Design Approaches For A Cycling Adsorbent/Photocatalyst System for Indoor Air Purification:Formaldehyde Example

摘要

A kinetic model for a cycling adsorbent/photocatalyst combination for formaldehyde removal in indoor air was previously developed in our lab, demonstrating agreement with lab-scale batch operation data of Shiraishi, Yamaguchi, and Ohbuchi. Model parameters evaluated included adsorption equilibrium and rate constants for the adsorbent (activated carbon) honeycomb rotor, and catalytic rate constant for pseudo- first-order formaldehyde destruction in the titanium-dioxide photoreactor. The present paper explores design consequences for this novel system. In particular, the batch parameter values are used to model both adsorbent and photocatalyst behavior for continuous operation in typical residential home challenges. Design variables, including realistic make-up air fractions, adsorbent honeycomb rotation speed, and formaldehyde source emission rates, are considered to evaluate the ability of the system to achieve World Health Organization pollutant guidelines. In all circumstances, the size of the required rotating adsorbent bed and photoreactor for single stage operation, and the resultant formaldehyde concentration in the home is calculated. The ability of how well such a system might be accommodated within the typical dimensions of commercial ventilation ducts is also considered.