Optimization of Ammonia Oxidation Using Response Surface Methodology

Abstract

In this paper, the design of experiments and response surface methodology were proposed to study ammonia oxidation process. The following independent variables were selected: the reactor’s load, the temperature of reaction and the number of catalytic gauzes, whereas ammonia oxidation efficiency and N2O concentration in nitrous gases were assumed as dependent variables (response). Based on the achieved results, statistically significant mathematical models were developed which describe the effect of independent variables on the analysed responses. In case of ammonia oxidation efficiency, its achieved value depends on the reactor’s load and the number of catalytic gauzes, whereas the temperature in the studied range (870–910 °C) has no effect on this dependent variable. The concentration of nitrous oxide in nitrous gases depends on all three parameters. The developed models were used for the multi-criteria optimization with the application of desirability function. Sets of parameters were achieved for which optimization assumptions were met: maximization of ammonia oxidation efficiency and minimization of the N2O amount being formed in the reaction.

Emissions Control Catalysis

“…Finally, Ingel et al [28] in a different approach for controlling N 2 O emissions in ammonia oxidation process at high temperature, proposed the design of experiments and response surface methodology to study this process. The reactor's load, the temperature of reaction and the number of catalytic gauzes were selected as independent variables, whereas ammonia oxidation efficiency and N 2 O concentration in nitrous gases were assumed as dependent variables (response).…”

“…The review of Smirniotis P. and co-workers [18] concerns the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR of NO x ) focusing to low temperature applications that is a highly desirable perspective, and finally the review of Bogaerts A. and co-workers [19] covering a hot recent trend in emissions control implicating cyclic economy strategies, that is the conversion and utilization of CO 2 for the production of value-added chemicals. On the other hand, a major part of contributions (9/21) concerns original research on nitrogen oxides reduction processes [20][21][22][23][24][25][26][27][28], reflecting the fact that this topic still remains hot among the targets of environmental catalysis. Five out of 21 studies concern CO and hydrocarbons oxidation processes [29][30][31][32][33] while the remained 4/21 concern CO 2 capture/recycling processes under the view of cyclic economy [34][35][36][37].…”

Two-Stage Catalytic Abatement of N2O Emission in Nitric Acid Plants

“…The operating parameters of ammonia oxidation can also affect the final N 2 O emission [1]. The results presented in Figure 3, where the concentration of N 2 O in the post-reaction gas was expressed, take into account the variability of the amount of N 2 O formed during the ammonia oxidation.…”

“…The activity of the PKR catalyst for a high-temperature N 2 O decomposition was tested in a pilot nitric acid plant, which was presented in previous work [1,44]. The plant consists of the analogical units as existing in industrial plants, i.e., ammonia-air mixture preparation, ammonia oxidation, heat exchange, nitric oxide oxygenation and absorption unit.…”

“…The first method relies on using appropriately designed Pt-Rh catalytic packages, so-called low-emission packages or optimizing ammonia oxidation parameters (e.g., temperature, reactor's load) [1]. This method can be treated as a preliminary one because it is not sufficient to meet the applicable emission standards.…”