The State of NY is expanding its Clean School Bus Program to install diesel oxidation catalysts (DOC) on up to 1,500–2,000 New York City school buses. The $6 million program had initially sought to retrofit up to 1,000 school buses.

In support of the initiative, the New York Power Authority (NYPA) has contracted with Lubrizol Engine Control Systems for the purchase and installation of 1,000 DOCs, the first of which will begin to be installed on buses operating in the Bronx later next month.

After completing installation of the first 1,000 diesel oxidation catalysts, NYPA will install devices on an additional 500-1,000 buses.

The NYPA program is already providing ultra low-sulfur diesel fuel for 2,800 school buses in New York City—more than two-thirds of the school buses operating in NYC.

With the assistance of the New York City Department of Education, the Power Authority's Clean School Bus Program is helping to significantly cut diesel emissions that can contribute to asthma and other respiratory illnesses. This initiative is part of our two-pronged approach that is helping to install pollution-reducing technology on existing diesel buses while we seek to ensure that in the future, every new school bus purchased in the State will run on clean fuel.

—NY Governor George Pataki

A diesel oxidation catalyst (DOC) is a flow-through device installed on the exhaust pipe. DOCs are canisters containing a honeycomb-like structure or substrate. The substrate offers a large surface area and is coated with an active catalyst layer, currently usually containing a small, well dispersed amount of a precious metal such as platinum or palladium.

As exhaust gases flow through the canister, the catalyst, carbon monoxide, gaseous hydrocarbons and liquid hydrocarbon particles (unburned fuel and oil) oxidize, thereby reducing emissions.

Actual emission reductions vary as a result of engine type, size, age, duty cycle, condition, maintenance procedures, baseline emissions, test procedure, product manufacturer and the fuel sulfur level.

The Lubrizol DOC has been certified by the EPA (on certain school bus engine types) to reduce PM emissions by 40%, carbon monoxide (CO) by 70% and unburned hydrocarbons (HC) by 85%, when used with ultra low-sulfur diesel fuel.

As a side note, NYPA’s Clean School Bus Program is part of its voluntary $23 million initiative to offset emissions from the installation of small, clean power plants at six sites in Brooklyn, Queens and Staten Island.

Other elements of the program include the installation of eight 200-kilowatt fuel cells at New York City wastewater treatment facilities. The fuel cells now produce electricity from waste gases which had been burned-off, producing greenhouse gases in the atmosphere. The program has also included deployment of electric vehicles.