Determination of the Clean Air Delivery Rate (CADR) of Photocatalytic Oxidation (PCO) Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part I: Theoretical Considerations
Abstract
:1. Introduction
2. Model
- (i)
- Idealized plug flow occurs in the PCO device;
- (ii)
- The reservoir is a perfectly-mixed system;
- (iii)
- The mass transfer of pollutant occurs under convective-diffusion control;
- (iv)
- The kinetic constant does not change during the experiment;
- (v)
- The flow rate Q is constant with time and with position in the system;
- (vi)
- Temperature and thus the physical properties of air are constant both in space and time.
2.1. First Assumption
2.2. Second Assumption
3. Discussion
Can the Model Be Used in a Large Closed Chamber?
4. Conclusions
Author Contributions
Conflicts of Interest
Appendix A. Nomenclature
- A: cross-sectional area of the PCO device (m2)
- C: pollutant concentration (mol∙m−3)
- CADR: Clean Air Delivery Rate (m3∙s−1)
- E: efficiency (dimensionless)
- k: overall degradation rate constant (s−1)
- ke: pollutant decay rate constant with the PCO device in operation (s−1)
- kn: natural decay rate constant (s−1)
- L: length of the PCO device (m)
- Q: flow rate (m3∙s−1)
- r: degradation rate (mol m−3∙s−1)
- t: time (s)
- tc: time constant of the closed-loop reactor (s)
- V: chamber volume (m3)
- VP: PCO device volume (m3)
- VR: reservoir volume (m3)
Appendix B. Greek letters
- τP: residence time in the PCO device (s)
- τR: residence time in the reservoir (s)
- α: fractional yield of the treated flow rate (dimensionless)
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Time (s) | Time (h) | Difference (%) |
---|---|---|
900 | 0.25 | 0.04 |
2700 | 0.75 | 0.16 |
5400 | 1.50 | 0.83 |
9000 | 2.50 | 3.00 |
10800 | 3.00 | 7.35 |
13500 | 3.75 | 23.72 |
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Dumont, É.; Héquet, V. Determination of the Clean Air Delivery Rate (CADR) of Photocatalytic Oxidation (PCO) Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part I: Theoretical Considerations. Molecules 2017, 22, 407. https://doi.org/10.3390/molecules22030407
Dumont É, Héquet V. Determination of the Clean Air Delivery Rate (CADR) of Photocatalytic Oxidation (PCO) Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part I: Theoretical Considerations. Molecules. 2017; 22(3):407. https://doi.org/10.3390/molecules22030407
Chicago/Turabian StyleDumont, Éric, and Valérie Héquet. 2017. "Determination of the Clean Air Delivery Rate (CADR) of Photocatalytic Oxidation (PCO) Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part I: Theoretical Considerations" Molecules 22, no. 3: 407. https://doi.org/10.3390/molecules22030407