Bagasse-Based Desiccant Wheel Dehumidifier

Abstract

R & D Journal of the South African Institution of Mechanical Engineering 2019, 35, 31-37 http://dx.doi.org/10.17159/2309-8988/2019/v35a4 http://www.saimeche.org.za (open access) © SAIMechE All rights reserved. 31 Abstract: Green desiccants are obtained from natural waste products like bagasse. They are fully biodegradable and cause no harm to the environment compared to chemical desiccants. A bagasse-based desiccant wheel dehumidifier that uses a green desiccant like sugarcane bagasse to remove humidity from air has been implemented and tested. Sugarcane bagasse was chosen as the main desiccant since it not only shows high adsorption properties but is also abundant in Mauritius and is much cheaper compared to other desiccants. The prototype was implemented and tested under various input parameters. A mathematical model was constructed to show how the dehumidification rate varies with airflow, desiccant wheel speed and bagasse thickness. It was found that dehumidification rate increases with an increase of the previously mentioned parameters. Another finding showed that as dehumidification rate increases, a higher regeneration rate for the desiccant is required. At maximum operating conditions, the dehum idifier has a Coefficient of Performance of 0.0118 and a Moisture Removal Capacity of 2.06 g/min. It could also be deduced that at lower temperature, the prototype has a better efficiency. A controller was implemented and incorporated in the dehumidifier which responded well to different inlet air relative humidity and temperature.