Comparison of the Moisture Adsorption Properties of Starch Particles and Flax Fiber Coatings for Energy Wheel Applications

Wahab O Alabi; Abdalla H Karoyo; Easwaran N Krishnan; Leila Dehabadi; Lee D Wilson; Carey J Simonson

doi:10.1021/acsomega.0c00762

Comparison of the Moisture Adsorption Properties of Starch Particles and Flax Fiber Coatings for Energy Wheel Applications

ACS Omega. 2020 Apr 13;5(16):9529-9539. doi: 10.1021/acsomega.0c00762. eCollection 2020 Apr 28.

Authors

Wahab O Alabi¹, Abdalla H Karoyo², Easwaran N Krishnan¹, Leila Dehabadi², Lee D Wilson², Carey J Simonson¹

Affiliations

¹ Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada.
² Department of Chemistry, University of Saskatchewan, 110 Science Place-Room 165 Thorvaldson Building, Saskatoon, Saskatchewan S7N 5C9, Canada.

Abstract

The adsorption-desorption behavior of flax fibers (FFs) is reported in this paper. FFs are a potential desiccant material for air-to-air energy wheels, which transfer heat and moisture in building heating, ventilation, and air conditioning (HVAC) systems. The raw FFs sample was subjected to physical modification, followed by complementary material characterization to understand the relationship between its structure and its moisture uptake performance. The surface and textural properties of the modified FFs were determined by gas adsorption (N₂, H₂O) and gravimetric liquid water swelling studies and further supported by spectroscopic (infrared and scanning electron microscopy) results. A FF-coated small-scale energy exchanger was used to determine the moisture transfer (or latent effectiveness; ε_l) using single-step and cyclic testing. The FF-coated exchanger had ε_l values of ∼10 and 40% greater compared to similar exchangers coated with starch particles (SPs) and silica gel (SG) reported in a previous study. The enhanced surface and textural properties, along with the complex compositional structure of FFs and its greater propensity to swell in water, account for the improved performance over SPs. Thus, FFs offer an alternative low-cost, environment-friendly, and sustainable biodesiccant for air-to-air energy wheel applications in buildings. The current study contributes to an improved understanding of the structure-function relationship of biodesiccants for such energy wheel applications.