The NOx-Out device contains a three-stage system to remove pollutants. First, a glass quartz filter captures particulate matter. Next, an ultra-fine spray of urea solution is dispersed into the exhaust stream. The urea spray primes the dirty air for the final stage, when a catalyst converts the harmful nitrogen oxide and ammonia into harmless nitrogen gas and water and releases them into the air.

Inspired by two of their fathers, who work cutting lawns and driving a truck, a team of University of California, Riverside Bourns College of Engineering students have created a device that reduces harmful emissions drastically when attached to the muffler port of a lawnmower.

The creation of the device comes at an opportune time. In 2008, the EPA instituted new standards for small engines and required manufacturers to be compliant by 2011-2012. The California Air Resources Board also implemented regulations recently to reduce the amount of emissions from lawnmowers and other small engine devices, such as leaf blowers, dirt bikes and snowmobiles.

Regulations are tightening on lawn mowers and other small engine devices because studies have shown they produce between 100 to 1,000 times more emissions than automobiles over the same operating time.

To help lawnmowers meet these new regulations, the student engineers created "NOx-Out", a retrofitted air filter for small engines. The device is attached in place of the muffler and substantially reduces harmful pollutants, such as carbon monoxide (87 percent emission reduction), nitrogen oxides (67 percent), and particulate matter (44 percent).

The device is about six inches long, and consists of a filter, a glass jar that holds two ounces of urea solution, and the original lawnmower muffler, which the students modified by packing with a custom-made catalyst. (Similar catalysts have been developed for diesel fuel, but not for gasoline, and the students are considering patenting the product.) A series of stainless steel nuts and bolts connect everything and attach to the lawnmower muffler port.

They expect to sell the device for $30, which would also include a 16-ounce refill bottle of the urea solution and 10 quartz replacement filters. The innovative pollutant-eradicating compound developed by the team could also be adapted for leaf blowers, dirt bikes, and snowmobiles.

The new gadget won two first place awards at the WERC: A Consortium for Environmental Education and Technology Development competition, which is run by the Institute for Energy & the Environment (IEE).

To view a video of the team and the device, visit this link.