New Diesel Emission Control Technology Cuts California Bus Emissions by 90-95%

Phillip Roberts, President of Extengine, October 22, 2003

With the successful test of a new diesel-emission control technology on its buses, the Santa Clara Valley Transit Authority (VTA) may be taking California a step closer to eliminating older diesel bus emissions as a major source of pollution in the state.

Soot-spewing buses just moved onto the endangered species list, and a new, relatively low-cost diesel emission control technology is the reason.

The Santa Clara Valley Transit Authority recently installed The Extengine Advanced Diesel Emission Control (ADEC) System on a 10 year-old bus as part of a demonstration project funded by the California Transit Association. The recent California Air Resources Board (CARB) verified test revealed over a 90% reduction in Oxides of Nitrogen (NOx) emissions and a 95% reduction in Particulate Matter (PM), both the toxic visible and invisible diesel exhaust emissions emitted from the vehicle's tailpipe. For diesel engine and vehicle manufacturers the simultaneous 90% and 95% reductions in NOx and PM have been next to impossible to achieve, and no other diesel emission control system has matched ADEC's performance in head to head competition.

In an effort to demonstrate the most effective NOx control technology, CARB has required bus operators in California to demonstrate they can lower diesel exhaust emissions, particularly NOx, on existing diesel bus fleets throughout California. CARB's position is that if NOx fleet averages remain very high, then bus operators could be forced to convert their fleets to much costlier and less efficient alternative fueled buses.

"Each older diesel bus can spew hundreds of pounds of NOx, soot, and other pollutants into the air each year, but the test results show that number can be reduced to a mere fraction by installing the ADEC System," said Phil Roberts, president of Extengine Transport Systems of Fullerton, California. "Plus, the retrofit system's cost is substantially lower than buying a new diesel or CNG bus. There just aren't many transit bus operators that can afford to replace their diesel-powered fleets in these days of big budget deficits."

The ADEC System is based on Selective Catalytic Reduction (SCR), which has been used for nearly 35 years in controlling NOx emissions from stationary diesel fueled power plants. The System designed for vehicle applications diffuses minute quantities of a reductant into the exhaust stream after combustion has taken place; the small refill tanks are swapped out periodically as needed.

In these days of large local, State, and Federal budget deficits, Air Quality Regulators are working with public and private fleet operators to find cost-effective solutions to reduce diesel emissions, so that many large cities may meet stringent federal air pollution standards or risk losing billions of federal highway funds.

Nick Vermet, Stewart & Stevenson Vice President of Sales and Marketing stated: "In addition to the VTA bus installation, we recently assisted the City of Houston and the Texas Department of Transportation with retrofitting the ADEC system on their dump trucks. Implementation of this innovative technology can play a significant part in the achievement of federal air standards. We are excited about the prospect of assisting other municipal fleet operators and cities with similar projects."

Santa Clara VTA chose the ADEC System for the bus demonstration program over other retrofit technologies partially due to its low cost and successful implementation on City of Houston diesel vehicles. Extengine, the California- based firm, has requests from the largest transit operator in Europe to install the ADEC System on both buses and locomotives in Europe. In addition, a major Japanese firm has initiated talks for licensing the technology for use in Japan, where many diesel vehicle operators are currently being restricted in driving their diesel trucks and buses in Tokyo unless they substantially reduce diesel exhaust emissions.

The ADEC System tested contains Extengine proprietary, patent-pending components and software. Some Extengine(R) ADEC Systems employed for urban bus applications utilize KleenAir technology under an exclusive license.

For more on ADEC, see - http://extengine.com/adec.html

For more on Houston's diesel project, see - http://www.ci.houston.tx.us/citygovt/mayor/dieseldemo.pdf

What about switching to a cleaner, vegetable oil based fuel called biodiesel? It can be created out of used frying oil, and functions in any diesel engine.

These emission control devices are nice, but, leave you reliant on foreign fuel supplies, and is a nonrenewable energy source. Prices set by OPEC lead to war and death. Prices for biodiesel are predictable based on farm production levels and weather. (Plus, it means fewer farm subsidies as demand for biodiesel crops increaes.)

These devices also allow you to continue to increase the net amount of greenhouse gasses in the atmosphere. The carbon in crude oil was put there millions of years ago, and are being released as greenhouse gasses into the atmosphere. The carbon in biodiesel was taken from the atmosphere by the plant, and is being released back into it. The net effect is no change in the amount of greenhouse gasses.

Soot is not the main problem with diesel fuel. (That thinking is so 1950s!) The problems are greenhouse gasses and people dying because we're fighting for control over oil.

Yes, it would be nice to switch over now -- but where will the governments come up with the dough to replace fleets of thousands of vehicles?

In the meantime, the existing buses will be cleaner. A small step for sure, but an important one.

The fuel works in current diesel engines. There's no need to replace fleets.

In fact, the money spent on those little smokestack scrubbers could be used, instead, to build some biodiesel or biodiesel blend fueling station service for the fleets. They could sell the fuel to the public as a way to offset any short term costs of conversion.