A “honeycomb-rotor adsorber” is proposed for the catalytic reaction process of NTA, NOx-To-Ammonia, which reduces the nitrogen oxides (NOx) emitted from a combustion process using hydrogen to produce ammonia, as a highly efficient and continuous production process. The honeycomb is divided into three zones: NOx selective adsorption from low temperature exhaust; temperature-programmed desorption for the adsorbed NOx; and cell cooling to the exhaust gas temperature. In this study, a single cell within the honeycomb was investigated, and guidelines for the design of the honeycomb-rotor adsorber established by constructing a numerical model of the NOx concentration and temperature changes within the cell. For selective NOx adsorption, palladium zeolite was applied, which has been successfully used in automobile cold-start NOx adsorbers, even in the copresence of oxygen and water vapor. Infrared spectroscopic analysis was carried out to observe the time-dependent changes in the surface NOx adsorbed species, and an NOx adsorption step on the Pd-zeolite was created. Additionally, the temperature-dependent desorption of the adsorbed NOx species was measured and combined with the equations for heat transfer in the cell to model the desorption process of the adsorbed NOx during the temperature-dependent desorption step.
HATANAKA et al. (Sat,) studied this question.