Browsing by Author "Chwu, JW"

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Design model for selective catalytic reduction process: Solution of convective diffusion and NOx reaction
(1998-12-01)
Bai, HL
;
Chwu, JW
;
環境工程研究所
;
Institute of Environmental Engineering
A simple model for the design of selective catalytic reduction (SCR) process is presented. The two-dimensional mass transfer equation shown in Bai and Chwu (1997) is simplified and the analytic solution is obtained. The analytic solution is verified by the solution of the numerical two-dimensional model as well as published experimental data. Then it is applied for the design of the SCR reactor. Effects of operating temperature, inlet molar ratio of NH3/NO, channel pitch, and gas flow rate on the SCR reactor volume are evaluated based on a designed NO removal efficiency. The NH3 slip problem of a given inlet ratio of NH3/NO also is discussed. It is shown that the injection ratio of NH3/NO must be slightly higher than the desired NO removal efficiency so that the reactor volume can be reduced and the problem of NH, slip is not a major concern.
Design model for selective catalytic reduction process: Solution of convective diffusion and NOx reaction
(1998-12-01)
Bai, HL
;
Chwu, JW
;
環境工程研究所
;
Institute of Environmental Engineering
A simple model for the design of selective catalytic reduction (SCR) process is presented. The two-dimensional mass transfer equation shown in Bai and Chwu (1997) is simplified and the analytic solution is obtained. The analytic solution is verified by the solution of the numerical two-dimensional model as well as published experimental data. Then it is applied for the design of the SCR reactor. Effects of operating temperature, inlet molar ratio of NH3/NO, channel pitch, and gas flow rate on the SCR reactor volume are evaluated based on a designed NO removal efficiency. The NH3 slip problem of a given inlet ratio of NH3/NO also is discussed. It is shown that the injection ratio of NH3/NO must be slightly higher than the desired NO removal efficiency so that the reactor volume can be reduced and the problem of NH, slip is not a major concern.
Theoretical analysis of selective catalytic reduction catalysts
(1997-05-01)
Bai, HL
;
Chwu, JW
;
交大名義發表
;
環境工程研究所
;
National Chiao Tung University
A theoretical analysis of the selective catalytic reduction (SCR) process is presented to assist in the selection of a catalyst for efficient control of NOx from flue gases. It is a two-dimensional (2D) numerical model accounting for the simultaneous effects of external diffusion and catalytic chemical kinetics. Experimental data of SCR performance employing different types of catalysts are taken from the literature and analyzed for their NH3 adsorption constant and effective-rate constant. The catalysts' characteristics are then used to predict their SCR performance. Good agreement is obtained between model results and experimental observations on the NO removals. The activites of the catalysts are compared and strategies affecting SCR performance are discussed. It is shown that the effective reaction rate of a catalyst is the key parameter influencing its activity. The catalyst preparation procedure as well as the V2O5 content are important for determining its NO removal rate.