Simulation of the catalyzed isotopic exchange between hydrogen and water in a trickle bed reactor

- Limiting step of overall isotopic exchange alters near bottom of the reactor.
- Molar flow rate ratio in feed and dilution ratio in catalyst bed are optimized.
- Hydrogen humidifying affects deuterium removal in hydrogen.

The catalytic exchange column of countercurrent trickle bed for deuterium removal from hydrogen is simulated based on experimental results along with established reaction and mass transfer models, accounting for the humidification of hydrogen in a catalyst bed filled with platinum/styrene-divinylbenzene copolymer pellets and Dixon rings. Relative deviations of less than 30% are achieved between the experimental and the simulated HD molar fractions at the column outlet. Simulation results indicate that hydrogen humidification exerts a noticeable influence on gas and liquid phase flow rates, leading to an overestimated removal percentage of deuterium when such flow rate variances are neglected. Rate limiting step for the overall gas-liquid isotopic exchange is discussed. Finally, the operation conditions are optimized using the developed model.