Study of Pulsed Plasma in a Crossed Flow Dielectric Barrier Discharge Reactor for Improvement of NOx Removal in Raw Diesel Engine Exhaust

Improved performance of plasma in raw engine exhaust treatment is reported. A new type of reactor referred to as of cross-flow dielectric barrier discharge (DBD) was used, in which the gas flow is perpendicular to the corona electrode. In raw exhaust environment, the cross-flow (radial-flow) reactor exhibits a superior performance with regard to NOX removal when compared to that with axial flow of gas. Experiments were conducted at different flow rates ranging from 2 L/min to 25 L/min. The plasma assisted barrier discharge reactor has shown encouraging results in NOx removal at high flow rates.

The effect of nature of raw coal on the adhesion of bacteria to coal surface

The surface properties of coal and solution pH play a major role in determining the adhesion of microorganisms. In this study, three Indian coal samples with different compositions have been used and the adhesion of the bacterium Bacillus polymyxa to these coals has been investigated. It was found that due to the high ash content of coal, the zeta-potential was negative over most of the pH range which is close to the values exhibited by pure quartz as well as B. polymyxa. Similarly, the surface free energy components of coal (derived from contact angle measurements) showed that the electron-donor component increased with ash content. Adhesion experiments revealed that maximum adhesion of the bacterium B. polymyxa occurred on to the coal samples around the point-of-zero-charge of the coal and the bacterium i.e. about pH 2. Further, adhesion was found to be dependent on the ash content and the surface free energy of the coals. (C) 2002 Published by Elsevier Science Ltd.

Enhanced Performance of Discharge Plasma in Raw Engine Exhaust Treatment-Operation under Different Temperatures and Loads

This paper reports improved performance of discharge plasma in raw engine exhaust treatment. For the purpose of investigation, both filtered and raw diesel engine exhaust were separately treated by the discharge plasma. In raw exhaust environment, the discharge plasma exhibits a superior performance with regard to NOx removal, energy consumption and formation of by-products. In this study, experiments were conducted at conditions of different temperatures and loads.