Analysis on plasma chemistry and particle growth in corona discharge process for NOx removal using discrete-sectional method

초록

The particle formation and growth combined with plasma chemistry in the pulsed corona discharge process (PCDP) to remove NO<inf>x</inf> were analyzed by the discrete-sectional model. In the PCDP, most of the NO is converted into NO<inf>2</inf> and, later, into HNO<inf>3</inf> which reacts with NH<inf>3</inf> to form the NH<inf>4</inf> NO<inf>3</inf> particle. In the beginning of the reactor, we have the high concentration of small size particles and, later, the particle size distribution in the reactor becomes bimodal with the large size and small size particles and, finally, becomes monodisperse with the large size particles. As the average electron concentration increases, it takes a shorter reactor length to remove the NO<inf>x</inf>. As the initial NO and H<inf>2</inf>O concentrations decrease, the NH<inf>3</inf> is consumed more slowly to form the ammonium nitrates particles. As the averaged electron concentration and initial H<inf>2</inf>O concentration increase, the large size particles grow more quickly and the particle size distribution becomes bi-modal earlier. As the initial NO and NH<inf>3</inf> concentrations Increase, the diameter of large size particles becomes larger by the faster coagulation between particles. The predicted NO<inf>x</inf> conversion and particle size distribution were in close agreements with the published experimental results at the averaged electron concentration of 2 × 105 cm-3 in this study.

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