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ETV Verifies Diesel Emission Controls

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Developing a new environmental technology is one thing; getting it accepted in the marketplace is another. To help bridge this gap in 1995, the EPA created the Environmental Technology Verification Program (ETV). Its goal is to verify the performance of commercial-ready environmental products, thereby helping to speed their entry into the marketplace. Through six non-profit verification centers, ETV provides uniform, controlled, and objective testing of technologies in all media—air, water, and land—that support EPA’s goal of a cleaner and healthier environment. A notable example is the ongoing verification of 11 innovative diesel retrofit (upgrade) technologies designed to reduce particulate matter, hydrocarbons, nitrogen oxides, and carbon monoxide emissions from diesel engine exhaust.

Background

Diesel engine in a dynamometer test cell.

Diesel engines in trucks and buses are popular because they are durable and provide good fuel economy. But they are a serious environmental challenge because the more than 11 million diesel-powered vehicles currently on U.S. highways emit significant quantities of air pollutants. Diesel emissions contribute to ozone levels that prevent many communities from meeting national minimum standards for ambient air quality, and contribute to forestry and crop losses. Further, the particulate matter in diesel exhaust is linked to many respiratory and cardiovascular diseases; EPA has determined that diesel exhaust including particulate matter is a likely carcinogen.

Private-sector developers have responded with a variety of innovative retrofit technologies for trucks, buses, and non-road equipment. To assist with its entry into the marketplace, the ETV program, in cooperation with its Air Pollution Control Technology Center, is providing independent, quality-assured data on the performance of some of these technologies. They involve three basic approaches, Exhaust Treatments, Retrofit Fuels, and Crankcase Filtration Systems.

Exhaust Treatments
Exhaust systems such as Diesel Particulate Filters (DPFs), Diesel Oxidation Catalysts (DOCs), and Selective Catalytic Reduction (SCR) systems are devices that are installed in the exhaust system, similar to a muffler. The DPFs trap particulate matter and burn it in the exhaust stream. The DOCs reduce particulate matter, hydrocarbons, and carbon monoxide emissions by converting them to water vapor and carbon dioxide. The SCR systems reduce nitrogen oxide emissions by converting them to harmless nitrogen gas.

Retrofit Fuels
Retrofit fuels include fuel reformulations and fuel additives that modify the properties of diesel fuel, allowing it to burn more cleanly.

Crankcase Filtration Systems
Crankcase filtration systems work by capturing the “blowby” (unburned) diesel gases and removing their particulate matter through the use of filters before routing them to the engine intake.

The goal of the ETV diesel retrofit testing is to determine the percent of emission reduction achieved for particulate matter, nitrogen oxides, hydrocarbons, and carbon monoxide, compared to the percent emissions of the same engine without the retrofit technology. ETV does not verify performance claims. Rather, it provides a credible, highly quality-assured data set on technology performance, which is “verified” to be correct. It is then up to others to evaluate the vendor/manufacturer’s claim in light of the data. For example, a diesel retrofit vendor would probably take its data set to the National Clean Diesel Campaign, sponsored by the EPA’s Office of Transportation and Air Quality, for review and posting to its verified technology list.

In addition to the verification reports and statements, the ETV process also includes the development of test/quality assurance plans, and verification protocols (uniform testing for a specific category of technologies).

Selected Outcomes

The ETV diesel retrofit program calculated some potential environmental benefits based on adoption of the tested technologies at selected market penetration rates. Using EPA’s regulatory impact analysis data for diesel fuel sulfur control requirements,* and assuming 10 percent market penetration of the first seven verified diesel retrofit technologies, the following outcomes can be calculated over a seven-year period:

9,000 to 31,000 tons of particulate matter would be reduced.
$4.4–$15.5 billion (in 1995 dollars) would be saved through the prevention of adverse health and environmental effects.
680–2,400 deaths could be avoided.
Cities and states would be assisted in meeting national air quality standards, especially in the 10 areas of the country now at risk for exceeding particulate matter standards and the 45 areas at risk for exceeding ozone standards.

A full reporting of outcomes, actual and projected, can be found in Environmental Technology Verification (ETV) Program Case Studies, Demonstrating Program Outcomes (PDF) (117 pp, 3 MB) (EPA/600/R-06/001) which is on the ETV Outcomes Web page.

*EPA Regulatory Impact Analysis: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (EPA/420/R-00/026), December 2000

Contact

Jane Ice, NRMRL Office of Public Affairs (513) 569-7311

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