| Title: | Computational analysis of an electrostatic separator design for removal of volatile organic compounds from indoor air |
| Author(s): | Anttalainen O; Lattouf E; Vanninen P; Hakulinen H; Kotiaho T; Eiceman G; |
| Address: | "VERIFIN, Finnish Institute for Verification of the Chemical Weapons Convention, Department of Chemistry, University of Helsinki, Helsinki, Finland. Helsinki, FinlandDrug Research Program and Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki institution. Department of Chemistry, Faculty of Science, University of Helsinki, Helsinki, Finland. New Mexico State University, Las Cruces, New Mexico, USA" |
| DOI: | 10.1080/10962247.2023.2265329 |
| ISSN/ISBN: | 2162-2906 (Electronic) 1096-2247 (Linking) |
| Abstract: | "Concentrations of volatile organic compounds (VOCs) in air can be reduced in electrostatic separators where VOCs are ionized using ion-molecule reactions, extracted using electric fields, and eliminated in a waste flow. Embodiments for such separator technology have been explored in only a few studies, despite the possible advantage of purification without adsorbent filters. In one design, based on ionization of VOCs in positive polarity with hydrated protons as reactant ions, efficiencies for removal were measured as 30 to 40% . The results were fitted to a one dimensional convective diffusion model requiring an unexpectedly high production rate of reactant ions to match both the model and data. A realistic rate of reactant ion production was used in finite element method simulations (COMSOL) and demonstrated that low removal efficiency could be attributed to non-uniform patterns of sample flow and to incomplete mixing of VOCs with reactant ions. In analysis of complex systems, such as this model, even limited computational modeling can outperform a pure analytical approach and bring insights into limiting factors or system bottlenecks.Implications: In this work, we applied modern computational methods to understand the performance of an air purifier based on electrostatics and ionized volatile organic compounds (VOCs). These were described by Ito, et al. in the early 2000s.35-37 The model presented by Ito, et al. was one dimensional and did not account the effects of flow. The model was fitted with experimental data using unexpectedly high production rate of reactant ions. In our multi-physics finite element models, the efficiency and operation of the filter is better explained by the patterns of flow and flow influences on ion distributions in electric fields. Critically, we have no new experimental data on technology and only bring new understandings to existing data sets. Based on the findings, we also present a computational model for improved purification method. The findings from our modeling studies should be interesting, we believe, to those working in air purification technologies vis-a-vis VOC removal (a growing interest in indoor air quality). Others may be interested in how we applied COMSOL modeling of gases at atmospheric pressure ionization and ions in electric fields. In general, this work helps using and applying computational modeling to understand and improve the performance bottlenecks in air purification system designs" |
| Notes: | "PublisherAnttalainen, Osmo Lattouf, Elie Vanninen, Paula Hakulinen, Hanna Kotiaho, Tapio Eiceman, Gary eng 2023/10/05 J Air Waste Manag Assoc. 2023 Oct 5. doi: 10.1080/10962247.2023.2265329" |
