Car pollution reduction device close to road testing

The device, known as a plasmatron, is expected to be inexpensive and compatible with present engine technology.

The plasmatron was recently installed in a commercial car engine for the first time. It is said to have operated reliably over two weeks, and met the expectations of its inventors at the Massuchusetts Institute of Technology (MIT) for reducing emissions of pollutants, particularly nitrogen oxides (NOx).

MIT say NOx emissions were reduced by two orders of magnitude compared to the normal emissions of an engine running on gasoline.

“This is a major milestone in showing the feasibility of a plasma-boosted fuel reformer for reducing vehicle pollution,” said Daniel R. Cohn, head of the Plasma Technology Division at the Plasma Science and Fusion Center (PSFC).

Now that the researchers have successfully coupled the plasmatron to an engine, the next step is to install the device in an actual vehicle.

Essentially the plasmatron, which is about the size of a wine bottle, works as an onboard ‘oil refinery.’ It converts a variety of fuels into high-quality hydrogen-rich gas. Adding only a small amount of such gas to the fossil fuel powering a car is known to significantly decrease emissions of pollutants like NOx.

Fuel injected into the plasmatron is exposed to an electric discharge that turns the fuel and surrounding air into an electrically charged gas, or plasma. The plasma accelerates reaction rates allowing the production of hydrogen-rich gas.

Plasmatrons have traditionally been used to produce hydrogen-rich gas for industrial applications like metallurgical processing. They are usually quite large – about the size of a car engine – and require large amounts of electrical power.

“To our knowledge we’re the first to develop a plasma-boosted fuel reformer that’s this small and that operates at low power (less than one kilowatt),” said Dr. Cohn.

The plasmatron ran reliably for four to six hours a day over two weeks, with no traces of deterioration. In addition, the researchers found that emissions of key pollutants were significantly reduced. For example, NOx was reduced from an average 2,700 parts per million (ppm) without the plasmatron to 20 ppm with the

device.

“This is the first time anyone’s been able to integrate a

compact plasma-boosted fuel reformer with an auto engine and show a

large reduction in pollutants,” Dr. Cohn said.

In an actual vehicle these reductions will not be as dramatic (due to help from the catalytic converter), but the researchers still expect to reduce NOx emissions by a factor of 10.

The recent engine tests were conducted using gasoline. However, laboratory tests have shown the device can also process diesel and biofuels.