![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban Buses; Certification of Equipment
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: October 22, 1996 (Volume 61, Number 205)] [Notices] [Page 54790-54798] From the Federal Register Online via GPO Access [wais.access.gpo.gov]
ENVIRONMENTAL PROTECTION AGENCY [FRL-5638-3] Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban Buses; Certification of Equipment AGENCY: Environmental Protection Agency. ACTION: Notice of Certification of Equipment Supplied by Twin Rivers Technologies for the Urban Bus Retrofit/Rebuild Program.
SUMMARY: The Agency received a notification of intent to certify equipment signed August 21, 1995, from Twin Rivers Technologies (TRT) with principal place of business at 780 Washington Street, Quincy, Massachusetts 02159, for certification of urban bus retrofit/rebuild equipment pursuant to 40 CFR 85.1401-85.1415. On December 13, 1995, EPA published a notice (60 FR 64051) in the Federal Register that the notification had been received and made the notification available for public review and comment for a period of 45 days. The Agency has completed its review of this notification, and the comments received, and the Director of the Engine Programs and Compliance Division has determined that certain configurations of the candidate equipment meet the requirements for certification. Accordingly, today's Federal Register notice announces the Agency's decision to certify this equipment, as described below. The effective date of certification is established in a letter to TRT from the Director of the Engine Programs and Compliance Division, as described below. Two configurations of equipment are certified for applicable engines: (1) A particular biodiesel fuel additive in combination with a particular exhaust system oxidation catalyst; and, (2) the additive and the catalyst, plus retarded fuel injection timing. The certified equipment is applicable to petroleum-fueled Detroit Diesel Corporation (DDC) two-stroke/cycle engines originally installed in urban buses of model years 1979 through 1993, excluding 1990 model year DDC 6L71TA engines. The oxidation catalyst of this equipment is the CMX<SUP>TM catalyst which has been previously certified under the urban bus program by the Engelhard Corporation. Biodiesel is a potentially renewable, oxygen-containing fuel. As a component of this equipment, biodiesel is produced from original-use plant oil sources and methyl alcohol, consists of methyl esters of specified carbon chain-lengths, and must be blended at a ratio of 20 percent by volume with the balance federally required low-sulfur diesel fuel (having a maximum sulfur content of 0.05 weight percent). Some configurations of this equipment use retarded fuel injection timing to reduce exhaust emissions of NO<INF>X.
Today's Federal Register notice announces certification of equipment having a biodiesel component of restricted specification. This notice, however, is not meant to preclude other Agency actions or considerations with respect to other specifications involving biodiesel in the urban bus retrofit/rebuild program or other programs. Use of biodiesel of other specifications, or without the specified exhaust catalyst, is not part of the equipment described in today's notice. Some of the certified configurations do not reduce particulate matter (PM) emissions by at least 25 percent and, therefore, cannot be used to meet program requirements by bus operators that elect compliance option 1. Operators electing to use option 1 must, until such time that the 0.10 g/bhp-hr standard is triggered, use equipment certified to reduce PM emissions by at least 25 percent, when rebuilding or replacing engines.
Any certified configuration of the equipment may be used by operators electing compliance option 2, the fleet averaging option. Under option 2, an operator must use sufficient certified equipment so that its average fleet emission level complies with a specific annual target level.
Today's notice discusses limited data provided by TRT which indicate that engine emissions of unregulated aldehydes may increase when fuel injection timing is retarded. It is uncertain whether there would be an increase in ambient levels or, if there is an increase, whether it would become irritating to exposed populations. Operators concerned with the possibility for increased irritation to exposed populations may want to minimize the potential for increased ambient levels through management practices. The Agency concludes that the totality of available information support a net programmatic benefit from certifying B20 with the oxidation catalyst. The specified biodiesel blend, in combination with the specified exhaust catalyst, has been demonstrated to reduce PM. This certification will make the specified biodiesel acceptable, when used in conjunction with the specified catalytic converter, for use by operators to comply with the urban bus program requirements. The TRT notification, as well as other materials specifically relevant to it, are contained in Public Docket A-93-42, category X, entitled ``Certification of Urban Bus Retrofit/Rebuild Equipment.'' This docket is located in room M-1500, Waterside Mall (ground floor), U.S. Environmental Protection Agency, 401 M Street SW, Washington, DC 20460. Docket items may be inspected from 8:00 a.m. until 5:30 p.m., Monday through Friday. As provided in 40 CFR Part 2, a reasonable fee may be charged by the Agency for copying docket materials. DATES: Today's Federal Register notice announces the Agency's decision to certify equipment, as described below. The effective date of certification was established in a letter dated September 20, 1996, to TRT from the Director of the Engine Programs and Compliance Division. (A copy of the letter is in the public docket, which is located at the address noted above.) This certified equipment may be used immediately by urban bus operators, as described below. FOR FURTHER INFORMATION CONTACT: Mr. Bill Rutledge, Engine Programs and Compliance Division (6403-J), U.S. Environmental Protection Agency, 401 M St. SW, Washington, DC 20460. Telephone: (202) 233-9297. [[Page 54791]] SUPPLEMENTARY INFORMATION: I. Background By a notification of intent to certify signed August 21, 1995, TRT applied for certification of equipment applicable to petroleum-fueled Detroit Diesel Corporation (DDC) two-stroke/cycle engines originally equipped in urban buses from model year 1979 to model year 1993, excluding the 1990 model year DDC model 6L71TA engines. The notification of intent to certify contains two equipment configurations described more fully below: (1) A biodiesel fuel additive used in conjunction with an exhaust system catalytic converter muffler; and, (2) the biodiesel additive and catalytic converter used in conjunction with a fuel injection timing retard.
Using engine dynamometer (transient) testing in accordance with the Federal Test Procedure for heavy-duty diesel engines, TRT demonstrated reductions in PM emissions. Additional data were provided from chassis testing of an urban bus coach equipped with a 1988 model year 6V92TA DDEC II. The engine dynamometer data are shown below in Table 1, and are the bases for the PM reduction attributed to the equipment and the certification approval of the equipment when used on applicable engines. The emissions test data is part of TRT's notification of intent to certify, which is available in the public docket located at the above-mentioned address. All testing was conducted using soy methyl ester (SME) additive blended with #2 low-sulfur diesel fuel. Hereinafter, the term ``B20'' is used to mean biodiesel blended at the ratio of 20 percent by volume with federally required low-sulfur diesel fuel (with a maximum sulfur content of 0.05 weight percent). Table 1.--Test Engine Emissions (Transient Test) Gaseous and particulate Smoke ------------------------------------------------------------------------ <greek-D>PM Comment HC CO NO<INF>X PM (percent) ACC LUG Peak Engine: (3)g/bhp-hr (2)percent opacity 1.3 15.5 10.7 0.60 20 15 50 1988 HDDE Standards. Engine Dyno: 0.42 1.64 11.72 0.159 -43.6 1.4 2.1 2.1 2D+cat. 0.38 0.86 12.11 0.166 -41.1 0.9 1.7 1.7 B20<SUP>3+cat<SUP>4. 0.53 1.37 8.1 0.247 -12.4 4.6 5.4 5.6 2D, cat+4 deg. retard. 0.42 0.94 8.47 0.213 -24.5 2.2 2.8 2.9 B20, cat+4 deg. retard. II 0.21 0.95 9.06 0.11 -45.0 3.7 1.7 6.9 B20+cat. 0.29 1.21 8.18 0.14 -30.0 6.5 2.1 11.6 2D, cat+1 deg. retard. 0.25 1.05 8.35 0.12 -40.0 5.1 2.5 8 B20, cat+1 deg. retard. \1\ MUI=Mechanical Unit Injector. \2\ DDEC=Detroit Diesel Electronic Control. \3\ The B20 used is SME blended 20 percent by volume with low-sulfur diesel fuel. \4\ The data include an invalid cold cycle. See the text for discussion. Equipment configuration ------------------------- year Cat+stock B20, timing Cat+retard \2\ Not certified for compliance program 1. \3\ Not certified.