Challenge
A major source of air pollution is the carbon soot particles expelled from the exhaust of diesel cars and trucks. Not only is the soot a contaminate, it is environmentally destructive and unhealthy to humans and animals. Likewise, bio-hazards are a threat in an un-settled world. The need is an economical and effective means to capture the soot and life-threatening organics and dispose of them without unnecessary cost. As a result, the US Government and European Union has enacted legislation requiring a 90 percent reduction of particulate matter from diesel emissions.

Process Industrial Ceramics Solutions, LLC developed fibers from silicon carbide, which could be wetlaid with an proprietary binder having inert and high-temperature properties. Silicon carbide was selected because of its ability to withstand the atmosphere and temperatures of the diesel exhaust and extreme demands for cleaning of the filter.

Solution
Filters were designed and constructed, which capture 95 percent of diesel exhaust soot particles above 10 nanometers. Once the filter reaches a pre-determined differential pressure, an accompanying magnetron (microwave) device is activated and automatically raises the temperature of the silicon carbide fiber to 1100 degrees C in under 10 seconds. Soot is harmlessly volatized, in-situ, cleaning the filter rapidly for reuse. The diesel exhaust filter application was licensed to Honeywell Corporation in April 2007. Future applications for licensing include power generation, beer and wine processing and other applications where a high-flow, in-situ cleanable filter for organic particulate removal is advantageous.