and shaker tables that were used in the conventional system. (Katy Wolf, IRTA; David Price, Ultramar)

Committee members asked what type of pumps are used to move the slurry and how discharged water is cleaned up sufficiently to meet standards. The Ultramar representative responded that: (1) he did not know specifically what type of slurry pump is used but thought they are centrifugal and (2) no water is discharged from the system. (Greg Adams, Los Angeles County Sanitation Districts; David Price, Ultramar)

A committee member asked whether the higher moisture content of the coke presented any problems with regard to trucking or shipping and whether there was any concern that if all refineries converted to wet coke handling, shipping companies may then experience problems. The Ultramar representative responded that there were some special procedures followed to avoid excessive moisture being carried out in trucks, and that shippers apparently have no difficulties with the higher moisture levels. (Bill Dennison, Dennison and Associates; David Price, Ultramar)

In issuing a permit for a firewater pump located at the Ultramar Olympic Tank Farm, AQMD determined that ultra low-sulfur diesel (ULSD) fuel was available and could be used in this case. ULSD is limited to 15 ppm maximum sulfur content as opposed to the 500 ppm sulfur limit now required statewide by CARB (‘CARB diesel"). Use of ULSD instead of CARB diesel reduces both PM and SOx emissions. ULSD is available in southern California from the BP/ARCO refinery and should be increasingly available from other refiners because its widespread use is required in this area by AQMD Rule 431.2 starting in 2004 and nationwide by EPA starting in 2006. As required for issue of a permit containing new BACT, a 30-day public notice was issued. Written comments were received from several organizations. These organizations all expressed concern that ULSD may be difficult to obtain in some cases. Since ULSD availability was not an issue in the case in point, AQMD proceeded to issue the permit and placed the related BACT listing in queue to go on the web site. However, AQMD did incorporate a caveat in the BACT listing that supply logistics should be considered in each case.

Discussion: A committee member pointed out that requiring BACT for one of a set of multiple engines could create a difficult situation if the engines share common fuel storage. AQMD responded that this could be a consideration in determining whether ULSD should be required. (Martin Ledwitz, SCE; Marty Kay, AQMD)

A committee member mentioned that ULSD was not readily available a year ago. An audience member, representing BP/ARCO, responded that ULSD is now available through a number of distributors in the area. (Greg Adams, Los Angeles County Sanitation Dustricts; Ken Kimura, BP/ARCO)

It was asked whether ULSD may be cost-prohibitive in some cases. AQMD responded that, although cost is not a consideration in establishing BACT, it had gathered some information on ULSD cost. During the first quarter of 2002, ULSD wholesale ("rack") price has been running approximately 6 cents per gallon above CARB diesel. However, the cost of delivery depends on location and quantity ordered. A small quantity ordered to a remote location can have a substantial price premium. It was also noted, however, that emergency engines do not use much fuel, and thus a significant cost differential per gallon may not amount to much cost per year. (Audience Member; Marty Kay, AQMD; Howard Lange, AQMD)

The next meeting was scheduled for July 25, 2002 at 1:00 p.m. in AQMD conference room GB.

AQMD mentioned that staff will submit to the semi-annual report of new Part B BACT listings at the June board meeting. This report documents new Part B BACT listings that have been adopted during the past six months. The change in the title of Part B, Section II of the Guidelines will also be submitted to the board at that meeting.

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

 Attachments