Clinoptilolite zeolite as a potential catalyst for propane-SCR-NOx: Performance investigation and kinetic analysis

• The performance of H-clinoptilolite zeolite in propane-SCR-NOx is studied for the first time.
• The catalyst shows high activity and selectivity for the reaction.
• The kinetics has been studied using an integral reactor.
• A new Hinshelwood–Langmuir type correlation is proposed that predicts satisfactorily the conversion.
• The activation energy of the surface catalyzed reactions proposed is 43 and 51 kJ mol−1.

We report for the first time an investigation on the catalytic behavior of protonated clinoptilolite zeolite in propane-SCR-NOx. The protonated Iranian clinoptilolite zeolite shows a promising performance for NOx abatement via selective catalytic reduction by propane. Maximum activity (72% conversion of NOx to N2) is achieved at 450 °C at a low GHSV of 20,280 h−1. Size dependency of the nitrogen production reaction rate is insignificant for particle sizes equal or smaller than 500 μm. A Hinshelwood–Langmuir type reaction mechanism has been proposed that predicts satisfactorily the NO2/NO mixture conversion rate in the temperature range of 300–400 °C as a function of NO2 and NO concentration and reaction temperature for an GHSV in the range of 27,000–30,400 h−1. Kinetic analysis was performed based on the data obtained by an integral reactor system. The activation energy of the surface catalyzed reactions proposed has been calculated in the range of 43–51 kJ mol−1.

Nitrogen production rate as a function of conversion and temperature. Bold dashed lines represent the simulated data.Figure optionsDownload as PowerPoint slide